feat: Add server side csharp sdk

For Ophil
refactor: Move position model to spark_api
2025-12-06 17:35:08 +00:00 · 2025-12-06 17:32:11 +00:00 · 2025-12-05 15:56:24 +00:00 · 2025-12-05 15:56:24 +00:00 · 2025-12-05 15:56:24 +00:00 · 2025-12-05 15:56:23 +00:00
1193 changed files with 51525 additions and 16004 deletions
@@ -25,6 +25,12 @@
      "commands": [
        "fake"
      ]
+    },
+    "dotnet-t4": {
+      "version": "3.0.0",
+      "commands": [
+        "t4"
+      ]
    }
  }
 }
@@ -22,6 +22,7 @@
      "extensions": [
        "eamodio.gitlens",
        "llvm-vs-code-extensions.vscode-clangd",
+        "ms-python.python",
        "ms-vscode.cmake-tools",
        "ms-vscode.cpptools",
        "xaver.clang-format"
@@ -207,17 +207,23 @@ dotnet_naming_symbols.parameters.applicable_accessibilities = public,internal,pr
 dotnet_naming_symbols.private_symbols.applicable_kinds = property,method,field,event,delegate
 dotnet_naming_symbols.private_symbols.applicable_accessibilities = protected,private

+# local symbols
+dotnet_naming_symbols.local_symbols.applicable_kinds = local
+
+# parameter symbols
+dotnet_naming_symbols.parameter_symbols.applicable_kinds = parameter
+
 # Naming styles

-dotnet_naming_style.snake_case.required_prefix =
-dotnet_naming_style.snake_case.required_suffix =
-dotnet_naming_style.snake_case.word_separator = _
-dotnet_naming_style.snake_case.capitalization = all_lower
+dotnet_naming_style.pascal_case.required_prefix =
+dotnet_naming_style.pascal_case.required_suffix =
+dotnet_naming_style.pascal_case.word_separator =
+dotnet_naming_style.pascal_case.capitalization = pascal_case

-dotnet_naming_style.private_snake_case.required_prefix = _
-dotnet_naming_style.private_snake_case.required_suffix =
-dotnet_naming_style.private_snake_case.word_separator = _
-dotnet_naming_style.private_snake_case.capitalization = all_lower
+dotnet_naming_style.camel_case.required_prefix =
+dotnet_naming_style.camel_case.required_suffix =
+dotnet_naming_style.camel_case.word_separator =
+dotnet_naming_style.camel_case.capitalization = camel_case

 dotnet_naming_style.user_types.required_prefix =
 dotnet_naming_style.user_types.required_suffix =
@@ -229,6 +235,10 @@ dotnet_naming_style.interface.required_suffix =
 dotnet_naming_style.interface.word_separator =
 dotnet_naming_style.interface.capitalization = pascal_case

+dotnet_naming_style.local.capitalization = camel_case
+
+dotnet_naming_style.parameter.capitalization = camel_case
+
 # rules
 dotnet_naming_rule.user_types.symbols = user_types
 dotnet_naming_rule.user_types.style = user_types
@@ -238,14 +248,18 @@ dotnet_naming_rule.interfaces.symbols = interface
 dotnet_naming_rule.interfaces.style = interface_style
 dotnet_naming_rule.interfaces.severity = suggestion

-dotnet_naming_rule.public_members_snake_case.symbols = public_symbols
-dotnet_naming_rule.public_members_snake_case.style = snake_case
-dotnet_naming_rule.public_members_snake_case.severity = suggestion
+dotnet_naming_rule.public_members.symbols = public_symbols
+dotnet_naming_rule.public_members.style = pascal_case
+dotnet_naming_rule.public_members.severity = suggestion

-dotnet_naming_rule.private_members_snake_case.symbols = private_symbols
-dotnet_naming_rule.private_members_snake_case.style = private_snake_case
-dotnet_naming_rule.private_members_snake_case.severity = suggestion
+dotnet_naming_rule.private_members.symbols = private_symbols
+dotnet_naming_rule.private_members.style = camel_case
+dotnet_naming_rule.private_members.severity = suggestion

-dotnet_naming_rule.parameters.symbols = parameters
-dotnet_naming_rule.parameters.style = snake_case
+dotnet_naming_rule.variables_are_camel_case.severity = suggestion
+dotnet_naming_rule.variables_are_camel_case.symbols = local_symbols
+dotnet_naming_rule.variables_are_camel_case.style = local
+
+dotnet_naming_rule.parameters.symbols = parameter_symbols
+dotnet_naming_rule.parameters.style = parameter
 dotnet_naming_rule.parameters.severity = suggestion
@@ -34,7 +34,7 @@
 #   src/server/sparkd/Dockerfile
 SPARKD__IMAGE=sparkd
 # The config dir for this service to use
-SPARKD__CONFIG_DIR=src/server/sparkd/configurations/dev
+SPARKD__CONFIG_DIR=src/app_sparkd/configurations/dev
 # Mount a specific volume or dir to "~/sparkdata/data" inside the docker.
 # Defaults to a volume named "sparkd_<config_port>" (e.g., sparkd_8000).
 # SPARKD__DATA_DIR=/home/bts/sparkdata/data
@@ -44,5 +44,13 @@ SPARKD__CONFIG_PORT=8000
 SPARKD__QUICKBUS_PORT=8001
 SPARKD__SIM_FIX_PORT=8002
 SPARKD__SHM_SIZE=4gb
+SPARKD__PYTHON_REQUIREMENTS=requirements.txt

+### PubSubServer ###
+PUBSUB__CONFIG_DIR=src/DataStreamSuite/PubSubServer/Configurations/Development
+PUBSUB__SOURCE_DIR=build/Release/bin/net8.0/linux-x64/publish
+
+### MdPublisher ###
+MD_PUBLISHER__CONFIG_DIR=src/DataStreamSuite/DataStreamPublisher/Configurations/ReplayMarketData
+MD_PUBLISHER__SOURCE_DIR=build/Release/bin/net8.0/linux-x64/publish
 # TODO: add config for other services (pubsub, md-publisher, webapp, api-server, etc.)
@@ -11,6 +11,7 @@ cmake-build-debug/
 **.vscode/*
 !.vscode/launch.json
 !.vscode/tasks.json
+!.vscode/*.env
 .vs
 obj/
 *.csproj.user
@@ -54,6 +55,8 @@ trace_data/
 .cache/
 /src/Spark.Admin.WebApp/tsconfig.*.g.json
 /src/Spark.Admin.WebApp/src/bin/
+/src/**/*appsettings.Local.json
+/src/**/*/Configurations/Local/
 **/CMakeDeps.cmake
 **/CMakeDeps_win.cmake
 .devcontainer/
@@ -14,6 +14,49 @@
      "type": "coreclr",
      "request": "attach"
    },
+    {
+      "name": "Api Server",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "",
+      "preLaunchTask": "Build Api Server (Debug)",
+      "windows": {
+        "program": "spark_api_server.exe",
+      },
+      "linux": {
+        "program": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "cwd": "build/Debug/bin/net8.0",
+      "env": {
+        "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+      },
+      "stopAtEntry": false,
+      "console": "integratedTerminal"
+    },
+    {
+      "name": "Api Server (Skip Build)",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "",
+      "windows": {
+        "program": "spark_api_server.exe",
+      },
+      "linux": {
+        "program": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "cwd": "build/Debug/bin/net8.0",
+      "env": {
+        "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+      },
+      "stopAtEntry": false,
+      "console": "integratedTerminal"
+    },
    {
      "name": "DataStreamPublisher",
      "type": "coreclr",
@@ -26,11 +69,28 @@
      "windows": {
        "program": "DataStreamPublisher.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/DataStreamPublisher/Configurations/${input:dataStreamPublisherConfig}.json"
-      ],
      "cwd": "build/Debug/bin/net8.0",
+      "env": {
+        "DOTNET_ENVIRONMENT": "${input:dataStreamPublisherEnvironment}",
+      },
+      "stopAtEntry": false,
+      "console": "integratedTerminal"
+    },
+    {
+      "name": "DataStreamPublisher (Skip Build)",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "",
+      "linux": {
+        "program": "DataStreamPublisher",
+      },
+      "windows": {
+        "program": "DataStreamPublisher.exe",
+      },
+      "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
+      "env": {
+        "DOTNET_ENVIRONMENT": "${input:dataStreamPublisherEnvironment}",
+      },
      "stopAtEntry": false,
      "console": "integratedTerminal"
    },
@@ -82,16 +142,29 @@
      "name": "DataStreamQueryAnalyzer",
      "type": "coreclr",
      "request": "launch",
-      //"preLaunchTask": "Build DataStreamQueryAnalyzer (Debug)",
+      "preLaunchTask": "Build DataStreamQueryAnalyzer (Debug)",
      "program": "",
      "windows": {
        "program": "DataStreamQueryAnalyzer.exe",
-        "args": [
-          "--config",
-          "${workspaceFolder}/src/DataStreamSuite/DataStreamQueryAnalyzer/Configurations/DataStreamQueryAnalyzer.json"
-        ],
        "cwd": "build/Debug/bin/net8.0-windows",
        "env": {
+          "DOTNET_ENVIRONMENT": "${input:dataStreamQueryAnalyzerEnvironment}",
+          "PYTHON_EXE": "${workspaceFolder}/.venv/Scripts/python.exe"
+        },
+      },
+      "stopAtEntry": false,
+      "console": "integratedTerminal",
+    },
+    {
+      "name": "DataStreamQueryAnalyzer (Skip Build)",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "",
+      "windows": {
+        "program": "DataStreamQueryAnalyzer.exe",
+        "cwd": "build/Debug/bin/net8.0-windows",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:dataStreamQueryAnalyzerEnvironment}",
          "PYTHON_EXE": "${workspaceFolder}/.venv/Scripts/python.exe"
        },
      },
@@ -115,6 +188,27 @@
        "${workspaceFolder}/src/DataStreamSuite/PubSubServer/Configurations/${input:pubSubServerConfig}.json"
      ],
      "cwd": "build/Debug/bin/net8.0",
+      "env": {
+        "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+      },
+      "stopAtEntry": false,
+      "console": "integratedTerminal"
+    },
+    {
+      "name": "PubSubServer (Skip Build)",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "",
+      "linux": {
+        "program": "PubSubServer",
+      },
+      "windows": {
+        "program": "PubSubServer.exe",
+      },
+      "cwd": "build/Debug/bin/net8.0",
+      "env": {
+        "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+      },
      "stopAtEntry": false,
      "console": "integratedTerminal"
    },
@@ -127,6 +221,9 @@
        "preLaunchTask": "Build Spark (Debug)",
        "program": "Spark.exe",
        "cwd": "build/Debug/bin/net8.0-windows",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:sparkEnvironment}",
+        }
      },
      "stopAtEntry": false,
      "console": "integratedTerminal"
@@ -139,6 +236,9 @@
      "windows": {
        "program": "Spark.exe",
        "cwd": "build/Debug/bin/net8.0-windows",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:sparkEnvironment}",
+        }
      },
      "stopAtEntry": false,
      "console": "integratedTerminal"
@@ -251,6 +351,17 @@
    },
  ],
  "inputs": [
+    {
+      "id": "apiServerEnvironment",
+      "type": "pickString",
+      "description": "Api Server Configuration",
+      "options": [
+        "Development",
+        "Local",
+        "Staging",
+      ],
+      "default": "Development",
+    },
    {
      "id": "dataStreamPublisherConfig",
      "type": "pickString",
@@ -263,6 +374,16 @@
      ],
      "default": "MarketDataPublisher",
    },
+    {
+      "id": "dataStreamPublisherEnvironment",
+      "type": "pickString",
+      "description": "DataStreamPublisher Configuration",
+      "options": [
+        "Local",
+        "ReplayMarketData",
+      ],
+      "default": "Local",
+    },
    {
      "id": "pubSubServerConfig",
      "type": "pickString",
@@ -273,6 +394,37 @@
      ],
      "default": "PubSubServer",
    },
+    {
+      "id": "pubSubServerEnvironment",
+      "type": "pickString",
+      "description": "Api Server Configuration",
+      "options": [
+        "Development",
+        "Local",
+        "Staging",
+      ],
+      "default": "Development",
+    },
+    {
+      "id": "dataStreamQueryAnalyzerEnvironment",
+      "type": "pickString",
+      "description": "DataStreamQueryAnalyzer Configuration",
+      "options": [
+        "Development",
+        "Local",
+      ],
+      "default": "Development",
+    },
+    {
+      "id": "sparkEnvironment",
+      "type": "pickString",
+      "description": "Spark Configuration",
+      "options": [
+        "Development",
+        "Local",
+      ],
+      "default": "Development",
+    },
    {
      "id": "sparkConfigServer",
      "type": "promptString",
@@ -0,0 +1 @@
+PYTHONPATH=/workspaces/spark/build/sparkd-debug-clang/src/lib_python_interop;/workspaces/spark/src/lib_python_interop/python_interop_plugins;/workspaces/spark/tools/py
@@ -121,6 +121,57 @@
        "color": "terminal.ansiCyan"
      },
    },
+    {
+      "label": "Build DataStreamQueryAnalyzer",
+      "group": "build",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "tools/build_data_stream_query_analyzer.cmd",
+      },
+      "args": [
+        "--configuration",
+        "${input:buildConfiguration}",
+      ],
+      "icon": {
+        "id": "terminal",
+        "color": "terminal.ansiCyan"
+      },
+    },
+    {
+      "label": "Build DataStreamQueryAnalyzer (Debug)",
+      "group": "build",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "tools/build_data_stream_query_analyzer.cmd",
+      },
+      "args": [
+        "--configuration",
+        "Debug",
+      ],
+      "icon": {
+        "id": "terminal",
+        "color": "terminal.ansiCyan"
+      },
+    },
+    {
+      "label": "Build DataStreamQueryAnalyzer (Release)",
+      "group": "build",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "tools/build_data_stream_query_analyzer.cmd",
+      },
+      "args": [
+        "--configuration",
+        "Release",
+      ],
+      "icon": {
+        "id": "terminal",
+        "color": "terminal.ansiCyan"
+      },
+    },
    {
      "label": "Build Spark",
      "group": "build",
@@ -351,9 +402,132 @@
        "id": "wrench"
      },
    },
+    {
+      "label": "Run Api Server",
+      "dependsOn": "Build Api Server",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "spark_api_server.exe",
+      },
+      "linux": {
+        "command": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+        }
+      },
+      "icon": {
+        "id": "run",
+        "color": "terminal.ansiGreen",
+      },
+    },
+    {
+      "label": "Run Api Server (Debug)",
+      "dependsOn": "Build Api Server (Debug)",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "spark_api_server.exe",
+      },
+      "linux": {
+        "command": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+        }
+      },
+      "icon": {
+        "id": "run",
+        "color": "terminal.ansiGreen",
+      },
+    },
+    {
+      "label": "Run Api Server (Release)",
+      "dependsOn": "Build Api Server (Release)",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "spark_api_server.exe",
+      },
+      "linux": {
+        "command": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}/build/Release/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+        }
+      },
+      "icon": {
+        "id": "run",
+        "color": "terminal.ansiGreen",
+      },
+    },
+    {
+      "label": "Run Api Server (Debug | Skip Build)",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "spark_api_server.exe",
+      },
+      "linux": {
+        "command": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+        }
+      },
+      "icon": {
+        "id": "run",
+        "color": "terminal.ansiGreen",
+      },
+    },
+    {
+      "label": "Run Api Server (Release | Skip Build)",
+      "type": "process",
+      "command": "",
+      "windows": {
+        "command": "spark_api_server.exe",
+      },
+      "linux": {
+        "command": "spark_api_server",
+      },
+      "args": [
+        "run",
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}/build/Release/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:apiServerEnvironment}",
+        }
+      },
+      "icon": {
+        "id": "run",
+        "color": "terminal.ansiGreen",
+      },
+    },
    {
      "label": "Run DataStreamQueryAnalyzer",
-      "dependsOn": "Build DataStream",
+      "dependsOn": "Build DataStreamQueryAnalyzer",
      "type": "process",
      "command": "",
      "windows": {
@@ -363,7 +537,7 @@
          "${workspaceFolder}/src/DataStreamSuite/DataStreamQueryAnalyzer/Configurations/DataStreamQueryAnalyzer.json",
        ],
        "options": {
-          "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -373,7 +547,7 @@
    },
    {
      "label": "Run DataStreamQueryAnalyzer (Debug)",
-      "dependsOn": "Build DataStream (Debug)",
+      "dependsOn": "Build DataStreamQueryAnalyzer (Debug)",
      "type": "process",
      "command": "",
      "windows": {
@@ -383,7 +557,7 @@
          "${workspaceFolder}/src/DataStreamSuite/DataStreamQueryAnalyzer/Configurations/DataStreamQueryAnalyzer.json",
        ],
        "options": {
-          "cwd": "${workspaceFolder}/build/Debug/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/Debug/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -393,7 +567,7 @@
    },
    {
      "label": "Run DataStreamQueryAnalyzer (Release)",
-      "dependsOn": "Build DataStream (Release)",
+      "dependsOn": "Build DataStreamQueryAnalyzer (Release)",
      "type": "process",
      "command": "",
      "windows": {
@@ -403,7 +577,7 @@
          "${workspaceFolder}/src/DataStreamSuite/DataStreamQueryAnalyzer/Configurations/DataStreamQueryAnalyzer.json",
        ],
        "options": {
-          "cwd": "${workspaceFolder}/build/Release/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/Release/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -422,12 +596,11 @@
      "windows": {
        "command": "DataStreamPublisher.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/DataStreamPublisher/Configurations/${input:dataStreamPublisherConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:dataStreamPublisherEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -445,12 +618,11 @@
      "windows": {
        "command": "DataStreamPublisher.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/DataStreamPublisher/Configurations/${input:dataStreamPublisherConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/Debug/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:dataStreamPublisherEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -468,12 +640,11 @@
      "windows": {
        "command": "DataStreamPublisher.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/DataStreamPublisher/Configurations/${input:dataStreamPublisherConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/Release/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/Release/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:dataStreamPublisherEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -491,12 +662,11 @@
      "windows": {
        "command": "PubSubServer.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/PubSubServer/Configurations/${input:pubSubServerConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -514,12 +684,11 @@
      "windows": {
        "command": "PubSubServer.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/PubSubServer/Configurations/${input:pubSubServerConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/Debug/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -536,12 +705,11 @@
      "windows": {
        "command": "PubSubServer.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/PubSubServer/Configurations/${input:pubSubServerConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/Debug/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -559,12 +727,11 @@
      "windows": {
        "command": "PubSubServer.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/PubSubServer/Configurations/${input:pubSubServerConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/Release/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/Release/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -581,12 +748,11 @@
      "windows": {
        "command": "PubSubServer.exe",
      },
-      "args": [
-        "--config",
-        "${workspaceFolder}/src/DataStreamSuite/PubSubServer/Configurations/${input:pubSubServerConfig}.json",
-      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/Release/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/Release/bin/net8.0",
+        "env": {
+          "DOTNET_ENVIRONMENT": "${input:pubSubServerEnvironment}",
+        },
      },
      "icon": {
        "id": "run",
@@ -601,7 +767,7 @@
      "windows": {
        "command": "Spark.exe",
        "options": {
-          "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -617,7 +783,7 @@
      "windows": {
        "command": "Spark.exe",
        "options": {
-          "cwd": "${workspaceFolder}/build/Debug/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/Debug/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -633,7 +799,7 @@
      "windows": {
        "command": "Spark.exe",
        "options": {
-          "cwd": "${workspaceFolder}/build/Release/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/Release/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -648,7 +814,7 @@
      "windows": {
        "command": "Spark.exe",
        "options": {
-          "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net7.0-windows"
+          "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0-windows"
        },
      },
      "icon": {
@@ -673,7 +839,7 @@
        "${input:sparkConfigQuery}",
      ],
      "options": {
-        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net7.0"
+        "cwd": "${workspaceFolder}/build/${input:buildConfiguration}/bin/net8.0"
      },
      "icon": {
        "id": "run",
@@ -754,7 +920,7 @@
          "${input:sparkTest}"
        ],
        "options": {
-          "cwd": "${workspaceFolder}/build/Debug/bin/net7.0",
+          "cwd": "${workspaceFolder}/build/Debug/bin/net8.0",
        }
      },
    },
@@ -852,6 +1018,17 @@
    },
  ],
  "inputs": [
+    {
+      "id": "apiServerEnvironment",
+      "type": "pickString",
+      "description": "Api Server Configuration",
+      "options": [
+        "Development",
+        "Local",
+        "Staging",
+      ],
+      "default": "Development",
+    },
    {
      "id": "buildConfiguration",
      "type": "pickString",
@@ -885,26 +1062,31 @@
      "default": "sparkd-debug-clang",
    },
    {
-      "id": "dataStreamPublisherConfig",
+      "id": "dataStreamPublisherEnvironment",
      "type": "pickString",
      "description": "Publisher Configuration",
      "options": [
-        "MarketDataPublisher",
-        "SimpleEchoClient",
-        "SimpleTestDataPublisher",
-        "TestDataPublisher",
+        "Development",
+        "MarketData",
+        "Production",
+        "ProductionAws",
+        "Staging",
      ],
      "default": "MarketDataPublisher",
    },
    {
-      "id": "pubSubServerConfig",
+      "id": "pubSubServerEnvironment",
      "type": "pickString",
      "description": "PubSub Configuration",
      "options": [
-        "PubSubServer",
-        "SimpleEchoClient",
+        "Development",
+        "EchoServer",
+        "Local",
+        "Production",
+        "ProductionAws",
+        "Staging",
      ],
-      "default": "PubSubServer",
+      "default": "Development",
    },
    {
      "id": "sparkConfigQuery",
@@ -21,7 +21,7 @@ set(
 # SHARED_MEMORY_PREFIX serves as a kind of namespace so multiple applications
 # can run simultaneously without fighting over the same shm files (e.g., sparkd,
 # api server, etc.).
-set(SHARED_MEMORY_PREFIX "bts" CACHE STRING "Prefix to use when creating shared memory files")
+set(SHARED_MEMORY_PREFIX "\${BTS_SHARED_MEMORY_PREFIX}" CACHE STRING "Prefix to use when creating shared memory files")
 set(EXTERNALS_BIN "${EXTERNALS_ROOT}/bin")
 set(EXTERNALS_INCLUDE "${EXTERNALS_ROOT}/include")
 set(EXTERNALS_LIB "${EXTERNALS_ROOT}/lib/$<CONFIG>")
@@ -40,9 +40,8 @@ include_directories(BEFORE SYSTEM ${EXTERNALS_INCLUDE} ${EXTERNALS_ROOT}/include
 link_directories(${EXTERNALS_LIB})

 add_compile_definitions(SHARED_MEMORY_PREFIX="${SHARED_MEMORY_PREFIX}")
-add_compile_definitions(APP_DATA_DIR="${APP_DATA_DIR}")
-if(DEFINED APP_DATA_DIR_OVERRIDE)
-  add_compile_definitions(APP_DATA_DIR_OVERRIDE="${APP_DATA_DIR_OVERRIDE}")
+if(DEFINED APP_DATA_DIR)
+  add_compile_definitions(APP_DATA_DIR="${APP_DATA_DIR}")
 endif()
 add_compile_definitions(EXPORT_MD_CONSUMER="${EXPORT_MD_CONSUMER}")
 if(WIN32)
@@ -113,15 +112,15 @@ else()
  endif()

  # subdirs
+  add_subdirectory(src/lib_spark)
  if (BUILD_SPARKD)
+    add_subdirectory(src/lib_python_interop)
    add_subdirectory(src/lib_onixs_fix)
-    add_subdirectory(src/lib_binance_execution)
+    add_subdirectory(src/lib_binance)
    add_subdirectory(src/lib_okx_execution)
-    add_subdirectory(src/lib_python_md)
    add_subdirectory(src/app_sparkd)
    add_subdirectory(src/data_files)
  endif()
-  add_subdirectory(src/lib_spark)
  if (BUILD_ADMIN_WEB_APP)
    add_subdirectory(src/Spark.Admin.WebApp)
  endif()
@@ -20,8 +20,6 @@
        "SPARK_CMAKE_CXX_FLAGS": "/MP /WX /wd4250 /wd4251 /wd4244 /wd4267 /wd4355 /wd4275 /wd4345 /bigobj /EHsc /DCURL_STATICLIB /D_WINSOCK_DEPRECATED_NO_WARNINGS /D__TBB_NO_IMPLICIT_LINKAGE /DBOOST_ALL_NO_LIB /std:c++20 /D_SCL_SECURE_NO_WARNINGS /D_CRT_SECURE_NO_WARNINGS /D_WIN32_WINNT=0x0600"
      },
      "cacheVariables": {
-        "APP_DATA_DIR": "${dollar}{APPDATA}/bts",
-        "APP_DATA_DIR_OVERRIDE": "${dollar}{SPARK_DATA_DIR}",
        "CMAKE_CXX_FLAGS": "$env{SPARK_CMAKE_CXX_FLAGS}",
        "CMAKE_CXX_FLAGS_DEBUG": "$env{SPARK_CMAKE_CXX_FLAGS} /MTd",
        "CMAKE_CXX_FLAGS_RELEASE": "$env{SPARK_CMAKE_CXX_FLAGS} /MT",
@@ -36,8 +34,7 @@
        "EXPORT_MD_CONSUMER": {
          "type": "BOOL",
          "value": "ON"
-        },
-        "SHARED_MEMORY_PREFIX": "spark"
+        }
      }
    },

@@ -53,8 +50,6 @@
      "binaryDir": "${sourceDir}/build/${presetName}",
      "cacheVariables": {
        "platform": "",
-        "APP_DATA_DIR": "${dollar}{HOME}/sparkdata",
-        "APP_DATA_DIR_OVERRIDE": "${dollar}{SPARKD_DATA_DIR}",
        "CMAKE_BUILD_WITH_INSTALL_RPATH": {
          "type": "BOOL",
          "value": "OFF"
@@ -77,8 +72,7 @@
        "BUILD_ADMIN_WEB_APP": {
          "type": "BOOL",
          "value": "ON"
-        },
-        "SHARED_MEMORY_PREFIX": "sparkd"
+        }
      }
    },

@@ -159,11 +153,7 @@
    {
      "name": "spark-api-server-windows",
      "inherits": "spark",
-      "displayName": "Spark Api Server (Windows)",
-      "cacheVariables": {
-        "APP_DATA_DIR_OVERRIDE": "${dollar}{SPARK_API_SERVER_DATA_DIR}",
-        "SHARED_MEMORY_PREFIX": "spark_api_server"
-      }
+      "displayName": "Spark Api Server (Windows)"
    },

    {
@@ -172,7 +162,6 @@
      "displayName": "Spark Api Server (Linux)",
      "generator": "Ninja Multi-Config",
      "cacheVariables": {
-        "APP_DATA_DIR_OVERRIDE": "${dollar}{SPARK_API_SERVER_DATA_DIR}",
        "BUILD_ADMIN_WEB_APP": {
          "type": "BOOL",
          "value": "OFF"
@@ -229,10 +218,8 @@
      "description": "Data Stream utils ported over from Edge",
      "binaryDir": "${sourceDir}/build/${presetName}",
      "cacheVariables": {
-        "APP_DATA_DIR": "${dollar}{APPDATA}/bts/DataStream",
-        "APP_DATA_DIR_OVERRIDE": "${dollar}{DATA_STREAM_DATA_DIR}",
        "CONFIG_DEFAULTS_PATH": "spark/config/profiles/default/*.conf;spark/config/profiles/data_stream/*.conf",
-        "SHARED_MEMORY_PREFIX": "data_stream"
+        "DOTNET_BINARY_DIR": "${sourceDir}/build/$<CONFIG>/bin/net8.0;${sourceDir}/build/$<CONFIG>/bin/net8.0-windows"
      }
    },

@@ -248,8 +235,6 @@
      "inherits": "sparkd",
      "generator": "Ninja Multi-Config",
      "cacheVariables": {
-        "APP_DATA_DIR": "${dollar}{HOME}/.local/share/DataStream",
-        "APP_DATA_DIR_OVERRIDE": "${dollar}{DATA_STREAM_DATA_DIR}",
        "BUILD_ADMIN_WEB_APP": {
          "type": "BOOL",
          "value": "OFF"
@@ -267,12 +252,11 @@
        "CMAKE_CXX_FLAGS_DEBUG": "-g -fPIC -Wall -pedantic -Wextra -Werror -Wno-missing-braces -Wno-ignored-qualifiers --std=c++20 -fdiagnostics-color -DDEBUG",
        "CMAKE_CXX_FLAGS_RELEASE": "-fPIC -Wall -pedantic -Wextra -Werror -Wno-missing-braces -Wno-ignored-qualifiers --std=c++20 -fdiagnostics-color -fno-omit-frame-pointer -DNDEBUG -O3",
        "CONFIG_DEFAULTS_PATH": "spark/config/profiles/default/*.conf;spark/config/profiles/data_stream/*.conf",
-        "DOTNET_BINARY_DIR": "${sourceDir}/build/$<CONFIG>/bin/net7.0",
+        "DOTNET_BINARY_DIR": "${sourceDir}/build/$<CONFIG>/bin/net8.0",
        "EXPORT_MD_CONSUMER": {
          "type": "BOOL",
          "value": "ON"
-        },
-        "SHARED_MEMORY_PREFIX": "data_stream"
+        }
      }
    }
  ],
@@ -42,6 +42,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bts.ColumnExpressions", "sr
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DataStream", "src\DataStreamSuite\DataStream\DataStream.csproj", "{39AEA075-6457-46C0-8821-1158BE6EFA57}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "sdk", "sdk", "{56ACFCD1-60C7-4E2C-B90D-B1F95ECE33A1}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bts.Spark.Sdk", "src\sdk\Bts.Spark.Sdk\Bts.Spark.Sdk.csproj", "{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|x64 = Debug|x64
@@ -194,6 +198,14 @@ Global
 		{6BD3F6D8-B6FC-44E8-B8FE-06352F638B9B}.Release|x64.Build.0 = Release|Any CPU
 		{6BD3F6D8-B6FC-44E8-B8FE-06352F638B9B}.RelWithDebInfo|x64.ActiveCfg = Debug|Any CPU
 		{6BD3F6D8-B6FC-44E8-B8FE-06352F638B9B}.RelWithDebInfo|x64.Build.0 = Debug|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.Debug|x64.Build.0 = Debug|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.MinSizeRel|x64.ActiveCfg = Debug|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.MinSizeRel|x64.Build.0 = Debug|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.Release|x64.ActiveCfg = Release|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.Release|x64.Build.0 = Release|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.RelWithDebInfo|x64.ActiveCfg = Debug|Any CPU
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184}.RelWithDebInfo|x64.Build.0 = Debug|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -218,5 +230,7 @@ Global
 		{39AEA075-6457-46C0-8821-1158BE6EFA57} = {C09ED521-D2DF-40BC-A76F-EB3CB870B2F6}
 		{9F6D7DE8-185B-4C1D-B809-3314D092DF28} = {C09ED521-D2DF-40BC-A76F-EB3CB870B2F6}
 		{6BD3F6D8-B6FC-44E8-B8FE-06352F638B9B} = {C09ED521-D2DF-40BC-A76F-EB3CB870B2F6}
+		{56ACFCD1-60C7-4E2C-B90D-B1F95ECE33A1} = {267F81EF-A8AB-49FD-9F56-D7EC3C1F7C7C}
+		{ADA9E802-8EFA-4E72-8E9A-6AA1E4181184} = {56ACFCD1-60C7-4E2C-B90D-B1F95ECE33A1}
 	EndGlobalSection
 EndGlobal
@@ -0,0 +1,71 @@
+include_guard(DIRECTORY)
+include(GNUInstallDirs)
+include(${CMAKE_SOURCE_DIR}/cmake/ExportToParent.cmake)
+include(${CMAKE_SOURCE_DIR}/cmake/SetFirstDefined.cmake)
+
+function(init_python_module)
+  set(_options)
+  set(_one_value_args
+    NAME
+  )
+  set(_multi_value_args
+    SOURCES
+  )
+  cmake_parse_arguments(_ARGS "${_options}" "${_one_value_args}" "${_multi_value_args}" ${ARGN})
+  set_first_defined(_name _ARGS_NAME PROJECT_NAME)
+  set_first_defined(_sources _ARGS_SOURCES ${_name}_SOURCES)
+
+  set(module_proj ${_name}_module)
+  set(${module_proj}_SOURCES ${_sources})
+  pybind11_add_module(${module_proj} SHARED ${_sources})
+  target_link_libraries(
+    ${module_proj}
+    PUBLIC
+      pybind11::embed
+      spark
+      ${_name}
+  )
+  target_include_directories(
+    ${module_proj}
+    PRIVATE
+      $<BUILD_INTERFACE:${pybind11_INCLUDE_DIRS}>
+  )
+  target_include_directories(
+    ${module_proj}
+    PUBLIC
+      ${Python3_INCLUDE_DIRS}
+      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+      $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+  )
+  add_custom_command(
+    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/stubs/${_name}.pyi
+    DEPENDS ${_name} ${module_proj}
+    COMMAND PYTHONPATH=${CMAKE_CURRENT_BINARY_DIR} pybind11-stubgen --numpy-array-use-type-var --ignore-invalid-expressions '.*' ${_name}_module
+    COMMENT "Generating py stubs"
+  )
+  add_custom_target(
+    "${_name}_py_stubs"
+    ALL
+    DEPENDS
+      ${CMAKE_CURRENT_BINARY_DIR}/stubs/${_name}.pyi
+  )
+  install(
+    TARGETS ${module_proj}
+    EXPORT ${module_proj}Targets
+    RUNTIME
+      DESTINATION ${CMAKE_INSTALL_BINDIR}
+    LIBRARY
+      DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE
+      DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  )
+  foreach(dir ${pybind11_INCLUDE_DIRS})
+    install(DIRECTORY ${dir} DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+  endforeach()
+  install(
+    EXPORT ${module_proj}Targets
+    FILE ${module_proj}Targets.cmake
+    NAMESPACE ${_name}::
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${_name}
+  )
+endfunction()
@@ -0,0 +1,65 @@
+include_guard(DIRECTORY)
+include(GNUInstallDirs)
+
+function(init_python_plugin)
+  set(_options)
+  set(_one_value_args NAME PLUGIN_NAME)
+  set(_multi_value_args SOURCES)
+  cmake_parse_arguments(_ARGS "${_options}" "${_one_value_args}" "${_multi_value_args}" ${ARGN})
+  set_first_defined(_name _ARGS_NAME PROJECT_NAME)
+  set(_plugin_name ${_ARGS_PLUGIN_NAME})
+  if (NOT DEFINED _ARGS_PLUGIN_NAME)
+    set(_plugin_name ${_name}_plugins)
+  endif()
+  set(${_plugin_name}_SOURCES ${_ARGS_SOURCES})
+  if (NOT DEFINED _ARGS_SOURCES)
+    file(
+      GLOB_RECURSE ${_plugin_name}_SOURCES
+      RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+      ${_plugin_name}/*.py)
+  endif()
+  set(src_outs)
+  foreach(_src ${${_plugin_name}_SOURCES})
+    set(_src_in ${CMAKE_CURRENT_SOURCE_DIR}/${_src})
+    set(_src_out ${CMAKE_CURRENT_BINARY_DIR}/${_src})
+    add_custom_command(
+      OUTPUT ${_src_out}
+      COMMAND ${CMAKE_COMMAND} -E copy ${_src_in} ${_src_out}
+      DEPENDS ${_src_in}
+      COMMENT "Copying ${_plugin_name} plugin ${_src} to ${_src_out}"
+    )
+    list(APPEND src_outs ${_src_out})
+  endforeach()
+  
+  add_custom_target(copy_${_plugin_name} ALL DEPENDS ${src_outs})
+  
+  add_library(${_plugin_name} INTERFACE)
+  add_library(${_name}::${_plugin_name} ALIAS ${_plugin_name})
+  
+  set_target_properties(
+    ${_plugin_name}
+    PROPERTIES
+      INTERFACE_PYTHON_SCRIPTS_DIR
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/${_plugin_name}>$<INSTALL_INTERFACE:${CMAKE_INSTALL_BINDIR}/${_plugin_name}>
+  )
+  
+  set_target_properties(
+    ${_plugin_name}
+    PROPERTIES
+    INTERFACE_PYTHON_SCRIPTS $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/${${_plugin_name}_SOURCES}>$<INSTALL_INTERFACE:${CMAKE_INSTALL_BINDIR}/${${_plugin_name}_SOURCES}>
+  )
+  
+  install(
+    TARGETS ${_plugin_name}
+    EXPORT ${_plugin_name}Targets
+    DESTINATION ${CMAKE_INSTALL_BINDIR}
+  )
+  
+  install(
+    EXPORT ${_plugin_name}Targets
+    FILE ${_plugin_name}Targets.cmake
+    NAMESPACE ${_name}::
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${_name}
+  )
+  install(DIRECTORY ${_plugin_name} DESTINATION ${CMAKE_INSTALL_BINDIR})
+endfunction()
@@ -29,36 +29,43 @@ function(Protobuf_Generate_Cpp)
    list(APPEND ${_ARGS_CXX_HEADERS} "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h")

    add_custom_command(
-      OUTPUT "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.cc"
-             "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h"
+      OUTPUT
+        "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.cc"
+        "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h"
      COMMAND
-        ${Protobuf_PROTOC_EXECUTABLE} ARGS --cpp_out=${_ARGS_CXX_OUT_DIR} ${_proto_include_cli_args} ${ABS_FIL}
+        ${Protobuf_PROTOC_EXECUTABLE}
+      ARGS
+        --cpp_out=${_ARGS_CXX_OUT_DIR} ${_proto_include_cli_args} ${ABS_FIL}
      DEPENDS ${ABS_FIL}
      COMMENT "Running C++ protocol buffer compiler on ${FIL}"
-      VERBATIM)
+      VERBATIM
+    )
  endforeach()

