private void Delete(ulong txnId, InternalNode parentInternalNode, byte[] key, out bool underAllocation, BrightstarProfiler profiler)
{
if (parentInternalNode.RightmostKey == null)
{
throw new ArgumentException("Parent node right key is null");
}
var childNodeId = parentInternalNode.GetChildNodeId(key);
var childNode = GetNode(childNodeId, profiler);
if (childNode is LeafNode)
{
var childLeafNode = childNode as LeafNode;
// Delete the key and mark the node as updated. This may update the child node id
childLeafNode.Delete(key);
MarkDirty(txnId, childLeafNode, profiler);
if (childLeafNode.PageId != childNodeId)
{
parentInternalNode.UpdateChildPointer(childNodeId, childLeafNode.PageId);
childNodeId = childLeafNode.PageId;
}
if (childLeafNode.NeedsJoin)
{
ulong leftSiblingId, rightSiblingId;
LeafNode leftSibling = null, rightSibling = null;
bool hasLeftSibling = parentInternalNode.GetLeftSibling(childNodeId, out leftSiblingId);
if (hasLeftSibling)
{
leftSibling = GetNode(leftSiblingId, profiler) as LeafNode;
if (childLeafNode.RedistributeFromLeft(leftSibling))
{
parentInternalNode.SetLeftKey(childLeafNode.PageId, childLeafNode.LeftmostKey);
MarkDirty(txnId, parentInternalNode, profiler);
MarkDirty(txnId, leftSibling, null);
parentInternalNode.UpdateChildPointer(leftSiblingId, leftSibling.PageId);
underAllocation = false;
return;
}
}
bool hasRightSibling = parentInternalNode.GetRightSiblingId(childNodeId, out rightSiblingId);
if (hasRightSibling)
{
rightSibling = GetNode(rightSiblingId, profiler) as LeafNode;
#if DEBUG
if (rightSibling.LeftmostKey.Compare(childLeafNode.RightmostKey) <= 0)
{
throw new Exception("Right-hand sibling has a left key lower than this nodes right key.");
}
#endif
if (childLeafNode.RedistributeFromRight(rightSibling))
{
MarkDirty(txnId, rightSibling, profiler);
parentInternalNode.UpdateChildPointer(rightSiblingId, rightSibling.PageId);
parentInternalNode.SetLeftKey(rightSibling.PageId, rightSibling.LeftmostKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = false;
return;
}
}
if (hasLeftSibling && childLeafNode.Merge(leftSibling))
{
parentInternalNode.RemoveChildPointer(leftSiblingId);
parentInternalNode.SetLeftKey(childLeafNode.PageId, childLeafNode.LeftmostKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
if (hasRightSibling && childLeafNode.Merge(rightSibling))
{
byte[] nodeKey = parentInternalNode.RemoveChildPointer(rightSiblingId);
if (nodeKey == null)
{
// We merged in the right-most node, so we need to generate a key
nodeKey = new byte[_config.KeySize];
Array.Copy(rightSibling.RightmostKey, nodeKey, _config.KeySize);
ByteArrayHelper.Increment(nodeKey);
}
parentInternalNode.SetKey(childLeafNode.PageId, nodeKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
}
underAllocation = false;
return;
}
if (childNode is InternalNode)
{
bool childUnderAllocated;
var childInternalNode = childNode as InternalNode;
Delete(txnId, childInternalNode, key, out childUnderAllocated, profiler);
if (childInternalNode.PageId != childNodeId)
{
// Child node page changed
parentInternalNode.UpdateChildPointer(childNodeId, childInternalNode.PageId);
MarkDirty(txnId, parentInternalNode, profiler);
childNodeId = childInternalNode.PageId;
}
if (childUnderAllocated)
{
InternalNode leftSibling = null, rightSibling = null;
ulong leftSiblingId, rightSiblingId;
// Redistribute values from left-hand sibling
