k3s/vendor/github.com/robfig/cron/v3/logger.go

87 lines
2.5 KiB
Go

package cron
import (
"io/ioutil"
"log"
"os"
"strings"
"time"
)
// DefaultLogger is used by Cron if none is specified.
var DefaultLogger Logger = PrintfLogger(log.New(os.Stdout, "cron: ", log.LstdFlags))
// DiscardLogger can be used by callers to discard all log messages.
var DiscardLogger Logger = PrintfLogger(log.New(ioutil.Discard, "", 0))
// Logger is the interface used in this package for logging, so that any backend
// can be plugged in. It is a subset of the github.com/go-logr/logr interface.
type Logger interface {
// Info logs routine messages about cron's operation.
Info(msg string, keysAndValues ...interface{})
// Error logs an error condition.
Error(err error, msg string, keysAndValues ...interface{})
}
// PrintfLogger wraps a Printf-based logger (such as the standard library "log")
// into an implementation of the Logger interface which logs errors only.
func PrintfLogger(l interface{ Printf(string, ...interface{}) }) Logger {
return printfLogger{l, false}
}
// VerbosePrintfLogger wraps a Printf-based logger (such as the standard library
// "log") into an implementation of the Logger interface which logs everything.
func VerbosePrintfLogger(l interface{ Printf(string, ...interface{}) }) Logger {
return printfLogger{l, true}
}
type printfLogger struct {
logger interface{ Printf(string, ...interface{}) }
logInfo bool
}
func (pl printfLogger) Info(msg string, keysAndValues ...interface{}) {
if pl.logInfo {
keysAndValues = formatTimes(keysAndValues)
pl.logger.Printf(
formatString(len(keysAndValues)),
append([]interface{}{msg}, keysAndValues...)...)
}
}
func (pl printfLogger) Error(err error, msg string, keysAndValues ...interface{}) {
keysAndValues = formatTimes(keysAndValues)
pl.logger.Printf(
formatString(len(keysAndValues)+2),
append([]interface{}{msg, "error", err}, keysAndValues...)...)
}
// formatString returns a logfmt-like format string for the number of
// key/values.
func formatString(numKeysAndValues int) string {
var sb strings.Builder
sb.WriteString("%s")
if numKeysAndValues > 0 {
sb.WriteString(", ")
}
for i := 0; i < numKeysAndValues/2; i++ {
if i > 0 {
sb.WriteString(", ")
}
sb.WriteString("%v=%v")
}
return sb.String()
}
// formatTimes formats any time.Time values as RFC3339.
func formatTimes(keysAndValues []interface{}) []interface{} {
var formattedArgs []interface{}
for _, arg := range keysAndValues {
if t, ok := arg.(time.Time); ok {
arg = t.Format(time.RFC3339)
}
formattedArgs = append(formattedArgs, arg)
}
return formattedArgs
}