Move Resource to SDK

api/lib/opentelemetry.rb

@@ -10,7 +10,6 @@
 require 'opentelemetry/distributed_context'
 require 'opentelemetry/internal'
 require 'opentelemetry/metrics'
-require 'opentelemetry/resources'
 require 'opentelemetry/trace'
 require 'opentelemetry/version'
 

sdk/lib/opentelemetry/sdk.rb

@@ -13,5 +13,6 @@ module SDK
 end
 
 require 'opentelemetry/sdk/internal'
+require 'opentelemetry/sdk/resources'
 require 'opentelemetry/sdk/trace'
 require 'opentelemetry/sdk/version'

api/lib/opentelemetry/resources.rb → sdk/lib/opentelemetry/sdk/resources.rb

@@ -4,4 +4,4 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-require 'opentelemetry/resources/resource'
+require 'opentelemetry/sdk/resources/resource'

sdk/lib/opentelemetry/sdk/resources/resource.rb

@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+# Copyright 2019 OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module SDK
+    module Resources
+      # Resource represents a resource, which captures identifying information about the entities
+      # for which telemetry (metrics or traces) is reported.
+      class Resource
+        class << self
+          private :new # rubocop:disable Style/AccessModifierDeclarations
+
+          # Returns a newly created {Resource} with the specified labels
+          #
+          # @param [Hash<String, String>] labels Hash of key-value pairs to be used
+          #   as labels for this resource
+          # @raise [ArgumentError] If label keys and values are not strings
+          # @return [Resource]
+          def create(labels = {})
+            frozen_labels = labels.each_with_object({}) do |(k, v), memo|
+              raise ArgumentError, 'label keys and values must be strings' unless k.is_a?(String) && v.is_a?(String)
+
+              memo[-k] = -v
+            end.freeze
+
+            new(frozen_labels)
+          end
+        end
+
+        # @api private
+        # The constructor is private and only for use internally by the class.
+        # Users should use the {create} factory method to obtain a {Resource}
+        # instance.
+        #
+        # @param [Hash<String, String>] frozen_labels Frozen-hash of frozen-string
+        #  key-value pairs to be used as labels for this resource
+        # @return [Resource]
+        def initialize(frozen_labels)
+          @labels = frozen_labels
+        end
+
+        # Returns an enumerator for labels of this {Resource}
+        #
+        # @return [Enumerator]
+        def label_enumerator
+          @label_enumerator ||= labels.to_enum
+        end
+
+        # Returns a new, merged {Resource} by merging the current {Resource} with
+        # the other {Resource}. In case of a collision, the current {Resource}
+        # takes precedence
+        #
+        # @param [Resource] other The other resource to merge
+        # @return [Resource] A new resource formed by merging the current resource
+        #   with other
+        def merge(other)
+          raise ArgumentError unless other.is_a?(Resource)
+
+          merged_labels = labels.merge(other.labels) do |_, old_v, new_v|
+            old_v.empty? ? new_v : old_v
+          end
+
+          self.class.send(:new, merged_labels.freeze)
+        end
+
+        protected
+
+        attr_reader :labels
+      end
+    end
+  end
+end

sdk/lib/opentelemetry/sdk/trace/tracer.rb

@@ -10,6 +10,7 @@ module Trace
       # {Tracer} is the SDK implementation of {OpenTelemetry::Trace::Tracer}.
       class Tracer < OpenTelemetry::Trace::Tracer
         attr_accessor :active_trace_config
+        attr_accessor :resource # TODO: should this be read-only? If not, how should exporters know when it is updated?
 
         # Returns a new {Tracer} instance.
         #
@@ -20,6 +21,7 @@ def initialize
           @registered_span_processors = []
           @mutex = Mutex.new
           @stopped = false
+          @resource = Resources::Resource.create # TODO: should this initialize from env vars instead?
         end
 
         # Attempts to stop all the activity for this {Tracer}. Calls

api/test/opentelemetry/resources/resource_test.rb → sdk/test/opentelemetry/sdk/resources/resource_test.rb

@@ -6,42 +6,40 @@
 
 require 'test_helper'
 
-describe OpenTelemetry::Resources::Resource do
+describe OpenTelemetry::SDK::Resources::Resource do
+  Resource = OpenTelemetry::SDK::Resources::Resource
+
   describe '.new' do
     it 'is private' do
-      -> { OpenTelemetry::Resources::Resource.new('k1' => 'v1') }\
-        .must_raise(NoMethodError)
+      proc { Resource.new('k1' => 'v1') }.must_raise(NoMethodError)
     end
   end
+
   describe '.create' do
     it 'can be initialized with labels' do
       expected_labels = { 'k1' => 'v1', 'k2' => 'v2' }
-      resource = OpenTelemetry::Resources::Resource.create(expected_labels)
+      resource = Resource.create(expected_labels)
       resource.label_enumerator.to_h.must_equal(expected_labels)
     end
 
     it 'can be empty' do
-      resource = OpenTelemetry::Resources::Resource.create
+      resource = Resource.create
       resource.label_enumerator.to_h.must_be_empty
     end
 
     it 'enforces keys are strings' do
-      -> { OpenTelemetry::Resources::Resource.create(k1: 'v1') }\
-        .must_raise(ArgumentError)
+      proc { Resource.create(k1: 'v1') }.must_raise(ArgumentError)
     end
 
     it 'enforces values are strings' do
-      -> { OpenTelemetry::Resources::Resource.create('k1' => :v1) }\
-        .must_raise(ArgumentError)
+      proc { Resource.create('k1' => :v1) }.must_raise(ArgumentError)
     end
   end
 
   describe '#merge' do
     it 'merges two resources into a third' do
-      res1 = OpenTelemetry::Resources::Resource.create('k1' => 'v1',
-                                                       'k2' => 'v2')
-      res2 = OpenTelemetry::Resources::Resource.create('k3' => 'v3',
-                                                       'k4' => 'v4')
+      res1 = Resource.create('k1' => 'v1', 'k2' => 'v2')
+      res2 = Resource.create('k3' => 'v3', 'k4' => 'v4')
       res3 = res1.merge(res2)
 
       res3.label_enumerator.to_h.must_equal('k1' => 'v1', 'k2' => 'v2',
@@ -51,10 +49,8 @@
     end
 
     it 'does not overwrite receiver\'s keys when value is non-empty' do
-      res1 = OpenTelemetry::Resources::Resource.create('k1' => 'v1',
-                                                       'k2' => 'v2')
-      res2 = OpenTelemetry::Resources::Resource.create('k2' => '2v2',
-                                                       'k3' => '2v3')
+      res1 = Resource.create('k1' => 'v1', 'k2' => 'v2')
+      res2 = Resource.create('k2' => '2v2', 'k3' => '2v3')
       res3 = res1.merge(res2)
 
       res3.label_enumerator.to_h.must_equal('k1' => 'v1',
@@ -63,10 +59,8 @@
     end
 
     it 'overwrites receiver\'s key when value is empty' do
-      res1 = OpenTelemetry::Resources::Resource.create('k1' => 'v1',
-                                                       'k2' => '')
-      res2 = OpenTelemetry::Resources::Resource.create('k2' => '2v2',
-                                                       'k3' => '2v3')
+      res1 = Resource.create('k1' => 'v1', 'k2' => '')
+      res2 = Resource.create('k2' => '2v2', 'k3' => '2v3')
       res3 = res1.merge(res2)
 
       res3.label_enumerator.to_h.must_equal('k1' => 'v1',