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



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# 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)


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

def active?
  @active
end

#closeObject

Close the stream

Waits for acknowledge from peer, may throw ServerError



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# 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

#flushObject

Empty the send-buffer by sending remaining data



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# 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

#readObject

Receive data

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



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# 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


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# 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