snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

stats/opentelemetry/server_tracing.go

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package opentelemetry
+
+import (
+	"context"
+	"log"
+	"strings"
+
+	"go.opentelemetry.io/otel/trace"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/stats"
+	otelinternaltracing "google.golang.org/grpc/stats/opentelemetry/internal/tracing"
+)
+
+type serverTracingHandler struct {
+	options Options
+}
+
+func (h *serverTracingHandler) initializeTraces() {
+	if h.options.TraceOptions.TracerProvider == nil {
+		log.Printf("TracerProvider is not provided in server TraceOptions")
+		return
+	}
+}
+
+// TagRPC implements per RPC attempt context management for traces.
+func (h *serverTracingHandler) TagRPC(ctx context.Context, info *stats.RPCTagInfo) context.Context {
+	ctx, ri := getOrCreateServerRPCInfo(ctx, info, h.options.MetricsOptions)
+	ctx, _ = h.traceTagRPC(ctx, ri.ai)
+	return ctx
+}
+
+// traceTagRPC populates context with new span data using the TextMapPropagator
+// supplied in trace options and internal itracing.Carrier. It creates a new
+// incoming carrier which extracts an existing span context (if present) by
+// deserializing from provided context. If valid span context is extracted, it
+// is set as parent of the new span otherwise new span remains the root span.
+// If TextMapPropagator is not provided in the trace options, it returns context
+// as is.
+func (h *serverTracingHandler) traceTagRPC(ctx context.Context, ai *attemptInfo) (context.Context, *attemptInfo) {
+	mn := "Recv." + strings.Replace(ai.method, "/", ".", -1)
+	var span trace.Span
+	tracer := h.options.TraceOptions.TracerProvider.Tracer(tracerName, trace.WithInstrumentationVersion(grpc.Version))
+	ctx = h.options.TraceOptions.TextMapPropagator.Extract(ctx, otelinternaltracing.NewIncomingCarrier(ctx))
+	// If the context.Context provided in `ctx` to tracer.Start(), contains a
+	// span then the newly-created Span will be a child of that span,
+	// otherwise it will be a root span.
+	ctx, span = tracer.Start(ctx, mn, trace.WithSpanKind(trace.SpanKindServer))
+	ai.traceSpan = span
+	return ctx, ai
+}
+
+// HandleRPC handles per RPC tracing implementation.
+func (h *serverTracingHandler) HandleRPC(ctx context.Context, rs stats.RPCStats) {
+	ri := serverRPCInfo(ctx)
+	if ri == nil {
+		logger.Error("ctx passed into server side tracing handler trace event handling has no server call data present")
+		return
+	}
+	populateSpan(rs, ri.ai)
+}
+
+// TagConn exists to satisfy stats.Handler for tracing.
+func (h *serverTracingHandler) TagConn(ctx context.Context, _ *stats.ConnTagInfo) context.Context {
+	return ctx
+}
+
+// HandleConn exists to satisfy stats.Handler for tracing.
+func (h *serverTracingHandler) HandleConn(context.Context, stats.ConnStats) {}