public void DeleteBytes(long index, long length)
{
try
{
long bytesToDelete = length;
long blockOffset;
DataBlock block = GetDataBlock(index, out blockOffset);
while ((bytesToDelete > 0) && (block != null))
{
long blockLength = block.Length;
DataBlock nextBlock = block.NextBlock;
long count = Math.Min(bytesToDelete, blockLength - (index - blockOffset));
block.RemoveBytes(index - blockOffset, count);
if (block.Length == 0)
{
_dataMap.Remove(block);
if (_dataMap.FirstBlock == null)
{
_dataMap.AddFirst(new MemoryDataBlock(new byte[0]));
}
}
bytesToDelete -= count;
blockOffset += block.Length;
block = (bytesToDelete > 0) ? nextBlock : null;
}
}
finally
{
_totalLength -= length;
OnLengthChanged(EventArgs.Empty);
OnChanged(EventArgs.Empty);
}
}
void ReInitialize()
{
_dataMap = new DataMap();
_dataMap.AddFirst(new FileDataBlock(0, _stream.Length));
_totalLength = _stream.Length;
}