make span context management public

api/include/opentelemetry/trace/context.h

@@ -0,0 +1,33 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "opentelemetry/context/context.h"
+#include "opentelemetry/trace/default_span.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace trace
+{
+
+// Get Span from explicit context
+inline nostd::shared_ptr<Span> GetSpan(const opentelemetry::context::Context &context)
+{
+  context::ContextValue span = context.GetValue(kSpanKey);
+  if (nostd::holds_alternative<nostd::shared_ptr<Span>>(span))
+  {
+    return nostd::get<nostd::shared_ptr<Span>>(span);
+  }
+  return nostd::shared_ptr<Span>(new DefaultSpan(SpanContext::GetInvalid()));
+}
+
+// Set Span into explicit context
+inline context::Context SetSpan(opentelemetry::context::Context &context,
+                                nostd::shared_ptr<Span> span)
+{
+  return context.SetValue(kSpanKey, span);
+}
+
+}  // namespace trace
+OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/trace/propagation/b3_propagator.h

@@ -3,10 +3,10 @@
 
 #pragma once
 
-#include "detail/context.h"
 #include "detail/hex.h"
 #include "detail/string.h"
 #include "opentelemetry/context/propagation/text_map_propagator.h"
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/default_span.h"
 
 #include <array>
@@ -50,7 +50,7 @@ class B3PropagatorExtractor : public opentelemetry::context::propagation::TextMa
   {
     SpanContext span_context = ExtractImpl(carrier);
     nostd::shared_ptr<Span> sp{new DefaultSpan(span_context)};
-    return SetSpan(context, sp);
+    return trace::SetSpan(context, sp);
   }
 
   static TraceId TraceIdFromHex(nostd::string_view trace_id)
@@ -131,7 +131,7 @@ class B3Propagator : public B3PropagatorExtractor
   void Inject(opentelemetry::context::propagation::TextMapCarrier &carrier,
               const context::Context &context) noexcept override
   {
-    SpanContext span_context = GetSpan(context)->GetContext();
+    SpanContext span_context = trace::GetSpan(context)->GetContext();
     if (!span_context.IsValid())
     {
       return;

api/include/opentelemetry/trace/propagation/http_trace_context.h

@@ -2,11 +2,11 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include <array>
-#include "detail/context.h"
 #include "detail/hex.h"
 #include "detail/string.h"
 #include "opentelemetry/context/propagation/text_map_propagator.h"
 #include "opentelemetry/nostd/string_view.h"
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/default_span.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -34,7 +34,7 @@ class HttpTraceContext : public opentelemetry::context::propagation::TextMapProp
   void Inject(opentelemetry::context::propagation::TextMapCarrier &carrier,
               const context::Context &context) noexcept override
   {
-    SpanContext span_context = GetSpan(context)->GetContext();
+    SpanContext span_context = trace::GetSpan(context)->GetContext();
     if (!span_context.IsValid())
     {
       return;
@@ -47,7 +47,7 @@ class HttpTraceContext : public opentelemetry::context::propagation::TextMapProp
   {
     SpanContext span_context = ExtractImpl(carrier);
     nostd::shared_ptr<Span> sp{new DefaultSpan(span_context)};
-    return SetSpan(context, sp);
+    return trace::SetSpan(context, sp);
   }
 
   static TraceId TraceIdFromHex(nostd::string_view trace_id)

api/include/opentelemetry/trace/propagation/jaeger.h

@@ -3,10 +3,10 @@
 
 #pragma once
 
-#include "detail/context.h"
 #include "detail/hex.h"
 #include "detail/string.h"
 #include "opentelemetry/context/propagation/text_map_propagator.h"
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/default_span.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -23,7 +23,7 @@ class JaegerPropagator : public context::propagation::TextMapPropagator
   void Inject(context::propagation::TextMapCarrier &carrier,
               const context::Context &context) noexcept override
   {
-    SpanContext span_context = GetSpan(context)->GetContext();
+    SpanContext span_context = trace::GetSpan(context)->GetContext();
     if (!span_context.IsValid())
     {
       return;
@@ -53,7 +53,7 @@ class JaegerPropagator : public context::propagation::TextMapPropagator
   {
     SpanContext span_context = ExtractImpl(carrier);
     nostd::shared_ptr<Span> sp{new DefaultSpan(span_context)};
-    return SetSpan(context, sp);
+    return trace::SetSpan(context, sp);
   }
 
   bool Fields(nostd::function_ref<bool(nostd::string_view)> callback) const noexcept override

api/test/trace/propagation/http_text_format_test.cc

@@ -3,6 +3,7 @@
 
 #include "opentelemetry/context/propagation/global_propagator.h"
 #include "opentelemetry/context/runtime_context.h"
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/propagation/http_trace_context.h"
 #include "opentelemetry/trace/scope.h"
 #include "util.h"
@@ -150,7 +151,7 @@ TEST(TextMapPropagatorTest, InvalidIdentitiesAreNotExtracted)
     context::Context ctx1 = context::Context{};
     context::Context ctx2 = format.Extract(carrier, ctx1);
 
