public Usage Count_Empty_Slots()
{
int invalid = 0;
int valid = 0;
int blockSize = _node_Factory.Size_In_Bytes(3);
long position = Index_Stream.Position;
Index_Stream.Seek(8, SeekOrigin.Begin);
var buffer = new byte[blockSize];
while (Index_Stream.Read(buffer, 0, buffer.Length) > 0)
{
var node = _node_Factory.From_Bytes(buffer, 3);
if (node.IsValid)
{
valid++;
}
else
{
invalid++;
}
}
int used = valid * blockSize;
int wasted = invalid * blockSize;
Index_Stream.Seek(position, SeekOrigin.Begin);
return(new Usage {
Invalid = invalid, Valid = valid
});
}
protected Node <T> Read_Node(long address)
{
var buffer = new byte[_block_Size];
Index_Stream.Seek(address, SeekOrigin.Begin);
Index_Stream.Read(buffer, 0, buffer.Length);
return(_node_Factory.From_Bytes(buffer, Order));
}
public void Commit()
{
if (!_pending_Changes.Has_Pending_Changes())
{
return;
}
foreach (var address in _pending_Changes.Get_Freed_Empty_Slots())
{
_cache.Invalidate(address);
}
var newRoot = _pending_Changes.Commit(Index_Stream, Data_Stream);
writes++;
Metadata_Stream.Seek(0, SeekOrigin.Begin);
var buffer = new byte[512];
_metadata.DataStream_Length = _pending_Changes.Get_Current_Data_Pointer();
_metadata.IndexStream_Length = _pending_Changes.Get_Index_Pointer();
_metadata.Root_Address = newRoot.Address;
_metadata.Clustered_Data_Length = Cluster_Data_Length;
_metadata.Alignment = Alignment;
_metadata.Number_Of_Keys += key_added;
_metadata.Number_Of_Leaves += leaves_added;
_metadata.Number_Of_Nodes += nodes_added;
_metadata.Height = 0;
_metadata.To_Bytes_In_Buffer(buffer, 0);
Metadata_Stream.Write(buffer, 0, buffer.Length);
Metadata_Stream.Flush();
Root = newRoot;
_pending_Changes.Clean_Root();
key_added = leaves_added = nodes_added = 0;
// TODO persist empty pages on metadata ?
//Cached_Nodes.Clear();
//foreach (var node in Pending_Changes.Last_Cached_Nodes())
// Cached_Nodes[node.Address] = node;
_index_Pointer = _pending_Changes.Get_Index_Pointer();
Index_Stream.Flush();
}
public void Mark_As_Invalid(Stream index, long block_Address)
{
Index_Stream.Seek(block_Address, SeekOrigin.Begin);
Index_Stream.Write(BitConverter.GetBytes(-1), 0, 4);
}
public void Dispose()
{
Index_Stream.Dispose();
Metadata_Stream.Dispose();
Data_Stream.Dispose();
}
public void Flush()
{
Index_Stream.Flush();
}