Open Mash Cross Reference
mash/tcl/nsdr/source-mega.tcl

   # source-mega.tcl --
   #
   #       Used to tie-in SAP announcments with MeGa.
   #
   # Copyright (c) 1997-2002 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.
  
  import AnnounceListenManager/AS/Client/MeGa
  
  #FIXME making this class is a temporary hack
  Class AnnounceListenManager/SAP/MeGa -superclass AnnounceListenManager/SAP
  
  #
  AnnounceListenManager/SAP/MeGa public init {s spec {mtu 2048} } {
      $self next $spec $mtu
      $self set s_ $s
  }
  
  #
  AnnounceListenManager/SAP/MeGa private recv_announcement {args} {
      $self instvar s_
      eval $s_ recv $self $args
  }
  
  #FIXME
  AnnounceListenManager/SAP/MeGa private incrnsrcs {args} {}
  AnnounceListenManager/SAP/MeGa private sample_size {args} {}
  AnnounceListenManager/SAP/MeGa private interval {args} { return 0 }
  
  
  # Receives program announcements via SAP and uses the MeGa
  # architecture to receive announcements through a proxy.  (See
  # <a href=http://www.cs.berkeley.edu/~elan/mega/>Elan's MeGa page</a>
  # for more info about MeGa...)
  Class ProgramSource/SAP/MeGa -superclass ProgramSource/SAP
  
  # Initializes a new object.  Arguments have the same meaning as
  # for ProgramSource/SAP::init but there can be only a single address
  # rather than a list of them.
  ProgramSource/SAP/MeGa public init {ui addr} {
      # need to do these things before calling next constructor
      $self set name_ "MeGa Proxy: $addr"
      set addr [intoa [lookup_host_addr $addr]]
      set d [$self get_option cachedir]
      if {$d != ""} {
          $self set cache_ [file join $d $addr]
      }
  
      eval $self next $ui
  
      $self instvar app_
      set app_ [Application instance]
  
      $self instvar bw_
      set bw_ [$app_ get_option megaBW]
      # use 2% of capacity for sdp gateway
      set bw [expr 0.02 * $bw_]
  
      set spec "$addr/60000:10002/1"
      $app_ add_default megaStartupWait 60
      set sname sdp:0:0:IN:IP4:224.2.127.254
      set sspec 224.2.127.254/9875/127
      $app_ add_default megaCtrl $spec
      set rportspec 10000:10002
  
      $self instvar al_
      set loc [$self get_option serviceLocation]
      set al_ [new AnnounceListenManager/AS/Client/MeGa $self \
                   $spec $bw Nsdr sdp $sname $sspec $rportspec null $loc]
      $al_ start
  }
  
  # Used to set the name of the tag for this program source in the
  # user interface.
  ProgramSource/SAP/MeGa public name {} {
      return [$self set name_]
 }
 
 # Invoked by MeGa to tell the object it should listen for SAP
 # messages on the address/port given by <i>spec</i>.
 ProgramSource/SAP/MeGa public reset_spec {spec} {
     set l [split $spec /]
 
     $self instvar addr_ sport_ rport_ ttl_
     set addr_ [lindex $l 0]
     set ports [split [lindex $l 1] :]
     set sport_ [lindex $ports 0]
     set rport_ [lindex $ports 1]
     set ttl_ [lindex $l 3]
 
     $self instvar addrs_
     foreach a $addrs_ {
         delete $a
     }
     set addrs_ {}
     set s $addr_/$sport_:$rport_/$ttl_
     lappend addrs_ [new AnnounceListenManager/SAP/MeGa $self $s]
 }
 
 ProgramSource/SAP/MeGa public scopes {} {
     #FIXME
     return {}
 }
 
 #FIXME should this stuff be in AnnounceListenManager/MeGa/Client ?
 ProgramSource/SAP/MeGa instproc have_network {} {
     $self instvar addr_
     return [info exists addr_]
 }
 
 ProgramSource/SAP/MeGa instproc session-addr {} {
     $self instvar addr_
     return $addr_
 }
 
 ProgramSource/SAP/MeGa instproc session-sport {} {
     $self instvar sport_
     return $sport_
 }
 
 ProgramSource/SAP/MeGa instproc session-rport {} {
     $self instvar rport_
     return $rport_
 }
 
 ProgramSource/SAP/MeGa instproc session-ttl {} {
     $self instvar ttl_
     return $ttl_
 }