-  set_source_files_properties(${${_ARGS_CXX_SOURCES}} ${${_ARGS_CXX_HEADERS}} PROPERTIES GENERATED TRUE)
+  set_source_files_properties(
+    ${${_ARGS_CXX_SOURCES}}
+    ${${_ARGS_CXX_HEADERS}}
+    PROPERTIES
+      GENERATED TRUE
+  )

  # remove some warnings from protobuf generated files
  if(WIN32)
-    set_source_files_properties(${${_ARGS_CXX_SOURCES}} PROPERTIES COMPILE_FLAGS
-                                                      "/wd4309 /wd4838")
+    set_source_files_properties(
+      ${${_ARGS_CXX_SOURCES}}
+      PROPERTIES
+        COMPILE_FLAGS "/wd4309 /wd4838"
+    )
  else()
    set_source_files_properties(
      ${${_ARGS_CXX_SOURCES}}
      PROPERTIES
-        COMPILE_FLAGS
-        "-Wno-unused-parameter -Wno-effc++ -Wno-pedantic -Wno-sign-compare -Wno-uninitialized"
+        COMPILE_FLAGS "-Wno-unused-parameter -Wno-effc++ -Wno-pedantic -Wno-sign-compare -Wno-uninitialized"
    )
  endif()

-  set(${_ARGS_CXX_SOURCES}
-      ${${_ARGS_CXX_SOURCES}}
-      PARENT_SCOPE)
-  set(${_ARGS_CXX_HEADERS}
-      ${${_ARGS_CXX_HEADERS}}
-      PARENT_SCOPE)
+  set(${_ARGS_CXX_SOURCES} ${${_ARGS_CXX_SOURCES}} PARENT_SCOPE)
+  set(${_ARGS_CXX_HEADERS} ${${_ARGS_CXX_HEADERS}} PARENT_SCOPE)
 endfunction()

 function(Service_Compiler_Generate_Cpp)
@@ -92,40 +99,51 @@ function(Service_Compiler_Generate_Cpp)
    list(APPEND ${_ARGS_CXX_HEADERS} "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.h")

    set(TEMPLATES
-        ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/client.pb.cc
-        ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/client.pb.h
-        ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/server.pb.cc
-        ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/server.pb.h
+      ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/client.pb.cc
+      ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/client.pb.h
+      ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/server.pb.cc
+      ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/templates/cpp/server.pb.h
    )

    set(_plugin_py ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/plugin.py)
    if(WIN32)
      set(_plugin_cmd ${CMAKE_SOURCE_DIR}/src/lib_spark/spark/api/service_compiler/plugin.cmd)
      add_custom_command(
-        OUTPUT "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.cc"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.cc"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.h"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.cc"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.h"
+        OUTPUT
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.cc"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.cc"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.h"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.cc"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.h"
        COMMAND SET PYTHONPATH=${SPARK_PYTHON}
        COMMAND ${CMAKE_SOURCE_DIR}/.venv/Scripts/activate.bat
        COMMAND
-          ${Protobuf_PROTOC_EXECUTABLE} ARGS --cpp_out=${_ARGS_CXX_OUT_DIR}
-          --plugin=protoc-gen-service=${_plugin_cmd}
-          --service_out=lang=cpp:${_ARGS_CXX_OUT_DIR} -I
-          ${PROTOBUF_INCLUDE_DIRS} -I ${_protobuf_src_dir} ${ABS_FIL}
-        DEPENDS ${ABS_FIL} ${TEMPLATES} ${_plugin_cmd} ${_plugin_py}
+          ${Protobuf_PROTOC_EXECUTABLE}
+          ARGS
+            --cpp_out=${_ARGS_CXX_OUT_DIR}
+            --plugin=protoc-gen-service=${_plugin_cmd}
+            --service_out=lang=cpp:${_ARGS_CXX_OUT_DIR}
+            -I ${PROTOBUF_INCLUDE_DIRS}
+            -I ${_protobuf_src_dir}
+            ${ABS_FIL}
+        DEPENDS
+          ${ABS_FIL}
+          ${TEMPLATES}
+          ${_plugin_cmd}
+          ${_plugin_py}
        COMMENT "Running C++ service compiler on ${FIL}"
-        VERBATIM)
+        VERBATIM
+      )
    else()
      add_custom_command(
-        OUTPUT "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.cc"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.cc"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.h"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.cc"
-               "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.h"
+        OUTPUT
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.cc"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.pb.h"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.cc"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.client.pb.h"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.cc"
+          "${_ARGS_CXX_OUT_DIR}/${FIL_WE}.server.pb.h"
        COMMAND ${CMAKE_SOURCE_DIR}/tools/venv_exec.sh
        ARGS
          ${Protobuf_PROTOC_EXECUTABLE}
@@ -133,32 +151,32 @@ function(Service_Compiler_Generate_Cpp)
          --plugin=protoc-gen-service=${_plugin_py}
          --service_out=lang=cpp,make_file_name=${ABS_FIL}:${_ARGS_CXX_OUT_DIR}
          ${_proto_include_cli_args} ${ABS_FIL}
-        DEPENDS ${ABS_FIL} ${TEMPLATES} ${_plugin_py}
+        DEPENDS
+          ${ABS_FIL}
+          ${TEMPLATES}
+          ${_plugin_py}
        COMMENT "Running C++ service compiler on ${FIL}"
-        VERBATIM)
+        VERBATIM
+      )
    endif()
-
  endforeach()

  # remove some warnings from protobuf generated files
  if(WIN32)
-    set_source_files_properties(${${_ARGS_CXX_SOURCES}} PROPERTIES COMPILE_FLAGS
-                                                      "/wd4309 /wd4838")
+    set_source_files_properties(
+      ${${_ARGS_CXX_SOURCES}}
+      PROPERTIES
+        COMPILE_FLAGS "/wd4309 /wd4838"
+    )
  else()
    set_source_files_properties(
      ${${_ARGS_CXX_SOURCES}}
      PROPERTIES
-        COMPILE_FLAGS
-        "-Wno-unused-parameter -Wno-effc++ -Wno-pedantic -Wno-sign-compare -Wno-uninitialized"
+        COMPILE_FLAGS "-Wno-unused-parameter -Wno-effc++ -Wno-pedantic -Wno-sign-compare -Wno-uninitialized"
    )
  endif()

-  set(${_ARGS_CXX_SOURCES}
-      ${${_ARGS_CXX_SOURCES}}
-      PARENT_SCOPE)
-  set(${_ARGS_CXX_HEADERS}
-      ${${_ARGS_CXX_HEADERS}}
-      PARENT_SCOPE)
-
+  set(${_ARGS_CXX_SOURCES} ${${_ARGS_CXX_SOURCES}} PARENT_SCOPE)
+  set(${_ARGS_CXX_HEADERS} ${${_ARGS_CXX_HEADERS}} PARENT_SCOPE)
 endfunction()

@@ -0,0 +1,39 @@
+include_guard(DIRECTORY)
+include(${CMAKE_SOURCE_DIR}/cmake/SymLink.cmake)
+
+function(sym_link_python_module)
+  set(_options)
+  set(_one_value_args LIB_NAME MODULE_NAME PLUGIN_NAME)
+  set(_multi_value_args)
+  cmake_parse_arguments(_ARGS "${_options}" "${_one_value_args}"
+                        "${_multi_value_args}" ${ARGN})
+  if(NOT DEFINED _ARGS_LIB_NAME)
+    message(
+      FATAL_ERROR "LIB_NAME must be specified for sym_link_python_module()")
+  endif()
+  set(_lib_name ${_ARGS_LIB_NAME})
+  set(_module_name ${_ARGS_MODULE_NAME})
+  if(NOT DEFINED _ARGS_MODULE_NAME)
+    set(_module_name ${_lib_name}_module)
+  endif()
+  set(_plugin_name ${_ARGS_PLUGIN_NAME})
+  set(_deps ${_lib_name} ${_module_name})
+  if(DEFINED _ARGS_PLUGIN_NAME)
+    list(APPEND _deps ${_plugin_name} copy_${_plugin_name})
+  endif()
+  add_dependencies(${PROJECT_NAME} ${_deps})
+  sym_link_local_lib(${_lib_name})
+  set(_module_suffix cpython-310-x86_64-linux-gnu.so)
+  sym_link_file(
+    SOURCE
+    ${CMAKE_BINARY_DIR}/src/lib_${_lib_name}/${_module_name}.${_module_suffix}
+    DEST
+    ${CMAKE_CURRENT_BINARY_DIR}/${_module_name}.${_module_suffix}
+    INSTALL_DEST
+    ${CMAKE_INSTALL_BINDIR}/)
+  if(DEFINED _ARGS_PLUGIN_NAME)
+    get_target_property(plugins ${_plugin_name} INTERFACE_PYTHON_SCRIPTS_DIR)
+    sym_link_dir(TARGET_NAME ${PROJECT_NAME}_link_${_plugin_name} SOURCE
+                 ${plugins} DEST ${CMAKE_CURRENT_BINARY_DIR}/${_plugin_name})
+  endif()
+endfunction()
@@ -1,26 +1,31 @@
 services:
  sparkd:
    volumes:
-      - ${SPARKD__DATA_DIR:-sparkd_data}:/home/bts/sparkdata/data
+      - ${SPARKD__DATA_DIR:-sparkd_data}:/home/bts/.local/share/bts/sparkd/data
    build:
      dockerfile: src/app_sparkd/Dockerfile
      args:
        - IMAGE=${SPARKD__IMAGE}
        - SOURCE_DIR=${SPARKD__SOURCE_DIR}
        - CONFIG_DIR=${SPARKD__CONFIG_DIR}
+        - PYTHON_REQUIREMENTS=${SPARKD__PYTHON_REQUIREMENTS}
    shm_size: "${SPARKD__SHM_SIZE:-512mb}"
    command: >
      sh -c "
-        echo bts | sudo -S chown -R bts:bts /home/bts/sparkdata/data
-        if [ -e "/home/bts/sparkdata/data/logging.sparkd/log" ]; then
-          mv "/home/bts/sparkdata/data/logging.sparkd/log" "/home/bts/sparkdata/data/logging.sparkd/log_$(date '+%Y%m%d-%H%M')"
+        echo bts | sudo -S chown -R bts:bts /home/bts/.local/share/bts/sparkd/data
+        if [ -e "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log" ]; then
+          mv "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log" "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log_$(date '+%Y%m%d-%H%M')"
        fi
-        if [ -e "/home/bts/sparkdata/conf/.env.local" ]; then
-          echo 'Sourcing /home/bts/sparkdata/conf/.env.local'
+        if [ -e "/home/bts/.local/share/bts/sparkd/conf/.env.local" ]; then
+          echo 'Sourcing /home/bts/.local/share/bts/sparkd/conf/.env.local'
          set -a
-          . /home/bts/sparkdata/conf/.env.local
+          . /home/bts/.local/share/bts/sparkd/conf/.env.local
          set +a
        fi
+        if [ -d /home/bts/.local/share/bts/sparkd/conf/plugins ]; then
+          echo 'Copying /home/bts/.local/share/bts/sparkd/conf/plugins to runtime dir (/home/bts/bin)'
+          cp -r /home/bts/.local/share/bts/sparkd/conf/plugins /home/bts/bin/
+        fi
        ./sparkd run"
    env_file:
      - .env
@@ -36,29 +41,34 @@ services:

  sparkd-symbols:
    volumes:
-      - ${SPARKD__DATA_DIR:-sparkd_data}:/home/bts/sparkdata/data
-      - ${SPARKD__RUNTIME_CONF_DIR:-sparkd_conf}:/home/bts/sparkdata/conf
+      - ${SPARKD__DATA_DIR:-sparkd_data}:/home/bts/.local/share/bts/sparkd/data
+      - ${SPARKD__RUNTIME_CONF_DIR:-sparkd_conf}:/home/bts/.local/share/bts/sparkd/conf
    build:
-      dockerfile: src/server/sparkd/Dockerfile
+      dockerfile: src/app_sparkd/Dockerfile
      args:
        - IMAGE=${SPARKD__IMAGE}
        - SOURCE_DIR=${SPARKD__SOURCE_DIR}
        - CONFIG_DIR=${SPARKD__CONFIG_DIR}
+        - PYTHON_REQUIREMENTS=${SPARKD__PYTHON_REQUIREMENTS}
    shm_size: "${SPARKD__SHM_SIZE:-512mb}"
    command: >
      sh -c "
-        echo bts | sudo -S chown -R bts:bts /home/bts/sparkdata
-        if [ -e "/home/bts/sparkdata/data/logging.sparkd/log" ]; then
-          mv "/home/bts/sparkdata/data/logging.sparkd/log" "/home/bts/sparkdata/data/logging.sparkd/log_$(date '+%Y%m%d-%H%M')"
+        echo bts | sudo -S chown -R bts:bts /home/bts/.local/share/bts/sparkd
+        if [ -e "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log" ]; then
+          mv "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log" "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log_$(date '+%Y%m%d-%H%M')"
        fi
-        ls -alh /home/bts/sparkdata/conf/
-        cat /home/bts/sparkdata/conf/.env.local
-        if [ -e "/home/bts/sparkdata/conf/.env.local" ]; then
-          echo 'Sourcing /home/bts/sparkdata/conf/.env.local'
+        ls -alh /home/bts/.local/share/bts/sparkd/conf/
+        cat /home/bts/.local/share/bts/sparkd/conf/.env.local
+        if [ -e "/home/bts/.local/share/bts/sparkd/conf/.env.local" ]; then
+          echo 'Sourcing /home/bts/.local/share/bts/sparkd/conf/.env.local'
          set -a
-          . /home/bts/sparkdata/conf/.env.local
+          . /home/bts/.local/share/bts/sparkd/conf/.env.local
          set +a
        fi
+        if [ -d /home/bts/.local/share/bts/sparkd/conf/plugins ]; then
+          echo 'Copying /home/bts/.local/share/bts/sparkd/conf/plugins to runtime dir (/home/bts/bin)'
+          cp -r /home/bts/.local/share/bts/sparkd/conf/plugins /home/bts/bin/
+        fi
        ./sparkd run"
    env_file:
      - .env
@@ -81,10 +91,10 @@ services:
      - type: volume
        read_only: true
        source: sparkd_data
-        target: /home/bts/sparkdata/data/logging.sparkd
+        target: /home/bts/.local/share/bts/sparkd/data/logging.sparkd
        volume:
-          subpath: logging.sparkd
-    command: ["tail", "-f", "/home/bts/sparkdata/data/logging.sparkd/log"]
+          subpath: logging
+    command: ["tail", "-f", "/home/bts/.local/share/bts/sparkd/data/logging.sparkd/log"]

  sparkd-ping-test:
    depends_on:
@@ -99,6 +109,89 @@ services:
        RUN apt-get update && apt-get -y install iputils-ping
    command: [ "ping", "sparkd" ]

+  pubsub:
+    volumes:
+      - ${PUBSUB__DATA_DIR:-pubsub_data}:/home/bts/.local/share/bts/PubSubServer/data
+    build:
+      dockerfile: src/DataStreamSuite/PubSubServer/Dockerfile
+      args:
+        - SOURCE_DIR=${PUBSUB__SOURCE_DIR}
+        - CONFIG_DIR=${PUBSUB__CONFIG_DIR}
+    ports:
+      - 22019:22019
+    command: >
+      sh -c "
+        echo bts | sudo -S chown -R bts:bts /home/bts/.local/share/bts/PubSubServer
+        if [ -e "/home/bts/.local/share/bts/PubSubServer/data/logging.PubSubServer/log" ]; then
+          mv "/home/bts/.local/share/bts/PubSubServer/data/logging.PubSubServer/log" "/home/bts/.local/share/bts/PubSubServer/data/logging.PubSubServer/log_$(date '+%Y%m%d-%H%M')"
+        fi
+        if [ -e "/home/bts/.local/share/bts/PubSubServer/conf/.env" ]; then
+          echo 'Sourcing /home/bts/.local/share/bts/PubSubServer/conf/.env'
+          set -a
+          . /home/bts/.local/share/bts/PubSubServer/conf/.env
+          set +a
+        fi
+        if [ -e "/home/bts/.local/share/bts/PubSubServer/conf/.env.local" ]; then
+          echo 'Sourcing /home/bts/.local/share/bts/PubSubServer/conf/.env.local'
+          set -a
+          . /home/bts/.local/share/bts/PubSubServer/conf/.env.local
+          set +a
+        fi
+        ./PubSubServer"
+    env_file:
+      - .env
+      - ${PUBSUB__CONFIG_DIR}/.env
+
+  md-publisher:
+    volumes:
+      - ${MD_PUBLISHER__DATA_DIR:-md_publisher_data}:/home/bts/.local/share/bts/DataStreamPublisher/data
+      - historic_md:/home/bts/.local/share/bts/databento
+    build:
+      dockerfile: src/DataStreamSuite/DataStreamPublisher/Dockerfile
+      args:
+        - SOURCE_DIR=${MD_PUBLISHER__SOURCE_DIR}
+        - CONFIG_DIR=${MD_PUBLISHER__CONFIG_DIR}
+    command: >
+      sh -c "
+        echo bts | sudo -S chown -R bts:bts /home/bts/.local/share/bts/DataStreamPublisher
+        if [ -e "/home/bts/.local/share/bts/DataStreamPublisher/data/logging.DataStreamPublisher/log" ]; then
+          mv "/home/bts/.local/share/bts/DataStreamPublisher/data/logging.DataStreamPublisher/log" "/home/bts/.local/share/bts/DataStreamPublisher/data/logging.DataStreamPublisher/log_$(date '+%Y%m%d-%H%M')"
+        fi
+        if [ -e "/home/bts/.local/share/bts/DataStreamPublisher/conf/.env" ]; then
+          echo 'Sourcing /home/bts/.local/share/bts/DataStreamPublisher/conf/.env'
+          set -a
+          . /home/bts/.local/share/bts/DataStreamPublisher/conf/.env
+          set +a
+        fi
+        if [ -e "/home/bts/.local/share/bts/DataStreamPublisher/conf/.env.local" ]; then
+          echo 'Sourcing /home/bts/.local/share/bts/DataStreamPublisher/conf/.env.local'
+          set -a
+          . /home/bts/.local/share/bts/DataStreamPublisher/conf/.env.local
+          set +a
+        fi
+      dockerize -wait tcp://pubsub:22019 -timeout 10s ./DataStreamPublisher"
+    env_file:
+      - .env
+      - ${MD_PUBLISHER__CONFIG_DIR}/.env
+
+  api-server:
+    depends_on:
+      - sparkd
+    ports:
+      - 8008:8008
+      - 9443:9443
+    build:
+      dockerfile: src/client/spark_api_server/Dockerfile
+    command: [ "dockerize", "-wait", "tcp://sparkd:8000", "-timeout", "10s", "./spark_api_server", "run" ]
+    environment:
+      - ASPNETCORE_ENVIRONMENT=Staging
+
 volumes:
  sparkd_data:
    name: "sparkd_${SPARKD__CONFIG_PORT:-8000}"
+  pubsub_data:
+    name: "pubsub_22019"
+  md_publisher_data:
+    name: "md_publisher_22019"
+  historic_md:
+    name: "historic_md"
@@ -1,6 +0,0 @@
-{
-  "sdk": {
-    "version": "6.0.200",
-    "rollForward": "latestMajor"
-  }
-}
@@ -16,11 +16,16 @@ jmespath==1.0.1
 lazy-object-proxy==1.6.0
 MarkupSafe==3.0.2
 mccabe==0.6.1
+numpy==2.2.6
 platformdirs==2.3.0
 protobuf==4.21.12
 pybars3==0.9.7
+pybind11==2.13.6
+pybind11-stubgen==2.5.3
+pybit==5.11.0
 pycodestyle==2.7.0
 pycparser==2.20
+pycryptodome==3.23.0
 pylint==2.10.2
 PyMeta3==0.5.1
 python-dateutil==2.9.0.post0
@@ -31,6 +36,7 @@ six==1.17.0
 termcolor==1.1.0
 toml==0.10.2
 urllib3==2.0.3
+websocket-client==1.8.0
 Werkzeug==3.1.3
 wrapt==1.12.1
 yapf==0.31.0
@@ -1,103 +1,164 @@
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.3.32922.545
-MinimumVisualStudioVersion = 15.0.26124.0
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "spark_api", "src\client\spark_api\spark_api.csproj", "{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Spark", "src\client\spark\Spark.csproj", "{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Spark.Console", "src\client\Spark.Console\Spark.Console.csproj", "{387566C6-C6F6-412C-A30C-9855BBCB4816}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "spark_core", "src\client\spark_core\spark_core.csproj", "{6E449EB6-20AC-4FA6-B8D9-10F4BB7E1FEE}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "spark_sdk", "src\client\spark_sdk\spark_sdk.csproj", "{6963C314-83C4-4667-B0D0-C2F7AE208C29}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "spark_test", "src\client\spark_test\spark_test.csproj", "{ECD78CC5-138F-4809-A764-2358C2AC2E82}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "spark_websocket", "src\client\spark_websocket\spark_websocket.csproj", "{3201359D-C071-4089-9EDE-B04D759F1508}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "spark_api_server", "src\client\spark_api_server\spark_api_server.csproj", "{2B8C5D01-FF78-4BFA-B332-5E430586DAF9}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|x64 = Debug|x64
-		MinSizeRel|x64 = MinSizeRel|x64
-		Release|x64 = Release|x64
-		RelWithDebInfo|x64 = RelWithDebInfo|x64
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.Debug|x64.ActiveCfg = Debug|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.Debug|x64.Build.0 = Debug|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.MinSizeRel|x64.ActiveCfg = Release|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.MinSizeRel|x64.Build.0 = Release|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.Release|x64.ActiveCfg = Release|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.Release|x64.Build.0 = Release|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.RelWithDebInfo|x64.ActiveCfg = Release|x64
-		{DC9A8975-8211-4FC9-A9BA-C8B9D26AD481}.RelWithDebInfo|x64.Build.0 = Release|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.Debug|x64.ActiveCfg = Debug|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.Debug|x64.Build.0 = Debug|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.MinSizeRel|x64.ActiveCfg = Release|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.MinSizeRel|x64.Build.0 = Release|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.Release|x64.ActiveCfg = Release|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.Release|x64.Build.0 = Release|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.RelWithDebInfo|x64.ActiveCfg = Release|x64
-		{9A4D4D07-1AB6-4B2B-B111-A4F34D6C267E}.RelWithDebInfo|x64.Build.0 = Release|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.Debug|x64.ActiveCfg = Debug|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.Debug|x64.Build.0 = Debug|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.MinSizeRel|x64.ActiveCfg = Debug|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.MinSizeRel|x64.Build.0 = Debug|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.Release|x64.ActiveCfg = Release|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.Release|x64.Build.0 = Release|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.RelWithDebInfo|x64.ActiveCfg = Release|x64
-		{387566C6-C6F6-412C-A30C-9855BBCB4816}.RelWithDebInfo|x64.Build.0 = Release|x64
-		{6E449EB6-20AC-4FA6-B8D9-10F4BB7E1FEE}.Debug|x64.ActiveCfg = Debug|x64
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+		{4E0E51AA-7B59-4808-B7CC-9EAEDF397460}.Release|x64.Build.0 = Release|Any CPU
+		{4E0E51AA-7B59-4808-B7CC-9EAEDF397460}.RelWithDebInfo|x64.ActiveCfg = Debug|Any CPU
+		{4E0E51AA-7B59-4808-B7CC-9EAEDF397460}.RelWithDebInfo|x64.Build.0 = Debug|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {422D1620-0166-4C26-9A81-CA8A2EB1AB58}
+	EndGlobalSection
+	GlobalSection(Performance) = preSolution
+		HasPerformanceSessions = true
+	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{56A8A70A-DA03-4CED-A144-EC10F1379FD8} = {4564E677-343A-46CB-AF02-AFC4E38BF94B}
+		{915EF238-CA0D-4E73-AF50-88CB3F29C7AD} = {4564E677-343A-46CB-AF02-AFC4E38BF94B}
+		{4E0E51AA-7B59-4808-B7CC-9EAEDF397460} = {915EF238-CA0D-4E73-AF50-88CB3F29C7AD}
+	EndGlobalSection
+EndGlobal
@@ -8,7 +8,6 @@
   public int Integer;
   public double Real;
   public string Identifier;
-   public DateTime DateTime; 
   public ImmutableList<IArithmeticExpression> Arguments;
   public ImmutableList<Assignment> Assignments;
   public IArithmeticExpression Argument;
@@ -1,4 +1,6 @@
 using System;
+using System.Runtime.Versioning;
+
 using Microsoft.Win32;

 namespace BCG
@@ -10,6 +12,7 @@ namespace BCG
         rk.SetValue (name, value.ToString ());
      }

+      [SupportedOSPlatform("windows")]
      public static double getValue (RegistryKey rk, string name)
      {
         object v = rk.GetValue (name);
@@ -1,19 +1,11 @@
 namespace Bts.BooleanExpressions;

-using bts;
-
 class BooleanExpression : IBooleanExpression {
   readonly Func<IDictionary<string, object?>, bool> evaluate;

   public BooleanExpression(Func<IDictionary<string, object?>, bool> evaluate) =>
      this.evaluate = evaluate;

-   public bool Evaluate(IDictionary<string, object?> env) {
-      try {
-         return evaluate(env);
-      } catch (Exception ex) {
-         Log.assert(false, $"BooleanExpression.Evaluate failed: {ex}");
-         throw;
-      }
-   }
+   public bool Evaluate(IDictionary<string, object?> env) =>
+      evaluate(env);
 }
@@ -47,11 +47,6 @@ IsOfType                 '/'

 %%

-{StringConstant} {
-   yylval.String = yytext.Substring(1, yytext.Length - 2).Replace(@"\'", "'");
-   return (int)Token.STRING_CONSTANT;
-} 
-
 {BooleanConstant} {
   yylval.Boolean = yytext.ToLower() switch {
      "true" => true,
@@ -62,6 +57,11 @@ IsOfType                 '/'
   return (int)Token.BOOLEAN_CONSTANT;
 }

+{StringConstant} {
+   yylval.String = yytext.Substring(1, yytext.Length - 2).Replace(@"\'", "'");
+   return (int)Token.STRING_CONSTANT;
+} 
+
 {NullConstant} {
   yylval.Null = DBNull.Value;
   return (int)Token.NULL_CONSTANT;
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.0" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,71 @@
+namespace Bts.Extensions.Hosting;
+
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+using System.Diagnostics;
+
+public static class HostBuilderExtensions {
+   public static IHostBuilder CreateBtsBuilder(string[] args) {
+      // Obtain calling assembly name here, rather than in the lambda where it is actually needed,
+      // because want the name of the assembly that called this function, not the assembly that will eventually invoke
+      // the lambda...that will be the Microsoft.Extensions.Hosting assembly.
+      // Get the name of the assembly that called this function. That will act as the "appsettings"
+      // json file prefix
+      var exeName = GetCallingAssemblyName();
+      return Host.CreateDefaultBuilder(args)
+         .ConfigureAppConfiguration((context, configBuilder) =>
+            ConfigureApp(configBuilder, context.HostingEnvironment.EnvironmentName, exeName));
+   }
+
+   public static void ConfigureApp(IConfigurationBuilder configBuilder, string? environment = null, string? prefix = null) {
+      var baseFileName = prefix is null ? "appsettings" : $"{prefix}.appsettings";
+      AddJsonFile($"{baseFileName}.json");
+      if (environment is not null) {
+         AddJsonFile($"{baseFileName}.{environment}.json");
+      }
+
+      var cfg = configBuilder.Build().GetSection("config")?.Value;
+      if (!SetBasePath(cfg)) {
+         AddJsonFile(cfg);
+      }
+
+      bool SetBasePath(string? path) {
+         if (!Directory.Exists(path)) {
+            return false;
+         }
+         configBuilder.SetBasePath(path);
+         return true;
+      }
+
+      bool AddJsonFile(string? path) {
+         if (!File.Exists(path)) {
+            return false;
+         }
+         configBuilder.AddJsonFile(path);
+         return true;
+      }
+   }
+
+   public static void ConfigureLogging(ILoggingBuilder loggingBuilder, ILoggerProvider loggerProvider) =>
+      loggingBuilder.AddFilter("Microsoft", LogLevel.Warning)
+         .AddFilter("System", LogLevel.Warning)
+         .AddFilter("NToastNotify", LogLevel.Warning)
+         .AddProvider(loggerProvider)
+         .AddSimpleConsole(opts => {
+            opts.SingleLine = true;
+            opts.TimestampFormat = "yyyy-MM-dd HH:mm:ss.ffffff|";
+         })
+         .AddDebug();
+
+   public static string GetCallingAssemblyName() =>
+      new StackTrace()
+         .GetFrame(2)
+         ?.GetMethod()
+         ?.Module
+         ?.Assembly
+         ?.GetName()
+         ?.Name
+         ?? throw new InvalidOperationException("Failed to determine name of calling assembly (calling method is null)");
+}
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
@@ -0,0 +1,28 @@
+namespace Bts.Net;
+
+using System.Linq;
+using System.Net;
+
+/// <summary>
+/// Provides facilities to compare hosts for equality.
+/// <para>
+/// This class doesn't implement IEqualityComparer because a consistent hash code cannot be
+/// guarenteed for equivalent host strings. The equals impl relies on Dns.GetHostAddresses, which
+/// is non-determinstic (implementations that depends on mutable properties face a similar problem).
+/// </para>
+/// </summary>
+public class HostComparer {
+   public static bool Equals(string? x, string? y) {
+      if (x is null) {
+         return y is null;
+      }
+      if (y is null) {
+         return false;
+      }
+      return Dns.GetHostAddresses(x).Intersect(
+         Dns.GetHostAddresses(y), IpAddressComparer.Instance).Any();
+   }
+
+   public static bool Equals(IPHostEntry x, IPHostEntry y) =>
+      x.AddressList.Intersect(y.AddressList, IpAddressComparer.Instance).Any();
+}
@@ -0,0 +1,30 @@
+namespace Bts.Net;
+
+using System.Diagnostics.CodeAnalysis;
+using System.Net;
+
+/// <summary>
+/// Compares ip addresses. Unlike the default comparer, v4 and equivalent v6 addresses are
+/// considered equal.
+/// </summary>
+public class IpAddressComparer : IEqualityComparer<IPAddress> {
+   public static IEqualityComparer<IPAddress> Instance { get; } = new IpAddressComparer();
+
+   public bool Equals(IPAddress? x, IPAddress? y) {
+      if (x is null) {
+         return y is null;
+      }
+      if (y is null) {
+         return false;
+      }
+      return x.Equals(y) ||
+         (x.IsIPv4MappedToIPv6 && x.MapToIPv4().Equals(y)) ||
+         (y.IsIPv4MappedToIPv6 && y.MapToIPv4().Equals(x));
+   }
+
+   public int GetHashCode([DisallowNull] IPAddress address) =>
+      address.IsIPv4MappedToIPv6
+         // Return consistent hash code for v4 and equivalent v6
+         ? address.MapToIPv4().GetHashCode()
+         : address.GetHashCode();
+}
@@ -0,0 +1,33 @@
+namespace Bts.Net;
+
+using System;
+using System.Net;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+public class IpHostEntryJsonConverter : JsonConverter<IPHostEntry> {
+   public override IPHostEntry? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+      throw new NotImplementedException();
+   }
+
+   public override void Write(Utf8JsonWriter writer, IPHostEntry value, JsonSerializerOptions options) {
+      writer.WriteStartObject();
+      // HostName
+      writer.WriteString(nameof(value.HostName), value.HostName);
+      // Aliases
+      writer.WritePropertyName("Aliases");
+      writer.WriteStartArray();
+      foreach (var alias in value.Aliases) {
+         writer.WriteStringValue(alias);
+      }
+      writer.WriteEndArray();
+      // Addresses
+      writer.WritePropertyName("Addresses");
+      writer.WriteStartArray();
+      foreach (var address in value.AddressList) {
+         writer.WriteStringValue(address.ToString());
+      }
+      writer.WriteEndArray();
+      writer.WriteEndObject();
+   }
+}
@@ -0,0 +1,39 @@
+namespace Bts.Net;
+
+using System;
+using System.IO;
+using System.Net;
+using System.Text;
+using System.Text.Json;
+
+/// <summary>
+/// This class seriailzes IpHostEntry to json (string). A common buffer is used to reduce memory
+/// allocations on repeated calls to <see cref="Serialize"/>. For that reason, this class is NOT
+/// thread safe.
+/// </summary>
+public class IpHostEntryJsonSerializer {
+   readonly MemoryStream buffer = new();
+   readonly IpHostEntryJsonConverter converter;
+
+   public IpHostEntryJsonSerializer(IpHostEntryJsonConverter? converter = null) =>
+      this.converter = converter ?? new() { };
+
+   public string? Serialize(IPHostEntry dp, JsonSerializerOptions? opts = null) {
+      opts ??= JsonSerializerOptions.Default;
+      buffer.Position = 0;
+      buffer.SetLength(0);
+      using (var jsonWriter = new Utf8JsonWriter(buffer)) {
+         converter.Write(jsonWriter, dp, opts);
+      }
+      var bytes = buffer.GetBuffer();
+      var span = new ArraySegment<byte>(bytes, 0, (int)buffer.Length);
+      return Encoding.UTF8.GetString(span);
+   }
+
+   public void Serialize(IPHostEntry dp, Utf8JsonWriter jsonWriter, JsonSerializerOptions? opts = null) {
+      opts ??= JsonSerializerOptions.Default;
+      buffer.Position = 0;
+      buffer.SetLength(0);
+      converter.Write(jsonWriter, dp, opts);
+   }
+}
@@ -0,0 +1,94 @@
+namespace Bts.Net;
+
+using System.Diagnostics.CodeAnalysis;
+using System.Net;
+using System.Text.RegularExpressions;
+
+public static partial class IpUtils {
+   static readonly Regex ipv4Regex = new(string.Join('.', @"(((0|1)\d)|(2\d)|\d)?\d"));
+
+   // public static void ParseUri(string str, out string? scheme, out string? host, out string? port, out string? path, out string? queryParams) {
+   //    if (Uri.TryCreate(str, UriKind.Absolute, out var uri)) {
+   //    }
+   // }
+
+   // public static bool AreEndpointsEqual(Uri? x, Uri? y) {
+   //    if (x is null) {
+   //       return y is null;
+   //    }
+   //    if (y is null) {
+   //       return false;
+   //    }
+   //    if (x.IsAbsoluteUri != y.IsAbsoluteUri) {
+   //       return false;
+   //    }
+   //    if (x.IsAbsoluteUri) {
+   //       if (x.Scheme != y.Scheme) {
+   //          return false;
+   //       }
+   //    }
+   //    string? xHost = null;
+   // }
+
+   // static string ResolveHostIpv4(Uri uri) {
+   //    // switch (uri.HostNameType) {
+   //    //    case UriHostNameType.IPv4:
+   //    //       return uri.Host;
+   //    //    case UriHostNameType.Dns:
+   //    //       break;
+   //    //    case UriHostNameType.IPv6:
+   //    //       var addresses = Dns.GetHostAddresses(uri.Host);
+   //    //       foreach (var address in addresses) {
+   //    //          if (address.IsIPv4MappedToIPv6) {
+   //    //             return address.MapToIPv4().Address;
+   //    //          }
+   //    //       }
+   //    //       break;
+   //    // }
+   //    var hostAddresses = Dns.GetHostAddresses(uri.Host);
+   //    foreach (IPAddress address in hostAddresses) {
+   //       if (address.Equals(remoteEndPoint.Address) ||
+   //           (address.IsIPv4MappedToIPv6 && address.MapToIPv4().Equals(remoteEndPoint.Address)) ||
+   //           (remoteEndPoint.Address.IsIPv4MappedToIPv6 && remoteEndPoint.Address.MapToIPv4().Equals(address))) {
+   //          isMatch = true;
+   //          break;
+   //       }
+   //    }
+   // }
+
+   // public static bool AreEndpointsEqual(string? x, string? y) {
+   //    if (x == y) {
+   //       return true;
+   //    }
+   //    if (x is null) {
+   //       return y is null;
+   //    }
+   //    if (y is null) {
+   //       return false;
+   //    }
+   //    var xUri = new Uri(x);
+   //    var yUri = new Uri(y);
+   //    // return xUri.Equals(yUri);
+   // }
+
+   public static bool IsIpv4(string host) {
+      host = removeSchemaFromUrl(host);
+      host = removePortFromUrl(host);
+      return ipv4Regex.IsMatch(host);
+   }
+
+   static string removeSchemaFromUrl(string url) {
+      var i = url.IndexOf("://");
+      return i < 0 ? url : url.Substring(i + 3);
+   }
+
+   static string removePortFromUrl(string url) {
+      var match = MyRegex().Match(url);
+      return match.Success
+         ? string.Concat(url.AsSpan(0, match.Index), url.AsSpan(match.Index + match.Length))
+         : url;
+   }
+
+   [GeneratedRegex(":\\d{1,4}")]
+   private static partial Regex MyRegex();
+}
@@ -7,14 +7,11 @@
  </PropertyGroup>

