1 files changed, 40 insertions, 20 deletions
diff --git a/activesupport/lib/active_support/log_subscriber.rb b/activesupport/lib/active_support/log_subscriber.rb
index d2a6e1bd82..e5b4ca2738 100644
--- a/activesupport/lib/active_support/log_subscriber.rb
+++ b/activesupport/lib/active_support/log_subscriber.rb
@@ -48,20 +48,19 @@ module ActiveSupport
     mattr_accessor :colorize_logging
     self.colorize_logging = true
 
-    class_attribute :logger
-
     class << self
-      remove_method :logger
       def logger
         @logger ||= Rails.logger if defined?(Rails)
+        @logger
       end
 
+      attr_writer :logger
+
       def attach_to(namespace, log_subscriber=new, notifier=ActiveSupport::Notifications)
         log_subscribers << log_subscriber
-        @@flushable_loggers = nil
 
         log_subscriber.public_methods(false).each do |event|
-          next if 'call' == event.to_s
+          next if %w{ start finish }.include?(event.to_s)
 
           notifier.subscribe("#{event}.#{namespace}", log_subscriber)
         end
@@ -71,29 +70,44 @@ module ActiveSupport
         @@log_subscribers ||= []
       end
 
-      def flushable_loggers
-        @@flushable_loggers ||= begin
-          loggers = log_subscribers.map(&:logger)
-          loggers.uniq!
-          loggers.select! { |l| l.respond_to?(:flush) }
-          loggers
-        end
-      end
-
       # Flush all log_subscribers' logger.
       def flush_all!
-        flushable_loggers.each { |log| log.flush }
+        logger.flush if logger.respond_to?(:flush)
       end
     end
 
-    def call(message, *args)
+    def initialize
+      @queue_key = [self.class.name, object_id].join  "-"
+      super
+    end
+
+    def logger
+      LogSubscriber.logger
+    end
+
+    def start(name, id, payload)
       return unless logger
 
-      method = message.split('.').first
+      e = ActiveSupport::Notifications::Event.new(name, Time.now, nil, id, payload)
+      parent = event_stack.last
+      parent << e if parent
+
+      event_stack.push e
+    end
+
+    def finish(name, id, payload)
+      return unless logger
+
+      finished  = Time.now
+      event     = event_stack.pop
+      event.end = finished
+      event.payload.merge!(payload)
+
+      method = name.split('.').first
       begin
-        send(method, ActiveSupport::Notifications::Event.new(message, *args))
+        send(method, event)
       rescue Exception => e
-        logger.error "Could not log #{message.inspect} event. #{e.class}: #{e.message} #{e.backtrace}"
+        logger.error "Could not log #{name.inspect} event. #{e.class}: #{e.message} #{e.backtrace}"
       end
     end
 
@@ -114,9 +128,15 @@ module ActiveSupport
     #
     def color(text, color, bold=false)
       return text unless colorize_logging
-      color = self.class.const_get(color.to_s.upcase) if color.is_a?(Symbol)
+      color = self.class.const_get(color.upcase) if color.is_a?(Symbol)
       bold  = bold ? BOLD : ""
       "#{bold}#{color}#{text}#{CLEAR}"
     end
+
+    private
+
+    def event_stack
+      Thread.current[@queue_key] ||= []
+    end
   end
 end