Fresh start

1 files changed, 480 insertions, 0 deletions

diff --git a/jni/ruby/lib/rinda/ring.rb b/jni/ruby/lib/rinda/ring.rb
new file mode 100644
index 0000000..fe33420
--- /dev/null
+++ b/jni/ruby/lib/rinda/ring.rb
@@ -0,0 +1,480 @@
+#
+# Note: Rinda::Ring API is unstable.
+#
+require 'drb/drb'
+require 'rinda/rinda'
+require 'thread'
+require 'ipaddr'
+
+module Rinda
+
+  ##
+  # The default port Ring discovery will use.
+
+  Ring_PORT = 7647
+
+  ##
+  # A RingServer allows a Rinda::TupleSpace to be located via UDP broadcasts.
+  # Default service location uses the following steps:
+  #
+  # 1. A RingServer begins listening on the network 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.
+  #
+  # A RingServer requires a TupleSpace:
+  #
+  #   ts = Rinda::TupleSpace.new
+  #   rs = Rinda::RingServer.new
+  #
+  # RingServer can also listen on multicast addresses for announcements.  This
+  # allows multiple RingServers to run on the same host.  To use network
+  # broadcast and multicast:
+  #
+  #   ts = Rinda::TupleSpace.new
+  #   rs = Rinda::RingServer.new ts, %w[Socket::INADDR_ANY, 239.0.0.1 ff02::1]
+
+  class RingServer
+
+    include DRbUndumped
+
+    ##
+    # Special renewer for the RingServer to allow shutdown
+
+    class Renewer # :nodoc:
+      include DRbUndumped
+
+      ##
+      # Set to false to shutdown future requests using this Renewer
+
+      attr_writer :renew
+
+      def initialize # :nodoc:
+        @renew = true
+      end
+
+      def renew # :nodoc:
+        @renew ? 1 : true
+      end
+    end
+
+    ##
+    # Advertises +ts+ on the given +addresses+ at +port+.
+    #
+    # If +addresses+ is omitted only the UDP broadcast address is used.
+    #
+    # +addresses+ can contain multiple addresses.  If a multicast address is
+    # given in +addresses+ then the RingServer will listen for multicast
+    # queries.
+    #
+    # If you use IPv4 multicast you may need to set an address of the inbound
+    # interface which joins a multicast group.
+    #
+    #   ts = Rinda::TupleSpace.new
+    #   rs = Rinda::RingServer.new(ts, [['239.0.0.1', '9.5.1.1']])
+    #
+    # You can set addresses as an Array Object.  The first element of the
+    # Array is a multicast address and the second is an inbound interface
+    # address.  If the second is omitted then '0.0.0.0' is used.
+    #
+    # If you use IPv6 multicast you may need to set both the local interface
+    # address and the inbound interface index:
+    #
+    #   rs = Rinda::RingServer.new(ts, [['ff02::1', '::1', 1]])
+    #
+    # The first element is a multicast address and the second is an inbound
+    # interface address.  The third is an inbound interface index.
+    #
+    # At this time there is no easy way to get an interface index by name.
+    #
+    # If the second is omitted then '::1' is used.
+    # If the third is omitted then 0 (default interface) is used.
+
+    def initialize(ts, addresses=[Socket::INADDR_ANY], port=Ring_PORT)
+      @port = port
+
+      if Integer === addresses then
+        addresses, @port = [Socket::INADDR_ANY], addresses
+      end
+
+      @renewer = Renewer.new
+
+      @ts = ts
+      @sockets = []
+      addresses.each do |address|
+        if Array === address
+          make_socket(*address)
+        else
+          make_socket(address)
+        end
+      end
+
+      @w_services = write_services
+      @r_service  = reply_service
+    end
+
+    ##
+    # Creates a socket at +address+
+    #
+    # If +address+ is multicast address then +interface_address+ and
+    # +multicast_interface+ can be set as optional.
+    #
+    # A created socket is bound to +interface_address+.  If you use IPv4
+    # multicast then the interface of +interface_address+ is used as the
+    # inbound interface.  If +interface_address+ is omitted or nil then
+    # '0.0.0.0' or '::1' is used.
+    #
+    # If you use IPv6 multicast then +multicast_interface+ is used as the
+    # inbound interface.  +multicast_interface+ is a network interface index.
+    # If +multicast_interface+ is omitted then 0 (default interface) is used.
+
+    def make_socket(address, interface_address=nil, multicast_interface=0)
+      addrinfo = Addrinfo.udp(address, @port)
+
+      socket = Socket.new(addrinfo.pfamily, addrinfo.socktype,
+                          addrinfo.protocol)
+      @sockets << socket
+
+      if addrinfo.ipv4_multicast? or addrinfo.ipv6_multicast? then
+        if Socket.const_defined?(:SO_REUSEPORT) then
+          socket.setsockopt(:SOCKET, :SO_REUSEPORT, true)
+        else
+          socket.setsockopt(:SOCKET, :SO_REUSEADDR, true)
+        end
+
+        if addrinfo.ipv4_multicast? then
+          interface_address = '0.0.0.0' if interface_address.nil?