  <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.24.3" />
    <PackageReference Include="YaccLexTools" Version="1.2.2" />
  </ItemGroup>

  <ItemGroup>
-    <ProjectReference Include="..\DataStreamCore\DataStreamCore.csproj" />
    <ProjectReference Include="..\ExpressionCore\ExpressionCore.csproj" />
-    <ProjectReference Include="..\..\client\spark_core\spark_core.csproj" />
  </ItemGroup>

  <ItemGroup Label="ColumnMapExpression">
@@ -0,0 +1,11 @@
+namespace bts.BlueOrb {
+   using BCG;
+
+   [DataStreamUserRespresentation("AddColumnsStream")]
+   public class AddColumnsStream: ViewStream {
+      public AddColumnsStream(ViewStream parent_str, string add_col_expr) {
+         ViewStream rs = new BCG.AddColumnsStream(parent_str, add_col_expr);
+         mySetRealSource(rs);
+      }
+   }
+}
@@ -0,0 +1,118 @@
+namespace Bts.DataStream;
+
+using BCG;
+
+using bts.collections;
+using bts.utils;
+
+using Bts.DataStreamCore;
+
+using Spark.Core.Collections;
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+public class BlueAddIndexColumnTable : IBlueRowCollection {
+   readonly IBlueTableSchema schema;
+   readonly IList<object?>[] columnValues;
+   readonly int count;
+
+   BlueAddIndexColumnTable(IBlueTableSchema schema, IList<object?>[] columnValues, int? count = null) {
+      this.schema = schema;
+      this.columnValues = columnValues;
+      this.count = count ?? columnValues[0].Count;
+   }
+
+   IBlueTableSchema IBlueRowCollection.schema => schema;
+
+   public int Count => count;
+
+   public IBlueRow this[int id] =>
+      id > 0 && id <= count
+         ? GetRow(id - 1)
+         : throw new KeyNotFoundException();
+
+   public static BlueAddIndexColumnTable Create(string tableName, ColumnInfo[] columnInfos, IList<object?>[] columnValues) {
+      if (columnInfos.Any(c => c.colName == "id")) {
+         throw new ArgumentException("'id' column already exists", nameof(columnInfos));
+      }
+      if (columnInfos.Length != columnValues.Length) {
+         throw new ArgumentException("columnValues length differs from columnInfos length", nameof(columnValues));
+      }
+      int count = columnValues.FirstOrDefault()?.Count ?? 0;
+      var origCols = columnInfos;
+      var origColValues = columnValues;
+      columnInfos = new ColumnInfo[origCols.Length + 1];
+      columnInfos[0] = new ColumnInfo("id", 0, typeof(int));
+      columnValues = new IList<object?>[origCols.Length + 1];
+      columnValues[0] = new StepList<int>(1, 1, count).WrapSelector(id => (object?)id, null);
+      for (int i = 1; i < columnInfos.Length; i++) {
+         columnInfos[i] = new ColumnInfo(origCols[i - 1].colName, i, origCols[i - 1].colType);
+         columnValues[i] = origColValues[i - 1];
+      }
+      var schema = new BlueTableSchema(columnInfos, tableName);
+      return new(schema, columnValues, count);
+   }
+
+   public static BlueAddIndexColumnTable Create(IBlueTableSchema schema, IList<object?>[] columnValues) {
+      int count = columnValues.FirstOrDefault()?.Count ?? 0;
+      int? idColIdx = schema.TryResolveIndices("id");
+      var idColValues = new StepList<int>(1, 1, count).WrapSelector(id => (object?)id, null);
+      var columnInfos = schema.columnInfo;
+      if (idColIdx.HasValue) {
+         // Replace existing id column. columnValues may or may not contain the old ids (if its
+         // length is one less column than that of columnInfos, it doesn't contain them).
+         switch (columnValues.Length - schema.columnInfo.Length) {
+            case 0:
+               columnValues[idColIdx.Value] = idColValues;
+               break;
+            case -1:
+               columnValues = ArrayHelper.InsertExact(columnValues, idColIdx.Value, true, idColValues);
+               break;
+            default:
+               throw new ArgumentException("ColumnInfos length disagrees with columnValues length");
+         }
+      } else {
+         if (columnValues.Length != columnInfos.Length) {
+            throw new ArgumentException("ColumnInfos length disagrees with columnValues length");
+         }
+         var origColInfos = columnInfos;
+         columnInfos = new ColumnInfo[columnInfos.Length + 1];
+         columnInfos[0] = new("id", 0, typeof(int));
+         for (int i = 1; i < columnInfos.Length; i++) {
+            var c = origColInfos[i - 1];
+            columnInfos[i] = new(c.colName, c.colNo + 1, c.colType);
+         }
+         columnValues = ArrayHelper.InsertExact(columnValues, 0, true, idColValues);
+      }
+      return new(new BlueTableSchema(schema.tableName, columnInfos), columnValues);
+   }
+
+   public bool containsID(int id) =>
+      id > 0 && id <= count;
+
+   public IList<object?> GetColumn(int index) =>
+      columnValues[index];
+
+   public IBlueRow GetRow(int index) =>
+      new BlueRowColumnWrapper(schema, index, columnValues);
+
+   public int IndexOf(IBlueRow item) {
+      int id = item.Id();
+      return id > 0 && id <= count && BlueRowEqualityComparer.Equals(GetRow(id - 1), item)
+         ? id - 1
+         : -1;
+   }
+
+   public IEnumerator<IBlueRow> GetEnumerator() {
+      int count = Count;
+      for (int i = 0; i < count; i++) {
+         yield return GetRow(i);
+      }
+   }
+
+   IEnumerator IEnumerable.GetEnumerator() =>
+      GetEnumerator();
+}
@@ -0,0 +1,56 @@
+namespace Bts.DataStream;
+
+using BCG;
+
+using Bts.DataStreamCore;
+
+using mbts.utils;
+
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+public class BlueIndexedColumnTable : IBlueRowCollection {
+   readonly IBlueTableSchema schema;
+   readonly IList<object?>[] columnValues;
+   readonly Dictionary<int, int> rowIdToIndex;
+
+   public BlueIndexedColumnTable(IBlueTableSchema schema, IList<object?>[] columnValues) {
+      this.schema = schema;
+      this.columnValues = columnValues;
+      int idColumnIndex = schema.ResolveIndices("id");
+      rowIdToIndex = columnValues[idColumnIndex]
+         .Select((idObj, idx) => new KeyValuePair<int, int>(ExceptionAssert.Argument.Is<int>(idObj), idx))
+         .ToDictionary();
+   }
+
+   public IBlueRow this[int id] =>
+      rowIdToIndex.TryGetValue(id, out var idx)
+         ? GetRow(idx)
+         : throw new KeyNotFoundException();
+
+   IBlueTableSchema IBlueRowCollection.schema => schema;
+
+   public int Count => rowIdToIndex.Count;
+
+   public bool containsID(int id) =>
+      rowIdToIndex.ContainsKey(id);
+
+   public IEnumerator<IBlueRow> GetEnumerator() {
+      int count = Count;
+      for (int i = 0; i < count; i++) {
+         yield return GetRow(i);
+      }
+   }
+
+   public IBlueRow GetRow(int index) =>
+      new BlueRowColumnWrapper(schema, index, columnValues);
+
+   public int IndexOf(IBlueRow item) =>
+      rowIdToIndex.TryGetValue(item.Id(), out var idx) && BlueRowEqualityComparer.Equals(GetRow(idx), item)
+         ? idx
+         : -1;
+
+   IEnumerator IEnumerable.GetEnumerator() =>
+      GetEnumerator();
+}
@@ -0,0 +1,21 @@
+namespace Bts.DataStream;
+
+using BCG;
+
+using System.Collections.Generic;
+
+public class BlueRowColumnWrapper : IBlueRow {
+   readonly int index;
+   readonly IList<object?>[] columns;
+
+   public BlueRowColumnWrapper(IBlueTableSchema schema, int index, IList<object?>[] columns) {
+      this.schema = schema;
+      this.index = index;
+      this.columns = columns;
+   }
+
+   public object? this[int index] =>
+      columns[index][this.index];
+
+   public IBlueTableSchema schema { get; }
+}
@@ -0,0 +1,18 @@
+namespace bts.BlueOrb {
+   using System;
+
+   using BCG;
+
+   [DataStreamUserRespresentation("CSVReaderStream")]
+   public class CSVReaderStream : ViewStream {
+      public CSVReaderStream(string file_name)
+         : this(file_name, false) { }
+      public CSVReaderStream(string file_name, bool guess_schema) {
+         ViewStream rs = new BCG.CSVReaderStream(file_name);
+         if (guess_schema) {
+            rs = new SchemaGuesserStream(rs);
+         }
+         mySetRealSource(rs);
+      }
+   }
+}
@@ -0,0 +1,13 @@
+namespace bts.BlueOrb {
+   using BCG;
+
+   using System;
+
+   [DataStreamUserRespresentation("CSVSaverStream")]
+   public class CSVSaverStream: ViewStream {
+      public CSVSaverStream(ViewStream parent_str, string file_name) {
+         BCG.CSVSaverStream rs = new BCG.CSVSaverStream(parent_str, file_name, true, Int32.MaxValue, false);
+         mySetRealSource(rs);
+      }
+   }
+}
@@ -0,0 +1,46 @@
+using System;
+
+namespace BCG {
+   [DataStreamUserRespresentation("CountStream")]
+   public class CountStream : ViewStream {
+      private DataPacket myLastFiredDataPacket;
+      private IBlueTableSchema mySchema = new BlueTableSchema("count",
+         new ColumnInfo("id", 0, typeof(int)),
+         new ColumnInfo("count", 1, typeof(int)));
+      private int myId = 0;
+      private ViewStream myVS;
+
+      public CountStream(ViewStream vs) {
+         myVS = vs;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         myVS.onChange += new ChangeDelegate(myHandleChanges);
+      }
+      protected override void myOnLastSubscriber() {
+         myVS.onChange -= new ChangeDelegate(myHandleChanges);
+      }
+
+
+      private void myHandleChanges(object newValue) {
+         myFireEvent(
+            myLastFiredDataPacket =
+               myLastFiredDataPacket == null ?
+                  new DataPacket(myGetRows(newValue, ++myId), myGetRows(newValue, myId),
+                  new BlueTable(mySchema))
+                  :
+                  new DataPacket(myGetRows(newValue, ++myId), myGetRows(newValue, myId),
+                  myLastFiredDataPacket.newRows)
+            );
+      }
+
+      private IBlueRowCollection myGetRows(object dp, int id) {
+         BlueTable retVal = new BlueTable(mySchema);
+         retVal.addRow
+            (new BlueRow(mySchema, id, (dp as DataPacket).newRows.Count));
+         return retVal;
+      }
+
+
+   }
+}
@@ -1,4 +1,4 @@
-namespace bts.SilverPine {
+namespace bts.BlueOrb {
   using bts;

