libgocryptfs/internal/tlog/log.go
2017-01-26 20:01:45 +01:00

120 lines
2.7 KiB
Go

// Package tlog is a "toggled logger" that can be enabled and disabled and
// provides coloring.
package tlog
import (
"encoding/json"
"fmt"
"log"
"os"
"golang.org/x/crypto/ssh/terminal"
)
const (
// ProgramName is used in log reports.
ProgramName = "gocryptfs"
wpanicMsg = "-wpanic turns this warning into a panic: "
)
// Escape sequences for terminal colors. These are set in init() if and only
// if stdout is a terminal. Otherwise they are empty strings.
var (
// ColorReset is used to reset terminal colors.
ColorReset string
// ColorGrey is a terminal color setting string.
ColorGrey string
// ColorRed is a terminal color setting string.
ColorRed string
// ColorGreen is a terminal color setting string.
ColorGreen string
// ColorYellow is a terminal color setting string.
ColorYellow string
)
// JSONDump writes the object in json form.
func JSONDump(obj interface{}) string {
b, err := json.MarshalIndent(obj, "", "\t")
if err != nil {
return err.Error()
}
return string(b)
}
// toggledLogger - a Logger than can be enabled and disabled
type toggledLogger struct {
// Enable or disable output
Enabled bool
// Panic after logging a message, useful in regression tests
Wpanic bool
// Private prefix and postfix are used for coloring
prefix string
postfix string
*log.Logger
}
func (l *toggledLogger) Printf(format string, v ...interface{}) {
if !l.Enabled {
return
}
l.Logger.Printf(l.prefix + fmt.Sprintf(format, v...) + l.postfix)
if l.Wpanic {
l.Logger.Panic(wpanicMsg + fmt.Sprintf(format, v...))
}
}
func (l *toggledLogger) Println(v ...interface{}) {
if !l.Enabled {
return
}
l.Logger.Println(l.prefix + fmt.Sprint(v...) + l.postfix)
if l.Wpanic {
l.Logger.Panic(wpanicMsg + fmt.Sprint(v...))
}
}
// Debug logs debug messages
// Can be enabled by passing "-d"
var Debug *toggledLogger
// Info logs informational message
// Can be disabled by passing "-q"
var Info *toggledLogger
// Warn logs warnings,
// meaning nothing serious by itself but might indicate problems.
// Passing "-wpanic" will make this function panic after printing the message.
var Warn *toggledLogger
// Fatal error, we are about to exit
var Fatal *toggledLogger
func init() {
if terminal.IsTerminal(int(os.Stdout.Fd())) {
ColorReset = "\033[0m"
ColorGrey = "\033[2m"
ColorRed = "\033[31m"
ColorGreen = "\033[32m"
ColorYellow = "\033[33m"
}
Debug = &toggledLogger{
Logger: log.New(os.Stdout, "", 0),
}
Info = &toggledLogger{
Enabled: true,
Logger: log.New(os.Stdout, "", 0),
}
Warn = &toggledLogger{
Enabled: true,
Logger: log.New(os.Stderr, "", 0),
}
Fatal = &toggledLogger{
Enabled: true,
Logger: log.New(os.Stderr, "", 0),
prefix: ColorRed,
postfix: ColorReset,
}
}