spark/src/DataStreamSuite/DataStream/Primitives/Join/JoinStream.cs

using System;
using System.Data;
using System.Collections;
using System.Text.RegularExpressions;
using BCG.Utilities;
using BCG.Utilities.General;
using bts;

namespace BCG
{
   public class JoinStream : ViewStream
   {
      protected InternalJoinStream? myIjs;
      protected ProjectStream? myPs;
      protected ColumnMap? myLeftCm, myRightCm;
      protected bool myIsProject = true;
      private bool myUseSuperJoin = DataStreamLoadFileConfig.instance.useNewJoin;
      
      protected JoinStream () {}
      public JoinStream (ViewStream v1, string joinCol1, ColumnMap cm1,
         ViewStream v2, string joinCol2, ColumnMap cm2)
      {
         if (myUseSuperJoin)
         {
            ViewStream rs = this is LeftJoinStream ?
               new SuperLeftJoinStream(v1, joinCol1, cm1.columnExpression, v2, joinCol2, cm2.columnExpression) as ViewStream :
               new SuperJoinStream(v1, joinCol1, cm1.columnExpression, v2, joinCol2, cm2.columnExpression) as ViewStream;
            mySetRealSource(rs);
         }
         else
         {
            myLeftCm = cm1;
            myRightCm = cm2;
            //myIjs = new InternalJoinStream (v1, joinCol1, v2, joinCol2);
            myIjs = myConstructInternalJoinStream(v1, joinCol1, v2, joinCol2);
         }
      }

      public JoinStream (ViewStream v1, string joinCol1, string cmExp1,
         ViewStream v2, string joinCol2, string cmExp2)
         :
         this (
         v1,
         joinCol1, 
         (cmExp1 == null ? new ColumnMap("!"):new ColumnMap(cmExp1)),
         v2,
         joinCol2,
         (cmExp2 == null ? new ColumnMap("!"):new ColumnMap(cmExp2)))
      {}

      public JoinStream (ViewStream v1, string joinCol1, string cmExp1,
         ViewStream v2, string joinCol2)
         :
         this (v1,joinCol1, new ColumnMap(cmExp1), v2, joinCol2)
      {}

      public JoinStream (ViewStream v1, string joinCol1,
         ViewStream v2, string joinCol2, string cmExp2)
         :
         this (v1,joinCol1, v2, joinCol2, new ColumnMap(cmExp2))
      {}


      public JoinStream (ViewStream v1, string joinCol1, ViewStream v2, string joinCol2)
      {
         if (myUseSuperJoin)
         {
            ViewStream rs = this is LeftJoinStream ?
               new SuperLeftJoinStream(v1, joinCol1, v2, joinCol2) as ViewStream :
               new SuperJoinStream(v1, joinCol1, v2, joinCol2) as ViewStream;
            mySetRealSource(rs);
         }
         else
         {
            //myIjs = new InternalJoinStream (v1, joinCol1, v2, joinCol2);
            myIjs = myConstructInternalJoinStream(v1, joinCol1, v2, joinCol2);
            myIsProject = false;
         }
      }
  
      public JoinStream (ViewStream v1, string joinCol1, ColumnMap cm1, ViewStream v2, string joinCol2)
      {
         myLeftCm = cm1;
         myRightCm = new ColumnMap ("!");
         //myIjs = new InternalJoinStream (v1, joinCol1, v2, joinCol2);
         myIjs = myConstructInternalJoinStream (v1, joinCol1, v2, joinCol2);
      }

        
      public JoinStream (ViewStream v1, string joinCol1, ViewStream v2, string joinCol2, ColumnMap cm2)
      {
         myLeftCm = new ColumnMap ("!");
         myRightCm = cm2;
         //myIjs = new InternalJoinStream (v1, joinCol1, v2, joinCol2);
         myIjs = myConstructInternalJoinStream (v1, joinCol1, v2, joinCol2);
         
      }

      protected virtual InternalJoinStream myConstructInternalJoinStream (
         ViewStream vs1,
         string joinCol1,
         ViewStream vs2,
         string joinCol2)
      {
         return new InternalJoinStream (vs1, joinCol1, vs2, joinCol2);
      }

      protected void myInternalJoinChangeHandler (object o)
      {
         if (myIsProject)
         {
            if (myPs == null)
            {
               JoinNameResolver resolver = new JoinNameResolver ((JoinTableSchema)myIjs.schema, myIjs.getSchema (true), myLeftCm.columnExpression, 
                  myIjs.getSchema (false), myRightCm.columnExpression);
               IDictionary  map = resolver.getMap ();
               map["id"] = "id";
               myPs = new ProjectStream (myIjs, map);
               myPs.onChange += new DataStream.ChangeDelegate (myProjectChangeHandler);
               return;
            }
            else
               Log.assert(false, "This call back should not have been called");
         }
         else
            myFireEvent ((o as ICloneable).Clone());
      }

      private void myProjectChangeHandler (object o)
      {
         if (myIjs.myOnChangeDelegate.GetInvocationList().Length > 1)
            myIjs.onChange -= new DataStream.ChangeDelegate (myInternalJoinChangeHandler);
         myFireEvent ((o as ICloneable).Clone());
         
      }

      protected override void myOnFirstSubscriber ()
      {
         myIjs.onChange += new DataStream.ChangeDelegate (myInternalJoinChangeHandler);
      }

      protected override void myOnLastSubscriber ()
      {
         // how does this relate to the -= in myProjectChangeHandler?
         myIjs.onChange -= new DataStream.ChangeDelegate (myInternalJoinChangeHandler);

         // if there is a  project after the ijs we need to 
         // unsubscribe to it otherwise references will be kept and 
         // a memory leak will occur
         if (myPs != null)
            myPs.onChange -= new DataStream.ChangeDelegate (myProjectChangeHandler);
         myPs = null;
      }

      /**************************************TEST METHOD(S)*********************************************/
      /// <summary>
      /// Used for testing purposes only. This enables the test to work without a DataSource (PubServer,
      /// BaseServer etc), by directly calling the test method and passing data
      /// </summary>
      /// <param name="leftPacket"></param>
      /// <param name="rightPacket"></param>
      public void test (DataPacket dp, bool isLeft) {myIjs.test (dp, isLeft);}
      /***********************************************************************************************/
   }
}