Merge pull request #1 from rjbasitali/logfmt

Logfmt

LICENSE

@@ -0,0 +1,7 @@
+Copyright 2021 Basit Ali
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -0,0 +1,7 @@
+# go-log
+A Go logging library that provides simple leveled logging.
+
+## Documentation
+Documentation for the following library can be found at https://pkg.go.dev/github.com/rjbasitali/go-log
+
+[![GoDoc](https://godoc.org/github.com/rjbasitali/go-log?status.svg)](https://pkg.go.dev/github.com/rjbasitali/go-log)

doc.go

@@ -0,0 +1,38 @@
+/*
+Package log provides simple leveled logging.
+
+Usage
+
+To use this package get the logger using:
+
+	logger = log.NewLogger(os.Stdout)
+
+You can also get a leveled logger using:
+
+	Logger = log.NewLogger(os.Stdout).Level(6)
+
+(Note that we are passing Level as 6, which will log everything)
+
+Once you have the logger you can use it to log stuff like:
+
+	logger.Log("Hello world!")
+
+	logger.Inform("Someone knocked!")
+
+	logger.Alert("Intruder!")
+
+	logger.Warn("Threat found.")
+
+Or for formatted logging:
+
+	logger.Logf("Hello %s!", "John")
+
+	logger.Informf("%s knocked!", "John")
+
+	logger.Alertf("Intruder of level %d", 9)
+
+	logger.Warnf("Found %q threat!", "Impersonator")
+
+*/
+
+package log

fields.go

@@ -0,0 +1,12 @@
+package log
+
+func (l myLogger) WithFields(fields Fields) Logger {
+	if l.data != nil && len(l.data) > 0 {
+		for k, v := range fields {
+			l.data[k] = v
+		}
+	} else {
+		l.data = fields
+	}
+	return l
+}

logger.go

@@ -29,4 +29,6 @@ type Logger interface {
 	End(a ...interface{})
 
 	Level(uint8) Logger
+
+	WithFields(fields Fields) Logger
 }

logger_alert.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Alert(a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, alertFlag) {
 		return
 	}
-	l.log(a...)
+	l.log(alertFlag, a...)
 }
 
 func (l myLogger) Alertf(format string, a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, alertFlag) {
 		return
 	}
-	l.logf(format, a...)
+	l.logf(alertFlag, format, a...)
 }

logger_begin.go

@@ -3,7 +3,9 @@ package log
 import "time"
 
 func (l myLogger) Begin(s ...interface{}) Logger {
-	logger := myLogger{Writer: l.Writer, prefix: l.prefix, begin: time.Now(), level: l.level}
+	if hasLevel(l.level, logFlag) {
-	l.log(append([]interface{}{"BEGIN"}, s...)...)
+		l.log(logFlag, append([]interface{}{"BEGIN"}, s...)...)
+	}
+	logger := myLogger{Writer: l.Writer, ErrWriter: l.ErrWriter, prefix: l.prefix, begin: time.Now(), level: l.level, data: l.data}
 	return logger
 }

logger_end.go

@@ -6,6 +6,8 @@ import (
 )
 
 func (l myLogger) End(s ...interface{}) {
-	var p []interface{} = append([]interface{}{fmt.Sprintf("END δt=%dµs", time.Now().Sub(l.begin)/1000)}, s...)
+	if hasLevel(l.level, logFlag) {
-	l.log(p...)
+		var p []interface{} = append([]interface{}{fmt.Sprintf("END δt=%dµs", time.Now().Sub(l.begin)/1000)}, s...)
+		l.log(logFlag, p...)
+	}
 }

logger_error.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Error(a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, errorFlag) {
 		return
 	}
-	l.log(a...)
+	l.log(errorFlag, a...)
 }
 
 func (l myLogger) Errorf(format string, a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, errorFlag) {
 		return
 	}
-	l.logf(format, a...)
+	l.logf(errorFlag, format, a...)
 }

logger_highlight.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Highlight(a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, highlightFlag) {
 		return
 	}
-	l.log(a...)
+	l.log(highlightFlag, a...)
 }
 
 func (l myLogger) Highlightf(format string, a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, highlightFlag) {
 		return
 	}
-	l.logf(format, a...)
+	l.logf(highlightFlag, format, a...)
 }