   using BCG;
@@ -9,11 +9,11 @@ namespace bts.SilverPine {
      public DateTimeExpanstionStream(ViewStream parent_stream, string inp_col) {
         Func<IBlueTableSchema, IBlueTableSchema> get_schema = (s) => {
            IBlueTableSchema rv = s.add_column(System.TypeCode.DateTime, $"{inp_col}_date");
-            rv = rv.add_column(System.TypeCode.String, $"{inp_col}_day");
+            rv = rv.add_column(System.TypeCode.String, $"{inp_col}_day_of_week");
            rv = rv.add_column(System.TypeCode.Int32, $"{inp_col}_day_of_month");
            rv = rv.add_column(System.TypeCode.Int32, $"{inp_col}_month");
            rv = rv.add_column(System.TypeCode.Int32, $"{inp_col}_hour");
-            rv = rv.add_column(System.TypeCode.Int32, $"{inp_col}_min");
+            rv = rv.add_column(System.TypeCode.Int32, $"{inp_col}_minute");
            rv = rv.add_column(System.TypeCode.Int32, $"{inp_col}_seconds_of_day");
            return rv;
         };
@@ -35,4 +35,4 @@ namespace bts.SilverPine {
         mySetRealSource(rs);
      }
   }
-}
+}
@@ -0,0 +1,156 @@
+namespace bts.BlueOrb {
+   using BCG;
+   using System;
+   using System.Text.RegularExpressions;
+
+   [DataStreamUserRespresentation("FilterStream")]
+   public class FilterStream : ViewStream {
+      public class RegExpFilter : IStreamFilter {
+         private Regex[] myRegExps;
+         private string[] myCols;
+
+         public RegExpFilter(string col, string regExp)
+            : this(new string[] { col }, new string[] { regExp }) { }
+
+         public RegExpFilter(string[] cols, string[] regExps) {
+            myCols = cols;
+            myRegExps = new Regex[regExps.Length];
+            for (int i = 0; i < regExps.Length; i++)
+               myRegExps[i] = new Regex(regExps[i]);
+         }
+
+         #region IStreamFilter Members
+         public bool filter(IBlueRow dr) {
+            bool rv = true;
+            for (int i = 0; i < myCols.Length; i++) {
+               rv &= myRegExps[i].IsMatch(dr[myCols[i]] is DBNull ? "" : dr[myCols[i]].ToString());
+               if (!rv)
+                  return rv;
+            }
+            return rv;
+         }
+         #endregion
+      }
+      private BlueTable myLastFiredRows;
+      private IBlueRowCollection myLastReceivedRows;
+      private IStreamFilter myFilter;
+      private ViewStream myParentStream;
+      private string myFilterString;
+      private bool myUseNewFilter = false;// Configuration.get<DataStreamConfig>().UseNewFilter;
+
+      #region constructors
+      public delegate bool OnFilter(IBlueRow r);
+      private class OnFilterWrapper : IStreamFilter {
+         public OnFilterWrapper(OnFilter f) { this.f = f; }
+
+         public bool filter(IBlueRow dr) { return f(dr); }
+
+         private OnFilter f;
+      }
+      public FilterStream(ViewStream vs, OnFilter f)
+         : this(vs, new OnFilterWrapper(f)) { }
+
+
+      public FilterStream(ViewStream vs, IStreamFilter filter) {
+         {
+            myParentStream = vs;
+            myFilter = filter;
+            myFilterString = filter.ToString();
+            if (filter is IDynamicStreamFilter)
+               (filter as IDynamicStreamFilter).onFilterChange += new FilterChangeDelegate(myHandleFilterChange);
+         }
+      }
+
+      public FilterStream(ViewStream vs, string filterExpression)
+         : this(vs, new BooleanExpressionFilter(filterExpression)) {
+         myFilterString = filterExpression;
+      }
+
+      public FilterStream(ViewStream vs, string col, string regExp)
+         : this(vs, new RegExpFilter(col, regExp)) {
+         myFilterString = col + " , " + regExp;
+      }
+
+      public FilterStream(ViewStream vs)
+         : this(vs, new BinaryFilter(true)) {
+         myFilterString = true.ToString();
+      }
+      #endregion
+
+      #region overridden methods
+      protected override void myOnFirstSubscriber() { myParentStream.onChange += new ChangeDelegate(myHandleCallbacks); }
+
+      protected override void myOnLastSubscriber() {
+         myLastFiredRows = null;
+         myParentStream.onChange -= new ChangeDelegate(myHandleCallbacks);
+      }
+
+      protected override void myFireEvent(object o) {
+         DataPacket dp = o as DataPacket;
+         if (myLastValue == null || dp.addedRows.Count + dp.deletedRows.Count > 0)
+            base.myFireEvent(o);
+      }
+      #endregion
+
+      private void myHandleCallbacks(object newValue) {
+         DataPacket retVal;
+         DataPacket arrivedPacket = newValue as DataPacket;
+         myLastReceivedRows = arrivedPacket.newRows;
+         if (myLastFiredRows != null) {
+            retVal = new DataPacket(myLastFiredRows, new BlueTable(myLastFiredRows.schema),
+               new BlueTable(myLastFiredRows.schema));
+            foreach (IBlueRow r in arrivedPacket.deletedRows)
+               if (myLastFiredRows.containsID((int)r["id"])) {
+                  myLastFiredRows.deleteRow(r);
+                  (retVal.deletedRows as BlueTable).addRow(r);
+               }
+            foreach (IBlueRow r in arrivedPacket.addedRows)
+               if (myFilter.filter(r)) {
+                  myLastFiredRows.addRow(r);
+                  (retVal.addedRows as BlueTable).addRow(r);
+               }
+         } else {
+            myLastFiredRows = new BlueTable(arrivedPacket.schema);
+            retVal = new DataPacket(myLastFiredRows, myLastFiredRows, new BlueTable(myLastFiredRows.schema));
+            foreach (IBlueRow r in arrivedPacket.newRows)
+               if (myFilter.filter(r))
+                  myLastFiredRows.addRow(r);
+         }
+         myFireEvent(retVal);
+      }
+
+      public IStreamFilter filter {
+         set {
+            {
+               myFilter = value;
+               if (numberOfSubscribers > 0) {
+                  if (myLastReceivedRows != null) {
+                     BlueTable nRows = new BlueTable(myLastReceivedRows.schema);
+                     foreach (IBlueRow r in myLastReceivedRows)
+                        if (myFilter.filter(r))
+                           nRows.addRow(r);
+                     IBlueRowCollection dRows = new BlueTable(nRows.schema),
+                        aRows = new BlueTable(nRows.schema);
+                     BlueDataUtility.computeDifferences(nRows, myLastFiredRows, out dRows, out aRows);
+                     myLastFiredRows = nRows;
+                     myFireEvent(new DataPacket(nRows, aRows, dRows));
+                  }
+               }
+            }
+         }
+         get {            
+               return myFilter;
+         }
+      }
+
+      //public string filterString { set { filter = new BooleanExpressionFilter(value); } }
+
+      public override string ToString() {
+         return GetType().ToString() + " " + myFilterString;
+      }
+
+      private void myHandleFilterChange() {
+         filter = myFilter;
+      }
+   }
+}
@@ -0,0 +1,127 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text.Json;
+
+using bts;
+//using bts.SilverPine;
+using BCG;
+
+namespace bts.BlueOrb {
+   [DataStreamUserRespresentation("GroupByStream")]
+   public class GroupByStream : ViewStream {
+
+      public interface INonIncGroupByEvaluator {
+         // grouped_rows
+         IBlueRowCollection evaluate(IDictionary<int, List<IBlueRow>> grouped_rows);
+         string[] get_group_by_cols();
+      }
+
+      private class DelNonIncGroupByEvaluator : INonIncGroupByEvaluator {
+         Func<string[]> _groupby_cols_func;
+         Func<List<IBlueRow>, List<IBlueRow>> _evaluate_func;
+         public DelNonIncGroupByEvaluator(Func<string[]> groupby_cols_func,
+                                          Func<List<IBlueRow>, List<IBlueRow>> evaluate_func) {
+            _groupby_cols_func = groupby_cols_func;
+            _evaluate_func = evaluate_func;
+         }
+         public IBlueRowCollection evaluate(IDictionary<int, List<IBlueRow>> grouped_rows) {
+            BlueTable rv = null;
+            foreach (var kv in grouped_rows) {
+               List<IBlueRow> g_rows = kv.Value;
+               List<IBlueRow> out_rows = _evaluate_func.Invoke(g_rows);
+               if (out_rows != null && out_rows.Count > 0) {
+                  rv = rv ?? new BlueTable(out_rows.ElementAt(0).schema);
+               }
+               if (rv != null)
+                  rv.addRows(out_rows);
+            }
+            return rv;
+         }
+         public string[] get_group_by_cols() {
+            return _groupby_cols_func();
+         }
+
+      }
+      private ViewStream _main_stream;
+      private INonIncGroupByEvaluator _groupby_func;
+      private BlueRowHasher _row_hasher;
+      private string[] _groupby_cols;
+      private Stopwatch _timer = new();
+      private int _n_total_fires = 0, _n_expensive_fires = 0;
+
+      public GroupByStream(ViewStream main_stream, INonIncGroupByEvaluator groupby_func) {
+         _main_stream = main_stream;
+         _groupby_func = groupby_func;
+         _groupby_cols = _groupby_func.get_group_by_cols();
+         _row_hasher = new BlueRowHasher(_groupby_cols == null ? 0 : _groupby_cols.Length);
+      }
+
+      public GroupByStream(ViewStream main_stream, Func<string[]> groupby_cols_func,
+                                 Func<List<IBlueRow>, List<IBlueRow>> evaluate_func)
+                                 : this(main_stream, new DelNonIncGroupByEvaluator(groupby_cols_func, evaluate_func)) { }
+
+      public GroupByStream(ViewStream parent_str, string groupby_cols, string standard_group_by_text)
+      : this(parent_str, groupby_cols, standard_group_by_text, String.Empty) { }
+
+      // this is the main constructor that does everything
+      public GroupByStream(ViewStream parent_str, string groupby_cols, string standard_group_by_ops, string optional_sort_col) {
+         MultiRowOpHelper std_group_by = MultiRowOpHelper.parse_ops(standard_group_by_ops);
+         Func<string[]> groupby_cols_func = () => {
+            if (String.IsNullOrEmpty(groupby_cols))
+               return null;
+            return groupby_cols.Split(',').Select(x => x.Trim()).ToArray();
+         };
+         Func<List<IBlueRow>, List<IBlueRow>> evaluate_func = (group_rows) => {
+            if (!String.IsNullOrEmpty(optional_sort_col))
+               group_rows.Sort((r1, r2) => BlueDataUtility.compare_rows(r2, r1, optional_sort_col));
+            // this si where the group by aggregation happens
+            IBlueRow rv = MultiRowOpHelper.group_by_compute(group_rows, std_group_by);
+            if (rv == null)
+               return new List<IBlueRow>();
+            return new IBlueRow[] { rv }.ToList();
+         };
+         ViewStream rs = new GroupByStream(parent_str, groupby_cols_func, evaluate_func);
+         mySetRealSource(rs);
+      }
+      public GroupByStream(ViewStream parent_str, string standard_group_by_text) :
+      this(parent_str, String.Empty, standard_group_by_text) {
+      }
+
+
+      protected override void myOnFirstSubscriber() { _main_stream.onChange += _main_stream_onchange; }
+
+      protected override void myOnLastSubscriber() { _main_stream.onChange -= _main_stream_onchange; }
+
+      private void _main_stream_onchange(object nv) {
+         DataPacket dp = nv as DataPacket;
+         ///grouping together
+         _timer.Restart();
+         IDictionary<int, List<IBlueRow>> grouped_rows = (_groupby_cols == null || _groupby_cols.Length == 0) ?
+         new Dictionary<int, List<IBlueRow>>() { { 0, dp.newRows.to_list() } } :
+         BlueDataUtility.group_together(dp.newRows, _groupby_cols, ref _row_hasher);
+         _timer.Stop();
+         var groupElapsedMs = _timer.ElapsedMilliseconds;
+         if (groupElapsedMs >= 50) {
+            Log.DataFlow.info($"Time to group {dp.newRows.Count} rows into {grouped_rows.Count} groups: {_timer.ElapsedMilliseconds}ms");
+         }
+         // Log.log(bts.Log.Level.Info, bts.log.Subsystem.gen, String.Format("Time to group {0} rows into {1} groups = {2}", dp.newRows.Count, grouped_rows.Count, _timer.lastIntervalTime));
+         /// reducing
+         _timer.Restart();
+         IBlueRowCollection total_state = _groupby_func.evaluate(grouped_rows);
+         if (total_state == null)
+            // mayeb returna n empty table ?
+            return;
+         _timer.Stop();
+         var applyElapsedMs = _timer.ElapsedMilliseconds;
+         _n_total_fires++;
+         if (applyElapsedMs >= 50) {
+            _n_expensive_fires++;
+            Log.DataFlow.info(
+               $"Time to evaluate {grouped_rows.Count} groups {_timer.ElapsedMilliseconds}ms, ratio {_n_expensive_fires}/{_n_total_fires}");
+         }
+         myFireEvent(new DataPacket(total_state, total_state, myLastValue == null ? new BlueTable(total_state.schema) : (myLastValue as DataPacket).newRows));
+      }
+   }
+}
@@ -0,0 +1,196 @@
+namespace bts.BlueOrb {
+   using BCG;
+   using RowHash = System.Int32;
+   using System;
+   using System.Collections.Generic;
+   using System.Linq;
+   using System.Text;
+   using System.Threading.Tasks;
+   using System.Collections;
+   using System.Data.Entity.Core.Mapping;
+
+   [DataStreamUserRespresentation("JoinStream")]
+   public class SimpleJoinStream : ViewStream {
+      public class JoinBookkeepingData {
+         // initialized in cons
+         private readonly List<string> _join_col_names;
+         private readonly bool _is_left;
+         private readonly BlueRowHasher _hasher;
+         // initialized on first udpate         
+         private IBlueTableSchema _schema;
+         private int[] _join_cols;
+         private IDictionary<RowHash, List<IBlueRow>> _hash_row_map = new Dictionary<RowHash, List<IBlueRow>>();
+
+         public JoinBookkeepingData(ViewStream vs, List<string> join_cols, bool is_left, BlueRowHasher row_hasher) {
+            _join_col_names = join_cols.Where(c => !String.IsNullOrEmpty(c)).ToList();
+            _is_left = is_left;
+            _hasher = row_hasher;
+         }
+
+         public IBlueTableSchema schema => _schema;
+
+         public IDictionary<RowHash, List<IBlueRow>> rows => _hash_row_map;
+
+         public List<IBlueRow> get_matching_rows(int hash) {
+            List<IBlueRow> rv = null;
+            _hash_row_map.TryGetValue(hash, out rv);
+            return rv;
+         }
+
+         private RowHash _get_hash(IBlueRow r) {
+            if (_join_cols == null || _join_cols.Length == 0) {
+               return 0;
+            }
+            return _hasher.get_hash(r, _join_cols);
+         }
+
+         public void update_data(DataPacket dp) {
+            if (!ready) {
+               _schema = dp.newRows.schema;
+               _join_cols = _join_col_names.Count == 0 ? new int[] { } : _join_col_names.Select(n => dp.schema[n].colNo).ToArray();
+            }
+            _hash_row_map.Clear();
+            foreach (IBlueRow r in dp.newRows) {
+               int hash = _get_hash(r);
+               List<IBlueRow> hash_rows = null;
+               if (!_hash_row_map.TryGetValue(hash, out hash_rows)) {
+                  hash_rows = new List<IBlueRow>();
+                  _hash_row_map.Add(hash, hash_rows);
+               }
+               hash_rows.Add(r);
+            }
+         }
+
+         public bool ready {
+            get {
+               return _schema != null;
+            }
+         }
+
+      }
+
+      private ViewStream _ls, _rs;
+      private JoinBookkeepingData _ldata, _rdata;
+      private ViewStreamDatabase _vsd;
+      private IBlueTableSchema _schema = null;
+
+      public SimpleJoinStream(ViewStream ls, string ljc, ViewStream rs, string rjc) :
+         this(ViewStreamDatabase.instance, ls, ljc, rs, rjc) { }
+
+      public SimpleJoinStream(ViewStreamDatabase vsd, ViewStream ls, string ljc, ViewStream rs, string rjc) {
+         _ls = ls;
+         _rs = rs;
+         List<string> lj_col_list = ljc.Split(',').Where(x => !String.IsNullOrEmpty(x)).ToList();
+         List<string> rj_col_list = rjc.Split(',').Where(x => !String.IsNullOrEmpty(x)).ToList();
+         Log.assert(lj_col_list.Count == rj_col_list.Count);
+         int n_cols = lj_col_list.Count;
+         BlueRowHasher hasher = new BlueRowHasher(n_cols);
+         _ldata = new JoinBookkeepingData(ls, lj_col_list, true, hasher);
+         _rdata = new JoinBookkeepingData(rs, rj_col_list, false, hasher);
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _ls.onChange += _ls_onchange;
+         _rs.onChange += _rs_onchange;
+      }
+
+      private void _ls_onchange(object dp_obj) {
+         DataPacket dp = dp_obj as DataPacket;
+         _ldata.update_data(dp);
+         _form_and_fire();
+      }
+
+      private void _rs_onchange(object dp_obj) {
+         DataPacket dp = dp_obj as DataPacket;
+         _rdata.update_data(dp);
+         _form_and_fire();
+      }
+
+      protected override void myOnLastSubscriber() {
+         _ls.onChange -= _ls_onchange;
+         _rs.onChange -= _rs_onchange;
+      }
+
+      private void _build_schema() {
+         if (_schema != null)
+            return;
+         List<ColumnInfo> cis = new List<ColumnInfo>();
+         cis.Add(new ColumnInfo("id", 0, TypeCode.Int32));
+         foreach (ColumnInfo ci in _ldata.schema.columnInfo) {
+            string col_name = _rdata.schema.contains_column(ci.colName) ? $"left_{ci.colName}" : ci.colName;
+            cis.Add(new ColumnInfo(col_name, cis.Count, ci.colType));
+         }
+         foreach (ColumnInfo ci in _rdata.schema.columnInfo) {
+            string col_name = _ldata.schema.contains_column(ci.colName) ? $"right_{ci.colName}" : ci.colName;
+            cis.Add(new ColumnInfo(col_name, cis.Count, ci.colType));
+         }
+         _schema = new BlueTableSchema($"{_ldata.schema.tableName}_join_{_rdata.schema.tableName}", cis.ToArray());
+      }
+
+      private void _form_and_fire() {
+         if (!_ldata.ready || !_rdata.ready)
+            return;
+         _build_schema();
+         List<object[]> res_rows = new List<object[]>();
+
+         Action<object[], IBlueRow, bool> copy_row = (rval, r, is_left) => {
+            int offset = 1;
+            JoinBookkeepingData sdata = _ldata;
+            if (is_left) {
+               offset = 1;
+               sdata = _ldata;
+            } else {
+               sdata = _rdata;
+               offset = 1 + _ldata.schema.columnInfo.Length;
+            }
+            for (int i = 0; i < sdata.schema.columnInfo.Length; i++) {
+               rval[offset + i] = r[i];
+            }
+         };
+         Func<int, IBlueRow, object[]> build_row_array = (id, l_row) => {
+            object[] rv = new object[_schema.columnNames.Length];
+            for (int i = 0; i < _schema.columnNames.Length; i++) {
+               rv[i] = DBNull.Value;
+            }
+            rv[0] = id;
+            copy_row(rv, l_row, true);
+            return rv;
+         };
+         // this is where the join happens
+         foreach (var kv in _ldata.rows) {
+            RowHash hash = kv.Key;
+            List<IBlueRow> l_rows = kv.Value;
+            List<IBlueRow> r_rows = _rdata.get_matching_rows(hash);
+
+            foreach (IBlueRow lr in l_rows) {
+               if (r_rows != null) {
+                  foreach (IBlueRow r in r_rows) {
+                     object[] rowvals = build_row_array(res_rows.Count, lr);
+                     copy_row(rowvals, r, false);
+                     res_rows.Add(rowvals);
+                  }
+               } else {
+                  object[] rowvals = build_row_array(res_rows.Count, lr);
+                  res_rows.Add(rowvals);
+               }
+            }
+         }
+         BlueTable rv = new BlueTable(_schema);
+         foreach (object[] rval in res_rows) {
+            rv.addRow(new BlueRow(_schema, rval));
+         }
+         var dp = BlueDataUtility.build_dp(rv, myLastValue as DataPacket);
+         myFireEvent(dp);
+      }
+   }
+
+   [DataStreamUserRespresentation("FullJoinStream")]
+   public class FullJoinStream : ViewStream {
+      public FullJoinStream(ViewStream l_str, string ljcs, ViewStream r_str, string rjcs) {
+         ViewStream js = new SimpleJoinStream(l_str, ljcs, r_str, rjcs);
+         ViewStream rs = new bts.BlueOrb.FilterStream(js, r => !DBNull.Value.Equals(r["right_id"]));
+         mySetRealSource(rs);
+      }
+   }
+
+}
@@ -0,0 +1,28 @@
+//namespace bts.Blueorb {
+//   using BCG;
+
+//   public class JsonSaverStream : ViewStream {
+//      private ViewStream _stream;
+//      private string _file_name;
+//      public JsonSaverStream(ViewStream vs, string file_name) {
+//         _stream = vs;
+//         _file_name = file_name;
+//      }
+
+//      protected override void myOnFirstSubscriber() {
+//         _stream.onChange += _on_data;
+//      }
+
+//      private void _on_data(object dp_obj) {
+//         if (dp_obj == null) {
+//            return;
+//         }
+//         DataPacket dp = dp_obj as DataPacket;
+//         dp.newRows.write_to_json_file(dp.newRows, _file_name);
+//      }
+
+//      protected override void myOnLastSubscriber() {
+//         _stream.onChange -= _on_data;
+//      }
+//   }
+//}
@@ -0,0 +1,91 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+using Amazon.Runtime.Internal.Util;
+
+using BCG;
+using BCG.Utilities;
+
+using bts;
+
+namespace bts.BlueOrb{
+   public class LiteralStream : ViewStream {
+
+      public static List<Tuple<ColumnInfo, object>> parse_columns(string key_value_pairs) {
+         List<Tuple<ColumnInfo, object>> rv = new List<Tuple<ColumnInfo, object>>();
+         string[] pairs = key_value_pairs.Split(' ');
+         foreach (string p in pairs) {
+            string[] kvp = p.Split(':');
+            string col_name = kvp[0];
+            string val = kvp[1];
+            var tup = BlueDataUtility.guess_type(val);
+            var ci = new ColumnInfo(col_name, rv.Count, tup.Item1);
+            rv.Add(Tuple.Create(ci, tup.Item2));
+         }
+         return rv;
+      }
+
+      //literal("table1", "x:123, y:1.001, z:abc;x:123, y:1.001, z:abc")
+      // col_name: col_value ... ; col_name: col_value
+      public LiteralStream(string table_name, string rows) {
+         Func<string, int, IBlueRow> get_row = (json_row, id) => {
+            Dictionary<string, object> map = new Dictionary<string, object>();
+            string[] toks = json_row.Split(',', StringSplitOptions.TrimEntries);
+            //Logger.assert(col_vals.Length == 2);
+            foreach (string t in toks) {
+               var col_vals = t.Split(':', StringSplitOptions.TrimEntries);
+               string col = col_vals[0];
+               string val = col_vals[1];
+               map.Add(col, val);
+            }
+            map["id"] = id;
+            return new BlueRow(map);
+         };
+         string[] row_arr = rows.Split(';', StringSplitOptions.TrimEntries);
+         BlueTable table = null;
+         foreach (string json_string in row_arr) {
+            IBlueRow r = //BlueDataUtility.convert_json_to_row(json_string, table == null ? 0 : table.Count);
+            get_row(json_string, table == null ? 0 : table.Count);
+            table = table ?? new BlueTable(r.schema);
+            table.addRow(r);
+         }
+         ViewStream str = new BlueTableStream(table);
+         str = new SchemaGuesserStream(str);
+         mySetRealSource(str);
+      }
+
+      public LiteralStream(string tableName, string schema, string value) {
+         string[] columns = schema.Split(' ');
+
+
+         ColumnInfo[] ci = new ColumnInfo[columns.Length + 1];
+         ci[0] = new ColumnInfo("id", 0, typeof(int));
+         int n = 1;
+         foreach (string c in columns) {
+            string[] columnAndType = c.Split('/');
+            if (columnAndType.Length == 1)
+               ci[n] = new ColumnInfo(c, n, typeof(double));
+            else
+               ci[n] = new ColumnInfo(columnAndType[0], n, Type.GetType("System." + columnAndType[1], true));
+            n++;
+         }
+
+
+         BlueTable t = new BlueTable(new BlueTableSchema(tableName, ci));
+         string[] rows = value.Split(';');
+         n = 0;
+         foreach (string r in rows)
+            try {
+               if (r == string.Empty)
+                  continue;
+               t.addRow(
+                  BlueDataUtility.createRowFromCSVFileRow(r, t.schema, ++n));
+            } catch (Exception e) {
+               throw (new Exception("Error occured at line: " + n.ToString() + " " + e.Message));
+            }
+
+         mySetRealSource(new BlueRowCollectionStaticStream(t));
+      }
+   }
+}
@@ -0,0 +1,89 @@
+using System;
+
+using BCG.Utilities.General;
+using BCG;
+using bts;
+
+namespace bts.BlueOrb {
+   [DataStreamUserRespresentation("MillisecondStream")]
+   public class MillisecondStream : ViewStream, IWorker {
+      private DateTime _last_fire_time = DateTime.MinValue;
+      private readonly TimeSpan _period;
+      private readonly int _size;
+      private readonly ViewStreamDatabase _vsd;
+      private IBlueTableSchema _schema;
+      private bts.CircularBufferTable _table;
+
+      public MillisecondStream(int interval_msecs, int size)
+      : this(ViewStreamDatabase.instance, interval_msecs, size) {
+      }
+
+      public MillisecondStream(ViewStreamDatabase vsd, int interval_msecs, int size) {
+         _vsd = vsd;
+         _period = TimeSpan.FromMilliseconds(interval_msecs);
+         _size = size;
+         _schema = BlueDataUtility.form_schema("Milliseconds",
+               Tuple.Create("id", TypeCode.Int32),
+               Tuple.Create("time", TypeCode.DateTime),
+               Tuple.Create("display_time", TypeCode.String));
+         _table = new CircularBufferTable(_schema, _size);
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _vsd.addWorker(this);
+      }
+
+      protected override void myOnLastSubscriber() {
+         _vsd.removeWorker(this);
+      }
+
+      private int _id = 0;
+      public void doWork() {
+         if (DateTime.Now - _last_fire_time >= _period) {
+            _last_fire_time = DateTime.Now;
+            IBlueRow nr = new BlueRow(_schema, _id++, _last_fire_time,
+            _last_fire_time.ToString("yyyy-MM-dd HH:mm:ss.fff"));
+            _table = _table.Add(nr);
+            var dp = BlueDataUtility.build_dp_inc(_table, myLastValue as DataPacket);
+            myFireEvent(dp);
+         }
+      }
+   }
+   internal class MSecondStream : TimeUnitStream {
+      public MSecondStream(int intervalInms, int size)
+         : base(DateTime.Now, new TimeSpan(0, 0, 0, 0, intervalInms), size, ViewStreamDatabase.instance) { }
+
+      protected override DateTime myRoundTime(DateTime dt) { return dt; }
+   }
+
+   internal class DisplayableMillisecondStream : ViewStream, IStreamMapper {
+      private IBlueTableSchema mySchema = new BlueTableSchema("ms",
+                                                               new ColumnInfo("id", 0, typeof(int)),
+                                                               new ColumnInfo("time", 1, typeof(string)));
+      public DisplayableMillisecondStream(int intervalInMs, int sz) {
+         mySetRealSource(new MapStream(new MSecondStream(intervalInMs, sz), this));
+      }
+      #region IStreamMapper Members
+
+      public IBlueTableSchema getOutputSchema(IBlueTableSchema inputSchema) {
+         return mySchema;
+      }
+
+      #endregion
+
+      #region IDynamicStreamMapper Members
+
+      public IBlueRow map(IBlueRow row) {
+         DateTime time = row.get_datetime("time");
+         var time_txt = time.ToString("yyyy-MM-dd HH:mm:ss.fff");
+         return new BlueRow(mySchema, row["id"], time_txt);
+      }
+
+      #endregion
+
+      private string myToString(DateTime dt) {
+         string sep = ":";
+         return dt.Hour + sep + dt.Minute + sep + dt.Second + sep + dt.Millisecond;
+      }
+   }
+}
@@ -0,0 +1,169 @@
+namespace bts.BlueOrb {
+   using BCG;
+
+   using System;
+   using System.Collections.Generic;
+   using System.Linq;
+   //using MathNet.Numerics.Statistics;
+
+
+   public enum MultiRowOp {
+      Mean,
+      Median,
+      Mode,
+      Range,
+      StdDev,
+      Max,
+      Min,
+      First,
+      Last,
+      Sum,
+      EdgeDiff,
+      EdgeDiffPercentage,
+   }
+   public class MultiRowOpHelper {
+      // input + op
+      public readonly List<Tuple<string, MultiRowOp>> operations;
+
+      public static MultiRowOpHelper parse_ops(string text) {
+         // text is inp_col: op, inp_col: op, inp_col:op
+         // ex: "open:First, close:Last, high:Max, low:Min, volume:Sum")
+         List<Tuple<string, MultiRowOp>> rv = new List<Tuple<string, MultiRowOp>>();
+         string[] calcs = text.Split(',');
+         foreach (string c in calcs) {
+            string[] toks = c.Split(':');
+            string inp_col = toks[0].Trim();
+            string op_txt = toks[1].Trim();
+            MultiRowOp op = Enum.Parse<MultiRowOp>(op_txt, true);
+            rv.Add(Tuple.Create(inp_col, op));
+         }
+         return new MultiRowOpHelper(rv);
+      }
+
+      public MultiRowOpHelper(List<Tuple<string, MultiRowOp>> operations_) {
+         operations = operations_;
+      }
+
+      // aggregates multiple rows into one - ie does group_by compute
+      public static IBlueRow group_by_compute(List<IBlueRow> rows, MultiRowOpHelper parameters) {
+         if (rows.Count() == 0) {
+            return null;
+         }
+
+         IBlueRow ir = rows.ElementAt(0);
+         IBlueTableSchema in_schema = ir.schema;
+         IBlueTableSchema out_schema = in_schema;
+         IDictionary<string, Tuple<string, MultiRowOp>> out_col_map =
+            new Dictionary<string, Tuple<string, MultiRowOp>>();
+         foreach (var t in parameters.operations) {
+            string out_col_name = $"{t.Item1}_{t.Item2}".ToLower();
+            out_schema = out_schema.add_column(TypeCode.Double, out_col_name);
+            out_col_map[out_col_name] = t;
+         }
+         MutableBlueRow or = new MutableBlueRow(out_schema, ir);
+         foreach (var kv in out_col_map) {
+            string out_col_name = kv.Key;
+            string in_col_name = kv.Value.Item1;
+            MultiRowOp op = kv.Value.Item2;
+            IEnumerable<double> col_vals = BlueDataUtility.get_colvalues<double>(rows, in_col_name);
+            double comp_res = compute_op(col_vals, op);
+            or.setValue(out_col_name, comp_res);
+         }
+         return or;
+      }
+
+      // aggregates multiple rows into one, used by MultiRowRollingMathStream
+      public static IBlueRow group_by_compute(List<IBlueRow> rows, int start_idx, int n_rows, MultiRowOpHelper parameters) {
+         if (rows.Count() == 0) {
+            return null;
+         }
+         IBlueRow ir = rows.ElementAt(start_idx);
+         IBlueTableSchema in_schema = ir.schema;
+         IBlueTableSchema out_schema = in_schema;
+         // out_col vs inp_cal + type
+         IDictionary<string, Tuple<string, MultiRowOp>> out_col_map =
+            new Dictionary<string, Tuple<string, MultiRowOp>>();
+         foreach (var t in parameters.operations) {
+            string out_col_name = $"{t.Item1}_{t.Item2}".ToLower();
+            out_schema = out_schema.add_column(TypeCode.Double, out_col_name);
+            out_col_map[out_col_name] = t;
+         }
+         MutableBlueRow or = new MutableBlueRow(out_schema, ir);
+         foreach (var kv in out_col_map) {
+            string out_col_name = kv.Key;
+            string in_col_name = kv.Value.Item1;
+            MultiRowOp op = kv.Value.Item2;
+            IEnumerable<double> col_vals = BlueDataUtility.get_colvalues<double>(rows, start_idx, n_rows, in_col_name);
+            double comp_res = compute_op(col_vals, op);
+            or.setValue(out_col_name, comp_res);
+            or.setValue("id", ir["id"]);
+         }
+         return or;
+      }
+
+      // rolling_rows are the rolling window of rows. the 0th row is the one thats gettin
+      // calculated. rows 1 - n-1 are its window rows. the schema is based on the operations.
+
+      public IBlueRow rolling_calc(List<IBlueRow> rolling_rows) {
+         if (rolling_rows.Count() == 0) {
+            return null;
+         }
+         IBlueRow ir = rolling_rows.ElementAt(0);
+         IBlueTableSchema in_schema = ir.schema;
+         IBlueTableSchema out_schema = in_schema;
+         IDictionary<string, Tuple<string, MultiRowOp>> out_col_map =
+            new Dictionary<string, Tuple<string, MultiRowOp>>();
+         foreach (var t in operations) {
+            string out_col_name = $"{t.Item1}_{t.Item2}".ToLower();
+            out_schema = out_schema.add_column(TypeCode.Double, out_col_name);
+            out_col_map[out_col_name] = t;
+         }
+         MutableBlueRow or = new MutableBlueRow(out_schema, ir);
+         foreach (var kv in out_col_map) {
+            string out_col_name = kv.Key;
+            string in_col_name = kv.Value.Item1;
+            MultiRowOp op = kv.Value.Item2;
+            IEnumerable<double> col_vals = BlueDataUtility.get_colvalues<double>(rolling_rows, in_col_name);
+            double comp_res = compute_op(col_vals, op);
+            or.setValue(out_col_name, comp_res);
+         }
+         return or;
+      }
+
+      public static double compute_op(IEnumerable<double> col_vals, MultiRowOp op) {
+         switch (op) {
+            case MultiRowOp.Max:
+               return col_vals.Max<double>();
+            case MultiRowOp.Min:
+               return col_vals.Min<double>();
+            case MultiRowOp.Mean:
+               return MathNet.Numerics.Statistics.Statistics.Mean(col_vals);
+            case MultiRowOp.Sum:
+               return col_vals.Sum();
+            case MultiRowOp.Median:
+               return MathNet.Numerics.Statistics.Statistics.Median(col_vals);
+            //case MultiRowOp.Mode:
+            //   return MathNet.Numerics.Statistics.Statistics.(col_vals);
+            case MultiRowOp.First:
+               return col_vals.First();
+            case MultiRowOp.Last:
+               return col_vals.Last();
+            case MultiRowOp.StdDev:
+               return MathNet.Numerics.Statistics.Statistics.StandardDeviation(col_vals);
+            case MultiRowOp.EdgeDiff:
+               return col_vals.First() - col_vals.Last();
+            case MultiRowOp.EdgeDiffPercentage: {
+                  double first = col_vals.First();
+                  double last = col_vals.Last();
+                  return ((first - last) / last) * 100.0;
+                  return col_vals.First() - col_vals.Last();
+               }
+            default:
+               // TODO
+               Log.assert(false);
+               return Double.NaN;
+         }
+      }
+
+   }
+}
@@ -0,0 +1,40 @@
+namespace bts.BlueOrb {
+   using BCG;
+
+   using System.Collections.Generic;
+   using System.Net;
+
+   [DataStreamUserRespresentation("MultiRowRollingMathStream")]
+   public class MultiRowRollingMathStream : ViewStream {
+      private ViewStream _sorted_parent_str;
+      private MultiRowOpHelper _op;
+      private int _rolling_window_sz;
+      public MultiRowRollingMathStream(ViewStream parent_str, string op_txt, string sort_exp, int rolling_window_sz) {
+         _sorted_parent_str = new SortStream(parent_str, sort_exp);
+         _op = MultiRowOpHelper.parse_ops(op_txt);
+         _rolling_window_sz = rolling_window_sz;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _sorted_parent_str.onChange += _parent_str_onchange;
+      }      
+
+      protected override void myOnLastSubscriber() {
+         _sorted_parent_str.onChange -= _parent_str_onchange;
+      }
+
+      private void _parent_str_onchange(object dp_obj) {
+         DataPacket dp = dp_obj as DataPacket;
+         var rows = dp.newRows.to_list();
+         BlueTable out_table = null;
+         for (int i = 0; i < rows.Count; i++) {
+            var out_r = MultiRowOpHelper.group_by_compute(rows, i, _rolling_window_sz, _op);
+            if (out_table == null)
+               out_table = new BlueTable(out_r.schema);
+            out_table.addRow(out_r);
+         }            
+         var dp_out = BlueDataUtility.build_dp_inc(out_table, myLastValue as DataPacket, true);
+         myFireEvent(dp_out);
+      }
+   }
+}
@@ -0,0 +1,29 @@
+namespace Bts.DataStream.Parquet;
+
+using bts.collections;
+
+using System;
+using System.Collections.Generic;
+
+public interface IParquetColumnReader : IDisposable {
+   IList<object?> Read();
+   IList<object?> Read(int? start, int? stop);
+}
+
+public interface IParquetColumnReader<TLogical, TPhysical> : IParquetColumnReader {
+   new IList<TLogical?> Read();
+   new IList<TLogical?> Read(int? start, int? stop);
+
+   IList<object?> IParquetColumnReader.Read() =>
+      Read().WrapSelector(v => (object?)v, null);
+
+   IList<object?> IParquetColumnReader.Read(int? start, int? stop) =>
+      Read(start, stop).WrapSelector(v => (object?)v, null);
+}
+
+public interface IParquetColumnReader<T> : IParquetColumnReader<T, T> {
+   new IList<T?> Read();
+
+   IList<object?> IParquetColumnReader.Read() =>
+      Read().WrapSelector(v => (object?)v, null);
+}
@@ -0,0 +1,507 @@
+namespace Bts.DataStream.Parquet;
+
+using bts;
+using bts.collections;
+
+using mbts.utils;
+
+using ParquetSharp;
+
+using Spark.Core.Collections;
+
+using System;
+using System.Collections.Generic;
+
+public static class ParquetAdapter {
+   public static IParquetColumnReader GetColumnReader(this RowGroupReader rowGroupReader, int index, Type? colType = null) {
+      int rowCount = checked((int)rowGroupReader.MetaData.NumRows);
+      var colReader = rowGroupReader.Column(index);
+      return getColumnReader(colReader, rowCount, colType: colType);
+   }
+
+   public static IList<object?>[] ReadColumns(this ParquetFileReader fileReader) {
+      var schema = fileReader.FileMetaData.Schema.ToBlueSchema("parquetReader");
+      var colInfos = schema.columnInfo;
+      var colTypes = Array.ConvertAll(colInfos, c => c.colType);
+      var colValues = new IList<object?>[fileReader.FileMetaData.NumColumns];
+      int rowCount = checked((int)fileReader.FileMetaData.NumRows);
+      for (int i = 0; i < colValues.Length; i++) {
+         colValues[i] = new List<object?>(rowCount);
+      }
+      int rowGroupCount = fileReader.FileMetaData.NumRowGroups;
+      for (int rowGroup = 0; rowGroup < rowGroupCount; ++rowGroup) {
+         using var rowGroupReader = fileReader.RowGroup(rowGroup);
+         rowGroupReader.ReadColumnsTo(ref colValues, colTypes);
+      }
+      return colValues;
+   }
+
+   public static IList<object?>[] ReadColumns(this ParquetFileReader fileReader, int? start, int? stop) {
+      if (!start.HasValue && !stop.HasValue) {
+         return ReadColumns(fileReader);
+      }
+      var schema = fileReader.FileMetaData.ToBlueSchema("parquetReader");
+      var colInfos = schema.columnInfo;
+      var colTypes = Array.ConvertAll(colInfos, c => c.colType);
+      var colValues = new IList<object?>[fileReader.FileMetaData.NumColumns];
+      int rowCount = checked((int)fileReader.FileMetaData.NumRows);
+      start ??= 0;
+      stop ??= rowCount;
+      var sliceLength = stop.Value - start.Value;
+      for (int i = 0; i < colValues.Length; i++) {
+         colValues[i] = new List<object?>(sliceLength);
+      }
+      int numRowGroups = fileReader.FileMetaData.NumRowGroups;
+      int? numRowsPerGroup = null;
+      int rowIdx = 0;
+      for (int rowGroup = 0; rowGroup < numRowGroups; ++rowGroup) {
+         if (stop.Value <= rowIdx) {
+            break;
+         }
+         using var rowGroupReader = fileReader.RowGroup(rowGroup);
+         int numRowsInGroup = checked((int)rowGroupReader.MetaData.NumRows);
+         numRowsPerGroup ??= numRowsInGroup;
+         if (rowGroup < numRowGroups - 1) {
+            Log.assert(numRowsInGroup == numRowsPerGroup.Value);
+         } else {
+            Log.assert(numRowsInGroup <= numRowsPerGroup.Value);
+         }
+         int startIdx = start.Value - rowIdx;
+         int stopIdx = stop.Value - rowIdx;
+         rowIdx += numRowsInGroup;
+         if (startIdx >= numRowsInGroup) {
+            continue;
+         }
+         startIdx = Math.Max(0, startIdx);
+         stopIdx = Math.Min(stopIdx, numRowsInGroup);
+         int n = rowGroupReader.ReadColumnsTo(ref colValues, colTypes, startIdx, stopIdx);
+         Log.assert(n == (stopIdx - startIdx));
+      }
+      return colValues;
+   }
+
+   public static int ReadColumnsTo(this RowGroupReader rowGroupReader, ref IList<object?>[] columnValues, Type[] colTypes) {
+      int rowCount = checked((int)rowGroupReader.MetaData.NumRows);
+      for (int colIdx = rowGroupReader.MetaData.NumColumns - 1; colIdx > -1; colIdx--) {
+         using var colReader = rowGroupReader.GetColumnReader(colIdx, colTypes[colIdx]);
+         columnValues[colIdx].AddRange(colReader.Read());
+      }
+      return rowCount;
+   }
+
+   public static int ReadColumnsTo(this RowGroupReader rowGroupReader, ref IList<object?>[] columnValues, Type[] colTypes, int? start, int? stop) {
+      if (!start.HasValue && !stop.HasValue) {
+         return ReadColumnsTo(rowGroupReader, ref columnValues, colTypes);
+      }
+      int numRows = checked((int)rowGroupReader.MetaData.NumRows);
+      if (start.HasValue && start.Value >= numRows) {
+         return 0;
+      }
+      int? readRowCount = null;
+      for (int colIdx = rowGroupReader.MetaData.NumColumns - 1; colIdx > -1; colIdx--) {
+         using var colReader = rowGroupReader.GetColumnReader(colIdx, colTypes[colIdx]);
+         var colVals = colReader.Read(start, stop);
+         readRowCount ??= colVals.Count;
+         Log.assert(readRowCount == colVals.Count);
+         columnValues[colIdx].AddRange(colVals);
+      }
+      return readRowCount ?? throw new ArgumentException("Row group has no columns", nameof(rowGroupReader));
+   }
+
+   static IParquetColumnReader getColumnReader(ColumnReader reader, int bufferSize = 4096, Type? colType = null) {
+      var desc = reader.ColumnDescriptor;
+      var logicalType = desc.LogicalType;
+      return logicalType.Type switch {
+         LogicalTypeEnum.Int => IntReader(),
+         LogicalTypeEnum.String => new ParquetColumnReader<string?>(reader, bufferSize),
+         LogicalTypeEnum.Date => new ParquetColumnReader<DateTime?>(reader, bufferSize),
+         LogicalTypeEnum.Decimal => DecimalReader(),
+         LogicalTypeEnum.Timestamp => TimestampReader(),
+         LogicalTypeEnum.None => DefaultReader(),
+         _ => throw new NotImplementedException(),
+      };
+
+      IParquetColumnReader DefaultReader() {
+         return desc.PhysicalType switch {
+            PhysicalType.Boolean => new ParquetColumnReader<bool?>(reader, bufferSize),
+            PhysicalType.Int32 => new ParquetColumnReader<int?>(reader, bufferSize),
+            PhysicalType.Int64 => new ParquetColumnReader<long?>(reader, bufferSize),
+            PhysicalType.Float => new ParquetColumnReader<float?>(reader, bufferSize),
+            PhysicalType.Double => new ParquetColumnReader<double?>(reader, bufferSize),
+            _ => throw new NotImplementedException(),
+         };
+      }
+
+      IParquetColumnReader TimestampReader() {
+         var tlt = ExceptionAssert.of_type<TimestampLogicalType>(logicalType);
+         return new ParquetColumnReader<DateTimeNanos?, DateTime?>(reader, dtn => dtn?.DateTime, bufferSize);
+      }
+
+      IParquetColumnReader IntReader() {
+         var ilt = ExceptionAssert.of_type<IntLogicalType>(logicalType);
+         if (!ilt.IsSigned) {
+            if (colType is null) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<byte?>(reader, bufferSize),
+                  16 => new ParquetColumnReader<ushort?>(reader, bufferSize),
+                  32 => new ParquetColumnReader<uint?>(reader, bufferSize),
+                  64 => new ParquetColumnReader<ulong?>(reader, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(byte)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<byte?>(reader, bufferSize),
+                  16 => new ParquetColumnReader<ushort?, byte?>(reader, v => v.HasValue ? checked((byte)v.Value) : null, bufferSize),
+                  32 => new ParquetColumnReader<uint?, ushort?>(reader, v => v.HasValue ? checked((byte)v.Value) : null, bufferSize),
+                  64 => new ParquetColumnReader<ulong?, ushort?>(reader, v => v.HasValue ? checked((byte)v.Value) : null, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(ushort)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<byte?, ushort?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  16 => new ParquetColumnReader<ushort?>(reader, bufferSize),
+                  32 => new ParquetColumnReader<uint?, ushort?>(reader, v => v.HasValue ? checked((ushort)v.Value) : null, bufferSize),
+                  64 => new ParquetColumnReader<ulong?, ushort?>(reader, v => v.HasValue ? checked((ushort)v.Value) : null, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(uint)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<byte?, uint?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  16 => new ParquetColumnReader<ushort?, uint?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  32 => new ParquetColumnReader<uint?>(reader, bufferSize),
+                  64 => new ParquetColumnReader<ulong?, uint?>(reader, v => v.HasValue ? checked((uint)v.Value) : null, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(ulong)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<byte?, ulong?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  16 => new ParquetColumnReader<ushort?, ulong?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  32 => new ParquetColumnReader<uint?, ulong?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  64 => new ParquetColumnReader<ulong?>(reader, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            }
+            throw new NotImplementedException($"Expected signed int column type, but got {colType}");
+         } else {
+            if (colType is null) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<sbyte?>(reader, bufferSize),
+                  16 => new ParquetColumnReader<short?>(reader, bufferSize),
+                  32 => new ParquetColumnReader<int?>(reader, bufferSize),
+                  64 => new ParquetColumnReader<long?>(reader, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(sbyte)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<sbyte?>(reader, bufferSize),
+                  16 => new ParquetColumnReader<short?, sbyte?>(reader, v => v.HasValue ? checked((sbyte)v.Value) : null, bufferSize),
+                  32 => new ParquetColumnReader<int?, sbyte?>(reader, v => v.HasValue ? checked((sbyte)v.Value) : null, bufferSize),
+                  64 => new ParquetColumnReader<long?, sbyte?>(reader, v => v.HasValue ? checked((sbyte)v.Value) : null, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(short)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<char?, short?>(reader, v => v.HasValue ? checked((short)v.Value) : null, bufferSize),
+                  16 => new ParquetColumnReader<short?>(reader, bufferSize),
+                  32 => new ParquetColumnReader<int?, short?>(reader, v => v.HasValue ? checked((short)v.Value) : null, bufferSize),
+                  64 => new ParquetColumnReader<long?, short?>(reader, v => v.HasValue ? checked((short)v.Value) : null, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(int)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<char?, int?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  16 => new ParquetColumnReader<short?, int?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  32 => new ParquetColumnReader<int?>(reader, bufferSize),
+                  64 => new ParquetColumnReader<long?, int?>(reader, v => v.HasValue ? checked((int)v.Value) : null, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            } else if (colType == typeof(long)) {
+               return ilt.BitWidth switch {
+                  8 => new ParquetColumnReader<char?, long?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  16 => new ParquetColumnReader<short?, long?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  32 => new ParquetColumnReader<int?, long?>(reader, v => v.HasValue ? v.Value : null, bufferSize),
+                  64 => new ParquetColumnReader<long?>(reader, bufferSize),
+                  _ => throw new NotImplementedException(),
+               };
+            }
+            throw new NotImplementedException($"Expected unsigned int column type, but got {colType}");
+         }
+      }
+
+      IParquetColumnReader DecimalReader() {
+         var dlt = ExceptionAssert.of_type<DecimalLogicalType>(logicalType);
+         return new ParquetColumnReader<double?>(reader, bufferSize);
+      }
+   }
+
+   public static IColumnWriter GetColumnWriter(TypeCode typeCode, ColumnWriter writer, int bufferSize = 4096) {
+      return typeCode switch {
+         TypeCode.Boolean => new ColumnWriter<bool?>(writer, bufferSize),
+         TypeCode.SByte => new ColumnWriter<sbyte?>(writer, bufferSize, GetInt8Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.Int16 => new ColumnWriter<short?>(writer, bufferSize, GetInt16Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.Int32 => new ColumnWriter<int?>(writer, bufferSize, GetInt32Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.Int64 => new ColumnWriter<long?>(writer, bufferSize, GetInt64Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.Byte => new ColumnWriter<byte?>(writer, bufferSize, GetUInt8Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.UInt16 => new ColumnWriter<ushort?>(writer, bufferSize, GetUInt16Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.UInt32 => new ColumnWriter<uint?>(writer, bufferSize, GetUInt32Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.UInt64 => new ColumnWriter<ulong?>(writer, bufferSize, GetUInt64Converter((IntLogicalType)writer.ColumnDescriptor.LogicalType)),
+         TypeCode.Single => new ColumnWriter<float?>(writer, bufferSize),
+         TypeCode.Double => new ColumnWriter<double?>(writer, bufferSize),
+         TypeCode.DateTime => new ColumnWriter<DateTimeNanos?>(writer, bufferSize, ConvertDateTimeObj),
+         TypeCode.String => new ColumnWriter<string?>(writer, bufferSize),
+         _ => throw new NotSupportedException($"Unsupported column TypeCode {typeCode}"),
+      };
+
+      static DateTimeNanos? ConvertDateTimeObj(object? obj) {
+         if (obj is DateTime dt) {
+            return new(dt);
+         }
+         if (obj is DateTimeNanos dtn) {
+            return dtn;
+         }
+         throw new InvalidCastException($"Unable to convert object of type {obj?.GetType()} to DateTimeNanos");
+      }
+   }
+
+   public static Func<object?, sbyte?> GetInt8Converter(IntLogicalType logicalType) =>
+      GetInt8Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, sbyte?> GetInt8Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj as sbyte?,
+            16 => obj => obj is short v ? checked((sbyte)v) : null,
+            32 => obj => obj is int v ? checked((sbyte)v) : null,
+            64 => obj => obj is long v ? checked((sbyte)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? checked((sbyte)v) : null,
+            16 => obj => obj is ushort v ? checked((sbyte)v) : null,
+            32 => obj => obj is uint v ? checked((sbyte)v) : null,
+            64 => obj => obj is ulong v ? checked((sbyte)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, short?> GetInt16Converter(IntLogicalType logicalType) =>
+      GetInt16Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, short?> GetInt16Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? v : null,
+            16 => obj => obj as short?,
+            32 => obj => obj is int v ? checked((short)v) : null,
+            64 => obj => obj is long v ? checked((short)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? v : null,
+            16 => obj => obj is ushort v ? checked((short)v) : null,
+            32 => obj => obj is uint v ? checked((short)v) : null,
+            64 => obj => obj is ulong v ? checked((short)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, int?> GetInt32Converter(IntLogicalType logicalType) =>
+      GetInt32Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, int?> GetInt32Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? v : null,
+            16 => obj => obj is short v ? v : null,
+            32 => obj => obj as int?,
+            64 => obj => obj is long v ? checked((int)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? v : null,
+            16 => obj => obj is ushort v ? v : null,
+            32 => obj => obj is uint v ? checked((int)v) : null,
+            64 => obj => obj is ulong v ? checked((int)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, long?> GetInt64Converter(IntLogicalType logicalType) =>
+      GetInt64Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, long?> GetInt64Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? v : null,
+            16 => obj => obj is short v ? v : null,
+            32 => obj => obj is int v ? v : null,
+            64 => obj => obj as long?,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? v : null,
+            16 => obj => obj is ushort v ? v : null,
+            32 => obj => obj is uint v ? v : null,
+            64 => obj => obj is ulong v ? checked((long)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, byte?> GetUInt8Converter(IntLogicalType logicalType) =>
+      GetUInt8Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, byte?> GetUInt8Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? checked((byte)v) : null,
+            16 => obj => obj is short v ? checked((byte)v) : null,
+            32 => obj => obj is int v ? checked((byte)v) : null,
+            64 => obj => obj is long v ? checked((byte)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj as byte?,
+            16 => obj => obj is ushort v ? checked((byte)v) : null,
+            32 => obj => obj is uint v ? checked((byte)v) : null,
+            64 => obj => obj is ulong v ? checked((byte)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, ushort?> GetUInt16Converter(IntLogicalType logicalType) =>
+      GetUInt16Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, ushort?> GetUInt16Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? checked((ushort)v) : null,
+            16 => obj => obj is short v ? checked((ushort)v) : null,
+            32 => obj => obj is int v ? checked((ushort)v) : null,
+            64 => obj => obj is long v ? checked((ushort)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? v : null,
+            16 => obj => obj is ushort v ? v : null,
+            32 => obj => obj is uint v ? checked((ushort)v) : null,
+            64 => obj => obj is ulong v ? checked((ushort)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, uint?> GetUInt32Converter(IntLogicalType logicalType) =>
+      GetUInt32Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, uint?> GetUInt32Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? checked((uint)v) : null,
+            16 => obj => obj is short v ? checked((uint)v) : null,
+            32 => obj => obj is int v ? checked((uint)v) : null,
+            64 => obj => obj is long v ? checked((uint)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? v : null,
+            16 => obj => obj is ushort v ? v : null,
+            32 => obj => obj is uint v ? v : null,
+            64 => obj => obj is ulong v ? checked((uint)v) : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static Func<object?, ulong?> GetUInt64Converter(IntLogicalType logicalType) =>
+      GetUInt64Converter(logicalType.IsSigned, logicalType.BitWidth);
+
+   public static Func<object?, ulong?> GetUInt64Converter(bool isSigned, int bitWidth) =>
+      isSigned
+         ? bitWidth switch {
+            8 => obj => obj is sbyte v ? checked((ulong)v) : null,
+            16 => obj => obj is short v ? checked((ulong)v) : null,
+            32 => obj => obj is int v ? checked((ulong)v) : null,
+            64 => obj => obj is long v ? checked((ulong)v) : null,
+            _ => throw new NotImplementedException(),
+         }
+         : bitWidth switch {
+            8 => obj => obj is byte v ? v : null,
+            16 => obj => obj is ushort v ? v : null,
+            32 => obj => obj is uint v ? v : null,
+            64 => obj => obj is ulong v ? v : null,
+            _ => throw new NotImplementedException(),
+         };
+
+   public static string ColumnEnumTypeKey(string colName) =>
+      $"{colName}.EnumType";
+
+   public static KeyValuePair<string, string> ColumnEnumTypeEntry(string colName, Type enumType) {
+      if (enumType.IsNullable()) {
+         enumType = enumType.GetGenericArguments()[0];
+      }
+      if (!enumType.IsEnum) {
+         throw new ArgumentException($"Must be enum type (actually {enumType})", nameof(enumType));
+      }
+      return new(ColumnEnumTypeKey(colName), enumType.ToString());
+   }
+
+   public static Type? GetColumnEnumType(IReadOnlyDictionary<string, string>? keyValueMetadata, string columnName) {
+      if (keyValueMetadata is not null) {
+         var key = ColumnEnumTypeKey(columnName);
+         if (keyValueMetadata.TryGetValue(key, out var typeName)) {
+            return Type.GetType(typeName);
+         }
+      }
+      return null;
+   }
+
+   public interface IColumnWriter : IDisposable {
+      void Write(IReadOnlyCollection<object?> values);
+   }
+
+   public interface IColumnWriter<T> : IColumnWriter {
+      void Write(IReadOnlyCollection<T?> values);
+   }
+
+   class ColumnWriter<T> : IColumnWriter<T> {
+      readonly T?[] buffer;
+      readonly LogicalColumnWriter<T> writer;
+      readonly Func<object?, T?> convert;
+
+      public ColumnWriter(ColumnWriter writer, int bufferSize)
+         : this(writer, new T?[bufferSize]) { }
+
+      public ColumnWriter(ColumnWriter writer, int bufferSize, Func<object?, T?> convert)
+         : this(writer, new T?[bufferSize], convert) { }
+
+      public ColumnWriter(ColumnWriter writer, T?[] buffer)
+         : this(writer, buffer, obj => (T?)obj) { }
+
+      public ColumnWriter(ColumnWriter writer, T?[] buffer, Func<object?, T?> convert) {
+         this.buffer = buffer;
+         this.writer = writer.LogicalWriter<T>();
