inherit debug logging to custom loggers, fixes issue #384

logger.go

@@ -9,11 +9,9 @@ import (
 	"github.com/Shopify/sarama"
 )
 
-var (
-	defaultLogger = &std{
-		log: log.New(os.Stderr, "", log.LstdFlags),
-	}
-)
+var defaultLogger = &std{
+	log: log.New(os.Stderr, "", log.LstdFlags),
+}
 
 // Logger is the interface Goka and its subpackages use for logging.
 type Logger interface {
@@ -77,6 +75,8 @@ func DefaultLogger() Logger {
 }
 
 // Debug enables or disables debug logging using the global logger.
+// The goka debugging setting is applied to any custom loggers in goka components (Processors, Views, Emitters).
+// To enable debug logging for custom loggers in selected components only, pass 'true' in the respective 'WithLogger' options.
 func Debug(gokaDebug, saramaDebug bool) {
 	defaultLogger.debug = gokaDebug
 	if saramaDebug {
@@ -89,15 +89,17 @@ func SetSaramaLogger(logger Logger) {
 }
 
 // newLogger creates a new goka logger
-func wrapLogger(l Logger) logger {
+func wrapLogger(l Logger, debug bool) logger {
 	return &std{
-		log: l,
+		log:   l,
+		debug: debug,
 	}
 }
 
 func (s *std) CurrentPrefix() string {
 	return s.prefix
 }
+
 func (s *std) StackPrefix(prefix string) logger {
 	var prefPath []string
 	// append existing path

options.go

@@ -85,7 +85,6 @@ func DefaultHasher() func() hash.Hash32 {
 	return func() hash.Hash32 {
 		return fnv.New32a()
 	}
-
 }
 
 // DefaultUpdateContext implements the UpdateContext interface.
@@ -216,12 +215,13 @@ func WithPartitionChannelSize(size int) ProcessorOption {
 
 // WithLogger sets the logger the processor should use. By default, processors
 // use the standard library logger.
+// To enable debug logging, pass true as an optional parameter
 func WithLogger(l Logger) ProcessorOption {
 	return func(o *poptions, gg *GroupGraph) {
 		if prefixLogger, ok := l.(logger); ok {
 			o.log = prefixLogger
 		} else {
-			o.log = wrapLogger(l)
+			o.log = wrapLogger(l, defaultLogger.debug)
 		}
 	}
 }
@@ -401,12 +401,13 @@ type voptions struct {
 
 // WithViewLogger sets the logger the view should use. By default, views
 // use the standard library logger.
+// To enable debug logging, pass true as an optional parameter
 func WithViewLogger(l Logger) ViewOption {
 	return func(o *voptions, table Table, codec Codec) {
 		if prefixLogger, ok := l.(logger); ok {
 			o.log = prefixLogger
 		} else {
-			o.log = wrapLogger(l)
+			o.log = wrapLogger(l, defaultLogger.debug)
 		}
 	}
 }
@@ -550,12 +551,13 @@ type eoptions struct {
 
 // WithEmitterLogger sets the logger the emitter should use. By default,
 // emitters use the standard library logger.
+// To enable debug logging, pass true as an optional parameter
 func WithEmitterLogger(l Logger) EmitterOption {
 	return func(o *eoptions, topic Stream, codec Codec) {
 		if prefixLogger, ok := l.(logger); ok {
 			o.log = prefixLogger
 		} else {
-			o.log = wrapLogger(l)
+			o.log = wrapLogger(l, defaultLogger.debug)
 		}
 	}
 }