Merge branch 'master' of git://github.com/rails/rails into rails_master

1 files changed, 62 insertions, 40 deletions

diff --git a/activesupport/lib/active_support/notifications.rb b/activesupport/lib/active_support/notifications.rb
index 9eae3bebe2..e2540cd598 100644
--- a/activesupport/lib/active_support/notifications.rb
+++ b/activesupport/lib/active_support/notifications.rb
@@ -41,7 +41,7 @@ module ActiveSupport
   # to subscribers in a thread. You can use any queue implementation you want.
   #
   module Notifications
-    mattr_accessor :queue
+    mattr_accessor :queue, :listener
 
     class << self
       delegate :instrument, :transaction_id, :transaction, :to => :instrumenter
@@ -54,8 +54,13 @@ module ActiveSupport
         @publisher ||= Publisher.new(queue)
       end
 
-      def subscribe(pattern=nil, &block)
-        Subscriber.new(queue).bind(pattern).subscribe(&block)
+      def subscriber
+        @subscriber ||= Subscriber.new(queue)
+      end
+
+      def subscribe(pattern=nil, options={}, &block)
+        with = options[:with] || listener
+        subscriber.bind(with, pattern).subscribe(&block)
       end
     end
 
@@ -104,14 +109,15 @@ module ActiveSupport
         @queue = queue
       end
 
-      def bind(pattern)
-        @pattern = pattern
+      def bind(listener, pattern)
+        @listener = listener
+        @pattern  = pattern
         self
       end
 
       def subscribe
-        @queue.subscribe(@pattern) do |*args|
-          yield *args
+        @queue.subscribe(@listener, @pattern) do |*args|
+          yield(*args)
         end
       end
     end
@@ -138,54 +144,70 @@ module ActiveSupport
       end
     end
 
-    # This is a default queue implementation that ships with Notifications. It
-    # consumes events in a thread and publish them to all registered subscribers.
-    #
-    class LittleFanout
-      def initialize
-        @listeners = []
-        @stream    = Queue.new
+    class AsyncListener
+      def initialize(pattern, &block)
+        @pattern = pattern
+        @subscriber = block
+        @queue = Queue.new
         Thread.new { consume }
       end
 
-      def publish(*args)
-        @stream.push(args)
-      end
-
-      def subscribe(pattern=nil, &block)
-        @listeners << Listener.new(pattern, &block)
+      def publish(name, *args)
+        if !@pattern || @pattern === name.to_s
+          @queue << args.unshift(name)
+        end
       end
 
       def consume
-        while args = @stream.shift
-          @listeners.each { |l| l.publish(*args) }
+        while args = @queue.shift
+          @subscriber.call(*args)
         end
       end
 
-      class Listener
-        # attr_reader :thread
+      def drained?
+        @queue.size.zero?
+      end
+    end
 
-        def initialize(pattern, &block)
-          @pattern = pattern
-          @subscriber = block
-          @queue = Queue.new
-          Thread.new { consume }
-        end
+    class SyncListener
+      def initialize(pattern, &block)
+        @pattern = pattern
+        @subscriber = block
+      end
 
-        def publish(name, *args)
-          if !@pattern || @pattern === name.to_s
-            @queue << args.unshift(name)
-          end
+      def publish(name, *args)
+        if !@pattern || @pattern === name.to_s
+          @subscriber.call(*args.unshift(name))
         end
+      end
 
-        def consume
-          while args = @queue.shift
-            @subscriber.call(*args)
-          end
-        end
+      def drained?
+        true
+      end
+    end
+
+    # This is a default queue implementation that ships with Notifications. It
+    # consumes events in a thread and publish them to all registered subscribers.
+    #
+    class LittleFanout
+      def initialize
+        @listeners = []
+      end
+
+      def publish(*args)
+        @listeners.each { |l| l.publish(*args) }
+      end
+
+      def subscribe(listener, pattern=nil, &block)
+        @listeners << listener.new(pattern, &block)
+      end
+
+      def drained?
+        @listeners.all? &:drained?
       end
     end
   end
 
-  Notifications.queue = Notifications::LittleFanout.new
+  Notifications.queue    = Notifications::LittleFanout.new
+  Notifications.listener = Notifications::AsyncListener
 end