1// Copyright The OpenTelemetry Authors
 2// SPDX-License-Identifier: Apache-2.0
 3
 4package global // import "go.opentelemetry.io/otel/internal/global"
 5
 6import (
 7	"log"
 8	"os"
 9	"sync/atomic"
10
11	"github.com/go-logr/logr"
12	"github.com/go-logr/stdr"
13)
14
15// globalLogger holds a reference to the [logr.Logger] used within
16// go.opentelemetry.io/otel.
17//
18// The default logger uses stdr which is backed by the standard `log.Logger`
19// interface. This logger will only show messages at the Error Level.
20var globalLogger = func() *atomic.Pointer[logr.Logger] {
21	l := stdr.New(log.New(os.Stderr, "", log.LstdFlags|log.Lshortfile))
22
23	p := new(atomic.Pointer[logr.Logger])
24	p.Store(&l)
25	return p
26}()
27
28// SetLogger sets the global Logger to l.
29//
30// To see Warn messages use a logger with `l.V(1).Enabled() == true`
31// To see Info messages use a logger with `l.V(4).Enabled() == true`
32// To see Debug messages use a logger with `l.V(8).Enabled() == true`.
33func SetLogger(l logr.Logger) {
34	globalLogger.Store(&l)
35}
36
37// GetLogger returns the global logger.
38func GetLogger() logr.Logger {
39	return *globalLogger.Load()
40}
41
42// Info prints messages about the general state of the API or SDK.
43// This should usually be less than 5 messages a minute.
44func Info(msg string, keysAndValues ...interface{}) {
45	GetLogger().V(4).Info(msg, keysAndValues...)
46}
47
48// Error prints messages about exceptional states of the API or SDK.
49func Error(err error, msg string, keysAndValues ...interface{}) {
50	GetLogger().Error(err, msg, keysAndValues...)
51}
52
53// Debug prints messages about all internal changes in the API or SDK.
54func Debug(msg string, keysAndValues ...interface{}) {
55	GetLogger().V(8).Info(msg, keysAndValues...)
56}
57
58// Warn prints messages about warnings in the API or SDK.
59// Not an error but is likely more important than an informational event.
60func Warn(msg string, keysAndValues ...interface{}) {
61	GetLogger().V(1).Info(msg, keysAndValues...)
62}