+         this.convert = convert;
+      }
+
+      public void Write(IReadOnlyCollection<T?> values) {
+         if (buffer.Length == 0) {
+            throw new InvalidOperationException("Cannot write because buffer length is 0");
+         }
+         var count = values.Count;
+         var nPages = count / buffer.Length;
+         using var en = values.GetEnumerator();
+         for (int pg = 0; pg < nPages; pg++) {
+            for (int i = 0; i < buffer.Length; i++) {
+               Log.assert(en.MoveNext(), "Enumeration failed before reaching expected count");
+               buffer[i] = en.Current;
+            }
+            writer.WriteBatch(buffer!);
+         }
+         var remainder = count - nPages * buffer.Length;
+         if (remainder != 0) {
+            for (int i = 0; i < remainder; i++) {
+               Log.assert(en.MoveNext(), "Enumeration failed before reaching expected count");
+               buffer[i] = en.Current;
+            }
+            writer.WriteBatch(buffer!, 0, remainder);
+         }
+      }
+
+      public void Dispose() =>
+         writer.Dispose();
+
+      void IColumnWriter.Write(IReadOnlyCollection<object?> values) =>
+         Write(ReadOnlySelectorCollection.Create(values, convert));
+   }
+}
@@ -0,0 +1,111 @@
+namespace Bts.DataStream.Parquet;
+
+using bts;
+using bts.collections;
+
+using ParquetSharp;
+
+using System;
+using System.Collections.Generic;
+
+class ParquetColumnReader<T> : IParquetColumnReader<T> {
+   protected readonly LogicalColumnReader<T> reader;
+   protected readonly T?[] buffer;
+
+   public ParquetColumnReader(ColumnReader reader, int bufferSize)
+      : this(reader, new T?[bufferSize]) { }
+
+   protected ParquetColumnReader(ColumnReader reader, T?[] buffer) {
+      this.buffer = buffer;
+      this.reader = reader.LogicalReader<T>();
+   }
+
+   ~ParquetColumnReader() =>
+      Dispose();
+
+   public IList<T?> Read() {
+      if (buffer.Length == 0) {
+         throw new InvalidOperationException("Cannot write because buffer length is 0");
+      }
+      int n = reader.ReadBatch(buffer!);
+      return buffer.WrapSubRange(0, n);
+   }
+
+   public IList<T?> Read(int? start, int? stop) {
+      if (buffer.Length == 0) {
+         throw new InvalidOperationException("Cannot write because buffer length is 0");
+      }
+      start ??= 0;
+      stop ??= buffer.Length;
+      int length = stop.Value - start.Value;
+      if (length <= 0) {
+         return new List<T?>(0);
+      }
+      if (start.Value > 0) {
+         var nSkipped = checked((int)reader.Skip(start.Value));
+         Log.assert(nSkipped >= 0 && nSkipped <= start.Value);
+         if (nSkipped < start.Value) {
+            return new List<T?>(0);
+         }
+      }
+      int n = reader.ReadBatch(buffer!, 0, length);
+      return buffer.WrapSubRange(0, n);
+   }
+
+   public void Dispose() {
+      GC.SuppressFinalize(this);
+      reader.Dispose();
+   }
+}
+
+class ParquetColumnReader<TIn, TOut> : IParquetColumnReader<TOut> {
+   readonly Func<TIn, TOut?> convert;
+   readonly LogicalColumnReader<TIn> reader;
+   readonly TIn[] buffer;
+
+   public ParquetColumnReader(ColumnReader reader, Func<TIn, TOut?> convert, int bufferSize)
+      : this(reader, convert, new TIn[bufferSize]) { }
+
+   public ParquetColumnReader(ColumnReader reader, Func<TIn, TOut?> convert, TIn[] buffer) {
+      this.convert = convert;
+      this.reader = reader.LogicalReader<TIn>();
+      this.buffer = buffer;
+   }
+
+   ~ParquetColumnReader() =>
+      Dispose();
+
+   public IList<TOut?> Read() {
+      if (buffer.Length == 0) {
+         throw new InvalidOperationException("Cannot write because buffer length is 0");
+      }
+      int n = reader.ReadBatch(buffer!);
+      return buffer.WrapSelector(convert, null).WrapSubRange(0, n);
+   }
+
+   public IList<TOut?> Read(int? start, int? stop) {
+      if (buffer.Length == 0) {
+         throw new InvalidOperationException("Cannot write because buffer length is 0");
+      }
+      start ??= 0;
+      stop ??= buffer.Length;
+      int length = stop.Value - start.Value;
+      if (length <= 0) {
+         return new List<TOut?>(0);
+      }
+      if (start.Value > 0) {
+         var nSkipped = checked((int)reader.Skip(start.Value));
+         Log.assert(nSkipped >= 0 && nSkipped <= start.Value);
+         if (nSkipped < start.Value) {
+            return new List<TOut?>(0);
+         }
+      }
+      int n = reader.ReadBatch(buffer!, 0, length);
+      return buffer.WrapSelector(convert, null).WrapSubRange(0, n);
+   }
+
+   public void Dispose() {
+      GC.SuppressFinalize(this);
+      reader.Dispose();
+   }
+}
@@ -0,0 +1,159 @@
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using bts;
+using bts.collections;
+
+using Microsoft.Scripting.Utils;
+
+using ParquetSharp;
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+public static class ParquetExtensions {
+   public static int RowCount(this FileMetaData fileMetaData) =>
+      checked((int)fileMetaData.NumRows);
+
+   public static IBlueTableSchema ToBlueSchema(this SchemaDescriptor schemaDescriptor, string tableName = "parquet", IReadOnlyDictionary<string, string>? keyValueMetadata = null) {
+      var colInfos = new ColumnInfo[schemaDescriptor.NumColumns];
+      for (int i = 0; i < colInfos.Length; i++) {
+         colInfos[i] = schemaDescriptor.BlueColumn(i, keyValueMetadata);
+      }
+      return new BlueTableSchema(tableName, colInfos);
+   }
+
+   public static IBlueTableSchema ToBlueSchema(this FileMetaData fileMetaData, string tableName = "parquet") =>
+      ToBlueSchema(fileMetaData.Schema, tableName, fileMetaData.KeyValueMetadata);
+
+   public static ColumnInfo BlueColumn(this SchemaDescriptor schemaDescriptor, int index, IReadOnlyDictionary<string, string>? keyValueMetadata = null) {
+      var c = schemaDescriptor.Column(index);
+      var lt = c.LogicalType;
+      if (lt.Type == LogicalTypeEnum.Enum) {
+         var enumType = ParquetAdapter.GetColumnEnumType(keyValueMetadata, c.Name);
+         if (enumType is not null) {
+            return new(c.Name, index, enumType);
+         }
+      }
+      return new(c.Name, index, getTypeCode(c.LogicalType, c.PhysicalType));
+   }
+
+   public static IBlueRowCollection ReadBlueTable(this ParquetFileReader fileReader, int? start = null, int? stop = null) {
+      var schema = fileReader.FileMetaData.ToBlueSchema("parquetReader");
+      var colInfos = schema.columnInfo;
+      IBlueRowCollection? rv;
+      if (!schema.columnInfo.Any(c => c.colName == "id")) {
+         rv = BlueAddIndexColumnTable.Create(schema, fileReader.ReadColumns(start, stop));
+      } else {
+         rv = new BlueIndexedColumnTable(schema, fileReader.ReadColumns(start, stop));
+      }
+      Log.assert(!schema.columnInfo.Any(c => c is null));
+      return rv;
+   }
+
+   public static (Column[] Column, IReadOnlyDictionary<string, string> Meta) ToParquetSchema(this IBlueTableSchema schema) {
+      var blueColumns = schema.columnInfo;
+      var parquetColumns = new Column[blueColumns.Length];
+      var parquetMeta = new Dictionary<string, string>();
+      KeyValuePair<string, string>[] parquetColMeta;
+      for (int i = 0; i < blueColumns.Length; i++) {
+         (parquetColumns[i], parquetColMeta) = ToParquetColumn(blueColumns[i]);
+         parquetMeta.AddRange(parquetColMeta);
+      }
+      return (parquetColumns, parquetMeta);
+   }
+
+   public static (Column Column, KeyValuePair<string, string>[] Meta) ToParquetColumn(this ColumnInfo columnInfo) {
+      var colType = columnInfo.colType;
+      bool isNullable = colType.IsNullable();
+      if (isNullable) {
+         colType = colType.GetGenericArguments()[0];
+      }
+      KeyValuePair<string, string>[] meta;
+      TypeCode typeCode;
+      var colName = columnInfo.colName;
+      if (colType.IsEnum) {
+         typeCode = colType.GetEnumUnderlyingType().GetTypeCode();
+         meta = new[] { ParquetAdapter.ColumnEnumTypeEntry(columnInfo.colName, colType) };
+      } else {
+         typeCode = colType.GetTypeCode();
+         meta = Array.Empty<KeyValuePair<string, string>>();
+      }
+      return (ToParquetColumn(colName, typeCode), meta);
+
+      static Column ToParquetColumn(string colName, TypeCode typeCode) =>
+         typeCode switch {
+            TypeCode.Boolean => new Column<bool?>(colName),
+            TypeCode.Byte => new Column<byte?>(colName),
+            TypeCode.Int16 => new Column<short?>(colName),
+            TypeCode.Int32 => new Column<int?>(colName),
+            TypeCode.Int64 => new Column<long?>(colName),
+            TypeCode.UInt16 => new Column<ushort?>(colName),
+            TypeCode.UInt32 => new Column<uint?>(colName),
+            TypeCode.UInt64 => new Column<ulong?>(colName),
+            TypeCode.Single => new Column<float?>(colName),
+            TypeCode.Double => new Column<double?>(colName),
+            TypeCode.DateTime => new Column<DateTimeNanos?>(colName),
+            TypeCode.String => new Column<string?>(colName),
+            _ => throw new NotSupportedException($"Unsupported column TypeCode {typeCode}"),
+         };
+   }
+
+   static TypeCode getTypeCode(LogicalType logicalType, PhysicalType physicalType) {
+      return logicalType.Type switch {
+         // LogicalTypeEnum.Int => TypeCode.Int32,
+         // LogicalTypeEnum.Decimal => TypeCode.Double,
+         LogicalTypeEnum.Date or LogicalTypeEnum.Time or LogicalTypeEnum.Timestamp => TypeCode.DateTime,
+         LogicalTypeEnum.String => TypeCode.String,
+         LogicalTypeEnum.Int => FromInt(),
+         LogicalTypeEnum.Decimal => FromDecimal(),
+         _ => FromPhysicalType(),
+      };
+
+      TypeCode FromPhysicalType() =>
+         physicalType switch {
+            PhysicalType.Boolean => TypeCode.Boolean,
+            PhysicalType.Int32 => TypeCode.Int32,
+            PhysicalType.Int64 => TypeCode.Int64,
+            PhysicalType.Float => TypeCode.Single,
+            PhysicalType.Double => TypeCode.Double,
+            _ => throw new NotImplementedException($"TypeCode not implemented for {logicalType} (logical) {physicalType} (physical)"),
+         };
+
+      TypeCode FromInt() {
+         var ilt = (IntLogicalType)logicalType;
+         var bitWidth = ilt.BitWidth;
+         return ilt.IsSigned ? FromSignedInt() : FromUnsignedInt();
+
+         TypeCode FromSignedInt() =>
+            bitWidth switch {
+               8 => TypeCode.SByte,
+               16 => TypeCode.Int16,
+               32 => TypeCode.Int32,
+               64 => TypeCode.Int64,
+               _ => throw new NotSupportedException($"Bit width not supported for signed int ({bitWidth})"),
+            };
+
+         TypeCode FromUnsignedInt() =>
+            bitWidth switch {
+               8 => TypeCode.Byte,
+               16 => TypeCode.UInt16,
+               32 => TypeCode.UInt32,
+               64 => TypeCode.UInt64,
+               _ => throw new NotSupportedException($"Bit width not supported for unsigned int ({bitWidth})"),
+            };
+      }
+
+      TypeCode FromDecimal() {
+         var dlt = (DecimalLogicalType)logicalType;
+         var scale = dlt.Scale;
+         var precision = dlt.Precision;
+         return scale switch {
+            0 => throw new NotSupportedException($"Scale not supported for decimal ({scale})"),
+            _ => TypeCode.Double,
+         };
+      }
+   }
+}
@@ -0,0 +1,234 @@
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using bts;
+using bts.collections;
+
+using Bts.DataStreamCore;
+
+using ParquetSharp;
+
+using Spark.Core.Collections;
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+public class ParquetGroupTable : IBlueRowCollection, IDisposable {
+   readonly RowGroupReader reader;
+   readonly IBlueTableSchema schema;
+   readonly bool leaveOpen;
+   readonly int fullCount;
+   readonly object syncRoot = new();
+   readonly int? start;
+   readonly int? stop;
+   readonly int startIndex;
+   readonly int stopIndex;
+   readonly int idColumnIndex;
+   readonly int idColumnIndexInFile;
+   readonly Func<int, int>? rowIdFactory;
+   DataCache? dataCacheBacking;
+
+   public ParquetGroupTable(
+      RowGroupReader reader,
+      IBlueTableSchema schema,
+      int? start = null,
+      int? stop = null,
+      int idColumnIndex = -1,
+      int idColumnIndexInFile = -1,
+      Func<int, int>? rowIdFactory = null,
+      bool leaveOpen = false
+   ) {
+      this.reader = reader;
+      this.schema = schema;
+      this.start = start;
+      this.stop = stop;
+      this.idColumnIndex = idColumnIndex;
+      this.idColumnIndexInFile = idColumnIndexInFile;
+      this.rowIdFactory = rowIdFactory;
+      this.leaveOpen = leaveOpen;
+      fullCount = checked((int)reader.MetaData.NumRows);
+      Log.assert(fullCount >= 0);
+      startIndex = SliceList.GetStartIndex(start, fullCount, true);
+      stopIndex = SliceList.GetStopIndex(stop, fullCount, true);
+      stopIndex = Math.Max(stopIndex, startIndex);
+      Log.assert(
+         startIndex >= 0
+         && startIndex <= fullCount
+         && stopIndex >= 0
+         && stopIndex <= fullCount
+         && stopIndex >= startIndex);
+   }
+
+   ~ParquetGroupTable() =>
+      Dispose();
+
+   public int Count => stopIndex - startIndex;
+
+   IBlueTableSchema IBlueRowCollection.schema => schema;
+
+   DataCache dataCache =>
+      EnsureInit();
+
+   public IBlueRow this[int id] => dataCache[id];
+
+   public bool containsID(int id) =>
+      dataCache.RowIdToIndex.ContainsKey(id);
+
+   public IBlueRow GetRow(int index) =>
+      dataCache.Rows[index];
+
+   public int IndexOf(IBlueRow item) {
+      int id = item.Id();
+      return dataCache.RowIdToIndex.TryGetValue(id, out var idx) && BlueRowEqualityComparer.Equals(dataCache.Rows[idx], item)
+         ? idx
+         : -1;
+   }
+
+   public bool TryGetValue(int id, [NotNullWhen(true)] out IBlueRow? row) {
+      if (dataCache.RowIdToIndex.TryGetValue(id, out var idx)) {
+         row = dataCache.Rows[idx];
+         return true;
+      }
+      row = null;
+      return false;
+   }
+
+   public IEnumerator<IBlueRow> GetEnumerator() {
+      for (int i = 0; i < dataCache.Rows.Length; i++) {
+         yield return dataCache.Rows[i];
+      }
+   }
+
+   public void Dispose() {
+      GC.SuppressFinalize(this);
+      if (!leaveOpen) {
+         reader.Dispose();
+      }
+   }
+
+   [MemberNotNull(nameof(dataCacheBacking))]
+   internal DataCache EnsureInit() {
+      if (dataCacheBacking.HasValue) {
+         return dataCacheBacking.Value;
+      }
+      lock (syncRoot) {
+         if (dataCacheBacking.HasValue) {
+            return dataCacheBacking.Value;
+         }
+         var rows = new IBlueRow[Count];
+         int numColumns = reader.MetaData.NumColumns;
+         var blueColumns = schema.columnInfo;
+         Log.assert((blueColumns.Length - numColumns) switch {
+            0 or 1 => true,
+            _ => false,
+         });
+         var columnValues = allocateColumnValues(
+            reader, blueColumns.Length, Count, idColumnIndex, idColumnIndexInFile, startIndex, stopIndex, rowIdFactory);
+         var rowIdToIndex = new Dictionary<int, int>();
+         for (int i = 0; i < rows.Length; i++) {
+            rows[i] = new BlueRowColumnWrapper(schema, i, columnValues);
+         }
+         dataCacheBacking = new(rows, rowIdToIndex, columnValues);
+      }
+      return dataCacheBacking.Value;
+   }
+
+   static IList<object?>[] allocateColumnValues(
+      RowGroupReader reader,
+      int numColumns,
+      int numRows,
+      int idColIdx,
+      int idColIdxInFile,
+      int startIndex,
+      int stopIndex,
+      Func<int, int>? idFactory
+   ) {
+      if (idColIdx < 0 || idColIdx >= numColumns) {
+         throw new ArgumentException("Id column index out of bounds", nameof(idColIdx));
+      }
+      var columnValues = new IList<object?>[numColumns];
+      if (idColIdxInFile == -1) {
+         // Generate ids (there is no id column in the file)
+         ArgumentNullException.ThrowIfNull(idFactory);
+         for (int i = 0; i < numColumns; i++) {
+            if (i < idColIdx) {
+               ReadColumn(i, i);
+            } else if (i == idColIdx) {
+               columnValues[idColIdx] = new StepList<int>(0, 1, numRows).WrapSelector(idx => (object?)idFactory(idx), null);
+            } else {
+               ReadColumn(i - 1, i);
+            }
+         }
+      } else if (idFactory is not null) {
+         // Generate ids (skip id column in the file)
+         for (int i = 0; i < numColumns; i++) {
+            if (i == idColIdx) {
+               columnValues[idColIdx] = new StepList<int>(0, 1, numRows).WrapSelector(idx => (object?)idFactory(idx), null);
+            } else {
+               if (i > idColIdx && i < idColIdxInFile) {
+                  ReadColumn(i - 1, i);
+               } else if (i > idColIdxInFile && i < idColIdx) {
+                  ReadColumn(i + 1, i);
+               } else {
+                  ReadColumn(i, i);
+               }
+            }
+         }
+      } else {
+         // Get ids from the file (output table id column index may differ from file)
+         // Case 1) File id col index > output
+         //    src cols: a, b, c, d, (id), e, f, ...
+         //    dst cols: a, b, (id), c, d, e, f, ...
+         //
+         // Case 2) File id col index == output
+         //    src cols: a, b, (id), c, d, e, f, ...
+         //    dst cols: a, b, (id), c, d, e, f, ...
+         //
+         // Case 3) File id col index < output
+         //    src cols: a, b, (id), c, d, e, f, ...
+         //    dst cols: a, b, c, d, (id), e, f, ...
+
+         for (int i = 0; i < numColumns; i++) {
+            if (i == idColIdx) {
+               ReadColumn(idColIdxInFile, idColIdx);
+            } else if (i > idColIdx && i < idColIdxInFile) {
+               ReadColumn(i - 1, i);
+            } else if (i > idColIdxInFile && i < idColIdx) {
+               ReadColumn(i, i - 1);
+            } else {
+               ReadColumn(i, i);
+            }
+         }
+      }
+      return columnValues;
+
+      void ReadColumn(int srcIdx, int dstIdx) {
+         using var colReader = reader.GetColumnReader(srcIdx);
+         columnValues[dstIdx] = colReader.Read(startIndex, stopIndex);
+      }
+   }
+
+   IEnumerator IEnumerable.GetEnumerator() =>
+      GetEnumerator();
+
+   internal readonly struct DataCache {
+      public readonly IBlueRow[] Rows;
+      public readonly Dictionary<int, int> RowIdToIndex;
+      public readonly IList<object?>[] ColumnValues;
+
+      public DataCache(IBlueRow[] rows, Dictionary<int, int> rowIdToIndex, IList<object?>[] columnValues) {
+         Rows = rows;
+         RowIdToIndex = rowIdToIndex;
+         ColumnValues = columnValues;
+      }
+
+      public IBlueRow this[int id] =>
+         Rows[RowIdToIndex[id]];
+
+      public IBlueRow GetRow(int index) =>
+         Rows[index];
+   }
+}
@@ -0,0 +1,65 @@
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using bts;
+using bts.collections;
+
+using Bts.DataStreamCore;
+using Bts.PubSub;
+
+using Spark.Core.Disposables;
+
+using System;
+using System.Threading;
+
+[DataStreamUserRespresentation(false)]
+public class ParquetReaderStream : ViewStream {
+   readonly string file;
+   readonly int? start;
+   readonly int? stop;
+   readonly IWorkScheduler workScheduler;
+   IBlueRowCollection? table;
+   IDisposable? workerSub;
+
+   public ParquetReaderStream(string file, IWorkScheduler workScheduler) {
+      this.file = file;
+      this.workScheduler = workScheduler;
+   }
+
+   public ParquetReaderStream(string file, int? start, int? stop, IWorkScheduler workScheduler) {
+      this.file = file;
+      this.start = start;
+      this.stop = stop;
+      this.workScheduler = workScheduler;
+   }
+
+   protected override void myOnFirstSubscriber() {
+      Start();
+      var worker = new AnonymousWorker(DoWork);
+      workScheduler.Add(worker);
+      workerSub = Disposable.Create(() => workScheduler.Remove(worker));
+
+      async void Start() {
+         try {
+            Volatile.Write(ref table, await ParquetTableReader.ReadAsync(file, start, stop));
+         } catch (Exception ex) {
+            Log.DataFlow.error($"[parquet_reader_stream_err.json]{{ \"err\": \"{ex}\" }}");
+         }
+      }
+
+      void DoWork() {
+         var table = Volatile.Read(ref this.table);
+         if (table is null) {
+            return;
+         }
+         Disposable.dispose_thread_safe(ref workerSub);
+         if (table.schema.columnInfo.Length > 1) {
+            myFireEvent(new DataPacket(table, table, new BlueTableImmutable(table.schema)));
+         }
+      }
+   }
+
+   protected override void myOnLastSubscriber() =>
+      Disposable.dispose_thread_safe(ref workerSub);
+}
@@ -0,0 +1,26 @@
+// namespace Bts.DataStream.Parquet;
+
+// using BCG;
+
+// using global::Parquet.Data;
+
+// public class ParquetRow : IBlueRow {
+//    readonly int id;
+//    readonly int rowIndex;
+//    readonly DataColumn[] data;
+
+//    public ParquetRow(int id, int rowIndex, DataColumn[] data, IBlueTableSchema schema) {
+//       this.id = id;
+//       this.rowIndex = rowIndex;
+//       this.data = data;
+//       Schema = schema;
+//    }
+
+//    public object? this[int index] =>
+//       index == 0
+//          ? id
+//          : data[index - 1].Data.GetValue(rowIndex);
+
+//    public IBlueTableSchema Schema { get; }
+//    IBlueTableSchema IBlueRow.schema => Schema;
+// }
@@ -0,0 +1,145 @@
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using bts;
+using bts.collections;
+
+using Bts.DataStreamCore;
+
+using ParquetSharp;
+
+using Spark.Core.Collections;
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+public class ParquetTable : IBlueRowCollection, IDisposable {
+   readonly SortedList<int, ParquetGroupTable> groups = new();
+   readonly int fullCount;
+   readonly IBlueTableSchema schema;
+   readonly ParquetFileReader? reader;
+   readonly int startIndex;
+   readonly int stopIndex;
+
+   public ParquetTable(ParquetFileReader reader, string tableName = "parquet", int? start = null, int? stop = null, bool leaveOpen = false) {
+      schema = reader.FileMetaData.ToBlueSchema(tableName);
+      int idColIdx;
+      if (schema.TryResolveIndices("id", out int idColIdxInFile)) {
+         idColIdx = idColIdxInFile;
+      } else {
+         var origCols = schema.columnInfo;
+         var cols = new ColumnInfo[origCols.Length + 1];
+         idColIdx = 0;
+         cols[0] = new("id", 0, typeof(int));
+         for (int i = 0; i < origCols.Length; i++) {
+            var c = origCols[i];
+            cols[i + 1] = new(c.colName, i + 1, c.colType);
+         }
+         schema = new BlueTableSchema(cols, schema.tableName);
+      }
+      fullCount = checked((int)reader.FileMetaData.NumRows);
+      Log.assert(fullCount >= 0);
+      startIndex = SliceList.GetStartIndex(start, fullCount, true);
+      stopIndex = SliceList.GetStopIndex(stop, fullCount, true);
+      stopIndex = Math.Max(stopIndex, startIndex);
+      Log.assert(startIndex >= 0 && startIndex <= fullCount && stopIndex >= 0 && stopIndex <= fullCount && stopIndex >= startIndex);
+      int numRowGroups = reader.FileMetaData.NumRowGroups;
+      int rowGroupLastIdx = 0;
+      object syncRoot = new();
+      for (int i = 0; i < numRowGroups && rowGroupLastIdx < Count; i++) {
+         int? grpStart = start.HasValue ? startIndex - rowGroupLastIdx : null;
+         int? grpStop = stop.HasValue ? stopIndex - rowGroupLastIdx : null;
+         int offset = rowGroupLastIdx;
+         var grp = new ParquetGroupTable(reader.RowGroup(i), schema, grpStart, grpStop, idColIdx, idColIdxInFile, GetAutoId);
+         if (grp.Count == 0) {
+            continue;
+         }
+         rowGroupLastIdx += grp.Count;
+         groups.Add(rowGroupLastIdx, grp);
+
+         int GetAutoId(int index) =>
+            index + offset;
+      }
+      Parallel.For(0, groups.Count, i => groups.GetValueAtIndex(i).EnsureInit());
+      if (!leaveOpen) {
+         this.reader = reader;
+      }
+   }
+
+   ~ParquetTable() =>
+      Dispose();
+
+   public IBlueTableSchema Schema => schema;
+
+   public int Count => stopIndex - startIndex;
+
+   IBlueTableSchema IBlueRowCollection.schema => schema;
+
+   public IBlueRow this[int index] {
+      get {
+         foreach (var grp in groups.Values) {
+            if (grp.TryGetValue(index, out var r)) {
+               return r;
+            }
+         }
+         throw new KeyNotFoundException();
+      }
+   }
+
+   public static ParquetTable FromFile(string path, int? start = null, int? stop = null, string tableName = "parquet") =>
+      new(new(path), tableName, start, stop, false);
+
+   public IBlueRow GetRow(int index) {
+      if (index < 0 || index >= Count) {
+         throw new IndexOutOfRangeException();
+      }
+      int rowGroupIdx = groups.Keys.BinarySearch(index);
+      if (rowGroupIdx < 0) {
+         rowGroupIdx = ~rowGroupIdx;
+      }
+      Log.assert(rowGroupIdx <= groups.Count);
+      var grp = groups[rowGroupIdx];
+      int idxWithinGrp = index;
+      if (rowGroupIdx > 0) {
+         idxWithinGrp -= groups.Keys[rowGroupIdx - 1];
+      }
+      return grp[idxWithinGrp];
+   }
+
+   public bool containsID(int id) =>
+      groups.Values.Any(rgl => rgl.containsID(id));
+
+   public int IndexOf(IBlueRow item) {
+      int idx;
+      int grpFirstIdx = 0;
+      foreach (var (grpLastIdx, grp) in groups) {
+         idx = grp.IndexOf(item);
+         if (idx >= 0) {
+            return idx + grpFirstIdx;
+         }
+         grpFirstIdx = grpLastIdx;
+      }
+      return -1;
+   }
+
+   public IEnumerator<IBlueRow> GetEnumerator() {
+      foreach (var rgl in groups.Values) {
+         foreach (var r in rgl) {
+            yield return r;
+         }
+      }
+   }
+
+   public void Dispose() {
+      GC.SuppressFinalize(this);
+      groups.Values.DisposeAll();
+      reader?.Dispose();
+   }
+
+   IEnumerator IEnumerable.GetEnumerator() =>
+      GetEnumerator();
+}
@@ -0,0 +1,32 @@
+#nullable enable
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using Bts.DataStreamCore;
+
+using ParquetSharp;
+
+using System.IO;
+using System.Threading.Tasks;
+
+public class ParquetTableReader {
+   public static Task<IBlueRowCollection> ReadAsync(Stream stream, bool leaveOpen = false, int? start = null, int? stop = null) =>
+      Task.Run(() => Read(stream, leaveOpen, start, stop));
+
+   public static Task<IBlueRowCollection> ReadAsync(string path, int? start = null, int? stop = null) =>
+      Task.Run(() => Read(path, start, stop));
+
+   public static IBlueRowCollection Read(Stream stream, bool leaveOpen = false, int? start = null, int? stop = null) {
+      using var fileReader = new ParquetFileReader(stream, leaveOpen);
+      var rv = fileReader.ReadBlueTable(start, stop);
+      rv.schema.Validate();
+      return rv;
+   }
+
+   public static IBlueRowCollection Read(string path, int? start = null, int? stop = null) {
+      IBlueRowCollection rv = ParquetTable.FromFile(path, start, stop);
+      rv.schema.Validate();
+      return rv;
+   }
+}
@@ -0,0 +1,38 @@
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using Bts.DataStreamCore;
+
+using bts;
+
+using ParquetSharp;
+
+using System.IO;
+using System.Threading.Tasks;
+
+public static class ParquetTableWriter {
+   public static Task WriteAsync(IBlueRowCollection blueRows, Stream outStream, bool leaveOpen = false) =>
+      Task.Run(() => Write(blueRows, outStream, leaveOpen));
+
+   public static void Write(IBlueRowCollection blueRows, Stream outStream, bool leaveOpen = false) {
+      var (parquetColumns, parquetMeta) = blueRows.schema.ToParquetSchema();
+      using var schema = Column.CreateSchemaNode(parquetColumns);
+      using var writerProps = createWriterProperties();
+      using var writer = new ParquetFileWriter(outStream, schema, writerProps, keyValueMetadata: parquetMeta, leaveOpen: leaveOpen);
+      using var rowGroup = writer.AppendRowGroup();
+      for (int i = 0; i < blueRows.schema.columnInfo.Length; i++) {
+         var col = blueRows.schema.columnInfo[i];
+         Log.assert(col.colNo == i);
+         using var colWriter = ParquetAdapter.GetColumnWriter(col.type_code(), rowGroup.NextColumn());
+         colWriter.Write(blueRows.GetColumn(i));
+      }
+      writer.Close();
+   }
+
+   static WriterProperties createWriterProperties(Compression compression = Compression.Snappy) {
+      using var builder = new WriterPropertiesBuilder();
+      builder.Compression(compression);
+      return builder.Build();
+   }
+}
@@ -0,0 +1,87 @@
+namespace Bts.DataStream.Parquet;
+
+using BCG;
+
+using bts.collections;
+
+using Bts.DataStreamCore;
+using Bts.PubSub;
+
+using mbts.utils;
+
+using Spark.Core.Disposables;
+using Spark.Core.Threading;
+
+using System;
+using System.IO;
+
+[DataStreamUserRespresentation(false)]
+public class ParquetWriterStream : ViewStream {
+   readonly string file;
+   readonly ViewStream inputStream;
+   readonly IWorkScheduler workScheduler;
+   readonly AtomicGate gate = new();
+   IDataPacket? pendingOutput;
+   IDisposable? dispose;
+
+   public ParquetWriterStream(ViewStream inputStream, string file, IWorkScheduler workScheduler) {
+      this.inputStream = inputStream;
+      this.file = file;
+      this.workScheduler = workScheduler;
+   }
+
+   protected override void myOnFirstSubscriber() {
+      BlueTableImmutable.DataPacketBuilder? outputBuilder = null;
+      bool isFirstUpdate = false;
+      var worker = new AnonymousWorker(DoWork);
+      inputStream.onChange += OnInputStreamChange;
+      workScheduler.Add(worker);
+      dispose = Disposable.Create(Dispose);
+
+      void Dispose() {
+         workScheduler.Remove(worker);
+         inputStream.onChange -= OnInputStreamChange;
+      }
+
+      void OnInputStreamChange(object? dpObj) {
+         var dp = ExceptionAssert.Argument.Is<IDataPacket>(dpObj);
+         using (gate.BeginTransaction()) {
+            outputBuilder ??= new BlueTableImmutable(dp.Schema).ToDataPacketBuilder();
+            foreach (IBlueRow r in dp.addedRows) {
+               outputBuilder.AddOrUpdate(r);
+            }
+            foreach (IBlueRow r in dp.deletedRows) {
+               outputBuilder.Remove(r.Id());
+            }
+         }
+      }
+
+      async void DoWork() {
+         using (gate.BeginTransaction()) {
+            if (outputBuilder is null) {
+               return;
+            }
+            if (pendingOutput is not null) {
+               myFireEvent(pendingOutput);
+               pendingOutput = null;
+            }
+            var dp = outputBuilder.ToDataPacket();
+            if (isFirstUpdate) {
+               isFirstUpdate = false;
+            } else if (!dp.HasChanges()) {
+               return;
+            }
+            {
+               using var outStream = File.OpenWrite(file);
+               await ParquetTableWriter.WriteAsync(dp.newRows, outStream);
+            }
+            // Fire the update at the beginning of the next doWork call so it happens on the
+            // 'work' thread.
+            pendingOutput = dp;
+         }
+      }
+   }
+
+   protected override void myOnLastSubscriber() =>
+      Disposable.dispose_thread_safe(ref dispose);
+}
@@ -0,0 +1,188 @@
+namespace bts.BlueOrb {
+   using BCG;
+   using System;
+   using System.Collections;
+   using System.Collections.Generic;
+   using System.Linq;
+
+   #region mappings
+   internal class ProjectData {
+      // schema from the base stream
+      public readonly IBlueTableSchema in_schema;
+      // this is the projected schema
+      public readonly IBlueTableSchema out_schema;
+      // projected cols to the input cols, for cols who's names are changed
+      public readonly IDictionary<string, string> mapped_to_orig_col_map = new Dictionary<string, string>();
+      public ProjectData(IBlueTableSchema in_schema_, IBlueTableSchema out_schema_,
+                  IDictionary<string, string> mapped_to_orig_col_map_) {
+         in_schema = in_schema_;
+         out_schema = out_schema_;
+         mapped_to_orig_col_map = mapped_to_orig_col_map_;
+      }
+   }
+   #endregion
+
+
+#region Row with mappings build in
+   internal class NewProjectRow : IBlueRow {
+      #region IBlueRow members
+      private ProjectData _project_data;
+      private IBlueRow _row;
+      public NewProjectRow(ProjectData project_data, IBlueRow row) {
+         _project_data = project_data;
+         _row = row;
+      }
+      public IBlueTableSchema schema { get { return _project_data.out_schema; } }
+      #endregion
+
+      #region ICollection members
+      public int Count { get { return schema.columnNames.Length; } }
+
+      public bool IsSynchronized { get { return false; } }
+
+      public object SyncRoot { get { return this; } }
+
+      public void CopyTo(Array array, int index) {
+         int i = index;
+         foreach (object o in this as IEnumerable)
+            array.SetValue(o, i++);
+      }
+      #endregion
+
+      #region IDictionary members
+      public bool IsFixedSize { get { return true; } }
+
+      public bool IsReadOnly { get { return true; } }
+
+      public object this[object key] {
+         get {
+            if (key is string)
+               return this[(string)key];
+            return this[(int)key];
+         }
+         set { throw new NotSupportedException("The IBlueRow is readonly"); }
+      }
+
+      public object this[int index] {
+         get {
+            return this[schema.columnInfo[index].colName];
+         }
+      }
+
+      public object this[string col_name] {
+         get {
+            string mapped_to_col = null;
+            if (_project_data.mapped_to_orig_col_map.TryGetValue(col_name, out mapped_to_col)) {
+               return _row[mapped_to_col];
+            }
+            return _row[col_name];
+         }
+      }
+
+      public ICollection Keys { get { return schema.columnNames; } }
+
+      public ICollection Values {
+         get {
+            object[] retVal = new object[schema.columnNames.Length];
+            CopyTo(retVal, 0);
+            return retVal;
+         }
+      }
+
+      public void Add(object key, object value) { throw new NotSupportedException("The IBlueRow is readonly"); }
+
+      public void Clear() { throw new NotSupportedException("The IBlueRow is readonly"); }
+
+      public bool Contains(object key) { return schema[(string)key] != null; }
+
+      /// <summary>
+      /// Note, the default enumerator is the IDictionary's enumerator, so if user needs to
+      /// iterate through the values, typecast this into an IEnumerable
+      /// </summary>
+      /// <returns></returns>
+      public IDictionaryEnumerator GetEnumerator() { return new BlueRowDictionaryEnumerator(this); }
+
+      IEnumerator IEnumerable.GetEnumerator() { return new BlueRowEnumerator(this); }
+
+      public void Remove(object key) { throw new NotSupportedException("The IBlueRow is readonly"); }
+      #endregion
+   }
+   #endregion
+
+   [DataStreamUserRespresentation("ProjectStream")]
+   public class NewProjectStream : ViewStream, IStreamMapper {
+
+      private ViewStream _stream;
+      private string _project_expression;
+      private ProjectData _project_data = null;
+      //public ProjectData 
+      public NewProjectStream(ViewStream vs, string project_expression) {
+         _stream = vs;
+         _project_expression = project_expression;
+         _stream = new MapStream(vs, this);
+         mySetRealSource(_stream);
+      }
+
+      public IBlueTableSchema getOutputSchema(IBlueTableSchema input_schema) {
+         _project_data = _create_project_data(input_schema, _project_expression);
+         return _project_data.out_schema;
+      }
+
+      public IBlueRow map(IBlueRow row) {
+         return new NewProjectRow(_project_data, row);
+      }
+
+      // this is where most of the logic is, in terms of translating cols
+      private static ProjectData _create_project_data(IBlueTableSchema input_schema,
+                                                      string project_expression) {
+         project_expression = project_expression.Trim();
+         string[] project_toks = project_expression.Split(' ', ',');
+         HashSet<string> removed_cols = new HashSet<string>();
+         Dictionary<string, string> orig_to_mapped = new Dictionary<string, string>();      
+         // by default every col will show up, so if we have the projection as (a:a1)
+         // it will convert a to a1, 
+         // modifications (6/30/2025):
+         // only the columns represented here, either mapped
+         // or not, will show
+         // examples: if a schema has cols a b c
+         // project(parent_str, "a:aa b") -> aa b
+         foreach (string o_p_tok in project_toks) {
+            string p_tok = o_p_tok.Trim();
+            if (p_tok.Contains(":")) {
+               // explicit mapping
+               string[] map_toks = p_tok.Split(":");
+               string orig_col = map_toks[0];
+               string mapped_col = map_toks[1];
+               orig_to_mapped.Add(orig_col, mapped_col);  
+            } else {
+               // this is a col_name explicitely stated
+               if (input_schema.columnNames.Contains(p_tok)) {
+                  string orig_col = p_tok;
+                  string mapped_col = orig_col;
+                  orig_to_mapped.Add(orig_col, mapped_col);
+               }
+            }
+         }
+
+         // make the new schema
+         List<ColumnInfo> new_cols = new List<ColumnInfo>();
+         foreach (ColumnInfo ci in input_schema.columnInfo) {
+            if (ci.colName == "id") {
+               ColumnInfo nc = new ColumnInfo(ci.colName, new_cols.Count, ci.colType);
+               new_cols.Add(nc);
+               continue;           
+            } else if (orig_to_mapped.ContainsKey(ci.colName)) {
+               string mapped_name = orig_to_mapped[ci.colName];
+               ColumnInfo nc = new ColumnInfo(mapped_name, new_cols.Count, ci.colType);
+               new_cols.Add(nc);
+            }
+         }
+         IBlueTableSchema new_schema = new BlueTableSchema(input_schema.tableName, new_cols.ToArray());
+         var mapped_to_orig_map = orig_to_mapped.ToDictionary(kv => kv.Value, kv => kv.Key);
+         return new ProjectData(input_schema, new_schema, mapped_to_orig_map);
+      }
+
+   
+
+   }
+}
@@ -0,0 +1,128 @@
+namespace bts.BlueOrb {
+   using BCG;
+   using System.IO;
+   using System.Diagnostics;
+   using System;
+
+   [DataStreamUserRespresentation("PythonDataframeStream")]
+   public class PythonDataframeStream : ViewStream {
+      private ViewStream _parent_str;
+      private readonly string _in_csv_file_name;
+      private readonly string _out_csv_filename;
+      private readonly string _transform_function;
+      public PythonDataframeStream(ViewStream parent_str, string transform_function) {
+         var guid = System.Guid.NewGuid();
+         _in_csv_file_name = $"pdfs_in_{guid}.csv";
+         _out_csv_filename = $"pdfs_out_{guid}.csv";
+         _parent_str = new CSVSaverStream(parent_str, _in_csv_file_name);
+         _transform_function = transform_function;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _parent_str.onChange += _parent_str_onchange;
+      }
+
+      protected override void myOnLastSubscriber() {
+         _parent_str.onChange -= _parent_str_onchange;
+      }
+
+      private void _parent_str_onchange(object dp_obj) {
+         Log.assert(dp_obj != null);
+         // the file _in_csv_file_name is now populated.
+         // call py_func_wrapper_main and pass this file name as well
+         // as the output file name
+         // py_func_wrapper_main reads _in_csv_file_name into the df and calls 
+         // transform function, which returns the tranformed df. py_func_wrapper_main then
+         // writes it into the _out_csv_filename file.
+         // now this function should read _out_csv_filename into a dp
+         // and fire it
+         _compute_and_write();
+         //ViewStream rs = new SchemaGuesserStream(new CSVReaderStream(_out_csv_filename));
+         ViewStream rs = new CSVReaderStream(_out_csv_filename);
+         IBlueRowCollection nrows = null;
+         rs.onChange += (dp_obj) => {
+            nrows = (dp_obj as DataPacket).newRows;
+         };
+         var dp = BlueDataUtility.build_dp(nrows, myLastValue as DataPacket);
+         myFireEvent(dp);
+      }
+
+      private void _compute_and_write() {
+         File.WriteAllText("user_code.py", _transform_function);
+         // wrapper function
+         string py_func_wrapper_main = @"
+import sys
+from user_code import transform
+import pandas as pd
+
+if __name__ == '__main__':
+   input_file_name = sys.argv[1]
+   output_file_name = sys.argv[2]
+# 1. load input_file_name into df
+# 2. do some test calc
+# 3. write the output of 2 into output_file_name
+   df = pd.read_csv(input_file_name)   
+   df_out = transform(df)
+   df_out.to_csv(output_file_name, index=False)";
+
+
+         File.WriteAllText("runner.py", py_func_wrapper_main);
+
+         ProcessStartInfo psi = new ProcessStartInfo {
+            FileName = "python",
+            Arguments = $"runner.py {_in_csv_file_name} {_out_csv_filename}",
+            RedirectStandardOutput = false,
+            UseShellExecute = false
+         };
+         var proc = Process.Start(psi);
+         proc.WaitForExit();
+
+      }
+
+      #region Unused test code
+      private void _simple_test() {
+
+         // actual function that needs to be called ////////////////////////
+         string py_real_function = @"
+def test(x, out_path):
+   rv = x * 10
+   with open(out_path, 'w') as f:
+      f.write(str(rv))
+   return rv";
+         // the function is in a string object.
+         File.WriteAllText("user_code.py", py_real_function);
+
+
+         // runner app (top level main function) //////////////////////////////
+         string py_func_wrapper_main = @"
+import sys
+from user_code import test
+
+if __name__ == '__main__':
+   arg = int(sys.argv[1])
+   out_path = sys.argv[2]
+   rv = test(arg, out_path)
+   rv = rv + 12
+   with open(out_path, 'w') as f:to \
+      f.write(str(rv))";
+   
+         File.WriteAllText("runner.py", py_func_wrapper_main);
+
+         string outputPath = "py_out.txt";
+         ProcessStartInfo psi = new ProcessStartInfo {
+            FileName = "python",
+            Arguments = $"runner.py 4 {outputPath}",
+            RedirectStandardOutput = false,
+            UseShellExecute = false
+         };
+         var proc = Process.Start(psi);
+         proc.WaitForExit();
+
+         // Now read the output written by the function
+         string result = File.ReadAllText(outputPath);
+         Console.WriteLine(result); // Should print "6"
+
+      }
+      #endregion
+   }
+}
@@ -0,0 +1,30 @@
+using BCG;
+
+namespace bts.BlueOrb {
+   public class SchemaGuesserStream : ViewStream {
+
+      private IBlueRowCollection _rows = null;
+      private ViewStream _vs;
+      public SchemaGuesserStream(ViewStream vs) {
+         _vs = vs;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _vs.onChange += _on_data;
+      }
+      protected override void myOnLastSubscriber() {
+         _vs.onChange -= _on_data;
+      }
+
+      private void _on_data(object obj) {
+         DataPacket dp = obj as DataPacket;
+         if (_rows == null) {
+            _rows = BlueDataUtility.get_typed_table(dp.newRows);
+         }
+         var dp_out = BlueDataUtility.build_dp_inc(_rows, myLastValue as DataPacket);
+         myFireEvent(dp_out);
+
+      }
+
+   }
+}
@@ -0,0 +1,67 @@
+using Bts.ArithmeticExpressions;
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using BCG;
+
+namespace bts.BlueOrb {
+
+   [DataStreamUserRespresentation("SingleRowMathStream")]
+   public class MathStream : ViewStream, IStreamMapper {
+      private IArithmeticProgram myExp;
+      private BooleanExpressionFilter _bool;
+      List<string> myExtraColumns = new List<string>();
+      BlueTableSchema mySchema;
+
+
+      public MathStream(ViewStream vs, string mathExpression)
+         : this(vs, mathExpression, string.Empty) {
+      }
+
+      public MathStream(ViewStream vs, string mathExpression, string boolean_expression) {
+         myExp = ArithmeticProgramParser.Parse(mathExpression) ??
+            throw new Exception($"Failed to parse ArithmeticExpression '{mathExpression}'");
+         myExtraColumns = myExp.OutputIdentifiers.ToList();
+         if (!string.IsNullOrEmpty(boolean_expression))
+            _bool = new BooleanExpressionFilter(boolean_expression);
+         mySetRealSource(new MapStream(vs, this));
+      }
+
+      #region IStreamMapper Members
+
+      public IBlueTableSchema getOutputSchema(IBlueTableSchema inputSchema) {
+         if (mySchema == null) {
+            Dictionary<string, ColumnInfo> colIdx = new Dictionary<string, ColumnInfo>();
+            foreach (ColumnInfo ci in inputSchema.columnInfo)
+               colIdx[ci.colName] = ci;
+
+            foreach (string ncn in myExtraColumns) {
+               ColumnInfo newC;
+               if (colIdx.ContainsKey(ncn))
+                  newC = new ColumnInfo(colIdx[ncn].colName, colIdx[ncn].colNo, typeof(double));
+               else
+                  newC = new ColumnInfo(ncn, colIdx.Count, typeof(double));
+               colIdx[ncn] = newC;
+            }
+            mySchema = new BlueTableSchema(colIdx.Values.ToArray(), "math(" + inputSchema.tableName + ")");
+         }
+         return mySchema;
+      }
+
+      #endregion
+
+      #region IDynamicStreamMapper Members
+
+      public IBlueRow map(IBlueRow row) {
+         MutableBlueRow result = new MutableBlueRow(mySchema, row);
+         if (_bool == null || _bool.filter(row)) {
+            myExp.Evaluate(result.AsDictionary());
+         }
+         return result;
+      }
+
+      #endregion
+   }
+}
@@ -0,0 +1,17 @@
+namespace bts.BlueOrb {
+   using BCG;
+
+   using System;
+   using System.Collections.Generic;
+   using System.Linq;
+   using System.Text;
+   using System.Threading.Tasks;
+
+   [DataStreamUserRespresentation("SortStream")]
+   public class SortStream: ViewStream {
+      public SortStream (ViewStream parent_stream, string sort_expr) {
+         ViewStream rs = new BCG.SortStream(parent_stream, sort_expr);
+         mySetRealSource(rs);
+      }
+   }
+}
@@ -0,0 +1,16 @@
+namespace bts.BlueOrb {
+   using BCG;
+
+   using System;
+   using System.Collections.Generic;
+   using System.Linq;
+   using System.Text;
+   using System.Threading.Tasks;
+   [DataStreamUserRespresentation("TimeBasedRollingFilterStream")]
+   public class TimeBasedRollingFilterStream : ViewStream {
+      public TimeBasedRollingFilterStream(ViewStream parent_str, string time_col, double n_seconds) {
+         ViewStream rs = new BCG.TimeBasedFilterStream(ViewStreamDatabase.instance, parent_str, time_col, TimeSpan.FromSeconds(n_seconds));
+         mySetRealSource(rs);
+      }
+   }
+}
@@ -0,0 +1,81 @@
+using BCG;
+
+using bts.utils;
+
+using Bts.DataStreamCore;
+
+using mbts.utils;
+
+using Spark.Core.Collections;
+using Spark.Core.Threading;
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace bts.BlueOrb {
+   // Keeps adding changing rows to the stream, hence preserving the history
+   // and creating a time series, for example this can be used to make bbo updates
+   // into a time series of prices/qty
+   [DataStreamUserRespresentation("TimeSeriesStream")]
+   public class TimeSeriesStream : ViewStream {
+      readonly ViewStream _stream;
+      readonly string timeColumn;
+      readonly AtomicGate gate = new();
+      CircularBufferTable? _table;
+      private int _id = 0;
+      private int _size = 0;
+
+      public TimeSeriesStream(ViewStream stream)
+         : this(stream, Int32.MaxValue) { }
+
+      public TimeSeriesStream(ViewStream stream, int size, string timeColumn = "ts_event") {
+         _stream = stream;
+         _size = size;
+         this.timeColumn = timeColumn;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _stream.onChange += new ChangeDelegate(_onstream_change);
+      }
+      protected override void myOnLastSubscriber() {
+         _stream.onChange -= new ChangeDelegate(_onstream_change);
+      }
+
+
+      private void _onstream_change(object o) {
+         var dp = ExceptionAssert.Argument.Is<IDataPacket>(o);
+         DateTime now = DateTime.Now;
+         using var _ = gate.BeginTransaction();
+         if (_table == null) {
+            var colInfos = dp.newRows.schema.columnInfo;
+            if (colInfos.TryGetFirst(c => c.colName == timeColumn, out var currTimeCol, out var currTimeColIdx)) {
+               colInfos = colInfos.ToArray();
+               colInfos[currTimeColIdx] = new(timeColumn, currTimeCol.colNo, typeof(DateTime));
+            } else {
+               colInfos = ArrayHelper.add(colInfos, new(timeColumn, colInfos.Length, typeof(DateTime)));
+            }
+            _table = new CircularBufferTable(new BlueTableSchema(colInfos, dp.newRows.schema.tableName), _size);
+         }
+         var addedRowsBd = new BlueTableImmutable(_table.schema).ToDataPacketBuilder();
+         var deletedRowsBd = new BlueTableImmutable(_table.schema).ToDataPacketBuilder();
+         foreach (IBlueRow r in dp.addedRows) {
+            MutableBlueRow ar = new MutableBlueRow(_table.schema, r);
+            ar.setValue(timeColumn, now);
+            int id = _id++;
+            ar.setValue("id", id);
+            _table = _table.Add(ar, out var oldRow);
+            addedRowsBd.AddOrUpdate(ar);
+            if (oldRow is not null) {
+               deletedRowsBd.AddOrUpdate(oldRow);
+            }
+         }
+         var addedRows = addedRowsBd.ToImmutable();
+         var deletedRows = deletedRowsBd.ToImmutable();
+         var dp_out = new DataPacket(_table, addedRows, deletedRows);
+         myFireEvent(dp_out);
+      }
+   }
+}
+
@@ -0,0 +1,197 @@
+namespace Bts.DataStream;
+
+using bts;
+
+using Spark.Core.Collections;
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+
+/// <summary>
+/// Maps a timeseries of keys to unique int32 ids.
+/// </summary>
+public class TimeseriesIndex<T> where T : notnull {
+   static readonly IComparer<KeyValuePair<DateTime, int>> idTimeseriesComp =
+      KeyValuePairComparer.KeyComparer<DateTime, int>();
+
+   readonly ImmutableDictionary<T, ImmutableList<KeyValuePair<DateTime, int>>> nameToId;
+   readonly ImmutableDictionary<int, TimeseriesKey<T>> idToName;
+   readonly int idCounter;
+
+   public TimeseriesIndex()
+      : this(ImmutableDictionary<T, ImmutableList<KeyValuePair<DateTime, int>>>.Empty, ImmutableDictionary<int, TimeseriesKey<T>>.Empty, 0) { }
+
+   TimeseriesIndex(ImmutableDictionary<T, ImmutableList<KeyValuePair<DateTime, int>>> nameToId, ImmutableDictionary<int, TimeseriesKey<T>> idToName, int idCounter) {
+      this.nameToId = nameToId;
+      this.idToName = idToName;
+      this.idCounter = idCounter;
+   }
+
+   public int Count => idToName.Count;
+
+   public ImmutableDictionary<T, ImmutableList<KeyValuePair<DateTime, int>>> NameToId => nameToId;
+   public ImmutableDictionary<int, TimeseriesKey<T>> IdToName => idToName;
+
+   public bool ContainsId(int id) =>
+      idToName.ContainsKey(id);
+
+   public int GetNearest(TimeseriesKey<T> key) {
+      if (!nameToId.TryGetValue(key.Name, out var ids) || ids.Count == 0) {
+         throw new KeyNotFoundException();
+      }
+      int idx = ids.BinarySearch(new(key.Timestamp, -1), idTimeseriesComp);
+      if (idx < 0) {
+         idx = ~idx;
+         if (idx == 0) {
+            throw new KeyNotFoundException();
+         }
+         idx--;
+      }
+      return ids[idx].Value;
+   }
+
+   public bool TryGetNearest(TimeseriesKey<T> key, out int result) {
+      if (!nameToId.TryGetValue(key.Name, out var ids) || ids.Count == 0) {
+         result = -1;
+         return false;
+      }
+      int idx = ids.BinarySearch(new(key.Timestamp, -1), idTimeseriesComp);
+      if (idx < 0) {
+         idx = ~idx;
+         if (idx == 0) {
+            result = -1;
+            return false;
+         }
+         idx--;
+      }
+      result = ids[idx].Value;
+      return true;
+   }
+
+   public TimeseriesIndex<T> GetNearestOrAdd(TimeseriesKey<T> key, out int result) {
+      int idx;
+      if (!nameToId.TryGetValue(key.Name, out var ids) || ids.Count == 0) {
+         ids = ImmutableList<KeyValuePair<DateTime, int>>.Empty;
+         idx = 0;
+      } else {
+         idx = ids.BinarySearch(new(key.Timestamp, -1), idTimeseriesComp);
+         if (idx < 0) {
+            idx = ~idx;
+         }
+      }
+      if (idx == 0) {
+         result = idCounter + 1;
+         ids = ids.Insert(0, new(key.Timestamp, result));
+         return new(
+            nameToId.SetItem(key.Name, ids),
+            idToName.SetItem(result, key),
+            result);
+      }
+      result = ids[idx].Value;
+      return this;
+   }
+
+   public TimeseriesIndex<T> GetOrAdd(TimeseriesKey<T> key, out int result) {
+      int idx;
+      if (!nameToId.TryGetValue(key.Name, out var ids) || ids.Count == 0) {
+         ids = ImmutableList<KeyValuePair<DateTime, int>>.Empty;
+         idx = 0;
+      } else {
+         idx = ids.BinarySearch(new(key.Timestamp, -1), idTimeseriesComp);
+         if (idx < 0) {
+            idx = ~idx;
+         } else {
+            result = ids[idx].Value;
+            return this;
+         }
+      }
+      result = idCounter + 1;
+      ids = ids.Insert(idx, new(key.Timestamp, result));
+      return new(
+         nameToId.SetItem(key.Name, ids),
+         idToName.SetItem(result, key),
+         result);
+   }
+
+   public IList<KeyValuePair<DateTime, int>> GetIds(T name) =>
+      nameToId[name];
+
+   public Builder ToBuilder() =>
+      new(this);
+
+   public class Builder {
+      readonly ImmutableDictionary<T, ImmutableList<KeyValuePair<DateTime, int>>>.Builder nameToId;
+      readonly ImmutableDictionary<int, TimeseriesKey<T>>.Builder idToName;
+      int idCounter;
+
+      public Builder(TimeseriesIndex<T> source)
+         : this(source.nameToId, source.idToName, source.idCounter) { }
+
+      public Builder(ImmutableDictionary<T, ImmutableList<KeyValuePair<DateTime, int>>> nameToId, ImmutableDictionary<int, TimeseriesKey<T>> idToName, int idCounter) {
+         this.nameToId = nameToId.ToBuilder();
+         this.idToName = idToName.ToBuilder();
+         this.idCounter = idCounter;
+      }
+
+      public int GetNearest(TimeseriesKey<T> key) =>
+         getOrAdd(key, false, false);
+
+      public int GetNearestOrAdd(TimeseriesKey<T> key) =>
+         getOrAdd(key, false, true);
+
+      public int GetOrAdd(TimeseriesKey<T> key) =>
+         getOrAdd(key, true, true);
+
+      public int GetLatest(T key) =>
+         nameToId.TryGetValue(key, out var ids)
+            ? ids[^1].Value
+            : throw new KeyNotFoundException();
+
+      public bool TryGetLatest(T key, out int result) {
+         if (nameToId.TryGetValue(key, out var ids)) {
+            result = ids[^1].Value;
+            return true;
+         }
+         result = 0;
+         return false;
+      }
+
+      public ImmutableList<KeyValuePair<DateTime, int>> GetIds(T name) =>
+         nameToId.TryGetValue(name, out var ids)
+            ? ids
+            : ImmutableList<KeyValuePair<DateTime, int>>.Empty;
+
+      public TimeseriesIndex<T> ToImmutable() =>
+         new(nameToId.ToImmutable(), idToName.ToImmutable(), idCounter);
+
+      int getOrAdd(TimeseriesKey<T> key, bool requireExactTimestamp, bool canAdd) {
+         var ids = nameToId.GetOrAdd(key.Name, _ => ImmutableList<KeyValuePair<DateTime, int>>.Empty);
+         int idx = ids.BinarySearch(new(key.Timestamp, 0), idTimeseriesComp);
+         int id;
+         if (idx < 0) {
+            Log.Gen.info($"Adding key to timeseries index ({key.Timestamp}, {key.Name})");
+            // We didn't get an exact match. If requireExactTimestamp is false and a record with an
+            // earlier Timestamp exists, use that. Otherwise, add a new record with this Timestamp.
+            idx = ~idx;
+            if (requireExactTimestamp || idx == 0) {
+               if (!canAdd) {
+                  throw new KeyNotFoundException();
+               }
+               id = ++idCounter;
+               ids = ids.Insert(idx, new(key.Timestamp, id));
+               nameToId[key.Name] = ids;
+               idToName.Add(id, key);
+            } else {
+               if (idx == ids.Count) {
+                  --idx;
+               }
+               id = ids[idx].Value;
+            }
+         } else {
+            id = ids[idx].Value;
+         }
+         return id;
+      }
+   }
+}
@@ -0,0 +1,22 @@
+namespace Bts.DataStream;
+
+using Spark.Core.Collections;
+
+using System;
+using System.Collections.Generic;
+
+public readonly record struct TimeseriesKey<T>(T Name, DateTime Timestamp) : IDualComparable<TimeseriesKey<T>> {
+   public int CompareTo(TimeseriesKey<T> other) {
+      var rv = Timestamp.CompareTo(other.Timestamp);
+      if (rv == 0) {
+         rv = Comparer<T>.Default.Compare(Name, other.Name);
+      }
+      return rv;
+   }
+
+   public static implicit operator (T Name, DateTime Timestamp)(TimeseriesKey<T> key) =>
+      (key.Name, key.Timestamp);
+
+   public static implicit operator TimeseriesKey<T>((T Name, DateTime Timestamp) tup) =>
+      new(tup.Name, tup.Timestamp);
+}
@@ -0,0 +1,11 @@
+namespace bts.BlueOrb {
+   using BCG;
+   [DataStreamUserRespresentation("TopStream")]
+   public class TopStream : ViewStream { 
+      public TopStream(ViewStream vs, int n_rows, string sort_col) {
+         ViewStream rs = new BCG.TopStream (vs, n_rows, sort_col);
+         mySetRealSource(rs);
+      }
+   }
+
+}
@@ -0,0 +1,16 @@
+namespace bts.BlueOrb {
+   using System;
+   using System.Collections.Generic;
+
+   using mbts;
+   using BCG;
+
+   [DataStreamUserRespresentation("UnionStream")]
+   public class UnionStream : ViewStream {
+      public UnionStream(ViewStream left_stream, ViewStream right_stream) {
+         ViewStream rs = new BCG.MutableAppendStream(left_stream, right_stream);
+         mySetRealSource(rs);
+      }
+   }
+
+}
@@ -17,11 +17,11 @@
  </ItemGroup>

