public void Handle(FileChunkRequest message)
{
string filePath = Path.Combine(this.expanderSharedFiles, message.Type.ToString(), message.FileName);
long fileSize = new FileInfo(filePath).Length;
int chunkId = (int)(message.ChunkStart / message.ChunkSize);
int chunks = (int)(fileSize / message.ChunkSize);
this.log.Information("Request for file {0} chunk {1}/{2} for {3:N0} bytes", message.FileName, chunkId, chunks, message.ChunkSize);
using (var fs = File.OpenRead(filePath))
{
fs.Seek(message.ChunkStart, SeekOrigin.Begin);
int bytesToRead = Math.Min(message.ChunkSize, (int)(fs.Length - message.ChunkStart));
if (bytesToRead <= 0)
{
return;
}
byte[] chunk = new byte[bytesToRead];
fs.Read(chunk, 0, chunk.Length);
SendMessage(new FileChunkResponse
{
DownloadId = message.DownloadId,
ChunkStart = message.ChunkStart,
Chunk = chunk
});
}
}
/// <summary>
/// Read a file chunk request`
/// </summary>
/// <param name="from">Origin</param>
/// <param name="filename">Filename to read from</param>
/// <param name="offset">Offset in the file</param>
/// <param name="maxLength">Maximum chunk length</param>
/// <returns>Number of bytes read</returns>
public static int ReadFileChunkRequest(ReadOnlySpan <byte> from, out string filename, out uint offset, out uint maxLength)
{
FileChunkRequest header = MemoryMarshal.Cast <byte, FileChunkRequest>(from)[0];
int bytesRead = Marshal.SizeOf(header);
// Read header
offset = header.Offset;
maxLength = header.MaxLength;
// Read filename
ReadOnlySpan <byte> unicodeFilename = from.Slice(bytesRead, (int)header.FilenameLength);
filename = Encoding.UTF8.GetString(unicodeFilename);
bytesRead += (int)header.FilenameLength;
return(AddPadding(bytesRead));
}
