Add logging control

log/log.go

@@ -0,0 +1,107 @@
+package log
+
+import (
+	"errors"
+	"log"
+	"os"
+)
+
+const (
+	// DebugLevel for debug messages
+	DebugLevel int = iota
+	// InfoLevel for info messages
+	InfoLevel
+	// WarnLevel for warning messages
+	WarnLevel
+	// ErrorLevel for error messages
+	ErrorLevel
+	// FatalLevel for fatal messages
+	FatalLevel
+)
+
+var level int
+
+func init() {
+	level = WarnLevel
+}
+
+// SetLevel configures logging level
+func SetLevel(logLevel int) error {
+	if logLevel < DebugLevel || logLevel > FatalLevel {
+		return errors.New("Wrong logging level")
+	}
+	level = logLevel
+	return nil
+}
+
+// Debug prints debug messages
+func Debug(m string) {
+	if level <= DebugLevel {
+		log.Println("[DEBUG] " + m)
+	}
+}
+
+// Debugf prints debug messages with printf format
+func Debugf(format string, values ...interface{}) {
+	if level <= DebugLevel {
+		log.Printf("[DEBUG] "+format, values...)
+	}
+}
+
+// Info prints info messages
+func Info(m string) {
+	if level <= InfoLevel {
+		log.Println("[INFO] " + m)
+	}
+}
+
+// Infof prints info messages with printf format
+func Infof(format string, values ...interface{}) {
+	if level <= InfoLevel {
+		log.Printf("[INFO] "+format, values...)
+	}
+}
+
+// Warn prints warning messages
+func Warn(m string) {
+	if level <= WarnLevel {
+		log.Println("[WARN] " + m)
+	}
+}
+
+// Warnf prints warning messages with printf format
+func Warnf(format string, values ...interface{}) {
+	if level <= WarnLevel {
+		log.Printf("[WARN] "+format, values...)
+	}
+}
+
+// Error prints error messages
+func Error(m string) {
+	if level <= ErrorLevel {
+		log.Println("[ERROR] " + m)
+	}
+}
+
+// Errorf prints error messages with printf format
+func Errorf(format string, values ...interface{}) {
+	if level <= WarnLevel {
+		log.Printf("[ERROR] "+format, values...)
+	}
+}
+
+// Fatal prints fatal messages and exit
+func Fatal(m string) {
+	if level <= FatalLevel {
+		log.Println("[FATAL] " + m)
+	}
+	os.Exit(1)
+}
+
+// Fatalf prints fatal messages with printf format and exit
+func Fatalf(format string, values ...interface{}) {
+	if level <= FatalLevel {
+		log.Printf("[FATAL] "+format, values...)
+	}
+	os.Exit(1)
+}