-    auto span = trace::propagation::GetSpan(ctx2)->GetContext();
+    auto span = trace::GetSpan(ctx2)->GetContext();
     EXPECT_FALSE(span.IsValid());
   }
 }

api/test/trace/propagation/jaeger_propagation_test.cc

@@ -98,7 +98,7 @@ TEST(JaegerPropagatorTest, ExtractValidSpans)
     context::Context ctx1 = context::Context{};
     context::Context ctx2 = format.Extract(carrier, ctx1);
 
-    auto span = trace::propagation::GetSpan(ctx2)->GetContext();
+    auto span = trace::GetSpan(ctx2)->GetContext();
     EXPECT_TRUE(span.IsValid());
 
     EXPECT_EQ(Hex(span.trace_id()), test_trace.expected_trace_id);
@@ -129,7 +129,7 @@ TEST(JaegerPropagatorTest, ExctractInvalidSpans)
     context::Context ctx1 = context::Context{};
     context::Context ctx2 = format.Extract(carrier, ctx1);
 
-    auto span = trace::propagation::GetSpan(ctx2)->GetContext();
+    auto span = trace::GetSpan(ctx2)->GetContext();
     EXPECT_FALSE(span.IsValid());
   }
 }

api/test/trace/span_benchmark.cc

@@ -2,8 +2,8 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "opentelemetry/nostd/shared_ptr.h"
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/noop.h"
-#include "opentelemetry/trace/propagation/detail/context.h"
 #include "opentelemetry/trace/span_id.h"
 #include "opentelemetry/trace/trace_id.h"
 
@@ -112,7 +112,7 @@ void BM_SpanCreationWitContextPropagation(benchmark::State &state)
     auto outer_span_context = SpanContext(trace_id, span_id, trace_api::TraceFlags(), false);
     auto outer_span =
         nostd::shared_ptr<trace_api::Span>(new trace_api::DefaultSpan(outer_span_context));
-    trace_api::propagation::SetSpan(current_ctx, outer_span);
+    trace_api::SetSpan(current_ctx, outer_span);
     auto inner_child = tracer->StartSpan("inner");
     auto scope       = tracer->WithActiveSpan(inner_child);
     {

examples/grpc/server.cpp

@@ -3,9 +3,11 @@
 #else
 #include "messages.grpc.pb.h"
 #endif
-#include "tracer_common.h"
-#include "opentelemetry/trace/span_context_kv_iterable_view.h"
+
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/semantic_conventions.h"
+#include "opentelemetry/trace/span_context_kv_iterable_view.h"
+#include "tracer_common.h"
 
 #include <grpcpp/grpcpp.h>
 #include <grpcpp/server.h>
@@ -56,7 +58,7 @@ class GreeterServer final : public Greeter::Service
     auto prop = opentelemetry::context::propagation::GlobalTextMapPropagator::GetGlobalPropagator();
     auto current_ctx = opentelemetry::context::RuntimeContext::GetCurrent();
     auto new_context = prop->Extract(carrier, current_ctx);
-    options.parent   = opentelemetry::trace::propagation::GetSpan(new_context)->GetContext();
+    options.parent   = opentelemetry::trace::GetSpan(new_context)->GetContext();
 
     std::string span_name = "GreeterService/Greet";
     auto span             = get_tracer("grpc")

examples/http/server.cc

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "server.h"
+#include "opentelemetry/trace/context.h"
 #include "opentelemetry/trace/semantic_conventions.h"
 #include "tracer_common.h"
 
@@ -12,7 +13,7 @@ namespace
 {
 
 using namespace opentelemetry::trace;
-;
+
 uint16_t server_port              = 8800;
 constexpr const char *server_name = "localhost";
 
@@ -32,7 +33,7 @@ class RequestHandler : public HTTP_SERVER_NS::HttpRequestCallback
     auto prop = opentelemetry::context::propagation::GlobalTextMapPropagator::GetGlobalPropagator();
     auto current_ctx = opentelemetry::context::RuntimeContext::GetCurrent();
     auto new_context = prop->Extract(carrier, current_ctx);
-    options.parent   = opentelemetry::trace::propagation::GetSpan(new_context)->GetContext();
+    options.parent   = GetSpan(new_context)->GetContext();
 
     // start span with parent context extracted from http header
     auto span = get_tracer("http-server")