go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/resultdb/internal/tracing/tracing.go (about)

     1  // Copyright 2023 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package tracing contains helper for reporting OpenTelemetry tracing spans.
    16  package tracing
    17  
    18  import (
    19  	"context"
    20  
    21  	"go.opentelemetry.io/otel"
    22  	"go.opentelemetry.io/otel/attribute"
    23  	"go.opentelemetry.io/otel/codes"
    24  	"go.opentelemetry.io/otel/trace"
    25  )
    26  
    27  var tracer = otel.Tracer("go.chromium.org/luci/resultdb")
    28  
    29  // Start opens a tracing span.
    30  //
    31  // Finish it with End, usually like this:
    32  //
    33  //	ctx, span := tracing.Start(ctx, "..."")
    34  //	defer func() { tracing.End(span, err) }()
    35  func Start(ctx context.Context, name string, attrs ...attribute.KeyValue) (context.Context, trace.Span) {
    36  	return tracer.Start(ctx, name, trace.WithAttributes(attrs...))
    37  }
    38  
    39  // End records the error (if any) and closes the span.
    40  func End(span trace.Span, err error, attrs ...attribute.KeyValue) {
    41  	span.SetAttributes(attrs...)
    42  	if err != nil {
    43  		span.RecordError(err)
    44  		span.SetStatus(codes.Error, err.Error())
    45  	}
    46  	span.End()
    47  }