public MessagesBlock ReadMessagesBlock(Int32 offset, Int32 blockLength)
{
if (_readStream == null)
{
_readStream = File.Open(_segmentFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
}
_readStream.Seek(offset, SeekOrigin.Begin);
var block = new MessagesBlock();
block.Data = new byte[blockLength];
block.Length = _readStream.Read(block.Data, 0, blockLength);
return block;
}