Add json LogSystem #538

logger/log.go

@@ -30,6 +30,8 @@ func New(datadir string, logFile string, logLevel int, logFormat string) LogSyst
 	switch logFormat {
 	case "raw":
 		sys = NewRawLogSystem(writer, 0, LogLevel(logLevel))
+	case "json":
+		sys = NewJsonLogSystem(writer, 0, LogLevel(logLevel))
 	default:
 		sys = NewStdLogSystem(writer, log.LstdFlags, LogLevel(logLevel))
 	}

logger/logsystem.go

@@ -61,3 +61,27 @@ func (t *rawLogSystem) SetLogLevel(i LogLevel) {
 func (t *rawLogSystem) GetLogLevel() LogLevel {
 	return LogLevel(atomic.LoadUint32(&t.level))
 }
+
+// NewRawLogSystem creates a LogSystem that prints to the given writer without
+// adding extra information. Suitable for preformatted output
+func NewJsonLogSystem(writer io.Writer, flags int, level LogLevel) LogSystem {
+	logger := log.New(writer, "", 0)
+	return &jsonLogSystem{logger, uint32(level)}
+}
+
+type jsonLogSystem struct {
+	logger *log.Logger
+	level  uint32
+}
+
+func (t *jsonLogSystem) LogPrint(level LogLevel, msg string) {
+	t.logger.Print(msg)
+}
+
+func (t *jsonLogSystem) SetLogLevel(i LogLevel) {
+	atomic.StoreUint32(&t.level, uint32(i))
+}
+
+func (t *jsonLogSystem) GetLogLevel() LogLevel {
+	return LogLevel(atomic.LoadUint32(&t.level))
+}

logger/sys.go

@@ -76,8 +76,7 @@ func dispatchLoop() {
 func sysLoop(sys LogSystem, in <-chan message, wg *sync.WaitGroup) {
 	for msg := range in {
 		switch sys.(type) {
-		case *rawLogSystem:
-			// This is a semantic hack since rawLogSystem has little to do with JsonLevel
+		case *jsonLogSystem:
 			if msg.level == JsonLevel {
 				sys.LogPrint(msg.level, msg.msg)
 			}