Class: EventMachine::Protocols::LineAndTextProtocol

Inherits:
Connection
  • Object
show all
Defined in:
lib/em/protocols/line_and_text.rb

Overview

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.

Constant Summary

MaxLineLength =
16*1024
MaxBinaryLength =
32*1024*1024

Instance Attribute Summary

Attributes inherited from Connection

signature

Instance Method Summary (collapse)

Methods inherited from Connection

#close_connection, #close_connection_after_writing, #comm_inactivity_timeout, #comm_inactivity_timeout=, #connection_completed, #detach, #error?, #get_idle_time, #get_peer_cert, #get_peername, #get_pid, #get_proxied_bytes, #get_sock_opt, #get_sockname, #get_status, #notify_readable=, #notify_readable?, #notify_writable=, #notify_writable?, #pause, #paused?, #pending_connect_timeout=, #post_init, #proxy_completed, #proxy_incoming_to, #proxy_target_unbound, #resume, #send_data, #send_datagram, #send_file_data, #set_sock_opt, #ssl_handshake_completed, #ssl_verify_peer, #start_tls, #stop_proxying, #stream_file_data

Constructor Details

- (LineAndTextProtocol) initialize(*args)

A new instance of LineAndTextProtocol



38
39
40
41
# File 'lib/em/protocols/line_and_text.rb', line 38

def initialize *args
  super
  lbp_init_line_state
end

Instance Method Details

- (Object) receive_data(data)



42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
# File 'lib/em/protocols/line_and_text.rb', line 42

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

- (Object) set_binary_mode(size = nil)

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.



95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
# File 'lib/em/protocols/line_and_text.rb', line 95

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

- (Object) unbind



77
78
79
80
81
82
83
# File 'lib/em/protocols/line_and_text.rb', line 77

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