+          socket.bind(Addrinfo.udp(interface_address, @port))
+
+          mreq = IPAddr.new(addrinfo.ip_address).hton +
+            IPAddr.new(interface_address).hton
+
+          socket.setsockopt(:IPPROTO_IP, :IP_ADD_MEMBERSHIP, mreq)
+        else
+          interface_address = '::1' if interface_address.nil?
+          socket.bind(Addrinfo.udp(interface_address, @port))
+
+          mreq = IPAddr.new(addrinfo.ip_address).hton +
+            [multicast_interface].pack('I')
+
+          socket.setsockopt(:IPPROTO_IPV6, :IPV6_JOIN_GROUP, mreq)
+        end
+      else
+        socket.bind(addrinfo)
+      end
+
+      socket
+    end
+
+    ##
+    # Creates threads that pick up UDP packets and passes them to do_write for
+    # decoding.
+
+    def write_services
+      @sockets.map do |s|
+        Thread.new(s) do |socket|
+          loop do
+            msg = socket.recv(1024)
+            do_write(msg)
+          end
+        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, nil], @renewer)
+      Thread.new { tuple[1].call(@ts) rescue nil}
+    rescue
+    end
+
+    ##
+    # Shuts down the RingServer
+
+    def shutdown
+      @renewer.renew = false
+
+      @w_services.each do |thread|
+        thread.kill
+        thread.join
+      end
+
+      @sockets.each do |socket|
+        socket.close
+      end
+
+      @r_service.kill
+      @r_service.join
+    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.
+  #
+  # To find the first available remote TupleSpace:
+  #
+  #   Rinda::RingFinger.primary
+  #
+  # To create a RingFinger that broadcasts to a custom list:
+  #
+  #   rf = Rinda::RingFinger.new  ['localhost', '192.0.2.1']
+  #   rf.primary
+  #
+  # Rinda::RingFinger also understands multicast addresses and sets them up
+  # properly.  This allows you to run multiple RingServers on the same host:
+  #
+  #   rf = Rinda::RingFinger.new ['239.0.0.1']
+  #   rf.primary
+  #
+  # You can set the hop count (or TTL) for multicast searches using
+  # #multicast_hops.
+  #
+  # If you use IPv6 multicast you may need to set both an address and the
+  # outbound interface index:
+  #
+  #   rf = Rinda::RingFinger.new ['ff02::1']
+  #   rf.multicast_interface = 1
+  #   rf.primary
+  #
+  # At this time there is no easy way to get an interface index by name.
+
+  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
+
+    ##
+    # Maximum number of hops for sent multicast packets (if using a multicast
+    # address in the broadcast list).  The default is 1 (same as UDP
+    # broadcast).
+
+    attr_accessor :multicast_hops
+
+    ##
+    # The interface index to send IPv6 multicast packets from.
+
+    attr_accessor :multicast_interface
+
+    ##
+    # 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+.
+    #
+    # If +broadcast_list+ contains a multicast address then multicast queries
+    # will be made using the given multicast_hops and multicast_interface.
+
+    def initialize(broadcast_list=@@broadcast_list, port=Ring_PORT)
+      @broadcast_list = broadcast_list || ['localhost']
+      @port = port
+      @primary = nil
+      @rings = []
+
+      @multicast_hops = 1
+      @multicast_interface = 0
+    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|
+        send_message(it, msg)
+      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
+
+      Thread.new do
+        self.lookup_ring(timeout) do |ts|
+          queue.push(ts)
+        end
+        queue.push(nil)
+      end
+
+      @primary = queue.pop
+      raise('RingNotFound') if @primary.nil?
+
+      Thread.new do
+        while it = queue.pop
+          @rings.push(it)
+        end
+      end
+
+      @primary
+    end
+
+    ##
+    # Creates a socket for +address+ with the appropriate multicast options
+    # for multicast addresses.
+
+    def make_socket(address) # :nodoc:
+      addrinfo = Addrinfo.udp(address, @port)
+
+      soc = Socket.new(addrinfo.pfamily, addrinfo.socktype, addrinfo.protocol)
+      begin
+        if addrinfo.ipv4_multicast? then
+          soc.setsockopt(Socket::Option.ipv4_multicast_loop(1))
+          soc.setsockopt(Socket::Option.ipv4_multicast_ttl(@multicast_hops))
+        elsif addrinfo.ipv6_multicast? then
+          soc.setsockopt(:IPPROTO_IPV6, :IPV6_MULTICAST_LOOP, true)
+          soc.setsockopt(:IPPROTO_IPV6, :IPV6_MULTICAST_HOPS,
+                         [@multicast_hops].pack('I'))
+          soc.setsockopt(:IPPROTO_IPV6, :IPV6_MULTICAST_IF,
+                         [@multicast_interface].pack('I'))
+        else
+          soc.setsockopt(:SOL_SOCKET, :SO_BROADCAST, true)
+        end
+
+        soc.connect(addrinfo)
+      rescue Exception
+        soc.close
+        raise
+      end
+
+      soc
+    end
+
+    def send_message(address, message) # :nodoc:
+      soc = make_socket(address)
+
+      soc.send(message, 0)
+    rescue
+      nil
+    ensure
+      soc.close if soc
+    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