Open Mash Cross Reference
mash/tcl/net/session-addr.tcl

   
   # Copyright (c) 2003 The Regents of the University of California.
   # All rights reserved.
   #
   # Redistribution and use in source and binary forms, with or without
   # modification, are permitted provided that the following conditions are met:
   #
   # A. Redistributions of source code must retain the above copyright notice,
   #    this list of conditions and the following disclaimer.
  # B. Redistributions in binary form must reproduce the above copyright notice,
  #    this list of conditions and the following disclaimer in the documentation
  #    and/or other materials provided with the distribution.
  # C. Neither the names of the copyright holders nor the names of its
  #    contributors may be used to endorse or promote products derived from this
  #    software without specific prior written permission.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
  # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  # ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
  # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  #
  # @(#) $Header: /usr/mash/src/repository/mash/mash-1/tcl/net/session-addr.tcl,v 1.1 2003/06/03 20:06:46 aswan Exp $
  
  #
  # SessionAddress is a base class that may be overridden
  # but should not be directly instantiated.  Its purpose
  # is to allow different types of networks
  # (e.g., IPv4, IPv6, application-level multicast) to exist
  # easily without requiring the rtp or media processing
  # code to understand all the different types.
  #
  # In particular, a SessionAddress contains the logic
  # to parse a user entered specification for a network
  # session (e.g., the specification "224.2.2.2/2222" is
  # shorthand for IPv4 multicast group 224.2.2.2 and UDP
  # port 2222).  A new subclass of SessionAddress should
  # be created for any new network type and the logic in
  # SessionAddress::parse below should be updated to
  # recognize the new specification.
  #
  # A new subclass of SessionAddress must override the
  # methods listed below and must set the instance
  # variable network_class_ which indicates what type
  # of network object should be created for this type
  # of session.
  #
  
  Class SessionAddress
  
  #XXX
  # this must go after the declaration of the SessionAddress
  # class so that SessionAddress exists when subclasses of
  # it are declared.
  
  import AddressBlock SessionAddress/SimpleRelay
  
  SessionAddress instproc init {} {
          $self next
  
          $self instvar network_class_
          set network_class_ UNKNOWN
  }
  
  SessionAddress instproc net-class {} {
          $self instvar network_class_
          return $network_class_
  }
  
  # addr, sport, rport, ttl take optional layer argument
  foreach method [list "fmt" "nchan" "maxbw" "addr" "sport" "rport" "ttl"] {
          SessionAddress instproc $method {args} "error \"\[\$self info class] does not implement method $method\""
  }
  
  
  SessionAddress proc parse { spec } {
          if [string match "relay:*" $spec] {
                  return [new SessionAddress/SimpleRelay $spec]
          }
          return [new AddressBlock $spec]
  }