instrumentation.rb in ddtrace-0.20.0

- old
+ new
@@ -1,33 +1,58 @@
+require 'ddtrace/ext/app_types'
 require 'ddtrace/ext/net'
 require 'ddtrace/contrib/dalli/quantize'
 
 module Datadog
   module Contrib
     module Dalli
       # Instruments every interaction with the memcached server
       module Instrumentation
-        module_function
+        def self.included(base)
+          if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.0.0')
+            base.class_eval do
+              alias_method :request_without_datadog, :request
+              remove_method :request
+              include InstanceMethods
+            end
+          else
+            base.send(:prepend, InstanceMethods)
+          end
+        end
 
-        def patch!
-          ::Dalli::Server.class_eval do
-            alias_method :__request, :request
+        # Compatibility shim for Rubies not supporting `.prepend`
+        module InstanceMethodsCompatibility
+          def request(*args, &block)
+            request_without_datadog(*args, &block)
+          end
+        end
 
-            def request(op, *args)
-              pin = Datadog::Pin.get_from(::Dalli)
+        # InstanceMethods - implementing instrumentation
+        module InstanceMethods
+          include InstanceMethodsCompatibility unless Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.0.0')
 
-              pin.tracer.trace(Datadog::Contrib::Dalli::Ext::SPAN_COMMAND) do |span|
-                span.resource = op.to_s.upcase
-                span.service = pin.service
-                span.span_type = pin.app_type
-                span.set_tag(Datadog::Ext::NET::TARGET_HOST, hostname)
-                span.set_tag(Datadog::Ext::NET::TARGET_PORT, port)
-                cmd = Datadog::Contrib::Dalli::Quantize.format_command(op, args)
-                span.set_tag(Datadog::Contrib::Dalli::Ext::TAG_COMMAND, cmd)
+          def request(op, *args)
+            tracer.trace(Datadog::Contrib::Dalli::Ext::SPAN_COMMAND) do |span|
+              span.resource = op.to_s.upcase
+              span.service = datadog_configuration[:service_name]
+              span.span_type = Datadog::Ext::AppTypes::CACHE
+              span.set_tag(Datadog::Ext::NET::TARGET_HOST, hostname)
+              span.set_tag(Datadog::Ext::NET::TARGET_PORT, port)
+              cmd = Datadog::Contrib::Dalli::Quantize.format_command(op, args)
+              span.set_tag(Datadog::Contrib::Dalli::Ext::TAG_COMMAND, cmd)
 
-                __request(op, *args)
-              end
+              super
             end
+          end
+
+          private
+
+          def tracer
+            datadog_configuration[:tracer]
+          end
+
+          def datadog_configuration
+            Datadog.configuration[:dalli]
           end
         end
       end
     end
   end