span.rb in opentelemetry-sdk-1.5.0

- old
+ new

@@ -116,10 +116,41 @@
             end
           end
           self
         end
 
+        # Add a link to a {Span}.
+        #
+        # Adding links at span creation using the `links` option is preferred
+        # to calling add_link later, because head sampling decisions can only
+        # consider information present during span creation.
+        #
+        # Example:
+        #
+        #   span.add_link(OpenTelemetry::Trace::Link.new(span_to_link_from.context))
+        #
+        # Note that the OpenTelemetry project
+        # {https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/data-semantic-conventions.md
+        # documents} certain "standard attributes" that have prescribed semantic
+        # meanings.
+        #
+        # @param [OpenTelemetry::Trace::Link] the link object to add on the {Span}.
+        #
+        # @return [self] returns itself
+        def add_link(link)
+          @mutex.synchronize do
+            if @ended
+              OpenTelemetry.logger.warn('Calling add_link on an ended Span.')
+            else
+              @links ||= []
+              @links = trim_links(@links << link, @span_limits.link_count_limit, @span_limits.link_attribute_count_limit)
+              @total_recorded_links += 1
+            end
+          end
+          self
+        end
+
         # Add an Event to a {Span}.
         #
         # Example:
         #
         #   span.add_event('event', attributes: {'eager' => true})
@@ -240,10 +271,11 @@
               return self
             end
             @end_timestamp = relative_timestamp(end_timestamp)
             @attributes = validated_attributes(@attributes).freeze
             @events.freeze
+            @links.freeze
             @ended = true
           end
           @span_processors.each { |processor| processor.on_finish(self) }
           self
         end
@@ -371,11 +403,11 @@
           # Fast path (likely) common cases.
           return nil if links.nil?
 
           if links.size <= link_count_limit &&
              links.all? { |link| link.span_context.valid? && link.attributes.size <= link_attribute_count_limit && Internal.valid_attributes?(name, 'link', link.attributes) }
-            return links.frozen? ? links : links.clone.freeze
+            return links
           end
 
           # Slow path: trim attributes for each Link.
           valid_links = links.select { |link| link.span_context.valid? }
           excess_link_count = valid_links.size - link_count_limit
@@ -384,10 +416,10 @@
             attrs = Hash[link.attributes] # link.attributes is frozen, so we need an unfrozen copy to adjust.
             attrs.keep_if { |key, value| Internal.valid_key?(key) && Internal.valid_value?(value) }
             excess = attrs.size - link_attribute_count_limit
             excess.times { attrs.shift } if excess.positive?
             OpenTelemetry::Trace::Link.new(link.span_context, attrs)
-          end.freeze
+          end
         end
 
         def append_event(events, event) # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
           event_count_limit = @span_limits.event_count_limit
           event_attribute_count_limit = @span_limits.event_attribute_count_limit