Improvements (#30)

NOTE: breaking change as now relying on go-playground/pkg/runtime for stack information previously within go-playground/errors

Added default logger. If you register your own logger, of any kind,
the default logger is removed and so is backward compatible. It is only registered when attached to a terminal.
Added Close methods to handlers to allow resource cleanup & automatic
removal of the logger now that RemoveHandler and AddHandler can be made
on the fly.
Updated to use go-playground/pkg/runtime.StackLevel(...) previously found int go-playground/errors

Author: Dean Karn

.travis.yml

@@ -0,0 +1,26 @@
+language: go
+go:
+  - 1.12.5
+  - tip
+matrix:
+  allow_failures:
+    - go: tip
+
+notifications:
+  email:
+    recipients: [email protected]
+    on_success: change
+    on_failure: always
+
+before_install:
+  - go get -u github.com/go-playground/overalls
+  - go get -u github.com/mattn/goveralls
+
+script:
+  - make test
+  - go vet ./...
+
+after_success: |
+  [ $TRAVIS_GO_VERSION = 1.12.5 ] &&
+  overalls -project="github.com/go-playground/log" -covermode=count -ignore=.git,examples -debug &&
+  goveralls -coverprofile=overalls.coverprofile -service travis-ci -repotoken $COVERALLS_TOKEN

README.md

@@ -1,6 +1,6 @@
 ## log
-<img align="right" src="https://raw.githubusercontent.com/go-playground/log/master/logo.png">![Project status](https://img.shields.io/badge/version-6.4.0-green.svg)
-[![Build Status](https://semaphoreci.com/api/v1/joeybloggs/log/branches/master/badge.svg)](https://semaphoreci.com/joeybloggs/log)
+<img align="right" src="https://raw.githubusercontent.com/go-playground/log/master/logo.png">![Project status](https://img.shields.io/badge/version-7.0.0-green.svg)
+[![Build Status](https://travis-ci.org/go-playground/log.svg?branch=master)](https://travis-ci.org/go-playground/log)
 [![Coverage Status](https://coveralls.io/repos/github/go-playground/log/badge.svg?branch=master)](https://coveralls.io/github/go-playground/log?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/go-playground/log)](https://goreportcard.com/report/github.com/go-playground/log)
 [![GoDoc](https://godoc.org/github.com/go-playground/log?status.svg)](https://godoc.org/github.com/go-playground/log)
@@ -18,7 +18,8 @@ Features
 - [x] Logger is simple, only logic to create the log entry and send it off to the handlers and they take it from there.
 - [x] Ability to specify which log levels get sent to each handler
 - [x] Built-in console, syslog, http, HipChat, json and email handlers
-- [x] Handlers are simple to write + easy to register
+- [x] Handlers are simple to write + easy to register + easy to remove
+- [x] Default logger for quick prototyping and cli applications. It is automatically removed when you register one of your own.
 - [x] Logger is a singleton ( one of the few instances a singleton is desired ) so the root package registers which handlers are used and any libraries just follow suit.
 - [x] Convenient context helpers `GetContext` & `SetContext`
 - [x] Works with go-playground/errors extracting types and tags when used with `WithError`, is the default
@@ -36,7 +37,7 @@ go get -u github.com/go-playground/log
 
