lib/em/io_streamer.rb
require 'em/streamer'
# Streams an IO object over a given connection. Streaming begins once the object is
# instantiated. Typically IOStreamer instances are not reused. IOStreamer includes
# a 16K buffer. If streaming from a file, FileStreamer is more efficient.
#
# @example
#
# module FileSender
# def post_init
# @example
#
# module SocketSender
# socket = TCPSocket.new('localhost', 2000)
# streamer = EventMachine::IOStreamer.new(self, socket)
# streamer.callback{
# # all data was sent successfully
# close_connection_after_writing
# }
# end
# end
# Stream from any IO object, similar to FileStreamer
module EventMachine
class IOStreamer
include Deferrable
CHUNK_SIZE = 16384
# @param [EventMachine::Connection] connection
# @param [IO] io Data source
#
# @option opts [Boolean] :http_chunks (false) Use HTTP 1.1 style chunked-encoding semantics.
def initialize(connection, io, opts = {})
@connection = connection
@io = io
@http_chunks = opts[:http_chunks]
@buff = String.new
@io.binmode if @io.respond_to?(:binmode)
stream_one_chunk
end
private
# Used internally to stream one chunk at a time over multiple reactor ticks
# @private
def stream_one_chunk
loop do
if @io.eof?
@connection.send_data "0\r\n\r\n" if @http_chunks
succeed
break
end
if @connection.respond_to?(:get_outbound_data_size) && (@connection.get_outbound_data_size > FileStreamer::BackpressureLevel)
EventMachine::next_tick { stream_one_chunk }
break
end
if @io.read(CHUNK_SIZE, @buff)
@connection.send_data("#{@buff.length.to_s(16)}\r\n") if @http_chunks
@connection.send_data(@buff)
@connection.send_data("\r\n") if @http_chunks
end
end
end
end
end