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

using System;
using System.Collections;
using System.IO;
using BCG.Utilities.General;

namespace BCG
{
   internal class JoinTable : IBlueRowCollection
   {
      protected JoinTableSchema mySchema;
      protected IDictionary myIdIndex = new Hashtable ();
      protected JoinDeletionIndex myLeftIndex, myRightIndex;
      private int myNewRowId;

      public JoinTable (JoinTableSchema schema) 
      {
         mySchema = schema;
         myLeftIndex = new JoinDeletionIndex (mySchema.getRenamedName ("id", true), true);
         myRightIndex = new JoinDeletionIndex (mySchema.getRenamedName ("id", false), false);
      }

      public IBlueRow this [int id] 
      {
         get
         {
            if (myIdIndex[id] == null)
               throw new BlueDataException ("ID " + id.ToString() + " does not exist in table " + mySchema.tableName);
            return (IBlueRow)myIdIndex[id];
         }
      }

      #region JoinTable members
      public virtual void addRow (IBlueRow leftRow, IBlueRow rightRow, DataPacket dp)
      {
         JoinRow newRow = new JoinRow (myNewRowId, leftRow, rightRow, mySchema);
         myIdIndex[myNewRowId ++] = newRow;
         ((BlueTable)(dp.addedRows)).addRow (newRow);
         myLeftIndex.add (newRow);
         if (rightRow != null) //in case of left joins when right row is null
            myRightIndex.add (newRow);
      }

      public virtual void deleteRow (bool isLeft, IBlueRow deletedRow, DataPacket dp)
      {
         JoinDeletionIndex thisIndex = myRightIndex, otherIndex = myLeftIndex;
         if (isLeft) 
         {
            thisIndex = myLeftIndex;
            otherIndex = myRightIndex;
         }
         RowList matchingNodes = thisIndex.getMatchingRows (deletedRow["id"]);
         foreach (RowNode node in matchingNodes)
         {
            JoinRow row = (JoinRow)node.row;
            RowNode correspondingNode = isLeft ? row.rightNode : row.leftNode;
            if (correspondingNode != null)
               otherIndex.remove (correspondingNode); //in case of partial left joinss
            myIdIndex.Remove (row["id"]);
            ((BlueTable)dp.deletedRows).addRow (row);
         }
         thisIndex.removeAll (deletedRow["id"]);
      }
      #endregion
      #region ICollection members
      public int Count{get{return myIdIndex.Count;}}

      public bool IsSynchronized {get{return false;}}

      public object SyncRoot{get{return this;}}

      public void CopyTo (Array array, int index)  {myIdIndex.Values.CopyTo (array, index);}
      #endregion

      #region IEnumerable members
      public IEnumerator GetEnumerator () {return myIdIndex.Values.GetEnumerator ();}
      #endregion

      #region IBlueRowCollection members
      public IBlueTableSchema schema {get{return mySchema;}}
      public bool containsID (int id)  {return myIdIndex[id] != null;}
      #endregion
   }

}