/// <summary>
/// Delete this node and free space
/// </summary>
public bool Delete()
{
//VSDebug.StopPoint(this.ID, 41);
bool root_deleted = ((PARENT == 0) & (LEFT == 0) & (RIGHT == 0));
sp.Free(ALLOCATION);
ALLOCATION = null;
return(root_deleted);
}
/// <summary>
/// Delete index
/// </summary>
internal void purge()
{
if (ALLOCATION == null)
{
return;
}
// Delete all cross-references
if (POOL > 0)
{
sp.ReleasePool(POOL); // Delete all nodes
}
sp.Free(ALLOCATION); // Delete descriptor
ALLOCATION = null;
}
/// <summary>
/// Delete existing ID
/// </summary>
/// <param name="sid"></param>
public int Delete(long key)
{
// Get key
long[] keyloc = SearchKey(key);
if (keyloc[0] == 0)
{
return(-1);
}
// Delete key in the block
long addr = keyloc[2] * KeyBlockDef.BLOCK_ITEM_LENGTH;
KeyBlockAllocWrite.Write(addr + KeyBlockDef.A_Address, KeyBlockDef.KEY_DELETED);
// Update descriptor (not last key)
if (KeyDescriptor[keyloc[1]].Used > 1)
{
KeyDescriptor[keyloc[1]].Used--;
addr = keyloc[1] * KeyDescriptorDef.DESCRIPTOR_ITEM_LENGTH;
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_Used, KeyDescriptor[keyloc[1]].Used);
}
// If last key in the block - free block
else
{
KeyBlockReadIndex = -1;
KeyBlockAllocRead = null;
sp.Free(KeyBlockAllocWrite, false);
KeyDescriptor[keyloc[1]].Used = 0;
KeyDescriptor[keyloc[1]].Address = 0;
KeyDescriptor[keyloc[1]].FirstKey = 0;
addr = keyloc[1] * KeyDescriptorDef.DESCRIPTOR_ITEM_LENGTH;
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_Used, KeyDescriptor[keyloc[1]].Used);
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_Address, KeyDescriptor[keyloc[1]].Address);
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_FirstKey, KeyDescriptor[keyloc[1]].FirstKey);
KeyHeader.DescriptorUsed--;
KeyHeaderAlloc.Write(KeyHeaderDef.A_DescriptorUsed, KeyHeader.DescriptorUsed);
for (int i = 0; i < KeyHeader.DescriptorLength; i++)
{
if (KeyDescriptor[i].Address == 0)
{
for (int j = i + 1; j < KeyHeader.DescriptorLength; j++)
{
if (KeyDescriptor[j].Address != 0)
{
KeyDescriptor[i].Address = KeyDescriptor[j].Address;
KeyDescriptor[i].FirstKey = KeyDescriptor[j].FirstKey;
KeyDescriptor[i].Used = KeyDescriptor[j].Used;
KeyDescriptor[j].Address = 0;
KeyDescriptor[j].FirstKey = 0;
KeyDescriptor[j].Used = 0;
break;
}
}
}
}
// Update header last
int save_last = KeyHeader.DescriptorLast;
KeyHeader.DescriptorLast = KeyHeader.DescriptorUsed - 1;
KeyHeaderAlloc.Write(KeyHeaderDef.A_DescriptorLast, KeyHeader.DescriptorLast);
// Rewrite header
for (int i = 0; i <= save_last; i++)
{
addr = i * KeyDescriptorDef.DESCRIPTOR_ITEM_LENGTH;
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_Address, KeyDescriptor[i].Address);
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_FirstKey, KeyDescriptor[i].FirstKey);
KeyDescriptorAlloc.Write(addr + KeyDescriptorDef.A_Used, KeyDescriptor[i].Used);
}
}
return(0);
}
