Contain the first advertised TupleSpace after #lookup_ring_any is called.
Object
RingFinger is used by RingServer clients to discover the RingServer's TupleSpace. Typically, all a client needs to do is call ::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.
Creates a singleton RingFinger and looks for a RingServer. Returns the created RingFinger.
# File rinda/ring.rb, line 288 def self.finger unless @@finger @@finger = self.new @@finger.lookup_ring_any end @@finger end
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.
# File rinda/ring.rb, line 344 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
Returns the first advertised TupleSpace.
# File rinda/ring.rb, line 299 def self.primary finger.primary end
Iterates over all discovered TupleSpaces starting with the primary.
# File rinda/ring.rb, line 364 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.
# File rinda/ring.rb, line 376 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
.
# File rinda/ring.rb, line 390 def lookup_ring_any(timeout=5) queue = Thread::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