Class: Jabber::Bytestreams::IBB

Inherits:
Object
  • Object
show all
Defined in:
lib/xmpp4r/bytestreams/helper/ibb/base.rb

Overview

In-Band Bytestreams (JEP-0047) implementation

Don’t use directly, use IBBInitiator and IBBTarget

In-Band Bytestreams should only be used when transferring very small amounts of binary data, because it is slow and increases server load drastically.

Note that the constructor takes a lot of arguments. In-Band Bytestreams do not specify a way to initiate the stream, this should be done via Stream Initiation.

Direct Known Subclasses

IBBInitiator, IBBTarget

Constant Summary collapse

NS_IBB = 
'http://jabber.org/protocol/ibb'

Instance Method Summary collapse

Constructor Details

#initialize(stream, session_id, my_jid, peer_jid) ⇒ IBB

Create a new bytestream

Will register a <message/> callback to intercept data of this stream. This data will be buffered, you can retrieve it with receive



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
 
# File 'lib/xmpp4r/bytestreams/helper/ibb/base.rb', line 30

def initialize(stream, session_id, my_jid, peer_jid)
  @stream = stream
  @session_id = session_id
  @my_jid = (my_jid.kind_of?(String) ? JID.new(my_jid) : my_jid)
  @peer_jid = (peer_jid.kind_of?(String) ? JID.new(peer_jid) : peer_jid)

  @active = false
  @seq_send = 0
  @seq_recv = 0
  @queue = []
  @queue_lock = Mutex.new
  @pending = Semaphore.new
  @sendbuf = ''
  @sendbuf_lock = Mutex.new

  @block_size = 4096  # Recommended by JEP0047
end

Instance Method Details

#active? ⇒ Boolean

Returns:

  • (Boolean) 


48
49
50
 
# File 'lib/xmpp4r/bytestreams/helper/ibb/base.rb', line 48

def active?
  @active
end

#close ⇒ Object

Close the stream

Waits for acknowledge from peer, may throw ServerError



128
129
130
131
132
133
134
135
136
137
138
139
140
 
# File 'lib/xmpp4r/bytestreams/helper/ibb/base.rb', line 128

def close
  if active?
    flush
    deactivate

    iq = Iq.new(:set, @peer_jid)
    close = iq.add REXML::Element.new('close')
    close.add_namespace IBB::NS_IBB
    close.attributes['sid'] = @session_id

    @stream.send_with_id(iq)
  end
end

#flush ⇒ Object

Empty the send-buffer by sending remaining data



72
73
74
75
76
77
78
79
 
# File 'lib/xmpp4r/bytestreams/helper/ibb/base.rb', line 72

def flush
  @sendbuf_lock.synchronize {
    while @sendbuf.size > 0
      send_data(@sendbuf[0..@block_size-1])
      @sendbuf = @sendbuf[@block_size..-1].to_s
    end
  }
end

#read ⇒ Object

Receive data

Will wait until the Message with the next sequence number is in the stanza queue.



86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
 
# File 'lib/xmpp4r/bytestreams/helper/ibb/base.rb', line 86

def read
  if active?
    res = nil

    while res.nil?
      @queue_lock.synchronize {
        @queue.each { |item|
          # Find next data
          if item.type == :data and item.seq == @seq_recv.to_s
            res = item
            break
          # No data? Find close
          elsif item.type == :close and res.nil?
            res = item
          end
        }

        @queue.delete_if { |item| item == res }
      }

      # No data? Wait for next to arrive...
      @pending.wait unless res
    end

    if res.type == :data
      @seq_recv += 1
      @seq_recv = 0 if @seq_recv > 65535
      res.data
    elsif res.type == :close
      deactivate
      nil # Closed
    end
  else
    nil
  end
end

#write(buf) ⇒ Object

Send data

Data is buffered to match block_size in each packet. If you need the data to be sent immediately, use flush afterwards.

buf
String 


59
60
61
62
63
64
65
66
67
68
 
# File 'lib/xmpp4r/bytestreams/helper/ibb/base.rb', line 59

def write(buf)
  @sendbuf_lock.synchronize {
    @sendbuf += buf

    while @sendbuf.size >= @block_size
      send_data(@sendbuf[0..@block_size-1])
      @sendbuf = @sendbuf[@block_size..-1].to_s
    end
  }
end