Notifications: extract central Notifier, cordon off the internal Fanout implementation, and segregate instrumentation concerns

1 files changed, 47 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/notifications/instrumenter.rb b/activesupport/lib/active_support/notifications/instrumenter.rb
new file mode 100644
index 0000000000..fb95422af2
--- /dev/null
+++ b/activesupport/lib/active_support/notifications/instrumenter.rb
@@ -0,0 +1,47 @@
+require 'active_support/secure_random'
+require 'active_support/core_ext/module/delegation'
+
+module ActiveSupport
+  module Notifications
+    class Instrumenter
+      def initialize(notifier)
+        @id = unique_id
+        @notifier = notifier
+      end
+
+      def instrument(name, payload={})
+        time   = Time.now
+        result = yield if block_given?
+      ensure
+        @notifier.publish(name, time, Time.now, result, @id, payload)
+      end
+
+      private
+        def unique_id
+          SecureRandom.hex(10)
+        end
+    end
+
+    class Event
+      attr_reader :name, :time, :end, :transaction_id, :result, :payload
+
+      def initialize(name, start, ending, result, transaction_id, payload)
+        @name           = name
+        @payload        = payload.dup
+        @time           = start
+        @transaction_id = transaction_id
+        @end            = ending
+        @result         = result
+      end
+
+      def duration
+        @duration ||= 1000.0 * (@end - @time)
+      end
+
+      def parent_of?(event)
+        start = (self.time - event.time) * 1000
+        start <= 0 && (start + duration >= event.duration)
+      end
+    end
+  end
+end