class EventMachine::Protocols::LineAndTextProtocol

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.

Constants

MaxBinaryLength

Public Class Methods

new(*args) click to toggle source
Calls superclass method EventMachine::Connection.new
# File lib/em/protocols/line_and_text.rb, line 37
def initialize *args
  super
  lbp_init_line_state
end

Public Instance Methods

receive_data(data) click to toggle source
# File lib/em/protocols/line_and_text.rb, line 41
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 Exception
      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
set_binary_mode(size = nil) click to toggle source

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.

# File lib/em/protocols/line_and_text.rb, line 94
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
unbind() click to toggle source
# File lib/em/protocols/line_and_text.rb, line 76
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

Private Instance Methods

lbp_init_line_state() click to toggle source
# File lib/em/protocols/line_and_text.rb, line 117
def lbp_init_line_state
  @lpb_buffer = BufferedTokenizer.new("\n")
  @lbp_mode = :lines
end