public static void MergeLeaves(BplusNode left, BplusNode right, out bool DeleteRight)
{
DeleteRight = false;
string[] allkeys = new string[left.Size*2];
long[] allseeks = new long[left.Size*2];
int index = 0;
for (int i=0; i<left.Size; i++)
{
if (left.ChildKeys[i]==null)
{
break;
}
allkeys[index] = left.ChildKeys[i];
allseeks[index] = left.ChildBufferNumbers[i];
index++;
}
for (int i=0; i<right.Size; i++)
{
if (right.ChildKeys[i]==null)
{
break;
}
allkeys[index] = right.ChildKeys[i];
allseeks[index] = right.ChildBufferNumbers[i];
index++;
}
if (index<=left.Size)
{
left.Clear();
DeleteRight = true;
for (int i=0; i<index; i++)
{
left.ChildKeys[i] = allkeys[i];
left.ChildBufferNumbers[i] = allseeks[i];
}
right.Free();
left.Soil();
return;
}
left.Clear();
right.Clear();
left.Soil();
right.Soil();
int rightcontent = index/2;
int leftcontent = index - rightcontent;
int newindex = 0;
for (int i=0; i<leftcontent; i++)
{
left.ChildKeys[i] = allkeys[newindex];
left.ChildBufferNumbers[i] = allseeks[newindex];
newindex++;
}
for (int i=0; i<rightcontent; i++)
{
right.ChildKeys[i] = allkeys[newindex];
right.ChildBufferNumbers[i] = allseeks[newindex];
newindex++;
}
}
public static void Merge(BplusNode left, string KeyBetween, BplusNode right, out string rightLeastKey,
out bool DeleteRight)
{
//System.Diagnostics.Debug.WriteLine("\r\n<br> merging "+right.myBufferNumber+" ("+KeyBetween+") "+left.myBufferNumber);
//System.Diagnostics.Debug.WriteLine(left.owner.toHtml());
rightLeastKey = null; // only if DeleteRight
if (left.isLeaf || right.isLeaf)
{
if (!(left.isLeaf&&right.isLeaf))
{
throw new BplusTreeException("can't merge leaf with non-leaf");
}
MergeLeaves(left, right, out DeleteRight);
rightLeastKey = right.ChildKeys[0];
return;
}
// merge non-leaves
DeleteRight = false;
string[] allkeys = new string[left.Size*2+1];
long[] allseeks = new long[left.Size*2+2];
BplusNode[] allMaterialized = new BplusNode[left.Size*2+2];
if (left.ChildBufferNumbers[0]==BplusTreeLong.NULLBUFFERNUMBER ||
right.ChildBufferNumbers[0]==BplusTreeLong.NULLBUFFERNUMBER)
{
throw new BplusTreeException("cannot merge empty non-leaf with non-leaf");
}
int index = 0;
allseeks[0] = left.ChildBufferNumbers[0];
allMaterialized[0] = left.MaterializedChildNodes[0];
for (int i=0; i<left.Size; i++)
{
if (left.ChildKeys[i]==null)
{
break;
}
allkeys[index] = left.ChildKeys[i];
allseeks[index+1] = left.ChildBufferNumbers[i+1];
allMaterialized[index+1] = left.MaterializedChildNodes[i+1];
index++;
}
allkeys[index] = KeyBetween;
index++;
allseeks[index] = right.ChildBufferNumbers[0];
allMaterialized[index] = right.MaterializedChildNodes[0];
int rightcount = 0;
for (int i=0; i<right.Size; i++)
{
if (right.ChildKeys[i]==null)
{
break;
}
allkeys[index] = right.ChildKeys[i];
allseeks[index+1] = right.ChildBufferNumbers[i+1];
allMaterialized[index+1] = right.MaterializedChildNodes[i+1];
index++;
rightcount++;
}
if (index<=left.Size)
{
// it will all fit in one node
//System.Diagnostics.Debug.WriteLine("deciding to forget "+right.myBufferNumber+" into "+left.myBufferNumber);
DeleteRight = true;
for (int i=0; i<index; i++)
{
left.ChildKeys[i] = allkeys[i];
left.ChildBufferNumbers[i] = allseeks[i];
left.MaterializedChildNodes[i] = allMaterialized[i];
}
left.ChildBufferNumbers[index] = allseeks[index];
left.MaterializedChildNodes[index] = allMaterialized[index];
left.reParentAllChildren();
left.Soil();
right.Free();
return;
}
// otherwise split the content between the nodes
left.Clear();
right.Clear();
left.Soil();
right.Soil();
int leftcontent = index/2;
int rightcontent = index-leftcontent-1;
rightLeastKey = allkeys[leftcontent];
int outputindex = 0;
for (int i=0; i<leftcontent; i++)
{
left.ChildKeys[i] = allkeys[outputindex];
left.ChildBufferNumbers[i] = allseeks[outputindex];
left.MaterializedChildNodes[i] = allMaterialized[outputindex];
outputindex++;
}
rightLeastKey = allkeys[outputindex];
left.ChildBufferNumbers[outputindex] = allseeks[outputindex];
left.MaterializedChildNodes[outputindex] = allMaterialized[outputindex];
outputindex++;
rightcount = 0;
for (int i=0; i<rightcontent; i++)
{
right.ChildKeys[i] = allkeys[outputindex];
right.ChildBufferNumbers[i] = allseeks[outputindex];
right.MaterializedChildNodes[i] = allMaterialized[outputindex];
outputindex++;
rightcount++;
}
right.ChildBufferNumbers[rightcount] = allseeks[outputindex];
right.MaterializedChildNodes[rightcount] = allMaterialized[outputindex];
left.reParentAllChildren();
right.reParentAllChildren();
}