  <ItemGroup>
-    <PackageReference Include="HtmlAgilityPack" Version="1.11.57" />
+    <PackageReference Include="IronPython" Version="3.4.2" />
    <PackageReference Include="Microsoft.Data.Analysis" Version="0.21.1" />
    <PackageReference Include="MongoDB.Bson" Version="2.23.1" />
    <PackageReference Include="MongoDB.Driver" Version="2.23.1" />
-    <PackageReference Include="Parquet.Net" Version="5.0.1" />
+    <PackageReference Include="ParquetSharp" Version="20.0.0" />
    <PackageReference Include="System.Data.SQLite" Version="1.0.118" />
    <PackageReference Include="MathNet.Numerics" Version="5.0.0" />
  </ItemGroup>
@@ -2,25 +2,277 @@ namespace Bts.DataStream;

 using BCG;

+using bts;
+using bts.api.core;
+
+using Bts.DataStreamCore;
+using Bts.PubSub;
+
+using Microsoft.Extensions.Logging;
+
 using Spark.Core.Disposables;
+using Spark.Core.Threading;

 using System;
+using System.Linq;
 using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;

 public static class DataStreamExtensions {
-   public static ViewStream AsViewStream(this IObservable<DataPacket> source) =>
-      source as ViewStream ?? new ObservableViewStream(source);
+   public static ViewStream AsViewStream<T>(this IObservable<IDataPacket<T>> source, string? name = null, ILogger? logger = null) where T : IBlueRow =>
+      source as ViewStream ?? new ObservableViewStream(source.Select(dp => new DataPacket(dp.newRows, dp.addedRows, dp.deletedRows)), name, logger);

-   public static IObservable<DataPacket> AsObservable(this ViewStream source) {
-      return source as IObservable<DataPacket> ?? Observable.Create<DataPacket>(Subscribe);
+   // public static IObservable<IDataPacket<T>> SelectDataPacket<T>(this IObservable<IDataPacket> source, Func<IBlueRow, T> selector) where T : IBlueRow =>
+   //    source.Select(dp => {
+   //       dp.get_new_added_deleted(out var newRows, out var addedRows, out var deletedRows);
+   //       return new DataPacket<T>(CastRows(newRows), CastRows(addedRows), CastRows(deletedRows));

-      IDisposable Subscribe(IObserver<DataPacket> observer) {
-         source.onChange += OnChange;
-         return Disposable.Create(() => source.onChange -= OnChange);
+   //       IBlueRowCollection<T> CastRows(ICollection rows) =>
+   //          new BlueTableSelectorWrapper<T>(
+   //             rows as IBlueRowCollection ?? new BlueRowCollection(rows, dp.Schema), selector);
+   //    });

-         void OnChange(object? newValue) =>
-            observer.OnNext(newValue as DataPacket ?? throw new ArgumentException(
-               $"Expected DataPacket, got {newValue?.GetType()}", nameof(newValue)));
+   public static IObservable<TableUpdate<IBlueRow, int>> AsTables(this IObservable<IDataPacket> source) =>
+      source.AsTables<IBlueRow, int>(r => r, r => r.Id());
+
+   public static IObservable<TableUpdate<T, int>> AsTables<T>(this IObservable<IDataPacket> source, Func<IBlueRow, T> valueSelector) where T : IBlueRow =>
+      source.AsTables<T, int>(valueSelector, r => r.Id());
+
+   public static IObservable<TableUpdate<T, int>> AsTables<T>(
+      this IObservable<IDataPacket> source, Func<IBlueRow, T> valueSelector, Func<T, int> keySelector) =>
+      source.AsTables<T, int>(valueSelector, keySelector);
+
+   public static IObservable<TableUpdate<T, TKey>> AsTables<T, TKey>(
+      this IObservable<IDataPacket> source, Func<IBlueRow, T> valueSelector, Func<T, TKey> keySelector, Func<IBlueRow, TKey>? rowKeySelector = null) where TKey : IEquatable<TKey> {
+      rowKeySelector ??= r => keySelector(valueSelector(r));
+      return source.Scan(TableUpdate<T, TKey>.mk_empty(keySelector), (res, dp) => {
+         var bd = res.to_builder();
+         dp.get_new_added_deleted(out var newRows, out var addedRows, out var deletedRows);
+         foreach (IBlueRow r in addedRows) {
+            bd.add_or_update(valueSelector(r));
+         }
+         foreach (IBlueRow r in deletedRows) {
+            bd.remove(rowKeySelector(r));
+         }
+         return bd.to_table();
+      });
+   }
+
+   public static IObservable<IDataPacket> AsDataPackets(this IObservable<TableUpdate<IBlueRow, int>> source) =>
+      source.Scan(
+         (Table: (BlueTableImmutable?)null, Dp: (IDataPacket?)null),
+         (res, table) => {
+            var resTable = res.Table;
+            if (resTable is null) {
+               if (table.state.Count == 0) {
+                  return (null, null);
+               }
+               resTable = new(table.state.Values.First().schema);
+            }
+            var bd = resTable.ToDataPacketBuilder();
+            foreach (var r in table.removed) {
+               bd.Remove(r.Id());
+            }
+            foreach (var r in table.added) {
+               bd.AddOrUpdate(r);
+            }
+            var resDp = bd.ToDataPacket(out var newRows);
+            return (newRows, resDp);
+         })
+         .Where(t => t.Dp is not null && (t.Dp.addedRows.Count > 0 || t.Dp.deletedRows.Count > 0))
+         .Select(t => t.Dp!);
+
+   public static IObservable<IDataPacket> AsDataPackets<T>(this IObservable<TableUpdate<T, int>> source, IBlueTableSchema schema) where T : IBlueRow =>
+      source.Scan(
+         (Table: new BlueTableImmutable(schema), Dp: (IDataPacket)new DataPacket(schema)),
+         (res, table) => {
+            var bd = res.Table.ToDataPacketBuilder();
+            foreach (var r in table.removed) {
+               bd.Remove(r.Id());
+            }
+            foreach (var r in table.added) {
+               bd.AddOrUpdate(r);
+            }
+            var resDp = bd.ToDataPacket(out var newRows);
+            return (newRows, resDp);
+         })
+         .Where(t => t.Dp.addedRows.Count > 0 || t.Dp.deletedRows.Count > 0)
+         .Select(t => t.Dp);
+
+   public static IObservable<IDataPacket> AsDataPackets<T, TKey>(this IObservable<TableUpdate<T, TKey>> source, BlueTableSchemaAdapter<T> schema) where TKey : IEquatable<TKey> {
+      return Observable.Create<IDataPacket>(Subscribe);
+
+      IDisposable Subscribe(IObserver<IDataPacket> o) {
+         var adapter = new BlueTableImmutableAdapter<T>(schema);
+         IDataPacket initDataPacket = new DataPacket(schema);
+         return source.Scan((Adapter: adapter, DataPacket: initDataPacket), OnUpdate).Select(res => res.DataPacket).Subscribe(o);
+
+         (BlueTableImmutableAdapter<T> Adapter, IDataPacket DataPacket) OnUpdate(
+            (BlueTableImmutableAdapter<T> Adapter, IDataPacket DataPacket) state, TableUpdate<T, TKey> tableUpdate) {
+            var bd = state.Adapter.ToDataPacketBuilder();
+            bd.Update(tableUpdate);
+            var newRows = bd.ToImmutable(out var dp);
+            return (newRows, dp);
+         }
+      }
+   }
+
+   public static ViewStream AsViewStream<T>(this IObservable<TableUpdate<T, int>> source, IBlueTableSchema schema) where T : IBlueRow =>
+      source.AsDataPackets(schema).AsViewStream();
+
+   public static IObservable<IDataPacket> OnWorkScheduler(this IObservable<IDataPacket> source, IWorkScheduler scheduler) =>
+      Observable.Create<IDataPacket>(o => {
+         var inputGate = new AtomicGate();
+         var outputGate = new AtomicGate();
+         BlueTableImmutable? lastTable = null;
+         BlueTableImmutable.DataPacketBuilder? bd = null;
+         IDataPacket? pendingDpOut = null;
+         return Disposable.Create(source.Subscribe(OnNext), scheduler.Subscribe(DoWork));
+
+         void OnNext(IDataPacket value) {
+            using (inputGate.BeginTransaction()) {
+               lastTable ??= new(value.newRows.schema);
+               bd ??= lastTable.ToDataPacketBuilder();
+               if (pendingDpOut is null) {
+                  // The last outgoing datapacket was just fired. Don't merge this update with the
+                  // previous one (otherwise its adds/removes would be fired twice).
+                  bd.Reset();
+               }
+               foreach (IBlueRow r in value.deletedRows) {
+                  bd.Remove(r.Id());
+               }
+               foreach (IBlueRow r in value.addedRows) {
+                  bd.AddOrUpdate(r);
+               }
+               pendingDpOut = bd.ToDataPacket(out lastTable, false);
+            }
+         }
+
+         void DoWork() {
+            IDataPacket? dpOut = null;
+            if (outputGate.TryEnter()) {
+               using var exit = Disposable.Create(outputGate.Exit);
+               (dpOut, pendingDpOut) = (pendingDpOut, dpOut);
+               if (dpOut is not null) {
+                  o.OnNext(dpOut);
+               }
+            }
+         }
+      });
+
+   public static IObservable<IDataPacket> NonIncrementalAsyncTransform(this IObservable<IDataPacket> source, Func<IBlueRowCollection, Task<IBlueRowCollection?>> transformAsync, IWorkScheduler workScheduler) {
+      const int STATE_IDLE = 0;
+      const int STATE_BUSY = 1;
+      const int STATE_DISPOSED = 2;
+      return Observable.Create<IDataPacket>(Subscribe);
+      IDisposable Subscribe(IObserver<IDataPacket> o) {
+         var syncRoot = new object();
+         IBlueRowCollection? lastTableIn = null;
+         BlueTableImmutable? lastTableOut = null;
+         int nConcurrentDoWorks = 0;
+         int state = STATE_IDLE;
+         IDisposable? dispose = null;
+         dispose = Disposable.Create(source.Subscribe(OnNext), workScheduler.Subscribe(DoWork));
+         return Disposable.Create(Dispose);
+
+         void Dispose() {
+            lock (syncRoot) {
+               switch (state) {
+                  case STATE_DISPOSED:
+                     return;
+                  case STATE_BUSY:
+                     state = STATE_DISPOSED;
+                     return;
+               }
+               state = STATE_DISPOSED;
+            }
+            Disposable.dispose(ref dispose);
+         }
+
+         void OnNext(IDataPacket value) =>
+            Volatile.Write(ref lastTableIn, value.newRows);
+
+         async void DoWork() {
+            lock (syncRoot) {
+               nConcurrentDoWorks++;
+               switch (state) {
+                  case STATE_DISPOSED:
+                  case STATE_BUSY:
+                     return;
+                  case STATE_IDLE:
+                     break;
+                  default:
+                     Log.assert(false, $"Unexpected state ({StateName(state)}) when DoWork called");
+                     return;
+               }
+               state = STATE_BUSY;
+            }
+            var dp = await PublishTable();
+            bool isDisposed = false;
+            lock (syncRoot) {
+               switch (state) {
+                  case STATE_DISPOSED:
+                     isDisposed = true;
+                     break;
+                  case STATE_BUSY:
+                     break;
+                  default:
+                     Log.assert(false, $"Unexpected state ({StateName(state)}) after building output table (async)");
+                     return;
+               }
+            }
+            if (isDisposed) {
+               Disposable.dispose(ref dispose);
+               return;
+            }
+            if (dp is not null) {
+               o.OnNext(dp);
+            }
+            lock (syncRoot) {
+               nConcurrentDoWorks = 0;
+               switch (state) {
+                  case STATE_DISPOSED:
+                     isDisposed = true;
+                     break;
+                  case STATE_BUSY:
+                     state = STATE_IDLE;
+                     break;
+                  default:
+                     Log.assert(false, $"Unexpected state ({StateName(state)}) after firing output table");
+                     return;
+               }
+            }
+            if (isDisposed) {
+               Disposable.dispose(ref dispose);
+            }
+
+            async Task<DataPacket?> PublishTable() {
+               var tableIn = Interlocked.Exchange(ref lastTableIn, null);
+               if (tableIn is null) {
+                  return null;
+               }
+               var tableOut = await transformAsync(tableIn);
+               if (tableOut is null) {
+                  return null;
+               }
+               lastTableOut ??= new(tableOut.schema);
+               var bd = lastTableOut.ToDataPacketBuilder();
+               bd.Clear();
+               foreach (IBlueRow r in tableOut) {
+                  bd.AddOrUpdate(r, BlueRowEqualityComparer.Instance);
+               }
+               return bd.ToDataPacket(out lastTableOut);
+            }
+         }
+
+         static string StateName(int state) =>
+            state switch {
+               STATE_IDLE => "IDLE",
+               STATE_BUSY => "BUSY",
+               STATE_DISPOSED => "DISPOSED",
+               _ => $"STATE_{state}",
+            };
      }
   }
 }
@@ -1,26 +1,26 @@
-namespace bts.SilverPine {
+namespace bts.BlueOrb {
   using System;
   using BCG;
   using System.Collections.Generic;
   using Bts.DataStreamExpressions;
+   using Bts.DataStreamCore;

