TracerProvider uses TracerConfig as per spec

sdk/include/opentelemetry/sdk/instrumentationscope/scope_configurator.h

@@ -0,0 +1,39 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include <functional>
+#include "instrumentation_scope.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace instrumentationscope
+{
+template <typename T>
+class ScopeConfigurator
+{
+public:
+  static nostd::unique_ptr<ScopeConfigurator> Create(
+      std::function<T(const InstrumentationScope &)> scope_configurator)
+  {
+    return nostd::unique_ptr<ScopeConfigurator>(new ScopeConfigurator(scope_configurator));
+  }
+
+  T ComputeConfig(const InstrumentationScope &instrumentation_scope)
+  {
+    return scope_configurator_(instrumentation_scope);
+  }
+
+private:
+  explicit ScopeConfigurator(
+      const std::function<T(const InstrumentationScope &)> scope_configurator)
+      : scope_configurator_(scope_configurator)
+  {}
+  const std::function<T(const InstrumentationScope &)> scope_configurator_;
+};
+}  // namespace instrumentationscope
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/trace/tracer.h

@@ -15,8 +15,8 @@
 #include "opentelemetry/sdk/trace/sampler.h"
 #include "opentelemetry/sdk/trace/tracer_config.h"
 #include "opentelemetry/sdk/trace/tracer_context.h"
+#include "opentelemetry/trace/noop.h"
 #include "opentelemetry/trace/span.h"
-#include "opentelemetry/trace/span_context_kv_iterable.h"
 #include "opentelemetry/trace/span_startoptions.h"
 #include "opentelemetry/trace/tracer.h"
 #include "opentelemetry/version.h"
@@ -108,6 +108,7 @@ class Tracer final : public opentelemetry::trace::Tracer,
   std::shared_ptr<InstrumentationScope> instrumentation_scope_;
   std::shared_ptr<TracerContext> context_;
   TracerConfig tracer_config_;
+  static const std::shared_ptr<opentelemetry::trace::NoopTracer> kNoopTracer;
 };
 }  // namespace trace
 }  // namespace sdk

sdk/include/opentelemetry/sdk/trace/tracer_config.h

@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include "opentelemetry/sdk/instrumentationscope/scope_configurator.h"
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -25,13 +26,15 @@ class TracerConfig
   static TracerConfig Disabled();
   static TracerConfig Enabled();
   static TracerConfig Default();
+  static const instrumentationscope::ScopeConfigurator<TracerConfig> &DefaultConfigurator();
 
 private:
   explicit TracerConfig(const bool disabled = false) : disabled_(disabled) {}
   bool disabled_;
-  static TracerConfig kDefaultConfig;
-  static TracerConfig kDisabledConfig;
+  static const TracerConfig kDefaultConfig;
+  static const TracerConfig kDisabledConfig;
+  static const instrumentationscope::ScopeConfigurator<TracerConfig> kDefaultTracerConfigurator;
 };
 }  // namespace trace
 }  // namespace sdk
-OPENTELEMETRY_END_NAMESPACE
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/trace/tracer_context.h

@@ -7,12 +7,14 @@
 #include <memory>
 #include <vector>
 
+#include "opentelemetry/sdk/instrumentationscope/scope_configurator.h"
 #include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/id_generator.h"
 #include "opentelemetry/sdk/trace/processor.h"
 #include "opentelemetry/sdk/trace/random_id_generator.h"
 #include "opentelemetry/sdk/trace/sampler.h"
 #include "opentelemetry/sdk/trace/samplers/always_on.h"
+#include "opentelemetry/sdk/trace/tracer_config.h"
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -21,6 +23,8 @@ namespace sdk
 namespace trace
 {
 
+using namespace opentelemetry::sdk::instrumentationscope;
+
 /**
  * A class which stores the TracerProvider context.
  *
@@ -43,7 +47,10 @@ class TracerContext
           opentelemetry::sdk::resource::Resource::Create({}),
       std::unique_ptr<Sampler> sampler = std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler),
       std::unique_ptr<IdGenerator> id_generator =
-          std::unique_ptr<IdGenerator>(new RandomIdGenerator())) noexcept;
+          std::unique_ptr<IdGenerator>(new RandomIdGenerator()),
+      std::unique_ptr<ScopeConfigurator<TracerConfig>> tracer_configurator =
+          std::make_unique<ScopeConfigurator<TracerConfig>>(
+              TracerConfig::DefaultConfigurator())) noexcept;
 
   virtual ~TracerContext() = default;
 
@@ -77,6 +84,8 @@ class TracerContext
    */
   const opentelemetry::sdk::resource::Resource &GetResource() const noexcept;
 