logger_inform.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Inform(a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, informFlag) {
 		return
 	}
-	l.log(a...)
+	l.log(informFlag, a...)
 }
 
 func (l myLogger) Informf(format string, a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, informFlag) {
 		return
 	}
-	l.logf(format, a...)
+	l.logf(informFlag, format, a...)
 }

logger_level.go

@@ -2,33 +2,67 @@ package log
 
 const (
 	alertFlag     = 0b00000001 // L1
-	errorFlag     = 0b00000001 // L1
+	errorFlag     = 0b00000010 // L2
-	warnFlag      = 0b00000010 // L2
+	warnFlag      = 0b00000100 // L3
-	highlightFlag = 0b00000100 // L3
+	highlightFlag = 0b00001000 // L4
-	informFlag    = 0b00001000 // L4
+	informFlag    = 0b00010000 // L5
-	logFlag       = 0b00010000 // L5
+	logFlag       = 0b00100000 // L6
-	traceFlag     = 0b00100000 // L6
+	traceFlag     = 0b01000000 // L7
 )
 
+// Level returns a leveled logger, level can be from 1 to 6.
+//		Level 1 — Alert or Error
+//		Level 2 — Warn
+//		Level 3 — Highlight
+//		Level 4 — Inform
+//		Level 5 — Log
+//		Level 6 — Trace
+// Anything above 6 as level will be considered Level 6.
+// Pass 0 to output no logs.
 func (l myLogger) Level(level uint8) Logger {
-	logger := myLogger{Writer: l.Writer, prefix: l.prefix, begin: l.begin}
+	logger := myLogger{Writer: l.Writer, ErrWriter: l.ErrWriter, prefix: l.prefix, begin: l.begin, data: l.data}
 	switch level {
 	case 1:
-		logger.level = alertFlag | errorFlag
+		logger.level = alertFlag
 	case 2:
-		logger.level = alertFlag | errorFlag | warnFlag
+		logger.level = alertFlag | errorFlag
 	case 3:
-		logger.level = alertFlag | errorFlag | warnFlag | highlightFlag
+		logger.level = alertFlag | errorFlag | warnFlag
 	case 4:
-		logger.level = alertFlag | errorFlag | warnFlag | highlightFlag | informFlag
+		logger.level = alertFlag | errorFlag | warnFlag | highlightFlag
 	case 5:
+		logger.level = alertFlag | errorFlag | warnFlag | highlightFlag | informFlag
+	case 6:
 		logger.level = alertFlag | errorFlag | warnFlag | highlightFlag | informFlag | logFlag
-	default:
+	case 7:
 		logger.level = alertFlag | errorFlag | warnFlag | highlightFlag | informFlag | logFlag | traceFlag
+	default:
+		logger.level = 0
 	}
 	return logger
 }
 
+func unmarshalLevel(level uint8) string {
+	switch level {
+	case alertFlag:
+		return "alert"
+	case errorFlag:
+		return "error"
+	case warnFlag:
+		return "warn"
+	case highlightFlag:
+		return "highlight"
+	case informFlag:
+		return "inform"
+	case logFlag:
+		return "log"
+	case traceFlag:
+		return "trace"
+	default:
+		return ""
+	}
+}
+
 func hasLevel(b uint8, flag uint8) bool {
 	return b&flag != 0
 }

logger_log.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Log(s ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, logFlag) {
 		return
 	}
-	l.log(s...)
+	l.log(logFlag, s...)
 }
 
 func (l myLogger) Logf(format string, s ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, logFlag) {
 		return
 	}
-	l.logf(format, s...)
+	l.logf(logFlag, format, s...)
 }

logger_prefix.go

@@ -11,6 +11,6 @@ func (l myLogger) Prefix(p ...string) Logger {
 	for _, prefix := range p {
 		buffer.WriteString(fmt.Sprintf("%s: ", prefix))
 	}
-	logger := myLogger{Writer: l.Writer, prefix: buffer.String()}
+	logger := myLogger{Writer: l.Writer, ErrWriter: l.ErrWriter, prefix: buffer.String(), data: l.data}
 	return logger
 }

logger_trace.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Trace(a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, traceFlag) {
 		return
 	}
-	l.log(a...)
+	l.log(traceFlag, a...)
 }
 
