static RowSetEntry RowSetEntryMerge(RowSetEntry a, RowSetEntry b)
{
RowSetEntry head = new RowSetEntry();
RowSetEntry tail = head;
while (a != null && b != null)
{
Debug.Assert(a.Right == null || a.V <= a.Right.V);
Debug.Assert(b.Right == null || b.V <= b.Right.V);
if (a.V < b.V)
{
tail.Right = a;
a = a.Right;
tail = tail.Right;
}
else if (b.V < a.V)
{
tail.Right = b;
b = b.Right;
tail = tail.Right;
}
else
{
a = a.Right;
}
}
if (a != null)
{
Debug.Assert(a.Right == null || a.V <= a.Right.V);
tail.Right = a;
}
else
{
Debug.Assert(b == null || b.Right == null || b.V <= b.Right.V);
tail.Right = b;
}
return(head.Right);
}
static void RowSetTreeToList(RowSetEntry parent, ref RowSetEntry first, ref RowSetEntry last)
{
Debug.Assert(parent != null);
if (parent.Left != null)
{
RowSetEntry p = new RowSetEntry();
RowSetTreeToList(parent.Left, ref first, ref p);
p.Right = parent;
}
else
{
first = parent;
}
if (parent.Right != null)
{
RowSetTreeToList(parent.Right, ref parent.Right, ref last);
}
else
{
last = parent;
}
Debug.Assert((last).Right == null);
}
static RowSetEntry RowSetEntrySort(RowSetEntry p)
{
uint i;
RowSetEntry next; RowSetEntry[] buckets = new RowSetEntry[40];
while (p != null)
{
next = p.Right;
p.Right = null;
for (i = 0; buckets[i] != null; i++)
{
p = RowSetEntryMerge(buckets[i], p);
buckets[i] = null;
}
buckets[i] = p;
p = next;
}
p = null;
for (i = 0; i < buckets.Length; i++)
{
p = RowSetEntryMerge(p, buckets[i]);
}
return(p);
}
public static bool RowSet_Test(RowSet rowSet, byte batch, long rowid)
{
// This routine is never called after sqlite3RowSetNext()
Debug.Assert(rowSet != null && (rowSet.Flags & ROWSET.NEXT) == 0);
// Sort entries into the forest on the first test of a new batch
RowSetEntry p, tree;
if (batch != rowSet.Batch)
{
p = rowSet.Entry;
if (p != null)
{
RowSetEntry prevTree = rowSet.Forest;
if ((rowSet.Flags & ROWSET.SORTED) == 0)
{
p = RowSetEntrySort(p);
}
for (tree = rowSet.Forest; tree != null; tree = tree.Right)
{
prevTree = tree.Right;
if (tree.Left == null)
{
tree.Left = RowSetListToTree(p);
break;
}
else
{
RowSetEntry aux = new RowSetEntry(), tail = new RowSetEntry();
RowSetTreeToList(tree.Left, ref aux, ref tail);
tree.Left = null;
p = RowSetEntryMerge(aux, p);
}
}
if (tree == null)
{
prevTree = tree = RowSetEntryAlloc(rowSet);
if (tree != null)
{
tree.V = 0;
tree.Right = null;
tree.Left = RowSetListToTree(p);
}
}
rowSet.Entry = null;
rowSet.Last = null;
rowSet.Flags |= ROWSET.SORTED;
}
rowSet.Batch = batch;
}
// Test to see if the iRowid value appears anywhere in the forest. Return 1 if it does and 0 if not.
for (tree = rowSet.Forest; tree != null; tree = tree.Right)
{
p = tree.Left;
while (p != null)
{
if (p.V < rowid)
{
p = p.Right;
}
else if (p.V > rowid)
{
p = p.Left;
}
else
{
return(true);
}
}
}
return(false);
}
