manager.rb in opentelemetry-api-0.17.0

- old
+ new
@@ -4,38 +4,101 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
 module OpenTelemetry
   module Baggage
-    # No op implementation of Baggage::Manager
+    # Operational Baggage Manager implementation
     class Manager
-      NOOP_BUILDER = Builder.new
-      EMPTY_VALUES = {}.freeze
-      private_constant(:NOOP_BUILDER, :EMPTY_VALUES)
+      BAGGAGE_KEY = OpenTelemetry::Baggage::Propagation::ContextKeys.baggage_key
+      EMPTY_BAGGAGE = {}.freeze
+      private_constant(:BAGGAGE_KEY, :EMPTY_BAGGAGE)
 
+      # Used to chain modifications to baggage. The result is a
+      # context with an updated baggage. If only a single
+      # modification is being made to baggage, use the other
+      # methods on +Manager+, if multiple modifications are being made, use
+      # this one.
+      #
+      # @param [optional Context] context The context to update with with new
+      #   modified baggage. Defaults to +Context.current+
+      # @return [Context]
       def build(context: Context.current)
-        yield NOOP_BUILDER
-        context
+        builder = Builder.new(baggage_for(context).dup)
+        yield builder
+        context.set_value(BAGGAGE_KEY, builder.entries)
       end
 
-      def set_value(key, value, context: Context.current)
-        context
+      # Returns a new context with empty baggage
+      #
+      # @param [optional Context] context Context to clear baggage from. Defaults
+      #   to +Context.current+
+      # @return [Context]
+      def clear(context: Context.current)
+        context.set_value(BAGGAGE_KEY, EMPTY_BAGGAGE)
       end
 
+      # Returns the corresponding baggage.entry (or nil) for key
+      #
+      # @param [String] key The lookup key
+      # @param [optional Context] context The context from which to retrieve
+      #   the key.
+      #   Defaults to +Context.current+
+      # @return [String]
       def value(key, context: Context.current)
-        nil
+        baggage_for(context)[key]&.value
       end
 
+      # Returns the baggage
+      #
+      # @param [optional Context] context The context from which to retrieve
+      #   the baggage.
+      #   Defaults to +Context.current+
+      # @return [Hash]
       def values(context: Context.current)
-        EMPTY_VALUES
+        baggage_for(context).transform_values(&:value)
       end
 
+      # @api private
+      def raw_entries(context: Context.current)
+        baggage_for(context).dup.freeze
+      end
+
+      # Returns a new context with new key-value pair
+      #
+      # @param [String] key The key to store this value under
+      # @param [String] value String value to be stored under key
+      # @param [optional String] metadata This is here to store properties
+      #   received from other W3C Baggage impelmentations but is not exposed in
+      #   OpenTelemetry. This is condsidered private API and not for use by
+      #   end-users.
+      # @param [optional Context] context The context to update with new
+      #   value. Defaults to +Context.current+
+      # @return [Context]
+      def set_value(key, value, metadata: nil, context: Context.current)
+        new_baggage = baggage_for(context).dup
+        new_baggage[key] = Entry.new(value, metadata)
+        context.set_value(BAGGAGE_KEY, new_baggage)
+      end
+
+      # Returns a new context with value at key removed
+      #
+      # @param [String] key The key to remove
+      # @param [optional Context] context The context to remove baggage
+      #   from. Defaults to +Context.current+
+      # @return [Context]
       def remove_value(key, context: Context.current)
-        context
+        baggage = baggage_for(context)
+        return context unless baggage.key?(key)
+
+        new_baggage = baggage.dup
+        new_baggage.delete(key)
+        context.set_value(BAGGAGE_KEY, new_baggage)
       end
 
-      def clear(context: Context.current)
-        context
+      private
+
+      def baggage_for(context)
+        context.value(BAGGAGE_KEY) || EMPTY_BAGGAGE
       end
     end
   end
 end