lib/em/protocols/line_and_text.rb
#--
#
# Author:: Francis Cianfrocca (gmail: blackhedd)
# Homepage:: http://rubyeventmachine.com
# Date:: 15 November 2006
#
# See EventMachine and EventMachine::Connection for documentation and
# usage examples.
#
#----------------------------------------------------------------------------
#
# Copyright (C) 2006-07 by Francis Cianfrocca. All Rights Reserved.
# Gmail: blackhedd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of either: 1) the GNU General Public License
# as published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version; or 2) Ruby's License.
#
# See the file COPYING for complete licensing information.
#
#---------------------------------------------------------------------------
#
#
#
module EventMachine
module Protocols
# A protocol that handles line-oriented data with interspersed binary text.
#
# This version is optimized for performance. See EventMachine::Protocols::LineText2
# for a version which is optimized for correctness with regard to binary text blocks
# that can switch back to line mode.
class LineAndTextProtocol < Connection
MaxBinaryLength = 32*1024*1024
def initialize *args
super
lbp_init_line_state
end
def receive_data data
if @lbp_mode == :lines
begin
@lpb_buffer.extract(data).each do |line|
receive_line(line.chomp) if respond_to?(:receive_line)
end
rescue
receive_error('overlength line') if respond_to?(:receive_error)
close_connection
return
end
else
if @lbp_binary_limit > 0
wanted = @lbp_binary_limit - @lbp_binary_bytes_received
chunk = nil
if data.length > wanted
chunk = data.slice!(0...wanted)
else
chunk = data
data = ""
end
@lbp_binary_buffer[@lbp_binary_bytes_received...(@lbp_binary_bytes_received+chunk.length)] = chunk
@lbp_binary_bytes_received += chunk.length
if @lbp_binary_bytes_received == @lbp_binary_limit
receive_binary_data(@lbp_binary_buffer) if respond_to?(:receive_binary_data)
lbp_init_line_state
end
receive_data(data) if data.length > 0
else
receive_binary_data(data) if respond_to?(:receive_binary_data)
data = ""
end
end
end
def unbind
if @lbp_mode == :binary and @lbp_binary_limit > 0
if respond_to?(:receive_binary_data)
receive_binary_data( @lbp_binary_buffer[0...@lbp_binary_bytes_received] )
end
end
end
# Set up to read the supplied number of binary bytes.
# This recycles all the data currently waiting in the line buffer, if any.
# If the limit is nil, then ALL subsequent data will be treated as binary
# data and passed to the upstream protocol handler as we receive it.
# If a limit is given, we'll hold the incoming binary data and not
# pass it upstream until we've seen it all, or until there is an unbind
# (in which case we'll pass up a partial).
# Specifying nil for the limit (the default) means there is no limit.
# Specifiyng zero for the limit will cause an immediate transition back to line mode.
#
def set_binary_mode size = nil
if @lbp_mode == :lines
if size == 0
receive_binary_data("") if respond_to?(:receive_binary_data)
# Do no more work here. Stay in line mode and keep consuming data.
else
@lbp_binary_limit = size.to_i # (nil will be stored as zero)
if @lbp_binary_limit > 0
raise "Overlength" if @lbp_binary_limit > MaxBinaryLength # arbitrary sanity check
@lbp_binary_buffer = "\0" * @lbp_binary_limit
@lbp_binary_bytes_received = 0
end
@lbp_mode = :binary
receive_data @lpb_buffer.flush
end
else
raise "invalid operation"
end
end
#--
# For internal use, establish protocol baseline for handling lines.
def lbp_init_line_state
@lpb_buffer = BufferedTokenizer.new("\n")
@lbp_mode = :lines
end
private :lbp_init_line_state
end
end
end