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

stats/opentelemetry/trace.go

@@ -0,0 +1,74 @@
+/*
+ * 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 (
+	"go.opentelemetry.io/otel/attribute"
+	otelcodes "go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+)
+
+// populateSpan populates span information based on stats passed in, representing
+// invariants of the RPC lifecycle. It ends the span, triggering its export.
+// This function handles attempt spans on the client-side and call spans on the
+// server-side.
+func populateSpan(rs stats.RPCStats, ai *attemptInfo) {
+	if ai == nil || ai.traceSpan == nil {
+		// Shouldn't happen, tagRPC call comes before this function gets called
+		// which populates this information.
+		logger.Error("ctx passed into stats handler tracing event handling has no traceSpan present")
+		return
+	}
+	span := ai.traceSpan
+
+	switch rs := rs.(type) {
+	case *stats.DelayedPickComplete:
+		span.AddEvent("Delayed LB pick complete")
+	case *stats.InPayload:
+		// message id - "must be calculated as two different counters starting
+		// from one for sent messages and one for received messages."
+		attrs := []attribute.KeyValue{
+			attribute.Int64("sequence-number", int64(ai.countRecvMsg)),
+			attribute.Int64("message-size", int64(rs.Length)),
+		}
+		if rs.CompressedLength != rs.Length {
+			attrs = append(attrs, attribute.Int64("message-size-compressed", int64(rs.CompressedLength)))
+		}
+		span.AddEvent("Inbound message", trace.WithAttributes(attrs...))
+		ai.countRecvMsg++
+	case *stats.OutPayload:
+		attrs := []attribute.KeyValue{
+			attribute.Int64("sequence-number", int64(ai.countSentMsg)),
+			attribute.Int64("message-size", int64(rs.Length)),
+		}
+		if rs.CompressedLength != rs.Length {
+			attrs = append(attrs, attribute.Int64("message-size-compressed", int64(rs.CompressedLength)))
+		}
+		span.AddEvent("Outbound message", trace.WithAttributes(attrs...))
+		ai.countSentMsg++
+	case *stats.End:
+		if rs.Error != nil {
+			s := status.Convert(rs.Error)
+			span.SetStatus(otelcodes.Error, s.Message())
+		} else {
+			span.SetStatus(otelcodes.Ok, "Ok")
+		}
+		span.End()
+	}
+}