bool hasLeftSibling = parentInternalNode.GetLeftSibling(childNodeId, out leftSiblingId);
if (hasLeftSibling)
{
leftSibling = GetNode(leftSiblingId, profiler) as InternalNode;
byte[] joinKey = parentInternalNode.GetKey(leftSiblingId);
var newJoinKey = new byte[_config.KeySize];
if (childInternalNode.RedistributeFromLeft(leftSibling, joinKey, newJoinKey))
{
MarkDirty(txnId, leftSibling, profiler);
parentInternalNode.UpdateChildPointer(leftSiblingId, leftSibling.PageId);
parentInternalNode.SetKey(leftSibling.PageId, newJoinKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = false;
return;
}
}
// Redistribute values from right-hand sibling
bool hasRightSibling = parentInternalNode.GetRightSiblingId(childNodeId, out rightSiblingId);
if (hasRightSibling)
{
rightSibling = GetNode(rightSiblingId, profiler) as InternalNode;
byte[] joinKey = parentInternalNode.GetKey(childInternalNode.PageId);
byte[] newJoinKey = new byte[_config.KeySize];
if (childInternalNode.RedistributeFromRight(rightSibling, joinKey, newJoinKey))
{
MarkDirty(txnId, rightSibling, profiler);
parentInternalNode.UpdateChildPointer(rightSiblingId, rightSibling.PageId);
// parentInternalNode.SetKey(rightSibling.PageId, newJoinKey); -- think this is wrong should be:
parentInternalNode.SetKey(childInternalNode.PageId, newJoinKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = false;
return;
}
}
// Merge with left-hand sibling
if (hasLeftSibling)
{
// Attempt to merge child node into its left sibling
var joinKey = parentInternalNode.GetKey(leftSibling.PageId);
var mergedNodeKey = parentInternalNode.GetKey(childInternalNode.PageId);
if (mergedNodeKey == null)
{
mergedNodeKey = new byte[_config.KeySize];
Array.Copy(childInternalNode.RightmostKey, mergedNodeKey, _config.KeySize);
ByteArrayHelper.Increment(mergedNodeKey);
}
if (leftSibling.Merge(childInternalNode, joinKey))
{
MarkDirty(txnId, leftSibling, profiler);
if (leftSibling.PageId != leftSiblingId)
{
// We have a new page id (append-only stores will do this)
parentInternalNode.UpdateChildPointer(leftSiblingId, leftSibling.PageId);
}
parentInternalNode.RemoveChildPointer(childInternalNode.PageId);
parentInternalNode.SetKey(leftSibling.PageId, mergedNodeKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
}
// Merge with right-hand sibling
if (hasRightSibling)
{
// Attempt to merge right sibling into child node
var joinKey = parentInternalNode.GetKey(childNodeId);
if (childInternalNode.Merge(rightSibling, joinKey))
{
MarkDirty(txnId, childInternalNode, profiler);
var nodeKey = parentInternalNode.RemoveChildPointer(rightSiblingId);
if (childInternalNode.PageId != childNodeId)
{
// We have a new page id for the child node (append-only stores will do this)
parentInternalNode.UpdateChildPointer(childNodeId, childInternalNode.PageId);
}
if (nodeKey == null)
{
// We merged in the right-most node, so we need to generate a key
nodeKey = new byte[_config.KeySize];
Array.Copy(rightSibling.RightmostKey, nodeKey, _config.KeySize);
ByteArrayHelper.Increment(nodeKey);
}
parentInternalNode.SetKey(childInternalNode.PageId, nodeKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
}
throw new NotImplementedException(
"Not yet implemented handling for internal node becoming under allocated");
}
underAllocation = false;
}
else
{
throw new BrightstarInternalException(String.Format("Unrecognised B+ Tree node class : {0}",
childNode.GetType()));
}
}