   // All this does is take in a dsl expression, parse it and fire the data that come out of running it.
   // So for example, if an expresison is passed 
   [DataStreamUserRespresentation("dsl")]
   public class DSLStream : ViewStream {
      private readonly string _dsl;
-      public DSLStream(string dsl) {
+      public DSLStream(string dsl, IDataStreamFactory streamFactory) {
         Log.Gen.info($"DSLStream.cons dsl: {dsl}");
         _dsl = dsl;
-         ViewStream rs = build_stream(dsl);
-         rs = rs ?? new LiteralStream("error", $"msg:invalid dsl \"{dsl}\"");
+         var rs = build_stream(streamFactory, dsl) ?? new LiteralStream("error", $"msg:invalid dsl");
         mySetRealSource(rs);
      }

-      static ViewStream? build_stream(string stream_expression) {
+      static ViewStream? build_stream(IDataStreamFactory streamFactory, string stream_expression) {
         try {
            var exp = DataStreamExpressionsInterpreter.Evaluate(stream_expression);
-            var rv = exp.getView(new Dictionary<string, StatementExpression>(0));
+            var rv = exp.getView(new Dictionary<string, StatementExpression>(0), streamFactory);
            return rv;

         } catch (Exception ex) {
@@ -29,4 +29,4 @@ namespace bts.SilverPine {
         }
      }
   }
-}
+}
@@ -40,7 +40,7 @@ namespace BCG {
        protected override void myOnFirstSubscriber() {
            MasterWorker.getInstance(false).addWorker(this, _send_period);
            var server_rci = new RemoteConnectionInfo(_ip, _port);
-            bts.AsyncTCPConnector_APM.connect_to(server_rci, this);
+            bts.AsyncTCPConnector_AsyncWrapper.connect_to(server_rci, this);
        }

        protected override void myOnLastSubscriber() {
@@ -76,4 +76,4 @@ namespace BCG {


    }
-}
+}
@@ -1,37 +0,0 @@
-namespace Bts.DataStream;
-
-using BCG;
-
-using bts;
-
-using System;
-
-public class ObservableViewStream : ViewStream, IObservable<DataPacket>, IDisposable {
-   readonly IObservable<DataPacket> source;
-   IDisposable? subscription;
-
-   public ObservableViewStream(IObservable<DataPacket> source) =>
-      this.source = source;
-
-   public void Dispose() {
-      GC.SuppressFinalize(this);
-      if (subscription is not null) {
-         subscription.Dispose();
-         subscription = null;
-      }
-   }
-
-   protected override void myOnFirstSubscriber() {
-      Log.isnull(subscription);
-      subscription = source.Subscribe(myFireEvent);
-   }
-
-   protected override void myOnLastSubscriber() {
-      Log.notnull(subscription);
-      subscription.Dispose();
-      subscription = null;
-   }
-
-   IDisposable IObservable<DataPacket>.Subscribe(IObserver<DataPacket> observer) =>
-      source.Subscribe(observer);
-}
@@ -1,90 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-using Bts.DataStreamExpressions;
-using BCG.Utilities.General;
-using bts;
-
-namespace BCG {
-   // listens to the requests posted on "cloud_streams" request table, and 
-   // if unfulfilled starts a ViewPubsliher
-   public class RemoteQueryManager : IWorker {
-      public class StreamPubUnit {
-         public string name;
-         public string stream_expression;
-         public ViewStream stream;
-         public bool persist;
-         public ViewPublisher view_publisher;
-
-         public StreamPubUnit(string name_, string stream_expression_, ViewStream stream_, bool persist_, ViewPublisher view_publisher_) {
-            name = name_;
-            stream_expression = stream_expression_;
-            stream = stream_;
-            persist = persist_;
-            view_publisher = view_publisher_;
-         }
-      }
-      static ViewStream? build_stream(string stream_expression)
-      {
-         try
-         {
-            var exp = DataStreamExpressionsInterpreter.Evaluate(stream_expression);
-            var rv = exp.getView(new Dictionary<string, StatementExpression>(0));
-            return rv;
-
-         } catch (Exception ex) {
-            bts.Log.assert(false, $"Could not build stream: {stream_expression} ex: {ex}");
-            return null;
-         }
-      }
-      private IDictionary<string, StreamPubUnit>
-         _stream_pub_map = new Dictionary<string, StreamPubUnit>();
-      private ViewStream _stream = new TableStream("cloud_streams");
-      private PubTableBroker _broker = new PubTableBroker();
-      private ManagedSubscriber _sub = ManagedSubscriber.instance;
-
-
-      public RemoteQueryManager() {
-         _stream.onChange += _on_str;
-         _sub.subscribe("RemoteRequest", (string tag, byte[] data) => {
-            RemoteRequest req = RemoteRequest.construct_from_bytes(data);
-            _spawn_remote_stream(req.published_table_name, req.stream_expression, false);
-         });
-      }
-      private void _on_str(object obj)
-      {
-         if (obj is not DataPacket dp) {
-            return;
-         }
-         foreach (IBlueRow r in dp.newRows)
-         {
-            string name = r.get<string>("name");
-            bool persist = r.get<bool>("persist");
-            string stream_exp = r.get<string>("stream_exp");
-            if (!_stream_pub_map.ContainsKey(name)) {
-               _spawn_remote_stream(name, stream_exp, persist);
-            }
-         }
-      }
-
-      private void _spawn_remote_stream(string name, string stream_expression, bool persist) {
-         bts.Log.Gen.info($"CloudStreamManager.assign name: {name} stream_expression: {stream_expression}");
-         ViewStream stream = build_stream(stream_expression);
-         _expose_to_ws(name, stream);
-         if (persist) {
-            stream = new PersistorStream(stream, name, "C:\\Temp\\", 1000000);   // 10MBs
-         }
-         ViewPublisher view_pub = new ViewPublisher(name, _broker, stream);
-         StreamPubUnit u = new StreamPubUnit(name, stream_expression, stream, persist, view_pub);
-         _stream_pub_map.Add(name, u);
-      }
-
-      private void _expose_to_ws(string name, ViewStream stream) {
-         // TODO: john
-      }
-
-      public void doWork() {
-
-      }
-   }
-}
@@ -0,0 +1,168 @@
+using bts;
+
+using Bts.DataStreamCore;
+using Bts.DataStreamExpressions;
+using Bts.PubSub;
+
+using Microsoft.Extensions.Hosting;
+
+using Spark.Core.Disposables;
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace BCG {
+   // listens to the requests posted on "cloud_streams" request table, and 
+   // if unfulfilled starts a ViewPubsliher
+   public class RemoteQueryManager : IHostedService {
+      public class StreamPubUnit {
+         public string name;
+         public string stream_expression;
+         public ViewStream stream;
+         public bool persist;
+         public ViewPublisher view_publisher;
+
+         public StreamPubUnit(string name_, string stream_expression_, ViewStream stream_, bool persist_, ViewPublisher view_publisher_) {
+            name = name_;
+            stream_expression = stream_expression_;
+            stream = stream_;
+            persist = persist_;
+            view_publisher = view_publisher_;
+         }
+      }
+      static ViewStream? build_stream(IDataStreamFactory streamFactory, string stream_expression)
+      {
+         try
+         {
+            var exp = DataStreamExpressionsInterpreter.Evaluate(stream_expression);
+            var rv = exp.getView(new Dictionary<string, StatementExpression>(0), streamFactory);
+            return rv;
+
+         } catch (Exception ex) {
+            bts.Log.assert(false, $"Could not build stream: {stream_expression} ex: {ex}");
+            return null;
+         }
+      }
+      private IDictionary<string, StreamPubUnit>
+         _stream_pub_map = new Dictionary<string, StreamPubUnit>();
+      readonly IPubTableBroker _broker;
+      readonly IManagedSubscriber _sub;
+      readonly IDataStreamFactory streamFactory;
+      readonly ITableStreamFactory tableStreamFactory;
+      readonly object syncRoot = new();
+      IDisposable? cloudStreamsSub;
+      IDisposable? remoteRequestsSub;
+      State state;
+
+      public RemoteQueryManager(IManagedSubscriber managedSubscriber, IPubTableBroker pubTableBroker, ITableStreamFactory tableStreamFactory, IEnumerable<IDataStreamFactory> streamFactories) {
+         _sub = managedSubscriber;
+         _broker = pubTableBroker;
+         this.tableStreamFactory = tableStreamFactory;
+         var streamFactoryList = streamFactories.ToList();
+         streamFactory = streamFactoryList.Count == 1
+            ? streamFactoryList[0]
+            : new CompositeDataStreamFactory(streamFactoryList);
+      }
+
+      enum State {
+         Idle = 0,
+         Running = 1,
+         Disposed = 2,
+         WaitingToDispose = 3,
+      }
+
+      public Task StartAsync(CancellationToken cancellationToken) {
+         lock (syncRoot) {
+            switch (state) {
+               case State.Idle:
+                  break;
+               case State.WaitingToDispose:
+               case State.Disposed:
+                  throw new ObjectDisposedException(nameof(RemoteQueryManager));
+               default:
+                  return Task.CompletedTask;
+            }
+            state = State.Running;
+         }
+         if (cloudStreamsSub is not null) {
+            throw new InvalidOperationException("cloudStreamsSub already created");
+         }
+         if (remoteRequestsSub is not null) {
+            throw new InvalidOperationException("remoteRequestsSub already created");
+         }
+         var cloudStream = tableStreamFactory.Create("cloud_streams")
+            ?? throw new Exception("Failed to create TableStream 'cloud_stream'");
+         cloudStreamsSub = cloudStream.AsObservable().Subscribe(_on_str);
+         remoteRequestsSub = _sub.Observe("RemoteRequest").Subscribe(data => {
+            RemoteRequest req = RemoteRequest.construct_from_bytes(data);
+            _spawn_remote_stream(req.published_table_name, req.stream_expression, false);
+         });
+         lock (syncRoot) {
+            if (state == State.WaitingToDispose) {
+               state = State.Disposed;
+            }
+         }
+         if (state == State.Disposed) {
+            Disposable.dispose(ref cloudStreamsSub);
+            Disposable.dispose(ref remoteRequestsSub);
+         }
+         return Task.CompletedTask;
+      }
+
+      public Task StopAsync(CancellationToken cancellationToken) {
+         lock (syncRoot) {
+            switch (state) {
+               case State.Running:
+                  break;
+               default:
+                  return Task.CompletedTask;
+            }
+            state = State.Disposed;
+         }
+         Disposable.dispose(ref cloudStreamsSub);
+         Disposable.dispose(ref remoteRequestsSub);
+         return Task.CompletedTask;
+      }
+
+      private void _on_str(IDataPacket dp)
+      {
+         foreach (IBlueRow r in dp.newRows)
+         {
+            string name = r.get<string>("name");
+            bool persist = r.get<bool>("persist");
+            string stream_exp = r.get<string>("stream_exp");
+            if (!_stream_pub_map.ContainsKey(name)) {
+               _spawn_remote_stream(name, stream_exp, persist);
+            }
+         }
+      }
+
+      private void _spawn_remote_stream(string name, string stream_expression, bool persist) {
+         bts.Log.Gen.info($"CloudStreamManager.assign name: {name} stream_expression: {stream_expression}");
+         var stream = build_stream(streamFactory, stream_expression);
+         if (stream is null) {
+            Log.DataFlow.error($"Failed to spawn remote stream. name: {name}; expression: {stream_expression}");
+            return;
+         }
+         _expose_to_ws(name, stream);
+         if (persist) {
+            string tempDir = Path.GetTempPath();
+        Directory.CreateDirectory(tempDir); // make sure it exists
+
+        stream = new PersistorStream(stream, name, tempDir, 10_000_000); // 10 MB
+         }
+         ViewPublisher view_pub = new ViewPublisher(name, _broker, stream);
+         StreamPubUnit u = new StreamPubUnit(name, stream_expression, stream, persist, view_pub);
+         _stream_pub_map.Add(name, u);
+      }
+
+      private void _expose_to_ws(string name, ViewStream stream) {
+         // TODO: john
+      }
+   }
+}
@@ -2,17 +2,30 @@ using BCG;

 using bts;

+using Bts.DataStreamCore;
+
+using Spark.Core.Disposables;
+
 using System;

 namespace BCG {
-   // this is a stream so we can run it from the DSQA (since dsqa can only load streams)
-   [DataStreamUserRespresentation("remoteQuery")]
+   /// <summary>
+   /// This is a stream so we can run it from the DSQA (since dsqa can only load streams).
+   /// <para>
+   /// Note: It's hidden because this stream is now created by an IDataStreamFactory
+   /// (see RemoteQueryStreamFactory.cs for details)
+   /// </para>
+   /// </summary>
+   [DataStreamUserRespresentation(false)]
   public class RemoteQueryStream : ViewStream {
      private readonly string _name, _stream_exp;
-      private PublisherCore _publisher_core = new PublisherCore();
-      private ViewStream _source_str;
+      readonly ITableStreamFactory tableStreamFactory;
+      readonly IPublisherCore _publisher_core;
+      IDisposable? subscription;

-      public RemoteQueryStream(params string[] lines) {
+      public RemoteQueryStream(ITableStreamFactory tableStreamFactory, IPublisherCore publisherCore, params string[] lines) {
+         this.tableStreamFactory = tableStreamFactory;
+         _publisher_core = publisherCore;
         _stream_exp = get_expression(lines);
         _name = Guid.NewGuid().ToString();
         _name = $"remotereq_{DateTimeOffset.UtcNow.ToUnixTimeMilliseconds().ToString()}";
@@ -21,17 +34,17 @@ namespace BCG {
      }

      protected override void myOnFirstSubscriber() {
+         Log.isnull(subscription);
         RemoteRequest rem_req = new RemoteRequest(_stream_exp, _name);
         byte[] rem_req_bytes = rem_req.serialize();
         _publisher_core.publish("System", "RemoteRequest", rem_req_bytes);
-         _source_str = new TableStream(_name);
-         _source_str.onChange += new ChangeDelegate(_handle_data);
+         var sourceStream = tableStreamFactory.Create(_name);
+         sourceStream.onChange += _handle_data;
+         subscription = Disposable.Create(() => sourceStream.onChange -= _handle_data);
      }

-      protected override void myOnLastSubscriber() {
-         //maybe there should be a way to turn remote requests off ?
-         _source_str.onChange -= new ChangeDelegate(_handle_data);
-      }
+      protected override void myOnLastSubscriber() =>
+         Disposable.dispose(ref subscription);

      static string get_expression(params string[] lines) {
         for (int i = 0; i < lines.Length; i++) {
@@ -1,33 +1,51 @@
 using System;
+using System.Collections.Generic;

-namespace BCG {
+namespace BCG {   
   public class AddColumnsStream : ViewStream {
-      public static Tuple<string, Type, object> parse_exp(string exp) {
+      public static Tuple<string, Type, object> parse_single_tok(string exp) {
         string[] toks = exp.Split(':');
-         string col_name = toks[0];
-         string col_value = toks[1];
+         string col_name = toks[0].Trim();
+         string col_value = toks[1].Trim();
         Tuple<Type, object> tup = BlueDataUtility.guess_type(col_value);
         return Tuple.Create(col_name, tup.Item1, tup.Item2);
      }

+      public static List<Tuple<string, Type, object>> parse_exp(string exp) {
+         string[] toks = exp.Split(",");
+         List<Tuple<string, Type, object>> rv = new List<Tuple<string, Type, object>>();
+         foreach (string s in toks) {
+            var tup = parse_single_tok(s.Trim());
+            rv.Add(tup);
+         }
+         return rv;
+      }
+
      private Tuple<string, Type, object> _new_col;
+      private List<Tuple<string, Type, object>> _new_col_map;
      private IBlueTableSchema _out_schema;

      public AddColumnsStream(ViewStream vs, string col_def) {
-         _new_col = parse_exp(col_def);
+         _new_col_map = parse_exp(col_def);
         ViewStream rs = new MapStream(vs, (IBlueTableSchema s) => _get_schema(s), (IBlueRow r) => _map(r));
         mySetRealSource(rs);
      }

      private IBlueTableSchema _get_schema(IBlueTableSchema input_schema) {
-         if (_out_schema == null)
-            _out_schema = BlueDataUtility.add_column(input_schema, _new_col.Item1, _new_col.Item2);
+         if (_out_schema == null) {
+            _out_schema = input_schema;
+            foreach (var m in _new_col_map) {
+               _out_schema = BlueDataUtility.add_column(_out_schema, m.Item1, m.Item2);
+            }
+         }
         return _out_schema;
      }

      private IBlueRow _map(IBlueRow r) {
         MutableBlueRow rv = new MutableBlueRow(_get_schema(r.schema), r);
-         rv.setValue(_new_col.Item1, _new_col.Item3);
+         foreach (var m in _new_col_map) {
+            rv.setValue(m.Item1, m.Item3);
+         }
         return rv;
      }
   }
@@ -1,52 +1,44 @@
 using System;

-namespace BCG
-{
-   [DataStreamUserRespresentation ("count")]
-	public class CountStream : ViewStream
-	{
+namespace bts.BlueOrb {
+   using BCG;
+   [DataStreamUserRespresentation("oldCount")]
+   public class CountStream : ViewStream {
      private DataPacket myLastFiredDataPacket;
-      private IBlueTableSchema mySchema = new BlueTableSchema ("count", 
-         new ColumnInfo ("id", 0, typeof(int)),
-         new ColumnInfo ("count", 1, typeof(int)));
+      private IBlueTableSchema mySchema = new BlueTableSchema("count",
+         new ColumnInfo("id", 0, typeof(int)),
+         new ColumnInfo("count", 1, typeof(int)));
      private int myId = 0;
      private ViewStream myVS;

-      public CountStream (ViewStream vs)
-      {
+      public CountStream(ViewStream vs) {
         myVS = vs;
      }

-      public CountStream (string tableName)
-         : this (new TableStream (tableName))
-      {}
-
-      protected override void myOnFirstSubscriber () {
+      protected override void myOnFirstSubscriber() {
         myVS.onChange += new ChangeDelegate(myHandleChanges);
      }
-      protected override void myOnLastSubscriber () {
+      protected override void myOnLastSubscriber() {
         myVS.onChange -= new ChangeDelegate(myHandleChanges);
      }


-      private void myHandleChanges(object newValue)
-      {
-         myFireEvent (
+      private void myHandleChanges(object newValue) {
+         myFireEvent(
            myLastFiredDataPacket =
               myLastFiredDataPacket == null ?
-                  new DataPacket (myGetRows (newValue, ++myId), myGetRows (newValue, myId), 
-                  new BlueTable (mySchema))
+                  new DataPacket(myGetRows(newValue, ++myId), myGetRows(newValue, myId),
+                  new BlueTable(mySchema))
                  :
-                  new DataPacket (myGetRows (newValue, ++myId), myGetRows (newValue, myId), 
+                  new DataPacket(myGetRows(newValue, ++myId), myGetRows(newValue, myId),
                  myLastFiredDataPacket.newRows)
            );
      }

-      private IBlueRowCollection myGetRows (object dp, int id)
-      {
-         BlueTable retVal = new BlueTable (mySchema);
+      private IBlueRowCollection myGetRows(object dp, int id) {
+         BlueTable retVal = new BlueTable(mySchema);
         retVal.addRow
-            (new BlueRow (mySchema, id, (dp as DataPacket).newRows.Count));
+            (new BlueRow(mySchema, id, (dp as DataPacket).newRows.Count));
         return retVal;
      }

@@ -1,93 +1,106 @@
+using bts;
+
 using Bts.DataStream;
+using Bts.DataStream.Primitives.Filter;

 using mbts.config;

 using System;
 using System.Text.RegularExpressions;

-namespace BCG.StreamWorld.Addition
-{
-   [DataStreamUserRespresentation (false)]
-   public class FilterStream : ViewStream
-   {
+namespace BCG.StreamWorld.Addition {
+   [DataStreamUserRespresentation(false)]
+   public class FilterStream : ViewStream {
      private ViewStream myBaseStream;
      private BlueTable myBaseTable, myStateTable;
      private IStreamFilter myFilter;

      public FilterStream(ViewStream vs)
-         : this(vs, "1=1")
-      { }
+         : this(vs, "1=1") { }

      public FilterStream(ViewStream vs, string filterExp)
-         : this(vs, new BooleanExpressionFilter(filterExp))
-      { }
+         : this(vs, new BooleanExpressionFilter(filterExp)) { }

-      public FilterStream(ViewStream vs, IStreamFilter filter)
-      {
+      public FilterStream(ViewStream vs, IStreamFilter filter) {
         myBaseStream = vs;
         myFilter = filter;
+         vs.ErrorChanged += OnError;
         if (filter is IDynamicStreamFilter)
            (filter as IDynamicStreamFilter).onFilterChange += new FilterChangeDelegate(myHandleFilterChange);
      }


-      protected override void myOnFirstSubscriber()
-      {
+      protected override void myOnFirstSubscriber() {
         myBaseStream.onChange += new ChangeDelegate(myHandleChanges);
      }

-      protected override void myOnLastSubscriber()
-      {
+      protected override void myOnLastSubscriber() {
         myBaseStream.onChange -= new ChangeDelegate(myHandleChanges);
         myBaseTable.clear();
         myStateTable.clear();
      }

-      private void myHandleChanges(object newValue)
-      {
-         DataPacket dp = newValue as DataPacket;
-         if (myStateTable == null)
-         {
-            bts.Log.assert(myBaseTable == null);
-            myStateTable = new BlueTable(dp.schema);
-            myBaseTable = new BlueTable(dp.schema);
+      bool filterRow(IBlueRow r) {
+         try {
+            return myFilter.filter(r);
+         } catch (Exception ex) {
+            Log.Gen.error($"FilterStream delegate threw exception: {ex}");
+            OnError(new StreamFilterException(StreamId, StreamName, null, ex, r));
         }
-         BlueTable dels = new BlueTable(dp.schema),
-                     adds = new BlueTable(dp.schema);
-         foreach (IBlueRow r in dp.deletedRows)
-         {
-            myBaseTable.deleteRow(r);
-            if (myStateTable.containsID((int)r["id"]))
-            {
-               dels.addRow(r);
-               myStateTable.deleteRow(r);
-            }
-         }
-         foreach (IBlueRow r in dp.addedRows)
-         {
-            myBaseTable.addRow(r);
-            if (myFilter.filter(r))
-            {
-               adds.addRow(r);
-               myStateTable.addRow(r);
-            }
-         }
-         if ((dels.Count > 0 || adds.Count > 0) || (myLastValue == null))
-            myFireEvent(new DataPacket(myStateTable, adds, dels));
+         return false;
      }

-      public IStreamFilter filter
-      {
-         set
-         {
+      private void myHandleChanges(object newValue) {
+         try {
+            DataPacket dp = newValue as DataPacket;
+            if (myStateTable == null) {
+               bts.Log.assert(myBaseTable == null);
+               myStateTable = new BlueTable(dp.schema);
+               myBaseTable = new BlueTable(dp.schema);
+            }
+            BlueTable dels = new BlueTable(dp.schema),
+                        adds = new BlueTable(dp.schema);
+            foreach (IBlueRow r in dp.deletedRows) {
+               myBaseTable.deleteRow(r);
+               if (myStateTable.containsID((int)r["id"])) {
+                  dels.addRow(r);
+                  myStateTable.deleteRow(r);
+               }
+            }
+            foreach (IBlueRow r in dp.addedRows) {
+               myBaseTable.addRow(r);
+               if (filterRow(r)) {
+                  adds.addRow(r);
+                  myStateTable.addRow(r);
+               }
+            }
+            if ((dels.Count > 0 || adds.Count > 0) || (myLastValue == null))
+               myFireEvent(new DataPacket(myStateTable, adds, dels));
+         } catch (Exception ex) {
+            OnError(ex);
+         }
+      }
+
+      public IStreamFilter filter {
+         set {
            myFilter = value;
-            if (myBaseTable != null)
-            {
+            if (myBaseTable != null) {
               IBlueRowCollection oldState = new BlueTable(myStateTable);
               myStateTable.clear();
-               foreach (IBlueRow r in myBaseTable)
-                  if (myFilter.filter(r))
-                     myStateTable.addRow(r);
+               // If the filter throws an exception, we can rethrow it as a StreamFilterException
+               // and include the 'currentRow' (for which the filter failed) to provide context.
+               IBlueRow? currentRow = null;
+               foreach (IBlueRow r in myBaseTable) {
+                  try {
+                     currentRow = r;
+                     if (filterRow(r)) {
+                        myStateTable.addRow(r);
+                     }
+                  } catch (Exception ex) {
+                     Log.Gen.error($"FilterStream delegate threw exception: {ex}");
+                     OnError(new StreamFilterException(StreamId, StreamName, null, ex, currentRow));
+                  }
+               }
               IBlueRowCollection dels, adds;
               BlueDataUtility.computeDifferences(myStateTable, oldState, out dels, out adds);
               myFireEvent(new DataPacket(myStateTable, adds, dels));
@@ -222,32 +235,36 @@ namespace BCG
         DataPacket retVal;
         DataPacket arrivedPacket = newValue as DataPacket;
         myLastReceivedRows = arrivedPacket.newRows;
-         if (myLastFiredRows != null)
-         {
-            retVal = new DataPacket(myLastFiredRows, new BlueTable(myLastFiredRows.schema),
-               new BlueTable(myLastFiredRows.schema));
-            foreach (IBlueRow r in arrivedPacket.deletedRows)
-               if (myLastFiredRows.containsID((int)r["id"]))
-               {
-                  myLastFiredRows.deleteRow(r);
-                  (retVal.deletedRows as BlueTable).addRow(r);
-               }
-            foreach (IBlueRow r in arrivedPacket.addedRows)
-               if (myFilter.filter(r))
-               {
-                  myLastFiredRows.addRow(r);
-                  (retVal.addedRows as BlueTable).addRow(r);
-               }
+         try {
+            if (myLastFiredRows != null)
+            {
+               retVal = new DataPacket(myLastFiredRows, new BlueTable(myLastFiredRows.schema),
+                  new BlueTable(myLastFiredRows.schema));
+               foreach (IBlueRow r in arrivedPacket.deletedRows)
+                  if (myLastFiredRows.containsID((int)r["id"]))
+                  {
+                     myLastFiredRows.deleteRow(r);
+                     (retVal.deletedRows as BlueTable).addRow(r);
+                  }
+               foreach (IBlueRow r in arrivedPacket.addedRows)
+                  if (filterRow(r))
+                  {
+                     myLastFiredRows.addRow(r);
+                     (retVal.addedRows as BlueTable).addRow(r);
+                  }
+            }
+            else
+            {
+               myLastFiredRows = new BlueTable(arrivedPacket.schema);
+               retVal = new DataPacket(myLastFiredRows, myLastFiredRows, new BlueTable(myLastFiredRows.schema));
+               foreach (IBlueRow r in arrivedPacket.newRows)
+                  if (filterRow(r))
+                     myLastFiredRows.addRow(r);
+            }
+            myFireEvent(retVal);
+         } catch (Exception ex) {
+            OnError(ex);
         }
-         else
-         {
-            myLastFiredRows = new BlueTable(arrivedPacket.schema);
-            retVal = new DataPacket(myLastFiredRows, myLastFiredRows, new BlueTable(myLastFiredRows.schema));
-            foreach (IBlueRow r in arrivedPacket.newRows)
-               if (myFilter.filter(r))
-                  myLastFiredRows.addRow(r);
-         }
-         myFireEvent(retVal);
      }

      public IStreamFilter filter
@@ -265,16 +282,20 @@ namespace BCG
               {
                   if (myLastReceivedRows != null)
                   {
+                     try {
                       BlueTable nRows = new BlueTable(myLastReceivedRows.schema);
                       foreach (IBlueRow r in myLastReceivedRows)
-                           if (myFilter.filter(r))
+                           if (filterRow(r))
                               nRows.addRow(r);
                       IBlueRowCollection dRows = new BlueTable(nRows.schema),
                          aRows = new BlueTable(nRows.schema);                      
                       BlueDataUtility.computeDifferences(nRows, myLastFiredRows, out dRows, out aRows);
                       myLastFiredRows = nRows;
                       myFireEvent(new DataPacket(nRows, aRows, dRows));
-                   }
+                     } catch (Exception ex) {
+                        OnError(ex);
+                     }
+                  }
               }
            }
         }
@@ -298,5 +319,15 @@ namespace BCG
      {
         filter = myFilter;
      }
+
+      bool filterRow(IBlueRow r) {
+         try {
+            return myFilter.filter(r);
+         } catch (Exception ex) {
+            Log.Gen.error($"FilterStream delegate threw exception: {ex}");
+            OnError(new StreamFilterException(StreamId, StreamName, null, ex, r));
+         }
+         return false;
+      }
   }
 }
@@ -0,0 +1,19 @@
+#nullable enable
+namespace Bts.DataStream.Primitives.Filter;
+
+using BCG;
+
+using System;
+
+public class StreamFilterException : Exception {
+   public StreamFilterException(Guid streamId, string streamName, string? message, Exception? innerException, IBlueRow? badRow = null)
+      : base(message, innerException) {
+      StreamId = streamId;
+      StreamName = streamName;
+      BadRow = badRow;
+   }
+
+   public Guid StreamId { get; }
+   public string StreamName { get; }
+   public IBlueRow? BadRow { get; }
+}
@@ -52,14 +52,14 @@ namespace BCG {
      }

      public TimeBasedFilter(ViewStreamDatabase vsd, string rowTimeColumnName, TimeSpan rowTimeToLive)
-      : this(vsd, rowTimeColumnName, rowTimeToLive, new TimeSpan(0, 1, 0) /* 1 minute */) {
+      : this(vsd, rowTimeColumnName, rowTimeToLive, rowTimeToLive) {
      }

-      public TimeBasedFilter(ViewStreamDatabase vsd, string rowTimeColumnName, TimeSpan rowTimeToLive, TimeSpan filterFrequency) {
+      public TimeBasedFilter(ViewStreamDatabase vsd, string rowTimeColumnName, TimeSpan rowTimeToLive, TimeSpan filter_period) {
         myVsd = vsd;
         _time_col = rowTimeColumnName;
         _ttl = rowTimeToLive;
-         myFilterFrequency = filterFrequency;
+         _filter_period = filter_period;
         myNextFilter = DateTime.MinValue;

