made hooks part of logger itself and godoc update

Author: jeevatkm

default.go

@@ -123,6 +123,11 @@ func AddContext(fields Fields) {
 	dl.AddContext(fields)
 }
 
+// AddHook method is to add logger hook function.
+func AddHook(name string, hook HookFunc) error {
+	return dl.AddHook(name, hook)
+}
+
 // WithFields method to add multiple key-value pairs into log.
 func WithFields(fields Fields) Loggerer {
 	return dl.WithFields(fields)

default_test.go

@@ -94,9 +94,11 @@ func TestDefaultContextLogging(t *testing.T) {
 	exit = os.Exit
 
 	// With Context
-	ctx := dl.New(Fields{
-		"key1": "key 1 value",
-		"key2": "key 2 value",
+	cfg, _ := config.ParseString("log { }")
+	ctx, _ := NewWithContext(cfg, Fields{
+		"myname": "logger with context",
+		"key1":   "key 1 value",
+		"key2":   "key 2 value",
 	})
 
 	ctx.Trace("I would like to see this message, trace is more fine grained for dev")
@@ -120,7 +122,7 @@ func TestDefaultContextLogging(t *testing.T) {
 	ctx.Fatalln("Yes, yes, yes ", "at last fatal")
 	exit = os.Exit
 
-	ctx2 := WithFields(Fields{"ctx2": "ctx 2 value"})
+	ctx2 := dl.New(Fields{"ctx2": "ctx 2 value"})
 	ctx2.Print("hi fields")
 }
 

formatter.go

@@ -58,14 +58,13 @@ var (
 	//    2006-01-02 15:04:05.000 INFO  This is my message
 	DefaultPattern = "%time:2006-01-02 15:04:05.000 %level:-5 %message"
 
-	// FmtFlags is the list of log format flags supported by aah/log library
+	// FmtFlags is the list of log format flags supported by aah log library
 	// Usage of flag order is up to format composition.
-	//    level     - outputs INFO, DEBUG, ERROR, so on
+	//    level     - outputs ERROR, WARN, INFO, DEBUG, TRACE
 	//    appname   - outputs Application Name
 	//    insname   - outputs Application Instance Name
 	//    reqid     - outputs Request ID from HTTP header
-	//    principal - outputs Logged-In subject primary principal
-	//    level     - outputs INFO, DEBUG, ERROR, so on
+	//    principal - outputs Logged-In subject primary principal value
 	//    time      - outputs local time as per format supplied
 	//    utctime   - outputs UTC time as per format supplied
 	//    longfile  - outputs full file name: /a/b/c/d.go

hook.go

@@ -37,28 +37,23 @@ func TestLogAddHook(t *testing.T) {
 }
 
 func TestLogHook(t *testing.T) {
-	// Add hook
-	_ = AddHook("hook1", func(e Entry) {
-		assert.NotNil(t, e)
-		fmt.Println(e)
-	})
-
 	configStr := `
   log {
     receiver = "console"
     level = "debug"
     pattern = "%utctime:2006-01-02 15:04:05.000 %level:-5 %line %custom:- %message"
   }
   `
-	testHooks(t, configStr)
-	time.Sleep(1 * time.Millisecond)
-}
-
-func testHooks(t *testing.T, cfgStr string) {
-	cfg, _ := config.ParseString(cfgStr)
+	cfg, _ := config.ParseString(configStr)
 	logger, err := New(cfg)
 	assert.FailNowOnError(t, err, "unexpected error")
 
+	// Add hook
+	_ = logger.AddHook("hook1", func(e Entry) {
+		assert.NotNil(t, e)
+		fmt.Println(e)
+	})
+
 	logger.Trace("I shoudn't see this msg, because standard logger level is DEBUG")
 	logger.Debug("I would like to see this message, debug is useful for dev")
 	logger.Info("Yes, I would love to see")
@@ -69,5 +64,5 @@ func testHooks(t *testing.T, cfgStr string) {
 	logger.Fatal("Yes, yes, yes - at last fatal")
 	exit = os.Exit
 
-	assert.NotNil(t, logger.ToGoLogger())
+	time.Sleep(1 * time.Millisecond)
 }

hook_test.go

@@ -36,6 +36,9 @@ import (
 // Level type definition
 type level uint8
 
+// HookFunc type is aah framework logger custom hook.
+type HookFunc func(e Entry)
+
 // Log Level definition
 const (
 	levelFatal level = iota
@@ -52,6 +55,9 @@ var (
 	// ErrLogReceiverIsNil returned when suppiled receiver is nil.
 	ErrLogReceiverIsNil = errors.New("log: receiver is nil")
 
+	// ErrHookFuncIsNil is returned when hook function is nil.
+	ErrHookFuncIsNil = errors.New("log: hook func is nil")
+
 	filePermission = os.FileMode(0755)
 
 	// abstract it, can be unit tested
@@ -66,10 +72,11 @@ type (
 	// it guarantees to serialize access to the Receivers.
 	Logger struct {
 		cfg      *config.Config
-		m        *sync.Mutex
+		m        *sync.RWMutex
 		level    level
 		receiver Receiver
 		ctx      Fields
+		hooks    map[string]HookFunc
 	}
 
 	// Receiver is the interface for pluggable log receiver.
@@ -123,7 +130,7 @@ func New(cfg *config.Config) (*Logger, error) {
 		return nil, errors.New("log: config is nil")
 	}
 
-	logger := &Logger{m: &sync.Mutex{}, cfg: cfg}
+	logger := &Logger{m: &sync.RWMutex{}, cfg: cfg}
 
 	// Receiver
 	receiverType := strings.ToUpper(cfg.StringDefault("log.receiver", "CONSOLE"))
@@ -142,10 +149,21 @@ func New(cfg *config.Config) (*Logger, error) {
 	}
 
 	logger.ctx = make(Fields)
+	logger.hooks = make(map[string]HookFunc)
 
 	return logger, nil
 }
 
+// NewWithContext method creates the aah logger based on supplied `config.Config`.
+func NewWithContext(cfg *config.Config, ctx Fields) (*Logger, error) {
+	l, err := New(cfg)
+	if err != nil {
+		return nil, err
+	}
+	l.AddContext(ctx)
+	return l, nil
+}
+
 //‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
 // Logger methods
 //___________________________________
@@ -169,6 +187,22 @@ func (l *Logger) AddContext(fields Fields) {
 	}
 }
 
+// AddHook method is to add logger hook function.
+func (l *Logger) AddHook(name string, hook HookFunc) error {
+	if hook == nil {
+		return ErrHookFuncIsNil
+	}
+
+	l.m.Lock()
+	defer l.m.Unlock()
+	if _, found := l.hooks[name]; found {
+		return fmt.Errorf("log: hook name '%v' is already added, skip it", name)
+	}
+
+	l.hooks[name] = hook
+	return nil
+}
+
 // Level method returns currently enabled logging level.
 func (l *Logger) Level() string {
 	return levelToLevelName[l.level]
@@ -442,5 +476,13 @@ func (l *Logger) output(e *Entry) {
 	l.receiver.Log(e)
 
 	// Execute logger hooks
-	go executeHooks(*e)
+	go l.executeHooks(*e)
+}
+
+func (l *Logger) executeHooks(e Entry) {
+	l.m.RLock()
+	defer l.m.RUnlock()
+	for _, fn := range l.hooks {
+		go fn(e)
+	}
 }