private void Delete(ulong txnId, InternalNode parentInternalNode, byte[] key, out bool underAllocation, BrightstarProfiler profiler)
{
if (parentInternalNode.RightmostKey == null)
{
throw new ArgumentException("Parent node right key is null");
}
var childNodeId = parentInternalNode.GetChildNodeId(key);
var childNode = GetNode(childNodeId, profiler);
if (childNode is LeafNode)
{
var childLeafNode = childNode as LeafNode;
// Delete the key and mark the node as updated. This may update the child node id
childLeafNode.Delete(key);
MarkDirty(txnId, childLeafNode, profiler);
if (childLeafNode.PageId != childNodeId)
{
parentInternalNode.UpdateChildPointer(childNodeId, childLeafNode.PageId);
childNodeId = childLeafNode.PageId;
}
if (childLeafNode.NeedsJoin)
{
ulong leftSiblingId, rightSiblingId;
LeafNode leftSibling = null, rightSibling = null;
bool hasLeftSibling = parentInternalNode.GetLeftSibling(childNodeId, out leftSiblingId);
if (hasLeftSibling)
{
leftSibling = GetNode(leftSiblingId, profiler) as LeafNode;
if (childLeafNode.RedistributeFromLeft(leftSibling))
{
parentInternalNode.SetLeftKey(childLeafNode.PageId, childLeafNode.LeftmostKey);
MarkDirty(txnId, parentInternalNode, profiler);
MarkDirty(txnId, leftSibling, null);
parentInternalNode.UpdateChildPointer(leftSiblingId, leftSibling.PageId);
underAllocation = false;
return;
}
}
bool hasRightSibling = parentInternalNode.GetRightSiblingId(childNodeId, out rightSiblingId);
if (hasRightSibling)
{
rightSibling = GetNode(rightSiblingId, profiler) as LeafNode;
#if DEBUG
if (rightSibling.LeftmostKey.Compare(childLeafNode.RightmostKey) <= 0)
{
throw new Exception("Right-hand sibling has a left key lower than this nodes right key.");
}
#endif
if (childLeafNode.RedistributeFromRight(rightSibling))
{
MarkDirty(txnId, rightSibling, profiler);
parentInternalNode.UpdateChildPointer(rightSiblingId, rightSibling.PageId);
parentInternalNode.SetLeftKey(rightSibling.PageId, rightSibling.LeftmostKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = false;
return;
}
}
if (hasLeftSibling && childLeafNode.Merge(leftSibling))
{
parentInternalNode.RemoveChildPointer(leftSiblingId);
parentInternalNode.SetLeftKey(childLeafNode.PageId, childLeafNode.LeftmostKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
if (hasRightSibling && childLeafNode.Merge(rightSibling))
{
byte[] nodeKey = parentInternalNode.RemoveChildPointer(rightSiblingId);
if (nodeKey == null)
{
// We merged in the right-most node, so we need to generate a key
nodeKey = new byte[_config.KeySize];
Array.Copy(rightSibling.RightmostKey, nodeKey, _config.KeySize);
ByteArrayHelper.Increment(nodeKey);
}
parentInternalNode.SetKey(childLeafNode.PageId, nodeKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
}
underAllocation = false;
return;
}
if (childNode is InternalNode)
{
bool childUnderAllocated;
var childInternalNode = childNode as InternalNode;
Delete(txnId, childInternalNode, key, out childUnderAllocated, profiler);
if (childInternalNode.PageId != childNodeId)
{
// Child node page changed
parentInternalNode.UpdateChildPointer(childNodeId, childInternalNode.PageId);
MarkDirty(txnId, parentInternalNode, profiler);
childNodeId = childInternalNode.PageId;
}
if (childUnderAllocated)
{
InternalNode leftSibling = null, rightSibling = null;
ulong leftSiblingId, rightSiblingId;
// Redistribute values from left-hand sibling
bool hasLeftSibling = parentInternalNode.GetLeftSibling(childNodeId, out leftSiblingId);
