package logger

code/go/0chain.net/core/logger/logger.go

@@ -0,0 +1,127 @@
+package logger
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+const (
+	NONE  = 0
+	FATAL = 1
+	ERROR = 2
+	INFO  = 3
+	DEBUG = 4
+)
+
+const cRed = "\u001b[31m"
+const cReset = "\u001b[0m"
+
+const (
+	strFATAL = cRed + "[FATAL]  "
+	strERROR = cRed + "[ERROR]  "
+	strINFO  = "[INFO]   "
+	strDEBUG = "[DEBUG]  "
+)
+
+type Logger struct {
+	lvl      int
+	prefix   string
+	logDebug *log.Logger
+	logInfo  *log.Logger
+	logError *log.Logger
+	logFatal *log.Logger
+	fWriter  io.Writer
+}
+
+// Init - Initialize logging
+func (l *Logger) Init(lvl int, prefix string) {
+
+	l.SetLevel(lvl)
+	l.prefix = prefix
+
+	l.logDebug = log.New(os.Stderr, prefix+": "+strDEBUG, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+	l.logInfo = log.New(os.Stderr, prefix+": "+strINFO, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+	l.logError = log.New(os.Stderr, prefix+": "+strERROR, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+	l.logFatal = log.New(os.Stderr, prefix+": "+strFATAL, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+}
+
+// SetLevel - Configures the log level. Higher the number more verbose.
+func (l *Logger) SetLevel(lvl int) {
+	l.lvl = lvl
+}
+
+// syncPrefixes - syncs the logger prefixes
+func syncPrefixes(maxPrefixLen int, loggers []*Logger) {
+
+	for _, lgr := range loggers {
+
+		if maxPrefixLen-len(lgr.prefix) > 0 {
+			lgr.prefix = fmt.Sprintf("%-*s", maxPrefixLen, lgr.prefix)
+		}
+	}
+}
+
+// SyncLoggers - syncs the loggers
+func SyncLoggers(loggers []*Logger) {
+
+	maxPrefixLen := 0
+
+	for _, lgr := range loggers {
+		if len(lgr.prefix) > maxPrefixLen {
+			maxPrefixLen = len(lgr.prefix)
+		}
+	}
+	syncPrefixes(maxPrefixLen, loggers)
+}
+
+// SetLogFile - Writes log to the file. set verbose false disables log to os.Stderr
+func (l *Logger) SetLogFile(logFile io.Writer, verbose bool) {
+
+	dLogs := []io.Writer{logFile}
+	iLogs := []io.Writer{logFile}
+	eLogs := []io.Writer{logFile}
+	fLogs := []io.Writer{logFile}
+
+	if verbose {
+		dLogs = append(dLogs, os.Stderr)
+		iLogs = append(iLogs, os.Stderr)
+		eLogs = append(eLogs, os.Stderr)
+		fLogs = append(fLogs, os.Stderr)
+	}
+	l.logDebug = log.New(io.MultiWriter(dLogs...), l.prefix+" "+strDEBUG, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+	l.logInfo = log.New(io.MultiWriter(iLogs...), l.prefix+" "+strINFO, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+	l.logError = log.New(io.MultiWriter(eLogs...), l.prefix+" "+strERROR, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+	l.logFatal = log.New(io.MultiWriter(fLogs...), l.prefix+" "+strFATAL, log.Ldate|log.Ltime|log.Lmicroseconds|log.Lshortfile)
+}
+
+func (l *Logger) Debug(v ...interface{}) {
+	if l.lvl >= DEBUG {
+		l.logDebug.Output(2, fmt.Sprint(v...))
+	}
+}
+
+func (l *Logger) Info(v ...interface{}) {
+	if l.lvl >= INFO {
+		l.logInfo.Output(2, fmt.Sprint(v...))
+	}
+}
+
+func (l *Logger) Error(v ...interface{}) {
+	if l.lvl >= ERROR {
+		l.logError.Output(2, fmt.Sprint(v...)+cReset)
+	}
+}
+
+func (l *Logger) Fatal(v ...interface{}) {
+	if l.lvl >= FATAL {
+		l.logFatal.Output(2, fmt.Sprint(v...)+cReset)
+	}
+}
+
+func (l *Logger) Close() {
+	if c, ok := l.fWriter.(io.Closer); ok && c != nil {
+		c.Close()
+	}
+}