feat(pkg): add logger and round direct over sensor interface

pkg/logger/default.go

@@ -0,0 +1,70 @@
+package logger
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"sync"
+	"time"
+)
+
+type defaultLogger struct {
+	logLevel LogLevel
+	mutex    *sync.Mutex
+	stdout   io.Writer
+	stderr   io.Writer
+}
+
+func (dl *defaultLogger) Debug(f string, v ...interface{}) {
+	dl.log(LogLevelDebug, f, v...)
+}
+
+func (dl *defaultLogger) Info(f string, v ...interface{}) {
+	dl.log(LogLevelInfo, f, v...)
+}
+
+func (dl *defaultLogger) Warn(f string, v ...interface{}) {
+	dl.log(LogLevelWarn, f, v...)
+}
+
+func (dl *defaultLogger) Error(f string, v ...interface{}) {
+	dl.log(LogLevelError, f, v...)
+}
+
+func (dl *defaultLogger) Fatal(f string, v ...interface{}) {
+	dl.log(LogLevelFatal, f, v...)
+	os.Exit(1)
+}
+
+func (dl *defaultLogger) log(ll LogLevel, f string, v ...interface{}) {
+	layout := "2006/01/02 15:04:05"
+	dw := dl.stdout
+	switch dl.logLevel {
+	case LogLevelError:
+		dw = dl.stderr
+	case LogLevelFatal:
+		dw = dl.stderr
+	}
+	dl.mutex.Lock()
+	fmt.Fprintf(dw, "%v %v: %v \n", time.Now().Format(layout), ll, fmt.Sprintf(f, v...))
+	dl.mutex.Unlock()
+}
+
+func NewDefaultLogger(logLevel LogLevel, time bool) *defaultLogger {
+	return &defaultLogger{
+		logLevel: logLevel,
+		mutex:    new(sync.Mutex),
+		stdout:   os.Stdout,
+		stderr:   os.Stderr,
+	}
+}
+
+func NewSilentLogger() *defaultLogger {
+	return &defaultLogger{
+		logLevel: LogLevelDebug,
+		mutex:    new(sync.Mutex),
+		stdout:   ioutil.Discard,
+		stderr:   ioutil.Discard,
+	}
+}

pkg/logger/interface.go

@@ -0,0 +1,9 @@
+package logger
+
+type Logger interface {
+	Debug(string, ...interface{})
+	Info(string, ...interface{})
+	Warn(string, ...interface{})
+	Error(string, ...interface{})
+	Fatal(string, ...interface{})
+}

pkg/logger/loglevel.go

@@ -0,0 +1,11 @@
+package logger
+
+type LogLevel string
+
+const (
+	LogLevelDebug LogLevel = "DEBUG"
+	LogLevelInfo  LogLevel = "INFO"
+	LogLevelWarn  LogLevel = "WARN"
+	LogLevelError LogLevel = "ERROR"
+	LogLevelFatal LogLevel = "FATAL"
+)