+  ScopeConfigurator<TracerConfig> &GetTracerConfigurator() const noexcept;
+
   /**
    * Obtain the Id Generator associated with this tracer context.
    * @return The ID Generator for this tracer context.
@@ -100,6 +109,7 @@ class TracerContext
   std::unique_ptr<Sampler> sampler_;
   std::unique_ptr<IdGenerator> id_generator_;
   std::unique_ptr<SpanProcessor> processor_;
+  std::unique_ptr<ScopeConfigurator<TracerConfig>> tracer_configurator_;
 };
 
 }  // namespace trace

sdk/include/opentelemetry/sdk/trace/tracer_provider.h

@@ -9,6 +9,7 @@
 
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/string_view.h"
+#include "opentelemetry/sdk/instrumentationscope/scope_configurator.h"
 #include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/id_generator.h"
 #include "opentelemetry/sdk/trace/processor.h"
@@ -27,6 +28,8 @@ namespace sdk
 namespace trace
 {
 
+using namespace opentelemetry::sdk::instrumentationscope;
+
 class OPENTELEMETRY_EXPORT TracerProvider final : public opentelemetry::trace::TracerProvider
 {
 public:
@@ -39,30 +42,30 @@ class OPENTELEMETRY_EXPORT TracerProvider final : public opentelemetry::trace::T
    * not be a nullptr.
    * @param id_generator The custom id generator for this tracer provider. This must
    * not be a nullptr
+   * @param tracer_configurator Provides access to a function that computes the TracerConfig for
+   * Tracers provided by this TracerProvider.
    */
   explicit TracerProvider(
       std::unique_ptr<SpanProcessor> processor,
       const opentelemetry::sdk::resource::Resource &resource =
           opentelemetry::sdk::resource::Resource::Create({}),
       std::unique_ptr<Sampler> sampler = std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler),
       std::unique_ptr<IdGenerator> id_generator =
-          std::unique_ptr<IdGenerator>(new RandomIdGenerator())) noexcept;
+          std::unique_ptr<IdGenerator>(new RandomIdGenerator()),
+      std::unique_ptr<ScopeConfigurator<TracerConfig>> tracer_configurator =
+          std::make_unique<ScopeConfigurator<TracerConfig>>(
+              TracerConfig::DefaultConfigurator())) noexcept;
 
   explicit TracerProvider(
       std::vector<std::unique_ptr<SpanProcessor>> &&processors,
       const opentelemetry::sdk::resource::Resource &resource =
           opentelemetry::sdk::resource::Resource::Create({}),
       std::unique_ptr<Sampler> sampler = std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler),
       std::unique_ptr<IdGenerator> id_generator =
-          std::unique_ptr<IdGenerator>(new RandomIdGenerator())) noexcept;
-
-  //  explicit TracerProvider(
-  //      std::vector<std::unique_ptr<SpanProcessor>> &&processors,
-  //      const opentelemetry::sdk::resource::Resource &resource =
-  //          opentelemetry::sdk::resource::Resource::Create({}),
-  //      std::unique_ptr<Sampler> sampler = std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler),
-  //      std::unique_ptr<IdGenerator> id_generator =
-  //          std::unique_ptr<IdGenerator>(new RandomIdGenerator())) noexcept;
+          std::unique_ptr<IdGenerator>(new RandomIdGenerator()),
+      std::unique_ptr<ScopeConfigurator<TracerConfig>> tracer_configurator =
+          std::make_unique<ScopeConfigurator<TracerConfig>>(
+              TracerConfig::DefaultConfigurator())) noexcept;
 
   /**
    * Initialize a new tracer provider with a specified context
@@ -121,6 +124,9 @@ class OPENTELEMETRY_EXPORT TracerProvider final : public opentelemetry::trace::T
   std::vector<std::shared_ptr<Tracer>> tracers_;
   std::shared_ptr<TracerContext> context_;
   std::mutex lock_;
+
+  // private helper to get TracerConfig from InstrumentationScope using tracer configurator.
+  TracerConfig GetTracerConfig(const InstrumentationScope &instrumentation_scope) const;
 };
 }  // namespace trace
 }  // namespace sdk

sdk/src/trace/CMakeLists.txt

@@ -21,8 +21,7 @@ add_library(
   samplers/trace_id_ratio_factory.cc
   random_id_generator.cc
   random_id_generator_factory.cc
-  tracer_config.cc
-)
+  tracer_config.cc)
 
 set_target_properties(opentelemetry_trace PROPERTIES EXPORT_NAME trace)
 set_target_version(opentelemetry_trace)

sdk/src/trace/tracer.cc

@@ -3,7 +3,6 @@
 
 #include <stdint.h>
 #include <chrono>
-#include <map>
 #include <new>
 #include <utility>
 
