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Diffstat (limited to 'trunk/lib/rinda/ring.rb')
| -rw-r--r-- | trunk/lib/rinda/ring.rb | 271 |
1 files changed, 0 insertions, 271 deletions
diff --git a/trunk/lib/rinda/ring.rb b/trunk/lib/rinda/ring.rb deleted file mode 100644 index f9ef3d1a52..0000000000 --- a/trunk/lib/rinda/ring.rb +++ /dev/null @@ -1,271 +0,0 @@ -# -# Note: Rinda::Ring API is unstable. -# -require 'drb/drb' -require 'rinda/rinda' -require 'thread' - -module Rinda - - ## - # The default port Ring discovery will use. - - Ring_PORT = 7647 - - ## - # A RingServer allows a Rinda::TupleSpace to be located via UDP broadcasts. - # Service location uses the following steps: - # - # 1. A RingServer begins listening on the broadcast UDP address. - # 2. A RingFinger sends a UDP packet containing the DRb URI where it will - # listen for a reply. - # 3. The RingServer receives the UDP packet and connects back to the - # provided DRb URI with the DRb service. - - class RingServer - - include DRbUndumped - - ## - # Advertises +ts+ on the UDP broadcast address at +port+. - - def initialize(ts, port=Ring_PORT) - @ts = ts - @soc = UDPSocket.open - @soc.bind('', port) - @w_service = write_service - @r_service = reply_service - end - - ## - # Creates a thread that picks up UDP packets and passes them to do_write - # for decoding. - - def write_service - Thread.new do - loop do - msg = @soc.recv(1024) - do_write(msg) - end - end - end - - ## - # Extracts the response URI from +msg+ and adds it to TupleSpace where it - # will be picked up by +reply_service+ for notification. - - def do_write(msg) - Thread.new do - begin - tuple, sec = Marshal.load(msg) - @ts.write(tuple, sec) - rescue - end - end - end - - ## - # Creates a thread that notifies waiting clients from the TupleSpace. - - def reply_service - Thread.new do - loop do - do_reply - end - end - end - - ## - # Pulls lookup tuples out of the TupleSpace and sends their DRb object the - # address of the local TupleSpace. - - def do_reply - tuple = @ts.take([:lookup_ring, DRbObject]) - Thread.new { tuple[1].call(@ts) rescue nil} - rescue - end - - end - - ## - # RingFinger is used by RingServer clients to discover the RingServer's - # TupleSpace. Typically, all a client needs to do is call - # RingFinger.primary to retrieve the remote TupleSpace, which it can then - # begin using. - - class RingFinger - - @@broadcast_list = ['<broadcast>', 'localhost'] - - @@finger = nil - - ## - # Creates a singleton RingFinger and looks for a RingServer. Returns the - # created RingFinger. - - def self.finger - unless @@finger - @@finger = self.new - @@finger.lookup_ring_any - end - @@finger - end - - ## - # Returns the first advertised TupleSpace. - - def self.primary - finger.primary - end - - ## - # Contains all discovered TupleSpaces except for the primary. - - def self.to_a - finger.to_a - end - - ## - # The list of addresses where RingFinger will send query packets. - - attr_accessor :broadcast_list - - ## - # The port that RingFinger will send query packets to. - - attr_accessor :port - - ## - # Contain the first advertised TupleSpace after lookup_ring_any is called. - - attr_accessor :primary - - ## - # Creates a new RingFinger that will look for RingServers at +port+ on - # the addresses in +broadcast_list+. - - def initialize(broadcast_list=@@broadcast_list, port=Ring_PORT) - @broadcast_list = broadcast_list || ['localhost'] - @port = port - @primary = nil - @rings = [] - end - - ## - # Contains all discovered TupleSpaces except for the primary. - - def to_a - @rings - end - - ## - # Iterates over all discovered TupleSpaces starting with the primary. - - def each - lookup_ring_any unless @primary - return unless @primary - yield(@primary) - @rings.each { |x| yield(x) } - end - - ## - # Looks up RingServers waiting +timeout+ seconds. RingServers will be - # given +block+ as a callback, which will be called with the remote - # TupleSpace. - - def lookup_ring(timeout=5, &block) - return lookup_ring_any(timeout) unless block_given? - - msg = Marshal.dump([[:lookup_ring, DRbObject.new(block)], timeout]) - @broadcast_list.each do |it| - soc = UDPSocket.open - begin - soc.setsockopt(Socket::SOL_SOCKET, Socket::SO_BROADCAST, true) - soc.send(msg, 0, it, @port) - rescue - nil - ensure - soc.close - end - end - sleep(timeout) - end - - ## - # Returns the first found remote TupleSpace. Any further recovered - # TupleSpaces can be found by calling +to_a+. - - def lookup_ring_any(timeout=5) - queue = Queue.new - - th = Thread.new do - self.lookup_ring(timeout) do |ts| - queue.push(ts) - end - queue.push(nil) - while it = queue.pop - @rings.push(it) - end - end - - @primary = queue.pop - raise('RingNotFound') if @primary.nil? - @primary - end - - end - - ## - # RingProvider uses a RingServer advertised TupleSpace as a name service. - # TupleSpace clients can register themselves with the remote TupleSpace and - # look up other provided services via the remote TupleSpace. - # - # Services are registered with a tuple of the format [:name, klass, - # DRbObject, description]. - - class RingProvider - - ## - # Creates a RingProvider that will provide a +klass+ service running on - # +front+, with a +description+. +renewer+ is optional. - - def initialize(klass, front, desc, renewer = nil) - @tuple = [:name, klass, front, desc] - @renewer = renewer || Rinda::SimpleRenewer.new - end - - ## - # Advertises this service on the primary remote TupleSpace. - - def provide - ts = Rinda::RingFinger.primary - ts.write(@tuple, @renewer) - end - - end - -end - -if __FILE__ == $0 - DRb.start_service - case ARGV.shift - when 's' - require 'rinda/tuplespace' - ts = Rinda::TupleSpace.new - place = Rinda::RingServer.new(ts) - $stdin.gets - when 'w' - finger = Rinda::RingFinger.new(nil) - finger.lookup_ring do |ts| - p ts - ts.write([:hello, :world]) - end - when 'r' - finger = Rinda::RingFinger.new(nil) - finger.lookup_ring do |ts| - p ts - p ts.take([nil, nil]) - end - end -end - |