tracker/pkg/log/log.go
2020-05-07 13:15:43 -04:00

134 lines
2.6 KiB
Go

// Package log adds a thin wrapper around logrus to improve non-debug logging
// performance.
package log
import (
"fmt"
"io"
"github.com/sirupsen/logrus"
)
var (
l = logrus.New()
debug = false
)
// SetDebug controls debug logging.
func SetDebug(to bool) {
debug = to
l.Level = logrus.DebugLevel
}
// SetFormatter sets the formatter.
func SetFormatter(to logrus.Formatter) {
l.Formatter = to
}
// SetOutput sets the output.
func SetOutput(to io.Writer) {
l.Out = to
}
// Fields is a map of logging fields.
type Fields map[string]interface{}
// LogFields implements Fielder for Fields.
func (f Fields) LogFields() Fields {
return f
}
// A Fielder provides Fields via the LogFields method.
type Fielder interface {
LogFields() Fields
}
// err is a wrapper around an error.
type err struct {
e error
}
// LogFields provides Fields for logging.
func (e err) LogFields() Fields {
return Fields{
"error": e.e.Error(),
"type": fmt.Sprintf("%T", e.e),
}
}
// Err is a wrapper around errors that implements Fielder.
func Err(e error) Fielder {
return err{e}
}
// mergeFielders merges the Fields of multiple Fielders.
// Fields from the first Fielder will be used unchanged, Fields from subsequent
// Fielders will be prefixed with "%d.", starting from 1.
//
// must be called with len(fielders) > 0
func mergeFielders(fielders ...Fielder) logrus.Fields {
if fielders[0] == nil {
return nil
}
fields := fielders[0].LogFields()
for i := 1; i < len(fielders); i++ {
if fielders[i] == nil {
continue
}
prefix := fmt.Sprint(i, ".")
ff := fielders[i].LogFields()
for k, v := range ff {
fields[prefix+k] = v
}
}
return logrus.Fields(fields)
}
// Debug logs at the debug level if debug logging is enabled.
func Debug(v interface{}, fielders ...Fielder) {
if debug {
if len(fielders) != 0 {
l.WithFields(mergeFielders(fielders...)).Debug(v)
} else {
l.Debug(v)
}
}
}
// Info logs at the info level.
func Info(v interface{}, fielders ...Fielder) {
if len(fielders) != 0 {
l.WithFields(mergeFielders(fielders...)).Info(v)
} else {
l.Info(v)
}
}
// Warn logs at the warning level.
func Warn(v interface{}, fielders ...Fielder) {
if len(fielders) != 0 {
l.WithFields(mergeFielders(fielders...)).Warn(v)
} else {
l.Warn(v)
}
}
// Error logs at the error level.
func Error(v interface{}, fielders ...Fielder) {
if len(fielders) != 0 {
l.WithFields(mergeFielders(fielders...)).Error(v)
} else {
l.Error(v)
}
}
// Fatal logs at the fatal level and exits with a status code != 0.
func Fatal(v interface{}, fielders ...Fielder) {
if len(fielders) != 0 {
l.WithFields(mergeFielders(fielders...)).Fatal(v)
} else {
l.Fatal(v)
}
}