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mumbledj/vendor/github.com/spf13/jwalterweatherman/thatswhyyoualwaysleaveanote.go
2016-06-20 17:50:40 -07:00

257 lines
6.6 KiB
Go

// Copyright © 2016 Steve Francia <spf@spf13.com>.
//
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.
package jwalterweatherman
import (
"fmt"
"io"
"io/ioutil"
"log"
"os"
"sync/atomic"
)
// Level describes the chosen log level between
// debug and critical.
type Level int
type NotePad struct {
Handle io.Writer
Level Level
Prefix string
Logger **log.Logger
counter uint64
}
func (n *NotePad) incr() {
atomic.AddUint64(&n.counter, 1)
}
func (n *NotePad) resetCounter() {
atomic.StoreUint64(&n.counter, 0)
}
func (n *NotePad) getCount() uint64 {
return atomic.LoadUint64(&n.counter)
}
type countingWriter struct {
incrFunc func()
}
func (cw *countingWriter) Write(p []byte) (n int, err error) {
cw.incrFunc()
return 0, nil
}
// Feedback is special. It writes plainly to the output while
// logging with the standard extra information (date, file, etc)
// Only Println and Printf are currently provided for this
type Feedback struct{}
const (
LevelTrace Level = iota
LevelDebug
LevelInfo
LevelWarn
LevelError
LevelCritical
LevelFatal
DefaultLogThreshold = LevelWarn
DefaultStdoutThreshold = LevelError
)
var (
TRACE *log.Logger
DEBUG *log.Logger
INFO *log.Logger
WARN *log.Logger
ERROR *log.Logger
CRITICAL *log.Logger
FATAL *log.Logger
LOG *log.Logger
FEEDBACK Feedback
LogHandle io.Writer = ioutil.Discard
OutHandle io.Writer = os.Stdout
BothHandle io.Writer = io.MultiWriter(LogHandle, OutHandle)
NotePads []*NotePad = []*NotePad{trace, debug, info, warn, err, critical, fatal}
trace *NotePad = &NotePad{Level: LevelTrace, Handle: os.Stdout, Logger: &TRACE, Prefix: "TRACE: "}
debug *NotePad = &NotePad{Level: LevelDebug, Handle: os.Stdout, Logger: &DEBUG, Prefix: "DEBUG: "}
info *NotePad = &NotePad{Level: LevelInfo, Handle: os.Stdout, Logger: &INFO, Prefix: "INFO: "}
warn *NotePad = &NotePad{Level: LevelWarn, Handle: os.Stdout, Logger: &WARN, Prefix: "WARN: "}
err *NotePad = &NotePad{Level: LevelError, Handle: os.Stdout, Logger: &ERROR, Prefix: "ERROR: "}
critical *NotePad = &NotePad{Level: LevelCritical, Handle: os.Stdout, Logger: &CRITICAL, Prefix: "CRITICAL: "}
fatal *NotePad = &NotePad{Level: LevelFatal, Handle: os.Stdout, Logger: &FATAL, Prefix: "FATAL: "}
logThreshold Level = DefaultLogThreshold
outputThreshold Level = DefaultStdoutThreshold
)
const (
DATE = log.Ldate
TIME = log.Ltime
SFILE = log.Lshortfile
LFILE = log.Llongfile
MSEC = log.Lmicroseconds
)
var logFlags = DATE | TIME | SFILE
func init() {
SetStdoutThreshold(DefaultStdoutThreshold)
}
// initialize will setup the jWalterWeatherman standard approach of providing the user
// some feedback and logging a potentially different amount based on independent log and output thresholds.
// By default the output has a lower threshold than logged
// Don't use if you have manually set the Handles of the different levels as it will overwrite them.
func initialize() {
BothHandle = io.MultiWriter(LogHandle, OutHandle)
for _, n := range NotePads {
if n.Level < outputThreshold && n.Level < logThreshold {
n.Handle = ioutil.Discard
} else if n.Level >= outputThreshold && n.Level >= logThreshold {
n.Handle = BothHandle
} else if n.Level >= outputThreshold && n.Level < logThreshold {
n.Handle = OutHandle
} else {
n.Handle = LogHandle
}
}
for _, n := range NotePads {
n.Handle = io.MultiWriter(n.Handle, &countingWriter{n.incr})
*n.Logger = log.New(n.Handle, n.Prefix, logFlags)
}
LOG = log.New(LogHandle,
"LOG: ",
logFlags)
}
// Set the log Flags (Available flag: DATE, TIME, SFILE, LFILE and MSEC)
func SetLogFlag(flags int) {
logFlags = flags
initialize()
}
// Level returns the current global log threshold.
func LogThreshold() Level {
return logThreshold
}
// Level returns the current global output threshold.
func StdoutThreshold() Level {
return outputThreshold
}
// Ensures that the level provided is within the bounds of available levels
func levelCheck(level Level) Level {
switch {
case level <= LevelTrace:
return LevelTrace
case level >= LevelFatal:
return LevelFatal
default:
return level
}
}
// Establishes a threshold where anything matching or above will be logged
func SetLogThreshold(level Level) {
logThreshold = levelCheck(level)
initialize()
}
// Establishes a threshold where anything matching or above will be output
func SetStdoutThreshold(level Level) {
outputThreshold = levelCheck(level)
initialize()
}
// Conveniently Sets the Log Handle to a io.writer created for the file behind the given filepath
// Will only append to this file
func SetLogFile(path string) {
file, err := os.OpenFile(path, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0666)
if err != nil {
CRITICAL.Println("Failed to open log file:", path, err)
os.Exit(-1)
}
INFO.Println("Logging to", file.Name())
LogHandle = file
initialize()
}
// Conveniently Creates a temporary file and sets the Log Handle to a io.writer created for it
func UseTempLogFile(prefix string) {
file, err := ioutil.TempFile(os.TempDir(), prefix)
if err != nil {
CRITICAL.Println(err)
}
INFO.Println("Logging to", file.Name())
LogHandle = file
initialize()
}
// LogCountForLevel returns the number of log invocations for a given level.
func LogCountForLevel(l Level) uint64 {
for _, np := range NotePads {
if np.Level == l {
return np.getCount()
}
}
return 0
}
// LogCountForLevelsGreaterThanorEqualTo returns the number of log invocations
// greater than or equal to a given level threshold.
func LogCountForLevelsGreaterThanorEqualTo(threshold Level) uint64 {
var cnt uint64
for _, np := range NotePads {
if np.Level >= threshold {
cnt += np.getCount()
}
}
return cnt
}
// ResetLogCounters resets the invocation counters for all levels.
func ResetLogCounters() {
for _, np := range NotePads {
np.resetCounter()
}
}
// Disables logging for the entire JWW system
func DiscardLogging() {
LogHandle = ioutil.Discard
initialize()
}
// Feedback is special. It writes plainly to the output while
// logging with the standard extra information (date, file, etc)
// Only Println and Printf are currently provided for this
func (fb *Feedback) Println(v ...interface{}) {
s := fmt.Sprintln(v...)
fmt.Print(s)
LOG.Output(2, s)
}
// Feedback is special. It writes plainly to the output while
// logging with the standard extra information (date, file, etc)
// Only Println and Printf are currently provided for this
func (fb *Feedback) Printf(format string, v ...interface{}) {
s := fmt.Sprintf(format, v...)
fmt.Print(s)
LOG.Output(2, s)
}