         // add worker
@@ -71,11 +71,10 @@ namespace BCG {

      #region IStreamFilter
      public bool filter(IBlueRow row) {
-         DateTime now = DateTime.Now;
-
-         DateTime row_time = row.get_datetime(_time_col, DateTime.Now);
-         if (now > row_time) {
-            TimeSpan span = now - row_time;
+         DateTime now_utc = DateTime.UtcNow;
+         DateTime row_time_utc = row.get_datetime(_time_col, DateTime.Now).ToUniversalTime();
+         if (now_utc > row_time_utc) {
+            TimeSpan span = now_utc - row_time_utc;
            if (span >= _ttl) {
               return (false);
            }
@@ -90,9 +89,9 @@ namespace BCG {

         if (now > myNextFilter) {
            // fire event
-            onFilterChange();
+            onFilterChange?.Invoke();

-            myNextFilter = now.Add(myFilterFrequency);
+            myNextFilter = now.Add(_filter_period);
         }
      }
      #endregion
@@ -108,7 +107,7 @@ namespace BCG {
      private ViewStreamDatabase myVsd;
      private string _time_col;
      private TimeSpan _ttl;
-      private TimeSpan myFilterFrequency;
+      private TimeSpan _filter_period;
      private DateTime myNextFilter;
      #endregion
   }
@@ -5,7 +5,7 @@ using System.Collections.Generic;
 using System.Linq;

 namespace BCG {
-   public class GroupByStream : MethodDrivenStream {
+   internal class GroupByStream : MethodDrivenStream {
      private class MyFuncGroupByEvaluator : IGroupByEvaluator {
         private string[] _groupby_cols;
         private Func<DataPacket, IBlueRow> _groupby_func;
@@ -8,7 +8,7 @@ using bts;
 using bts.SilverPine;

 namespace BCG {
-   [DataStreamUserRespresentation("AggregateStream")]
+   //[DataStreamUserRespresentation("AggregateStream")]
   public class NonIncGroupByStream : ViewStream {
      private class DelNonIncGroupByEvaluator : INonIncGroupByEvaluator {
         Func<string[]> _groupby_cols_func;
@@ -96,6 +96,10 @@ namespace BCG {
         _timer.Restart();
         IBlueRowCollection total_state = _groupby_func.evaluate(grouped_rows);
         _timer.Stop();
+         if (total_state is null) {
+            Log.Gen.warn("NonIncGroupByStream _groupby_func.evaluate returned null (ignoring last update).");
+            return;
+         }
         var applyElapsedMs = _timer.ElapsedMilliseconds;
         _n_total_fires++;
         if (applyElapsedMs >= 50) {
@@ -1,31 +1,31 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
+//using System;
+//using System.Collections.Generic;
+//using System.Linq;
+//using System.Text;

-namespace BCG
-{
-   public class FullJoinStream : ViewStream
-   {
-      private ViewStream myMainStream;
-      public FullJoinStream(ViewStream v1, string joinCol1, string cmExp1,
-         ViewStream v2, string joinCol2, string cmExp2, string empty_col)
-      {
-         myMainStream = new LeftJoinStream(v1, joinCol1, cmExp1, v2, joinCol2, cmExp2);
-         ViewStream filtered = new LeftJoinStream(v2, joinCol2, cmExp2, v1, joinCol1, cmExp1);
-         filtered = new FilterStream(filtered, String.Format("{0}=null", empty_col));
-         myMainStream = new AppendStream(myMainStream, filtered);
-      }
+//namespace BCG
+//{
+//   public class FullJoinStream : ViewStream
+//   {
+//      private ViewStream myMainStream;
+//      public FullJoinStream(ViewStream v1, string joinCol1, string cmExp1,
+//         ViewStream v2, string joinCol2, string cmExp2, string empty_col)
+//      {
+//         myMainStream = new LeftJoinStream(v1, joinCol1, cmExp1, v2, joinCol2, cmExp2);
+//         ViewStream filtered = new LeftJoinStream(v2, joinCol2, cmExp2, v1, joinCol1, cmExp1);
+//         filtered = new FilterStream(filtered, String.Format("{0}=null", empty_col));
+//         myMainStream = new AppendStream(myMainStream, filtered);
+//      }

-      protected override void myOnFirstSubscriber()
-      {
-         myMainStream.onChange += myHandleMainStreamChange;
-      }
+//      protected override void myOnFirstSubscriber()
+//      {
+//         myMainStream.onChange += myHandleMainStreamChange;
+//      }

-      private void myHandleMainStreamChange(object newData)
-      {
-         IBlueRowCollection result = (newData as DataPacket).newRows;
-         myFireEvent(new DataPacket(result, result, myLastValue == null ? new BlueTable(result.schema) : (myLastValue as DataPacket).newRows));
-      }
-   }
-}
+//      private void myHandleMainStreamChange(object newData)
+//      {
+//         IBlueRowCollection result = (newData as DataPacket).newRows;
+//         myFireEvent(new DataPacket(result, result, myLastValue == null ? new BlueTable(result.schema) : (myLastValue as DataPacket).newRows));
+//      }
+//   }
+//}
@@ -1,9 +1,7 @@
-using System;
+#nullable disable
+using System;
 using System.Collections;
 using System.Collections.Generic;
-using System.Text;
-using BCG.Utilities.General;
-using BCG.Utilities;

 namespace BCG
 {
@@ -10,6 +10,8 @@ using BCG.Utilities;
 using bts;

 namespace BCG {
+   // Prefixing with "old" to avoid name conflict with the BlueOrb LiteralStream
+   [DataStreamUserRespresentation("oldLiteral")]
   public class LiteralStream : ViewStream {

      public static List<Tuple<ColumnInfo, object>> parse_columns(string key_value_pairs) {
@@ -1,6 +1,10 @@
+using bts;
+
 using Bts.DataStream;
+using Bts.DataStreamCore;

 using mbts.config;
+using mbts.utils;

 using System;

@@ -15,8 +19,8 @@ namespace BCG {
   /// </summary>
   [DataStreamUserRespresentation(false)]
   public class MapStream : MethodDrivenStream {
-      protected IStreamMapper myMapper;
-      protected IChangeableStreamMapper myChangeableMapper = null;
+      protected IStreamMapper? myMapper;
+      protected IChangeableStreamMapper? myChangeableMapper;
      private bool myUseNewMap = Configuration.get<DataStreamConfig>().UseNewMap;

      public class FuncWrapper : IStreamMapper {
@@ -71,7 +75,7 @@ namespace BCG {


      protected override void myHandleFirstCall() {
-
+         ArgumentNullException.ThrowIfNull(myMapper);
         IBlueTableSchema outputSchema = myMapper.getOutputSchema(myLastArrivedPacket.newRows.schema);
         myLastFiredPacket = new DataPacket();
         myLastFiredPacket.newRows = new BlueTable(outputSchema);
@@ -82,28 +86,34 @@ namespace BCG {
      }

      protected override void myHandleIncrementalAdd() {
-         //t.start ();
-         myLastFiredPacket.addedRows = new BlueTable(myLastFiredPacket.newRows.schema);
-         foreach (IBlueRow row in myLastArrivedPacket.addedRows) {
-            IBlueRow newRow = myMapper.map(row);
-            (myLastFiredPacket.newRows as BlueTable).addRow(newRow);
-            (myLastFiredPacket.addedRows as BlueTable).addRow(newRow);
+         if (myLastArrivedPacket.addedRows.Count == 0) {
+            Log.Gen.warn("MapStream.myHandleIncrementalAdd called with 0 addedRows");
+            return;
         }
-         //t.stop ();
-         //System.Diagnostics.Trace.WriteLine ("adding " + myLastFiredPacket.addedRows.Count.ToString () + " : " + t.lastIntervalTime);
-         //System.Diagnostics.Trace.WriteLine (" ");
+         ArgumentNullException.ThrowIfNull(myMapper);
+         var addedRows = new BlueTable(myLastFiredPacket.newRows.schema);
+         var newRows = ExceptionAssert.Cast(myLastFiredPacket.newRows).To<BlueTable>();
+         foreach (IBlueRow row in myLastArrivedPacket.addedRows) {
+            var newRow = myMapper.map(row);
+            newRows.addRow(newRow);
+            addedRows.addRow(newRow);
+         }
+         myLastFiredPacket.addedRows = addedRows;
      }

      protected override void myHandleIncrementalDelete() {
-         //t.start ();
-         myLastFiredPacket.deletedRows = new BlueTable(myLastFiredPacket.newRows.schema);
-         foreach (IBlueRow row in myLastArrivedPacket.deletedRows) {
-            IBlueRow delRow = (myLastFiredPacket.newRows as BlueTable)[(int)row["id"]];
-            (myLastFiredPacket.deletedRows as BlueTable).addRow(delRow);
-            (myLastFiredPacket.newRows as BlueTable).deleteRow(row);
+         if (myLastArrivedPacket.deletedRows.Count == 0) {
+            Log.Gen.warn("MapStream.myHandleIncrementalDelete called with 0 deletedRows");
+            return;
         }
-         //t.stop ();
-         //System.Diagnostics.Trace.WriteLine ("deleting " + myLastFiredPacket.deletedRows.Count.ToString () + " : " + t.lastIntervalTime);
+         var deletedRows = new BlueTable(myLastFiredPacket.newRows.schema);
+         var newRows = ExceptionAssert.Cast(myLastFiredPacket.newRows).To<BlueTable>();
+         foreach (IBlueRow row in myLastArrivedPacket.deletedRows) {
+            var delRow = newRows[row.Id()];
+            deletedRows.addRow(delRow);
+            newRows.deleteRow(row);
+         }
+         myLastFiredPacket.deletedRows = deletedRows;
      }


@@ -1,11 +1,9 @@
+using Bts.DataStreamCore;
+
+using mbts.utils;
+
 using System;
 using System.Collections.Generic;
-using System.Text;
-
-using BCG.Utilities;
-using BCG.Utilities.General;
-
-using mbts;

 namespace BCG {
   /// <summary>
@@ -56,15 +54,15 @@ namespace BCG {
            return rows == null ? new IBlueRow[] { } : new List<IBlueRow>(rows).ToArray();
         }

-         public event MapperChangeDelegate onMapperChange;
-         private void _fake() { onMapperChange(); }
+         public event MapperChangeDelegate? onMapperChange;
      }

      //maps the id of the underlying stream to the
      //rows of the resulting stream
      private Dictionary<int, List<IBlueRow>> myMap = new Dictionary<int, List<IBlueRow>>();
      private int myID = 0;
-      private BlueTable myRows, myBaseRows;
+      private BlueTable? myRows;
+      private BlueTable? myBaseRows;
      private ViewStream myStream;
      private ISuperStreamMapper myMapper;
      public bool generate_ids = true;
@@ -92,49 +90,40 @@ namespace BCG {
         myRows = null;
         myBaseRows = null;
         myMap.Clear();
-         //myMapper.onMapperChange -= new MapperChangeDelegate(myHandleMapChange);
      }

      private void myHandleData(object newValue) {
-         DataPacket idp = newValue as DataPacket;
-         //HighPerformanceTimer timer = new HighPerformanceTimer();
-         //timer.start();
-         DataPacket dp = newValue as DataPacket;
-         myRows = myRows ?? new BlueTable(myMapper.getOutputSchema(dp.schema));
-         myBaseRows = myBaseRows ?? new BlueTable(dp.schema);
+         var dp = ExceptionAssert.Cast(newValue).To<DataPacket>();
+         myRows ??= new BlueTable(myMapper.getOutputSchema(dp.schema));
+         myBaseRows ??= new BlueTable(dp.schema);
         BlueDataUtility.absorbChanges(myBaseRows, dp.deletedRows, dp.addedRows);
-         BlueTable dels = new BlueTable(myRows.schema),
-                     adds = new BlueTable(myRows.schema);
+         var dels = new BlueTable(myRows.schema);
+         var adds = new BlueTable(myRows.schema);

         foreach (IBlueRow r in dp.deletedRows) {
-            List<IBlueRow> mappedRows = myMap[(int)r["id"]];
+            var mappedRows = myMap[r.Id()];
            foreach (IBlueRow mr in mappedRows) {
               dels.addRow(mr);
               myRows.deleteRow(mr);
            }
-            myMap.Remove((int)r["id"]);
+            myMap.Remove(r.Id());
         }
         foreach (IBlueRow r in dp.addedRows) {
            IBlueRow[] mappedRows = myMapper.map(r);
            foreach (IBlueRow mr in mappedRows) {
               IBlueRow idChangedMapRow = generate_ids ? BlueDataUtility.getNewReplacedRow(mr, myID++, "id") : mr;
-               if (!myMap.ContainsKey((int)r["id"])) {
-                  myMap.Add((int)r["id"], new List<IBlueRow>());
-               }
-               myMap[(int)r["id"]].Add(idChangedMapRow);
+               myMap.GetOrAdd(r.Id(), _ => new()).Add(idChangedMapRow);
               myRows.addRow(idChangedMapRow);
               adds.addRow(idChangedMapRow);
            }
         }
-         //timer.stop();
-         // if (timer.lastIntervalTime > 20)
-         //    {}//mbts.Logger.log(bts.log.Level.Info, bts.log.Subsystem.gen, String.Format("SuperMapper:myHandlerData for mapper {0} took {1} msecs", myMapper.GetType().ToString(), timer.lastIntervalTime));
         myFireEvent(new DataPacket(myRows, adds, dels));
      }

      private void myHandleMapChange() {
-         if (myBaseRows != null)
+         if (myBaseRows is not null) {
            myHandleData(new DataPacket(myBaseRows, new BlueTable(myBaseRows), new BlueTable(myBaseRows)));
+         }
      }
   }
 }
@@ -70,7 +70,8 @@ namespace bts
        private readonly int _msg_size;
        private readonly TimeSpan _publish_period;
        private DateTime _last_publish_time = DateTime.MinValue;
-        private PublisherCore _pub_core = new PublisherCore();
+        private IPublisherCore _pub_core;
+        readonly ISubscriberCore subscriberCore;
        private BlueTable _table;
        private int _n_pubs = 0;
        private readonly int _max_pubs;
@@ -82,8 +83,10 @@ namespace bts
        private readonly int _payload_sz;
        private const byte _payload_byte = (byte)'A';
        private readonly string _tag_name;
-        public PubSubTestingStream(int publish_period_msecs, int max_pubs, int payload_size, string tag_name, ViewStreamDatabase vsd)
+        public PubSubTestingStream(int publish_period_msecs, int max_pubs, int payload_size, string tag_name, IPublisherCore publisherCore, ISubscriberCore subscriberCore, ViewStreamDatabase vsd)
        {
+            _pub_core = publisherCore;
+            this.subscriberCore = subscriberCore;
            _vsd = vsd;
            _payload_sz = payload_size;
            var schema = BlueDataUtility.form_schema("PubSubTest",
@@ -103,9 +106,6 @@ namespace bts
            _tag_name = tag_name;
        }

-        public PubSubTestingStream(int publish_period_seconds, int max_pubs, int msg_size, string tag_name)
-        : this(publish_period_seconds, max_pubs, msg_size, tag_name, ViewStreamDatabase.instance) { }
-
        protected override void myOnFirstSubscriber()
        {
            _vsd.addWorker(this);
@@ -132,33 +132,31 @@ namespace bts

        private void _subscribe_thread_func()
        {
+           var sub = subscriberCore.Updates().Subscribe(onUpdate);
            // subscription is done in another thread
-            SubscriberCore sub_core = new SubscriberCore();
-            sub_core.subscribe(_tag_name);
+            subscriberCore.subscribe(_tag_name);
            while (_continue_sub_thread)
            {
                // TODO recv_id
-                var updates = sub_core.get_updates(TimeSpan.FromMilliseconds(250));
-                if (updates == null || updates.Count() == 0)
-                    continue;
-                _log_updates(updates);
-                _n_updates += updates.Count();
-                if (updates.Count() > 0)
-                {
-                    var server_msg = updates.Last();
-                    if (server_msg.data != null && server_msg.data.Length > 0)
-                    {
-                        _last_recvd_msg = PayloadMessage.deserialize(server_msg.data);
-                        _last_recvd_msg.travel_epoch_ms = epoch_now();
-                    }
-                    else
-                    {
-                        // why are we getting empty or null data ? (server is sending data regardless?)
-                    }
-                    _fire_dirty = true;
-                }
+                subscriberCore.get_updates(TimeSpan.FromMilliseconds(250));
            }
-        }
+            sub.Dispose();
+
+         void onUpdate(IEnumerable<PubSubServerMessage> updates) {
+            _log_updates(updates);
+            _n_updates += updates.Count();
+            if (updates.Count() > 0) {
+               var server_msg = updates.Last();
+               if (server_msg.data != null && server_msg.data.Length > 0) {
+                  _last_recvd_msg = PayloadMessage.deserialize(server_msg.data);
+                  _last_recvd_msg.travel_epoch_ms = epoch_now();
+               } else {
+                  // why are we getting empty or null data ? (server is sending data regardless?)
+               }
+               _fire_dirty = true;
+            }
+         }
+      }

        private void _publish_next_packet()
        {
@@ -224,4 +222,4 @@ namespace bts
        }

    }
-}
+}
@@ -8,10 +8,11 @@ using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using bts.api;
+using Bts.PubSub.Routing;

 namespace bts
 {
-   [DataStreamUserRespresentation("pss_echo")]
+   [DataStreamUserRespresentation(false)]
   public class PubsubEchoTestStream : ViewStream, IWorker
   {
      public class PayloadMessage
@@ -76,7 +77,7 @@ namespace bts
      private readonly int _msg_size;
      private readonly TimeSpan _publish_period;
      private DateTime _last_publish_time = DateTime.MinValue;
-      private PublisherCore _pub_core;
+      private IPublisherCore _pub_core;
      private ISubscriberCore _sub_core;
      private BlueTable _table;
      private int _n_pubs = 0;
@@ -95,10 +96,21 @@ namespace bts
      };
      IOState _state = IOState.SEND;

-      public PubsubEchoTestStream(string server_url, TimeSpan publish_period, int payload_size, string tag_name, ViewStreamDatabase vsd)
-      {
-         var route = new PubSubRoute(server_url, ".*");
-         _router = new PubSubRouter(route);
+      public PubsubEchoTestStream(
+         string server_url,
+         TimeSpan publish_period,
+         int payload_size,
+         string tag_name,
+         IPublisherCore publisherCore,
+         ISubscriberCore subscriberCore,
+         ViewStreamDatabase vsd
+      ) {
+         _router = new PubSubRouter(new PubSubRouterConfig() {
+            PublisherRoutes = new() { new(server_url, ".*") },
+            SubscriberRoutes = new() { new(server_url, ".*") },
+         });
+         _pub_core = publisherCore;
+         _sub_core = subscriberCore;
         _vsd = vsd;
         _payload_sz = payload_size;
         var schema = BlueDataUtility.form_schema("PubSubTest",
@@ -114,13 +126,8 @@ namespace bts
         _tag_name = tag_name;
      }

-      public PubsubEchoTestStream(string server_url, int publish_period_msecs, int payload_size, string tag_name)
-      : this(server_url, TimeSpan.FromMilliseconds(publish_period_msecs), payload_size, tag_name, ViewStreamDatabase.instance) { }
-
      protected override void myOnFirstSubscriber()
      {
-         _pub_core = new PublisherCore(_router);
-         _sub_core = new SubscriberCore(_router);
         _sub_core.subscribe(_tag_name);
         _vsd.addWorker(this);

@@ -220,4 +227,4 @@ namespace bts
      }

   }
-}
+}
@@ -66,7 +66,7 @@ namespace bts {
         if (_in_rows.Count > 0) {
            // fire row
            IBlueRow curr_row = _in_rows.ElementAt(_in_row_ptr++);
-            _out_table.add_row(curr_row);
+            _out_table = _out_table.Add(curr_row);
            DataPacket dp = BlueDataUtility.build_dp_inc(_out_table,
               myLastValue == null ? null : myLastValue as DataPacket, false);
            myFireEvent(dp);
@@ -74,4 +74,4 @@ namespace bts {
      }
   }

-}
+}
@@ -95,7 +95,7 @@ namespace BCG {
            sub_msg.serialize_into_str(str);
            str.Position = 0;
            bts.SubscribeMsg sub_msg_ = new bts.SubscribeMsg();
-            sub_msg_.consruct_deserialize(str);
+            sub_msg_.construct_deserialize(str);
            bool res = sub_msg.Equals(sub_msg_);
            return new TestResult {
                test_name = "SubscribeMsg",
@@ -117,7 +117,7 @@ namespace BCG {
            pub_msg.serialize_into_str(str);
            str.Position = 0;
            var pub_msg_ = new bts.PublishMsg();
-            pub_msg_.consruct_deserialize(str);
+            pub_msg_.construct_deserialize(str);
            bool res = pub_msg.Equals(pub_msg_);
            return new TestResult {
                test_name = "PublishMsg",
@@ -135,7 +135,7 @@ namespace BCG {
            msg.serialize_into_str(str);
            str.Position = 0;
            var msg_ = new bts.PubSubServerMessage();
-            msg_.consruct_deserialize(str);
+            msg_.construct_deserialize(str);
            bool res = msg.Equals(msg_);
            return new TestResult {
                test_name = "PubSubServerMessage",
@@ -156,7 +156,7 @@ namespace BCG {
            msg.serialize_into_str(str);
            str.Position = 0;
            var msg_ = new PubSubClientMessage();
-            msg_.consruct_deserialize(str);
+            msg_.construct_deserialize(str);
            var res = msg.Equals(msg_);
            return new TestResult {
                test_name = "PubSubClientMessage",
@@ -617,14 +617,15 @@ namespace BCG {


        private static TestResult _run_single_tag_data_test_clean() {
+            // var tagHandlerFactory
            // create message
-            var test_name = MethodBase.GetCurrentMethod().Name;
+            var test_name = MethodBase.GetCurrentMethod()?.Name;
            var schema = create_schema_with_all_types();
            var tag = "DS_" + schema.tableName;
            BlueTable table = new BlueTable(schema);
            IStreamIOMsgSerializer serializer = new StreamIOSerializationController();
            IStreamMsgDeserilizer deser = new StreamIODeserializationController();
-            bts.SingleTagData st_data = new bts.SingleTagData(tag, DSTagManager.DataStreamTagType);
+            bts.SingleTagData st_data = new bts.SingleTagData(tag, DSTagManager.DataStreamTagType, new PubsubServerStreamTagHandler());
            // create with 100 rows
            int n_rows = 100;
            bool is_succ = true;
@@ -1,51 +0,0 @@
-using System;
-
-using BCG;
-
-namespace bts.SilverPine {
-   // Keeps adding changing rows to the stream, hence preserving the history
-   // and creating a time series, for example this can be used to make bbo updates
-   // into a time series of prices/qty 
-   public class TimeSeriesStream : ViewStream {
-      private BlueTable _table;
-      private ViewStream _stream;
-      private int _id = 0;
-
-      public TimeSeriesStream(ViewStream stream) {
-         _stream = stream;
-      }
-
-      protected override void myOnFirstSubscriber() {
-         _stream.onChange += new ChangeDelegate(_onstream_change);
-      }
-      protected override void myOnLastSubscriber() {
-         _stream.onChange -= new ChangeDelegate(_onstream_change);
-      }
-
-
-      private void _onstream_change(object o) {
-         DataPacket dp = o as DataPacket;
-         DateTime now = DateTime.Now;
-         if (_table == null) {
-            IBlueTableSchema schema = new BlueTableSchema(dp.newRows.schema.columnInfo, dp.newRows.schema.tableName);
-            schema = schema.add_columns(Tuple.Create(typeof(DateTime), "timestamp"));
-            _table = new BlueTable(schema);
-         }
-         BlueTable added_rows = new BlueTable(_table.schema);
-         foreach (IBlueRow r in dp.addedRows) {
-            MutableBlueRow ar = new MutableBlueRow(_table.schema, r);
-            ar.setValue("timestamp", now);
-            ar.setValue("id", _id++);
-            added_rows.addRow(ar);
-         }
-         _table.addRows(added_rows);
-         myFireEvent(new DataPacket(_table, added_rows, new BlueTable(_table.schema)));
-      }
-   }
-
-
-
-}
-
-
-
@@ -1,121 +1,121 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Security.Cryptography.X509Certificates;
+// using System;
+// using System.Collections.Generic;
+// using System.IO;
+// using System.Security.Cryptography.X509Certificates;

-using BCG;
-using BCG.Utilities.General;
+// using BCG;
+// using BCG.Utilities.General;

-using HtmlAgilityPack;
+// using HtmlAgilityPack;

-namespace BCG {
-    class Program {
-        static void Main() {
-            string url = "http://quotes.toscrape.com";
-            List<string> quotes = ScrapeQuotes(url);
+// namespace BCG {
+//     class Program {
+//       //   static void Main() {
+//       //       string url = "http://quotes.toscrape.com";
+//       //       List<string> quotes = ScrapeQuotes(url);

-            Console.WriteLine("Quotes from http://quotes.toscrape.com:");
-            foreach (var quote in quotes) {
-                Console.WriteLine(quote);
-            }
-        }
+//       //       Console.WriteLine("Quotes from http://quotes.toscrape.com:");
+//       //       foreach (var quote in quotes) {
+//       //           Console.WriteLine(quote);
+//       //       }
+//       //   }

-        static List<string> ScrapeQuotes(string url) {
-            List<string> quotes = new List<string>();
+//         static List<string> ScrapeQuotes(string url) {
+//             List<string> quotes = new List<string>();

-            // Create a new HtmlWeb instance
-            HtmlWeb web = new HtmlWeb();
+//             // Create a new HtmlWeb instance
+//             HtmlWeb web = new HtmlWeb();

-            try {
-                // Load the HTML document from the specified URL
-                HtmlDocument document = web.Load(url);
+//             try {
+//                 // Load the HTML document from the specified URL
+//                 HtmlDocument document = web.Load(url);

-                // Extract quotes from the HTML document
-                var quoteNodes = document.DocumentNode.SelectNodes("//span[@class='text']");
-                if (quoteNodes != null) {
-                    foreach (var quoteNode in quoteNodes) {
-                        string quote = quoteNode.InnerText.Trim();
-                        quotes.Add(quote);
-                    }
-                }
-            } catch (Exception ex) {
-                Console.WriteLine($"Error: {ex.Message}");
-            }
+//                 // Extract quotes from the HTML document
+//                 var quoteNodes = document.DocumentNode.SelectNodes("//span[@class='text']");
+//                 if (quoteNodes != null) {
+//                     foreach (var quoteNode in quoteNodes) {
+//                         string quote = quoteNode.InnerText.Trim();
+//                         quotes.Add(quote);
+//                     }
+//                 }
+//             } catch (Exception ex) {
+//                 Console.WriteLine($"Error: {ex.Message}");
+//             }

-            return quotes;
-        }
-    }
+//             return quotes;
+//         }
+//     }

-    public class WebScapperStream : ViewStream, IWorker {
-        private readonly string _url;
-        private readonly string _xpath;
-        private readonly ViewStreamDatabase _vsd;
-        private IDictionary<string, int> _line_id_map = new Dictionary<string, int>();
-        private readonly IBlueTableSchema _schema;
+//     public class WebScapperStream : ViewStream, IWorker {
+//         private readonly string _url;
+//         private readonly string _xpath;
+//         private readonly ViewStreamDatabase _vsd;
+//         private IDictionary<string, int> _line_id_map = new Dictionary<string, int>();
+//         private readonly IBlueTableSchema _schema;

-        public WebScapperStream()
-        :
-        this("http://quotes.toscrape.com", "//span[@class='text']", ViewStreamDatabase.instance) { }
-        public WebScapperStream(string url, string xpath)
-        : this(url, xpath, ViewStreamDatabase.instance) { }
-        public WebScapperStream(string url, string xpath, ViewStreamDatabase vsd) {
-            bts.Log.Gen.info($"WebScapperStream cons url: {url} xpath: {xpath}");
-            _schema = BlueDataUtility.form_schema($"{url}_{xpath}",
-                                                Tuple.Create("id", TypeCode.Int32),
-                                                Tuple.Create("url", TypeCode.UInt32),
-                                                Tuple.Create("line", TypeCode.String));
-            _url = url;
-            _xpath = xpath;
-            _vsd = vsd;
-        }
+//         public WebScapperStream()
+//         :
+//         this("http://quotes.toscrape.com", "//span[@class='text']", ViewStreamDatabase.instance) { }
+//         public WebScapperStream(string url, string xpath)
+//         : this(url, xpath, ViewStreamDatabase.instance) { }
+//         public WebScapperStream(string url, string xpath, ViewStreamDatabase vsd) {
+//             bts.Log.Gen.info($"WebScapperStream cons url: {url} xpath: {xpath}");
+//             _schema = BlueDataUtility.form_schema($"{url}_{xpath}",
+//                                                 Tuple.Create("id", TypeCode.Int32),
+//                                                 Tuple.Create("url", TypeCode.UInt32),
+//                                                 Tuple.Create("line", TypeCode.String));
+//             _url = url;
+//             _xpath = xpath;
+//             _vsd = vsd;
+//         }

-        protected override void myOnFirstSubscriber() {
-            MasterWorker.getInstance(false).addWorker(this, TimeSpan.FromSeconds(1));
-        }
+//         protected override void myOnFirstSubscriber() {
+//             MasterWorker.getInstance(false).addWorker(this, TimeSpan.FromSeconds(1));
+//         }

-        protected override void myOnLastSubscriber() {
-            MasterWorker.getInstance(false).removeWorker(this);
-        }
+//         protected override void myOnLastSubscriber() {
+//             MasterWorker.getInstance(false).removeWorker(this);
+//         }

-        public void doWork() {
-            var lines = scrape_lines(_url, _xpath);
-            Func<string, int> get_id = (line) => {
-                int rv = 0;
-                if (!_line_id_map.TryGetValue(line, out rv))
-                    _line_id_map.Add(line, _line_id_map.Count);
-                return rv;
-            };
-            BlueTable nrows = new BlueTable(_schema);
-            foreach (var l in lines) {
-                bts.Log.Gen.info($"line: {l}");
-                var id = get_id(l);
-                BlueRow nr = new BlueRow(_schema, get_id(l), _url, l);
-                nrows.addRow(nr);
-            }
-            var dp = BlueDataUtility.build_dp_inc(nrows, myLastValue as DataPacket, true);
-            myFireEvent(dp);
-        }
+//         public void doWork() {
+//             var lines = scrape_lines(_url, _xpath);
+//             Func<string, int> get_id = (line) => {
+//                 int rv = 0;
+//                 if (!_line_id_map.TryGetValue(line, out rv))
+//                     _line_id_map.Add(line, _line_id_map.Count);
+//                 return rv;
+//             };
+//             BlueTable nrows = new BlueTable(_schema);
+//             foreach (var l in lines) {
+//                 bts.Log.Gen.info($"line: {l}");
+//                 var id = get_id(l);
+//                 BlueRow nr = new BlueRow(_schema, get_id(l), _url, l);
+//                 nrows.addRow(nr);
+//             }
+//             var dp = BlueDataUtility.build_dp_inc(nrows, myLastValue as DataPacket, true);
+//             myFireEvent(dp);
+//         }

-        static List<string> scrape_lines(string url, string xpath) {
-            List<string> quotes = new List<string>();
-            // Create a new HtmlWeb instance
-            HtmlWeb web = new HtmlWeb();
-            try {
-                // Load the HTML document from the specified URL
-                HtmlDocument document = web.Load(url);
-                // Extract quotes from the HTML document
-                var quote_nodes = document.DocumentNode.SelectNodes(xpath);
-                if (quote_nodes != null) {
-                    foreach (var qn in quote_nodes) {
-                        string quote = qn.InnerText.Trim();
-                        quotes.Add(quote);
-                    }
-                }
-            } catch (Exception ex) {
-                Console.WriteLine($"Error: {ex.Message}");
-            }
+//         static List<string> scrape_lines(string url, string xpath) {
+//             List<string> quotes = new List<string>();
+//             // Create a new HtmlWeb instance
+//             HtmlWeb web = new HtmlWeb();
+//             try {
+//                 // Load the HTML document from the specified URL
+//                 HtmlDocument document = web.Load(url);
+//                 // Extract quotes from the HTML document
+//                 var quote_nodes = document.DocumentNode.SelectNodes(xpath);
+//                 if (quote_nodes != null) {
+//                     foreach (var qn in quote_nodes) {
+//                         string quote = qn.InnerText.Trim();
+//                         quotes.Add(quote);
+//                     }
+//                 }
+//             } catch (Exception ex) {
+//                 Console.WriteLine($"Error: {ex.Message}");
+//             }

-            return quotes;
-        }
-    }
-}
+//             return quotes;
+//         }
+//     }
+// }
@@ -2,14 +2,16 @@ namespace Bts.DataStream;

 using bts;

+using Bts.DataStreamCore;
+
 using MongoDB.Bson;

 using System;
 using System.Collections.Generic;

 public static class MongoSchemaAdaptor {
-   public static BlueTableSchemaAdaptor<BsonDocument> InferSchema(IEnumerable<BsonDocument> docs) {
-      var schemaAdaptor = new BlueTableSchemaAdaptor<BsonDocument>("MongoCollectionStream");
+   public static BlueTableSchemaAdapter<BsonDocument> InferSchema(IEnumerable<BsonDocument> docs) {
+      var schemaAdaptor = new BlueTableSchemaAdapter<BsonDocument>("MongoCollectionStream");
      foreach (var doc in docs) {
         foreach (var el in doc) {
            if (schemaAdaptor.Contains(el.Name)) {
@@ -0,0 +1,54 @@
+namespace Bts.DataStream;
+
+using BCG;
+
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Data.SQLite;
+using System.Linq;
+using System.Threading;
+
+public class SQLiteEnumerable : IAsyncEnumerable<IBlueRowCollection> {
+   readonly string location;
+   readonly string statement;
+   readonly int pageSize;
+
+   public SQLiteEnumerable(string location, string statement, int pageSize = 65536) {
+      this.location = location;
+      this.statement = statement;
+      this.pageSize = pageSize;
+   }
+
+   public async IAsyncEnumerator<IBlueRowCollection> GetAsyncEnumerator(CancellationToken cancellationToken = default) {
+      var dataTable = new DataTable();
+      await using var conn = new SQLiteConnection($"Data Source={location};Version=3");
+      await conn.OpenAsync(cancellationToken);
+      await using var cmd = new SQLiteCommand(statement, conn);
+      await using var reader = cmd.ExecuteReader();
+      var schema = await reader.GetColumnSchemaAsync(cancellationToken);
+      var columns = schema.OrderBy(c => c.ColumnOrdinal ?? int.MaxValue)
+         .Select((c, i) => new ColumnInfo(c.ColumnName, c.ColumnOrdinal ?? i, c.DataType))
+         .Append(new ColumnInfo("id", schema.Count, typeof(int)))
+         .ToArray();
+      var blueSchema = new BlueTableSchema("anon", columns);
+      BlueTable? table = null;
+      int rowId = 1;
+      while (await reader.ReadAsync(cancellationToken)) {
+         table ??= new BlueTable(blueSchema);
+         var rowVals = new object[blueSchema.columnInfo.Length];
+         if (reader.GetValues(rowVals) != rowVals.Length - 1) {
+            throw new InvalidOperationException("Sqlite reader value count for single row not equal to column count");
+         }
+         rowVals[^1] = rowId++;
+         table.addRow(new BlueRow(blueSchema, rowVals));
+         if (table.Count == pageSize) {
+            yield return table;
+            table = null;
+         }
+      }
+      if (table is not null) {
+         yield return table;
+      }
+   }
+}
				`@@ -0,0 +1 @@`
				`PYTHONPATH=/workspaces/spark/build/sparkd-debug-clang/src/lib_python_interop;/workspaces/spark/src/lib_python_interop/python_interop_plugins;/workspaces/spark/tools/py`