 Usage
 ------
-import the log package, setup at least one handler
+import the log package, it is recommended to set up at least one handler, but there is a default console logger.
 ```go
 package main
 
@@ -48,6 +49,8 @@ import (
 )
 
 func main() {
+	// There is a default logger with the same settings
+	// once any other logger is registered the default logger is removed.
 	cLog := console.New(true)
 	log.AddHandler(cLog, log.AllLevels...)
 

_examples/basic/main.go

@@ -1,16 +1,11 @@
 package main
 
 import (
-	"errors"
-
+	"github.com/go-playground/errors"
 	"github.com/go-playground/log"
-	"github.com/go-playground/log/handlers/console"
 )
 
 func main() {
-	cLog := console.New(true)
-	log.AddHandler(cLog, log.AllLevels...)
-
 	// Trace
 	defer log.WithTrace().Info("time to run")
 

_examples/handler/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"github.com/go-playground/errors"
+
+	"github.com/go-playground/log"
+	"github.com/go-playground/log/handlers/console"
+)
+
+func main() {
+	cLog := console.New(true)
+	log.AddHandler(cLog, log.AllLevels...)
+
+	// Trace
+	defer log.WithTrace().Info("time to run")
+
+	log.Debug("debug")
+	log.Info("info")
+	log.Notice("notice")
+	log.Warn("warn")
+	log.Error("error")
+	// log.Panic("panic") // this will panic
+	log.Alert("alert")
+	// log.Fatal("fatal") // this will call os.Exit(1)
+
+	err := errors.New("the is an error")
+	// logging with fields can be used with any of the above
+	log.WithError(err).WithFields(log.F("key", "value")).Info("test info")
+
+	// predefined global fields
+	log.WithDefaultFields(log.Fields{
+		{"program", "test"},
+		{"version", "0.1.3"},
+	}...)
+
+	log.WithField("key", "value").Info("testing default fields")
+
+	// or request scoped default fields
+	logger := log.WithFields(
+		log.F("request", "req"),
+		log.F("scoped", "sco"),
+	)
+
+	logger.WithField("key", "value").Info("test")
+}

byte_pool.go

@@ -0,0 +1,17 @@
+package log
+
+import "sync"
+
+// BytePool represents a reusable byte pool. It is a centralized global instance for this package and can be accessed by
+// calling log.BytePool(). It is intended to be used by Handlers.
+type ByteArrayPool struct {
+	pool *sync.Pool
+}
+
+func (p *ByteArrayPool) Get() []byte {
+	return p.pool.Get().([]byte)
+}
+
+func (p *ByteArrayPool) Put(b []byte) {
+	p.pool.Put(b[:0])
+}

default_logger.go

@@ -0,0 +1,147 @@
+package log
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	stdlog "log"
+	"os"
+	"strconv"
+
+	"github.com/go-playground/ansi"
+)
+
+const (
+	space   = byte(' ')
+	equals  = byte('=')
+	newLine = byte('\n')
+	base10  = 10
+	v       = "%v"
+)
+
+var (
+	defaultLoggerWriter     io.Writer = os.Stderr                             // here for tests only
+	defaultLoggerTimeFormat           = "2006-01-02 15:04:05.000000000Z07:00" // here for tests only
+)
+
+// console is an instance of the console logger
+type console struct {
+	colors          [8]ansi.EscSeq
+	writer          io.Writer
+	timestampFormat string
+	r               *io.PipeReader
+}
+
+func newDefaultLogger() *console {
+	c := &console{
+		colors: [...]ansi.EscSeq{
+			DebugLevel:  ansi.Green,
+			InfoLevel:   ansi.Blue,
+			NoticeLevel: ansi.LightCyan,
+			WarnLevel:   ansi.LightYellow,
+			ErrorLevel:  ansi.LightRed,
+			PanicLevel:  ansi.Red,
+			AlertLevel:  ansi.Red + ansi.Underline,
+			FatalLevel:  ansi.Red + ansi.Underline + ansi.Blink,
+		},
+		writer:          defaultLoggerWriter,
+		timestampFormat: defaultLoggerTimeFormat,
+	}
+	done := make(chan struct{})
+	go c.handleStdLogger(done)
+	<-done // have to wait, it was running too quickly and some messages can be lost
+	return c
+}
+
+// this will redirect the output of
+func (c *console) handleStdLogger(done chan<- struct{}) {
+	var w *io.PipeWriter
+	c.r, w = io.Pipe()
+	stdlog.SetOutput(w)
+
+	scanner := bufio.NewScanner(c.r)
+	go func() {
+		done <- struct{}{}
+	}()
+
+	for scanner.Scan() {
+		WithField("stdlog", true).Info(scanner.Text())
+	}
+	_ = c.r.Close()
+	_ = w.Close()
+}
+
+// Log handles the log entry
+func (c *console) Log(e Entry) {
+	var i int
+
+	b := BytePool().Get()
+	lvl := e.Level.String()
+	color := c.colors[e.Level]
+	b = append(b, e.Timestamp.Format(c.timestampFormat)...)
+	b = append(b, space)
+	b = append(b, color...)
+
+	for i = 0; i < 6-len(lvl); i++ {
+		b = append(b, space)
+	}
+	b = append(b, lvl...)
+	b = append(b, ansi.Reset...)
+	b = append(b, space)
+	b = append(b, e.Message...)
+
+	for _, f := range e.Fields {
+		b = append(b, space)
+		b = append(b, color...)
+		b = append(b, f.Key...)
+		b = append(b, ansi.Reset...)
+		b = append(b, equals)
+
+		switch t := f.Value.(type) {
+		case string:
+			b = append(b, t...)
+		case int:
+			b = strconv.AppendInt(b, int64(t), base10)
+		case int8:
+			b = strconv.AppendInt(b, int64(t), base10)
+		case int16:
+			b = strconv.AppendInt(b, int64(t), base10)
+		case int32:
+			b = strconv.AppendInt(b, int64(t), base10)
+		case int64:
+			b = strconv.AppendInt(b, t, base10)
+		case uint:
+			b = strconv.AppendUint(b, uint64(t), base10)
+		case uint8:
+			b = strconv.AppendUint(b, uint64(t), base10)
+		case uint16:
+			b = strconv.AppendUint(b, uint64(t), base10)
+		case uint32:
+			b = strconv.AppendUint(b, uint64(t), base10)
+		case uint64:
+			b = strconv.AppendUint(b, t, base10)
+		case float32:
+			b = strconv.AppendFloat(b, float64(t), 'f', -1, 32)
+		case float64:
+			b = strconv.AppendFloat(b, t, 'f', -1, 64)
+		case bool:
+			b = strconv.AppendBool(b, t)
+		default:
+			b = append(b, fmt.Sprintf(v, f.Value)...)
+		}
+	}
+	b = append(b, newLine)
+	_, _ = c.writer.Write(b)
+	BytePool().Put(b)
+}
+
+// Close cleans up any resources
+func (c *console) Close() error {
+	// reset the output back to original
+	stdlog.SetOutput(os.Stderr)
+	// since we reset the output piror to closing we don't have to wait
+	if c.r != nil {
+		_ = c.r.Close()
+	}
+	return nil
+}