@@ -21,7 +20,6 @@
 #include "opentelemetry/trace/noop.h"
 #include "opentelemetry/trace/span.h"
 #include "opentelemetry/trace/span_context.h"
-#include "opentelemetry/trace/span_context_kv_iterable.h"
 #include "opentelemetry/trace/span_id.h"
 #include "opentelemetry/trace/span_startoptions.h"
 #include "opentelemetry/trace/trace_flags.h"
@@ -36,6 +34,8 @@ namespace sdk
 {
 namespace trace
 {
+const std::shared_ptr<opentelemetry::trace::NoopTracer> Tracer::kNoopTracer =
+    std::make_shared<opentelemetry::trace::NoopTracer>();
 
 Tracer::Tracer(std::shared_ptr<TracerContext> context,
                std::unique_ptr<InstrumentationScope> instrumentation_scope,
@@ -54,6 +54,10 @@ nostd::shared_ptr<opentelemetry::trace::Span> Tracer::StartSpan(
   opentelemetry::trace::SpanContext parent_context = GetCurrentSpan()->GetContext();
   if (nostd::holds_alternative<opentelemetry::trace::SpanContext>(options.parent))
   {
+    if (!tracer_config_.IsEnabled())
+    {
+      return kNoopTracer->StartSpan(name, attributes, links, options);
+    }
     auto span_context = nostd::get<opentelemetry::trace::SpanContext>(options.parent);
     if (span_context.IsValid())
     {

sdk/src/trace/tracer_config.cc

@@ -1,6 +1,5 @@
-//
-// Created by sharmapranav on 11/8/24.
-//
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
 
 #include "opentelemetry/sdk/trace/tracer_config.h"
 
@@ -10,8 +9,13 @@ namespace sdk
 namespace trace
 {
 
-TracerConfig TracerConfig::kDefaultConfig  = TracerConfig();
-TracerConfig TracerConfig::kDisabledConfig = TracerConfig(true);
+const TracerConfig TracerConfig::kDefaultConfig  = TracerConfig();
+const TracerConfig TracerConfig::kDisabledConfig = TracerConfig(true);
+
+const instrumentationscope::ScopeConfigurator<TracerConfig>
+    TracerConfig::kDefaultTracerConfigurator =
+        *instrumentationscope::ScopeConfigurator<TracerConfig>::Create(
+            [](const instrumentationscope::InstrumentationScope &) { return Default(); });
 
 TracerConfig TracerConfig::Disabled()
 {
@@ -28,10 +32,15 @@ TracerConfig TracerConfig::Default()
   return kDefaultConfig;
 }
 
+const instrumentationscope::ScopeConfigurator<TracerConfig> &TracerConfig::DefaultConfigurator()
+{
+  return kDefaultTracerConfigurator;
+}
+
 bool TracerConfig::IsEnabled() const noexcept
 {
   return !disabled_;
 }
 }  // namespace trace
 }  // namespace sdk
-OPENTELEMETRY_END_NAMESPACE
+OPENTELEMETRY_END_NAMESPACE

sdk/src/trace/tracer_context.cc

@@ -21,14 +21,17 @@ namespace trace
 {
 namespace resource = opentelemetry::sdk::resource;
 
-TracerContext::TracerContext(std::vector<std::unique_ptr<SpanProcessor>> &&processors,
-                             const resource::Resource &resource,
-                             std::unique_ptr<Sampler> sampler,
-                             std::unique_ptr<IdGenerator> id_generator) noexcept
+TracerContext::TracerContext(
+    std::vector<std::unique_ptr<SpanProcessor>> &&processors,
+    const resource::Resource &resource,
+    std::unique_ptr<Sampler> sampler,
+    std::unique_ptr<IdGenerator> id_generator,
+    std::unique_ptr<ScopeConfigurator<TracerConfig>> tracer_configurator) noexcept
     : resource_(resource),
       sampler_(std::move(sampler)),
       id_generator_(std::move(id_generator)),
-      processor_(std::unique_ptr<SpanProcessor>(new MultiSpanProcessor(std::move(processors))))
+      processor_(std::unique_ptr<SpanProcessor>(new MultiSpanProcessor(std::move(processors)))),
+      tracer_configurator_(std::move(tracer_configurator))
 {}
 
 Sampler &TracerContext::GetSampler() const noexcept
@@ -41,6 +44,11 @@ const resource::Resource &TracerContext::GetResource() const noexcept
   return resource_;
 }
 
+ScopeConfigurator<TracerConfig> &TracerContext::GetTracerConfigurator() const noexcept
+{
+  return *tracer_configurator_;
+}
+
 opentelemetry::sdk::trace::IdGenerator &TracerContext::GetIdGenerator() const noexcept
 {
   return *id_generator_;