delivery.rb in freddy-1.2.0

- old
+ new

@@ -1,15 +1,14 @@
 class Freddy
   class Delivery
-    attr_reader :routing_key, :payload, :tag, :trace
+    attr_reader :routing_key, :payload, :tag
 
     def initialize(payload, metadata, routing_key, tag)
       @payload = payload
       @metadata = metadata
       @routing_key = routing_key
       @tag = tag
-      @trace = build_trace(metadata.headers || {})
     end
 
     def correlation_id
       @metadata.correlation_id
     end
@@ -20,19 +19,27 @@
 
     def reply_to
       @metadata.reply_to
     end
 
+    def build_trace(operation_name, tags: {}, force_follows_from: false)
+      carrier = TraceCarrier.new(@metadata)
+      parent =
+        if carrier.has_required_fields? && expecting_response? && !force_follows_from
+          OpenTracing.global_tracer.extract(OpenTracing::FORMAT_TEXT_MAP, carrier)
+        else
+          nil
+        end
+
+      # Creating a child span when the message sender is expecting a response.
+      # Otherwise creating a new trace because the OpenTracing client does not
+      # support FollowsFrom yet.
+      OpenTracing.start_span(operation_name, child_of: parent, tags: tags)
+    end
+
     private
 
-    def build_trace(headers)
-      if headers['x-trace-id'] && headers['x-span-id']
-        Traces::Trace.build_from_existing_trace(
-          id: headers['x-trace-id'],
-          parent_id: headers['x-span-id']
-        )
-      else
-        Traces::Trace.build
-      end
+    def expecting_response?
+      type == 'request'
     end
   end
 end