public override void Invoke(SpoolSpace Memory)
{
// Add spools //
this.AddSpools(Memory);
// Render each table //
Table ltable = (this._Parameters[0]).Select(Memory);
Table rtable = (this._Parameters[1]).Select(Memory);
string lalias = this._Parameters[0].NameOf();
string ralias = this._Parameters[1].NameOf();
// Get the left and right join index //
TreeIndex lidx = ltable.GetIndex(this._LKey) ?? TreeIndex.BuildTemporaryIndex(ltable, this._LKey);
//lidx.Tree.DumpMeta(@"C:\Users\pwdlu_000\Documents\Spectre_Projects\Test\treeJoinT1.txt");
TreeIndex ridx = rtable.GetIndex(this._RKey) ?? TreeIndex.BuildTemporaryIndex(rtable, this._RKey);
// Get the join tags //
bool Intersection = (this._Affinity == JoinAffinity.Inner || this._Affinity == JoinAffinity.Left);
bool Antisection = (this._Affinity == JoinAffinity.Left || this._Affinity == JoinAffinity.AntiLeft);
// Open a read stream //
RecordReader lstream = lidx.OpenReader();
RecordReader rstream = ridx.OpenReader();
// Render some null records //
Record RNull = rstream.Columns.NullRecord;
// Main loop through both left and right
while (lstream.CanAdvance && rstream.CanAdvance)
{
Record lrec = lstream.Read();
Record rrec = rstream.Read();
int Compare = Record.Compare(lrec, this._LKey, rrec, this._RKey);
// Left is less than right, control left
if (Compare < 0)
{
lstream.Advance();
}
// AWValue is less than left, control right, but also output an anti join record
else if (Compare > 0)
{
if (Antisection)
{
Memory[lalias].Set(lrec);
Memory[ralias].Set(RNull);
if (this._Filter.Evaluate(Memory))
{
this.InvokeChildren(Memory);
}
}
rstream.Advance();
}
else if (Intersection) // Compare == 0
{
// Save the loop-result //
int NestedLoopCount = 0;
// Loop through all possible tuples //
while (Compare == 0)
{
// Render the record and potentially output //
Memory[lalias].Set(lstream.Read());
Memory[ralias].Set(rstream.Read());
if (this._Filter.Evaluate(Memory))
{
this.InvokeChildren(Memory);
}
// Advance the right table //
rstream.Advance();
NestedLoopCount++;
// Check if this advancing pushed us to the end of the table //
if (!rstream.CanAdvance)
{
break;
}
// Reset the compare token //
Compare = Record.Compare(lstream.Read(), this._LKey, rstream.Read(), this._RKey);
}
// Revert the nested loops //
rstream.Revert(NestedLoopCount);
// Step the left stream //
lstream.Advance();
}
else
{
lstream.Advance();
}
}
// Do Anti-Join //
if (Antisection)
{
// Assign the right table to null //
Memory[ralias].Set(RNull);
// Walk the rest of the left table //
while (lstream.CanAdvance)
{
Memory[lalias].Set(lstream.ReadNext());
if (this._Filter.Evaluate(Memory))
{
this.InvokeChildren(Memory);
}
}
}
// Add spools //
this.RemoveSpools(Memory);
}
