public void MoveToIndex(int index, Dictionary <int, int?> indicesToLeft, Dictionary <int, int?> indicesToRight)
{
if (currentIndex == -1)
{
pruningCursor.MoveToIndex(index);
currentIndex = index;
return;
}
if (currentIndex > index)
{
int?leftIndex;
while (indicesToLeft.TryGetValue(currentIndex, out leftIndex))
{
if (!leftIndex.HasValue)
{
throw new InvalidOperationException();
}
pruningCursor.MoveLeft();
currentIndex = leftIndex.Value;
if (currentIndex == index)
{
return;
}
else if (currentIndex < index)
{
break;
}
}
}
else if (currentIndex < index)
{
int?rightIndex;
while (indicesToRight.TryGetValue(currentIndex, out rightIndex))
{
if (!rightIndex.HasValue)
{
throw new InvalidOperationException();
}
pruningCursor.MoveRight();
currentIndex = rightIndex.Value;
if (currentIndex == index)
{
return;
}
else if (currentIndex > index)
{
break;
}
}
}
if (currentIndex != index)
{
pruningCursor.MoveToIndex(index);
currentIndex = index;
}
Debug.Assert(pruningCursor.ReadNode().Index == index);
}
public static void PruneNode(IMerkleTreePruningCursor cursor, int index)
{
if (!cursor.TryMoveToIndex(index))
{
return;
}
var node = cursor.ReadNode();
if (node.Depth != 0)
{
return;
}
if (!node.Pruned)
{
node = node.AsPruned();
cursor.WriteNode(node);
}
bool didWork;
do
{
didWork = false;
if (node.IsLeft)
{
if (cursor.TryMoveRight())
{
var rightNode = cursor.ReadNode();
if (node.Pruned && rightNode.Pruned && node.Depth == rightNode.Depth)
{
var newNode = node.PairWith(rightNode);
cursor.DeleteNode();
//TODO cursor.MoveLeft();
cursor.WriteNode(newNode);
node = newNode;
didWork = true;
}
}
else
{
if (node.Index != 0 && node.Pruned)
{
var newNode = node.PairWithSelf();
cursor.MoveLeft();
cursor.WriteNode(newNode);
node = newNode;
didWork = true;
}
}
}
else
{
if (cursor.TryMoveLeft())
{
var leftNode = cursor.ReadNode();
if (node.Pruned && leftNode.Pruned && node.Depth == leftNode.Depth)
{
var newNode = leftNode.PairWith(node);
cursor.WriteNode(newNode);
cursor.MoveRight();
cursor.DeleteNode();
//TODO cursor.MoveLeft();
node = newNode;
didWork = true;
}
}
}
} while (didWork);
}