Move logger into own logging package

logging/logging.go

@@ -0,0 +1,137 @@
+package logging
+
+import (
+	"io"
+	"log"
+)
+
+// Loglevel is used to set the current loglevel of Logger.
+type Loglevel int
+
+const (
+	// NONE is a loglevel for Logger.
+	NONE Loglevel = 0
+	// ERROR is a loglevel for Logger.
+	ERROR Loglevel = 1
+	// WARN is a loglevel for Logger.
+	WARN Loglevel = 2
+	// INFO is a loglevel for Logger.
+	INFO Loglevel = 3
+	// DEBUG is a loglevel for Logger.
+	DEBUG Loglevel = 4
+)
+
+// Logger uses multiple instances of log.Logger to provide logging methods for multiple loglevels.
+type Logger struct {
+	debug    *log.Logger
+	info     *log.Logger
+	warn     *log.Logger
+	error    *log.Logger
+	logDebug bool
+	logInfo  bool
+	logWarn  bool
+	logError bool
+}
+
+// NewLogger prepares a new instance of Logger for custom use.
+func NewLogger(stdOut io.Writer, stdErr io.Writer, logLevel Loglevel) Logger {
+	newLogger := Logger{}
+	newLogger.debug = log.New(stdOut, "DEBUG ", 0)
+	newLogger.info = log.New(stdOut, "INFO ", 0)
+	newLogger.warn = log.New(stdErr, "WARN ", 0)
+	newLogger.error = log.New(stdErr, "ERROR ", 0)
+	newLogger.SetLogLevel(logLevel)
+	return newLogger
+}
+
+// SetLogLevel can be used to change the loglevel of Logger on the fly.
+func (l *Logger) SetLogLevel(logLevel Loglevel) {
+	l.logDebug = (logLevel >= DEBUG)
+	l.logInfo = (logLevel >= INFO)
+	l.logWarn = (logLevel >= WARN)
+	l.logError = (logLevel >= ERROR)
+}
+
+// Debug is an alias for log.Logger.Print() with severity DEBUG.
+func (l *Logger) Debug(v ...interface{}) {
+	if l.logDebug {
+		l.debug.Print(v...)
+	}
+}
+
+// Debugln is an alias for log.Logger.Println() with severity DEBUG.
+func (l *Logger) Debugln(v ...interface{}) {
+	if l.logDebug {
+		l.debug.Println(v...)
+	}
+}
+
+// Debugf is an alias for log.Logger.Printf() with severity DEBUG.
+func (l *Logger) Debugf(format string, v ...interface{}) {
+	if l.logDebug {
+		l.debug.Printf(format, v...)
+	}
+}
+
+// Info is an alias for log.Logger.Print() with severity INFO.
+func (l *Logger) Info(v ...interface{}) {
+	if l.logInfo {
+		l.info.Print(v...)
+	}
+}
+
+// Infoln is an alias for log.Logger.Println() with severity INFO.
+func (l *Logger) Infoln(v ...interface{}) {
+	if l.logInfo {
+		l.info.Println(v...)
+	}
+}
+
+// Infof is an alias for log.Logger.Printf() with severity INFO.
+func (l *Logger) Infof(format string, v ...interface{}) {
+	if l.logInfo {
+		l.info.Printf(format, v...)
+	}
+}
+
+// Warn is an alias for log.Logger.Print() with severity WARN.
+func (l *Logger) Warn(v ...interface{}) {
+	if l.logWarn {
+		l.warn.Print(v...)
+	}
+}
+
+// Warnln is an alias for log.Logger.Println() with severity WARN.
+func (l *Logger) Warnln(v ...interface{}) {
+	if l.logWarn {
+		l.warn.Println(v...)
+	}
+}
+
+// Warnf is an alias for log.Logger.Printf() with severity WARN.
+func (l *Logger) Warnf(format string, v ...interface{}) {
+	if l.logWarn {
+		l.warn.Printf(format, v...)
+	}
+}
+
+// Error is an alias for log.Logger.Print() with severity ERROR.
+func (l *Logger) Error(v ...interface{}) {
+	if l.logError {
+		l.error.Print(v...)
+	}
+}
+
+// Errorln is an alias for log.Logger.Println() with severity ERROR.
+func (l *Logger) Errorln(v ...interface{}) {
+	if l.logError {
+		l.error.Println(v...)
+	}
+}
+
+// Errorf is an alias for log.Logger.Printf() with severity ERROR.
+func (l *Logger) Errorf(format string, v ...interface{}) {
+	if l.logError {
+		l.error.Printf(format, v...)
+	}
+}