Initial commit

common/logger.go

@@ -0,0 +1,109 @@
+package common
+
+import(
+	"fmt"
+	"log"
+	"log/syslog"
+	"io"
+)
+
+type Logger struct {
+	useSyslog bool
+	verbosity int
+	
+	syslog *syslog.Writer
+	stdlog *log.Logger
+}
+
+
+func NewLogger(prefix string, useSyslog bool, syslogFailOutput io.Writer, verbosity int) (*Logger, error) {
+	out := Logger{
+		verbosity: verbosity,
+		useSyslog: useSyslog}
+
+	var err error
+	out.stdlog = log.New(syslogFailOutput, prefix+" ", log.LstdFlags)
+
+	if useSyslog {
+		out.syslog, err = syslog.New(syslog.LOG_INFO, prefix)
+	}
+
+
+	return &out, err
+}
+
+
+func (l *Logger) Debug(m string, v ...interface{}) {
+	var err error
+	
+	if l.verbosity < 2 { // -vv
+		return
+	}
+
+	if l.useSyslog {
+		err = l.syslog.Debug(l.buildString("", m, v...))
+	}
+
+	if err != nil || !l.useSyslog {
+		l.stdlog.Println(l.buildString("DEBUG", m, v...))
+	}
+}
+
+func (l *Logger) Info(m string, v ...interface{}) {
+	var err error
+
+	if l.verbosity < 1 { // -v
+		return
+	}
+
+	if l.useSyslog {
+		err = l.syslog.Info(l.buildString("", m, v...))
+	}
+
+	if err != nil || !l.useSyslog {
+		l.stdlog.Println(l.buildString(" INFO", m, v...))
+	}
+}
+
+func (l *Logger) Warn(m string, v ...interface{}) {
+	var err error
+	
+	// Warnings are always shown
+
+	if l.useSyslog {
+		err = l.syslog.Warning(l.buildString("", m, v...))
+	}
+
+	if err != nil || !l.useSyslog {
+		l.stdlog.Println(l.buildString(" WARN", m, v...))
+	}
+}
+
+func (l *Logger) Error(m string, v ...interface{}) {
+	var err error
+	
+	// Errors are always shown
+
+	if l.useSyslog {
+		err = l.syslog.Err(l.buildString("", m, v...))
+	}
+
+	if err != nil || !l.useSyslog {
+		l.stdlog.Println(l.buildString("ERROR", m, v...))
+	}
+}
+
+func (l *Logger) buildString(level, m string, v ...interface{}) string {
+	out := m
+
+	if level != "" {
+		out = level + ":" + m
+	}
+
+	if len(v) > 0 {
+		out = fmt.Sprintf(out, v...)
+	}
+
+	return out
+}
+