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Diffstat (limited to 'jni/ruby/lib/rinda/ring.rb')
| -rw-r--r-- | jni/ruby/lib/rinda/ring.rb | 480 |
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 |