if (hasLeftSibling)
{
leftSibling = GetNode(leftSiblingId, profiler) as InternalNode;
byte[] joinKey = parentInternalNode.GetKey(leftSiblingId);
var newJoinKey = new byte[_config.KeySize];
if (childInternalNode.RedistributeFromLeft(leftSibling, joinKey, newJoinKey))
{
MarkDirty(txnId, leftSibling, profiler);
parentInternalNode.UpdateChildPointer(leftSiblingId, leftSibling.PageId);
parentInternalNode.SetKey(leftSibling.PageId, newJoinKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = false;
return;
}
}
// Redistribute values from right-hand sibling
bool hasRightSibling = parentInternalNode.GetRightSiblingId(childNodeId, out rightSiblingId);
if (hasRightSibling)
{
rightSibling = GetNode(rightSiblingId, profiler) as InternalNode;
byte[] joinKey = parentInternalNode.GetKey(childInternalNode.PageId);
byte[] newJoinKey = new byte[_config.KeySize];
if (childInternalNode.RedistributeFromRight(rightSibling, joinKey, newJoinKey))
{
MarkDirty(txnId, rightSibling, profiler);
parentInternalNode.UpdateChildPointer(rightSiblingId, rightSibling.PageId);
// parentInternalNode.SetKey(rightSibling.PageId, newJoinKey); -- think this is wrong should be:
parentInternalNode.SetKey(childInternalNode.PageId, newJoinKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = false;
return;
}
}
// Merge with left-hand sibling
if (hasLeftSibling)
{
// Attempt to merge child node into its left sibling
var joinKey = parentInternalNode.GetKey(leftSibling.PageId);
var mergedNodeKey = parentInternalNode.GetKey(childInternalNode.PageId);
if (mergedNodeKey == null)
{
mergedNodeKey = new byte[_config.KeySize];
Array.Copy(childInternalNode.RightmostKey, mergedNodeKey, _config.KeySize);
ByteArrayHelper.Increment(mergedNodeKey);
}
if (leftSibling.Merge(childInternalNode, joinKey))
{
MarkDirty(txnId, leftSibling, profiler);
if (leftSibling.PageId != leftSiblingId)
{
// We have a new page id (append-only stores will do this)
parentInternalNode.UpdateChildPointer(leftSiblingId, leftSibling.PageId);
}
parentInternalNode.RemoveChildPointer(childInternalNode.PageId);
parentInternalNode.SetKey(leftSibling.PageId, mergedNodeKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
}
// Merge with right-hand sibling
if (hasRightSibling)
{
// Attempt to merge right sibling into child node
var joinKey = parentInternalNode.GetKey(childNodeId);
if (childInternalNode.Merge(rightSibling, joinKey))
{
MarkDirty(txnId, childInternalNode, profiler);
var nodeKey = parentInternalNode.RemoveChildPointer(rightSiblingId);
if (childInternalNode.PageId != childNodeId)
{
// We have a new page id for the child node (append-only stores will do this)
parentInternalNode.UpdateChildPointer(childNodeId, childInternalNode.PageId);
}
if (nodeKey == null)
{
// We merged in the right-most node, so we need to generate a key
nodeKey = new byte[_config.KeySize];
Array.Copy(rightSibling.RightmostKey, nodeKey, _config.KeySize);
ByteArrayHelper.Increment(nodeKey);
}
parentInternalNode.SetKey(childInternalNode.PageId, nodeKey);
MarkDirty(txnId, parentInternalNode, profiler);
underAllocation = parentInternalNode.NeedJoin;
return;
}
}
throw new NotImplementedException(
"Not yet implemented handling for internal node becoming under allocated");
}
underAllocation = false;
}
else
{
throw new BrightstarInternalException(String.Format("Unrecognised B+ Tree node class : {0}",
childNode.GetType()));
}
}
