Class: QuartzTorrent::PieceIO

Inherits:
Object
  • Object
show all
Defined in:
lib/quartz_torrent/filemanager.rb

Overview

Can read and write pieces and blocks of a torrent.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(baseDirectory, torrinfo, ioManager = IOManager.new) ⇒ PieceIO

Create a new PieceIO that will map to files inside ‘baseDirectory’. Parameter ‘torrinfo’ should be a Metainfo::Info object (the info part of the metainfo).



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# File 'lib/quartz_torrent/filemanager.rb', line 148

def initialize(baseDirectory, torrinfo, ioManager = IOManager.new)
  @baseDirectory = baseDirectory
  @torrinfo = torrinfo
  @pieceMapper = PieceMapper.new(baseDirectory, torrinfo)
  @ioManager = ioManager
  @logger = LogManager.getLogger("pieceio")
  @torrentDataLength = torrinfo.dataLength
end

Instance Attribute Details

#torrentDataLength ⇒ Object (readonly)

Get the overall length of the torrent data



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# File 'lib/quartz_torrent/filemanager.rb', line 158

def torrentDataLength
  @torrentDataLength
end

Instance Method Details

#flush ⇒ Object 



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# File 'lib/quartz_torrent/filemanager.rb', line 214

def flush
  @ioManager.flush
end

#readBlock(pieceIndex, offset, length) ⇒ Object

Read a block from a completed piece. Returns nil if the block doesn’t exist yet. Throws exceptions on error (for example, opening a file failed)



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# File 'lib/quartz_torrent/filemanager.rb', line 203

def readBlock(pieceIndex, offset, length)
  readRegions @pieceMapper.findBlock(pieceIndex, offset, length)
end

#readPiece(pieceIndex) ⇒ Object

Read a piece. Returns nil if the piece is not yet present. NOTE: this method expects that if the ioManager is a reactor iomanager, that the io was set with errorHandler=false so that we get the EOF errors.



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# File 'lib/quartz_torrent/filemanager.rb', line 210

def readPiece(pieceIndex)
  readRegions @pieceMapper.findPiece(pieceIndex)
end

#writeBlock(pieceIndex, offset, block) ⇒ Object

Write a block to an in-progress piece. The block is written to piece ‘peiceIndex’, at offset ‘offset’. The block data is in block. Throws exceptions on failure.



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# File 'lib/quartz_torrent/filemanager.rb', line 163

def writeBlock(pieceIndex, offset, block)
  regions = @pieceMapper.findBlock(pieceIndex, offset, block.length)
  indexInBlock = 0
  regions.each do |region|
    # Get the IO for the file with path 'path'. If we are being used in a reactor, this is the IO facade. If we
    # are not then this is a real IO.
    io = @ioManager.get(region.path)
    if ! io
      # No IO for this file. 
      raise "This process doesn't have write permission for the file #{region.path}" if File.exists?(region.path) && ! File.writable?(region.path)

      # Ensure parent directories exist.
      dir = File.dirname region.path
      FileUtils.mkdir_p dir if ! File.directory?(dir)

      begin
        io = @ioManager.open(region.path)
      rescue
        @logger.error "Opening file #{region.path} failed: #{$!}"
        raise "Opening file #{region.path} failed"
      end
    end

    io.seek region.offset, IO::SEEK_SET
    begin
      io.write(block[indexInBlock, region.length])
      indexInBlock += region.length
    rescue
      # Error when writing...
      @logger.error "Writing block to file #{region.path} failed: #{$!}"
      piece = nil
      break
    end

    break if indexInBlock >= block.length
  end
end