module ChunkPipe

author :jdickson ChunkPipe An IO pipe that provides generic parsing / rewriting of a stream of packets (or lines in a file). It passes chunks of packets to a block The return value of the block is written to the other end of the pipe packet delimiter is not removed from packet suffix

Silly Example that simply passes through the data: ChunkPipe.open(STDIN, STDOUT, 1000, “n”) {|lines| lines.join }

Constants

MAX_CHUNK_SIZE

Public Class Methods

open(reader, writer, chunk_size, packet_delim, read_timeout=3) { |packets| ... } click to toggle source

# File lib/dumpr/chunkpipe.rb, line 16
def open(reader, writer, chunk_size, packet_delim, read_timeout=3, &block)
  if chunk_size < 1 || chunk_size > MAX_CHUNK_SIZE
    raise ArgumentError.new "invalid chunk size #{chunk_size.inspect}"
  end
  chunk_idx = 0
  packet_idx = 0
  packets = []
  stopblocking = Thread.new do
    sleep read_timeout
    reader.close # this can raise IOError
    raise IOError.new "ChunkPipe read time out (#{read_timeout}s)"
  end
  while packet = reader.gets(packet_delim) do
    stopblocking.kill if stopblocking.alive?
    packets << packet
    if ((packet_idx+1) % chunk_size == 0)
      data = yield packets 
      writer << data if data
      chunk_idx+=1
      packets = []
    end
    packet_idx+=1
    #break if reader.eof?
  end
  unless packets.empty?
    data = yield packets 
    writer << data if data
  end
ensure
  reader.close if reader && !reader.closed?
  writer.close if writer && !writer.closed?
end

Private Instance Methods

open(reader, writer, chunk_size, packet_delim, read_timeout=3) { |packets| ... } click to toggle source

# File lib/dumpr/chunkpipe.rb, line 16
def open(reader, writer, chunk_size, packet_delim, read_timeout=3, &block)
  if chunk_size < 1 || chunk_size > MAX_CHUNK_SIZE
    raise ArgumentError.new "invalid chunk size #{chunk_size.inspect}"
  end
  chunk_idx = 0
  packet_idx = 0
  packets = []
  stopblocking = Thread.new do
    sleep read_timeout
    reader.close # this can raise IOError
    raise IOError.new "ChunkPipe read time out (#{read_timeout}s)"
  end
  while packet = reader.gets(packet_delim) do
    stopblocking.kill if stopblocking.alive?
    packets << packet
    if ((packet_idx+1) % chunk_size == 0)
      data = yield packets 
      writer << data if data
      chunk_idx+=1
      packets = []
    end
    packet_idx+=1
    #break if reader.eof?
  end
  unless packets.empty?
    data = yield packets 
    writer << data if data
  end
ensure
  reader.close if reader && !reader.closed?
  writer.close if writer && !writer.closed?
end