Merge pull request #2704 from nirebu/nirebu/avoid-string-dup

DataDog · Apr 11, 2023 · 4ce935e · 4ce935e
2 parents c038cdd + 5872e60
commit 4ce935e
Show file tree

Hide file tree

Showing 2 changed files with 30 additions and 12 deletions.
diff --git a/lib/datadog/core/utils/safe_dup.rb b/lib/datadog/core/utils/safe_dup.rb
@@ -18,8 +18,26 @@ def dup
           using RefineNil
         end
 
-        def self.frozen_or_dup(v)
-          v.frozen? ? v : v.dup
+        # String#+@ was introduced in Ruby 2.3
+        if String.method_defined?(:+@) && String.method_defined?(:-@)
+          def self.frozen_or_dup(v)
+            # If the string is not frozen, the +(-v) will:
+            # - first create a frozen deduplicated copy with -v
+            # - then it will dup it more efficiently with +v
+            v.frozen? ? v : +(-v)
+          end
+
+          def self.frozen_dup(v)
+            -v if v
+          end
+        else
+          def self.frozen_or_dup(v)
+            v.frozen? ? v : v.dup
+          end
+
+          def self.frozen_dup(v)
+            v.frozen? ? v : v.dup.freeze
+          end
         end
       end
     end

diff --git a/lib/datadog/tracing/correlation.rb b/lib/datadog/tracing/correlation.rb
@@ -48,18 +48,18 @@ def initialize(
           version: nil
         )
           # Dup and freeze strings so they aren't modified by reference.
-          @env = Core::Utils::SafeDup.frozen_or_dup(env || Datadog.configuration.env).freeze
-          @service = Core::Utils::SafeDup.frozen_or_dup(service || Datadog.configuration.service).freeze
+          @env = Core::Utils::SafeDup.frozen_dup(env || Datadog.configuration.env)
+          @service = Core::Utils::SafeDup.frozen_dup(service || Datadog.configuration.service)
           @span_id = span_id || 0
-          @span_name = Core::Utils::SafeDup.frozen_or_dup(span_name).freeze
-          @span_resource = Core::Utils::SafeDup.frozen_or_dup(span_resource).freeze
-          @span_service = Core::Utils::SafeDup.frozen_or_dup(span_service).freeze
-          @span_type = Core::Utils::SafeDup.frozen_or_dup(span_type).freeze
+          @span_name = Core::Utils::SafeDup.frozen_dup(span_name)
+          @span_resource = Core::Utils::SafeDup.frozen_dup(span_resource)
+          @span_service = Core::Utils::SafeDup.frozen_dup(span_service)
+          @span_type = Core::Utils::SafeDup.frozen_dup(span_type)
           @trace_id = trace_id || 0
-          @trace_name = Core::Utils::SafeDup.frozen_or_dup(trace_name).freeze
-          @trace_resource = Core::Utils::SafeDup.frozen_or_dup(trace_resource).freeze
-          @trace_service = Core::Utils::SafeDup.frozen_or_dup(trace_service).freeze
-          @version = Core::Utils::SafeDup.frozen_or_dup(version || Datadog.configuration.version).freeze
+          @trace_name = Core::Utils::SafeDup.frozen_dup(trace_name)
+          @trace_resource = Core::Utils::SafeDup.frozen_dup(trace_resource)
+          @trace_service = Core::Utils::SafeDup.frozen_dup(trace_service)
+          @version = Core::Utils::SafeDup.frozen_dup(version || Datadog.configuration.version)
         end
 
         def to_log_format