 func (l myLogger) Tracef(format string, a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, traceFlag) {
 		return
 	}
-	l.logf(format, a...)
+	l.logf(traceFlag, format, a...)
 }

logger_warn.go

@@ -1,21 +1,15 @@
 package log
 
 func (l myLogger) Warn(a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, warnFlag) {
 		return
 	}
-	l.log(a...)
+	l.log(warnFlag, a...)
 }
 
 func (l myLogger) Warnf(format string, a ...interface{}) {
-	if l.Writer == nil {
-		return
-	}
 	if !hasLevel(l.level, warnFlag) {
 		return
 	}
-	l.logf(format, a...)
+	l.logf(warnFlag, format, a...)
 }

my_logger.go

@@ -9,27 +9,66 @@ import (
 	"time"
 )
 
+var (
+	DefaultTimeFormat = time.RFC3339
+)
+
+type Fields map[string]interface{}
+
 type myLogger struct {
-	Writer io.Writer
+	Writer    io.Writer
-	prefix string
+	ErrWriter io.Writer
-	begin  time.Time
+	prefix    string
-	level  uint8
+	begin     time.Time
+	level     uint8
+	data      Fields
 }
 
-func (l myLogger) log(s ...interface{}) {
+func logPrefix(level uint8) string {
-	if l.Writer == nil {
+	return fmt.Sprintf("time=%q level=%s function=%s", time.Now().Format(DefaultTimeFormat), unmarshalLevel(level), funcName())
-		return
-	}
-	s = append([]interface{}{l.prefix, funcName()}, s...)
-	fmt.Fprintln(l.Writer, s...)
 }
 
-func (l myLogger) logf(format string, s ...interface{}) {
+func (fields Fields) String() string {
-	if l.Writer == nil {
+	if len(fields) == 0 {
-		return
+		return ""
 	}
-	format = fmt.Sprintf("%s %s %s\n", l.prefix, funcName(), format)
+	var buffer strings.Builder
-	fmt.Fprintf(l.Writer, format, s...)
+	for k, v := range fields {
+		switch v := v.(type) {
+		case string:
+			buffer.WriteString(fmt.Sprintf(" %s=%q", k, v))
+		default:
+			buffer.WriteString(fmt.Sprintf(" %s=%v", k, v))
+		}
+	}
+	return buffer.String()
+}
+
+func (l myLogger) log(flag uint8, s ...interface{}) {
+	var w io.Writer
+	{
+		if flag == errorFlag {
+			w = l.ErrWriter
+		} else {
+			w = l.Writer
+		}
+	}
+	f := fmt.Sprintf("%s%s msg=%q%s", logPrefix(flag), l.prefix, fmt.Sprint(s...), l.data)
+	fmt.Fprintln(w, f)
+}
+
+func (l myLogger) logf(flag uint8, format string, s ...interface{}) {
+	var w io.Writer
+	{
+		if flag == errorFlag {
+			w = l.ErrWriter
+		} else {
+			w = l.Writer
+		}
+	}
+	format = fmt.Sprintf("%%s%%s msg=\"%s\"%s\n", format, l.data)
+	s = append([]interface{}{logPrefix(flag), l.prefix}, s...)
+	fmt.Fprintf(w, format, s...)
 }
 
 func funcName() string {
@@ -38,16 +77,28 @@ func funcName() string {
 	for _, p := range pc {
 		fn := runtime.FuncForPC(p)
 		if !strings.HasPrefix(fn.Name(), "github.com/rjbasitali/go-log") {
-			return fn.Name()
+			fname := fn.Name()
+			i := strings.LastIndexByte(fname, byte('/'))
+			if i == -1 {
+				return fname
+			}
+			return fname[i+1:]
 		}
 	}
 	return ""
 }
 
-func NewLogger() Logger {
+func NewLogger(w, errw io.Writer) Logger {
+	if w == nil {
+		w = os.Stdout
+	}
+	if errw == nil {
+		errw = os.Stderr
+	}
 	return myLogger{
-		Writer: os.Stdout,
+		Writer:    w,
-		begin:  time.Now(),
+		ErrWriter: errw,
-		level:  63,
+		begin:     time.Now(),
+		level:     traceFlag,
 	}
 }