Add log line deduplication

log/formatting.go

@@ -27,7 +27,7 @@ func (s severity) String() string {
 	}
 }
 
-func formatLine(line *logLine, useColor bool) string {
+func formatLine(line *logLine, duplicates uint64, useColor bool) string {
 
 	colorStart := ""
 	colorEnd := ""
@@ -40,14 +40,14 @@ func formatLine(line *logLine, useColor bool) string {
 
 	var fLine string
 	if line.line == 0 {
-		fLine = fmt.Sprintf("%s%s ? %s %s %03d%s %s", colorStart, line.time.Format("060102 15:04:05.000"), rightArrow, line.level.String(), counter, colorEnd, line.msg)
+		fLine = fmt.Sprintf("%s%s ? %s %s %03d%s%s %s", colorStart, line.time.Format("060102 15:04:05.000"), rightArrow, line.level.String(), counter, formatDuplicates(duplicates), colorEnd, line.msg)
 	} else {
 		fLen := len(line.file)
 		fPartStart := fLen - 10
 		if fPartStart < 0 {
 			fPartStart = 0
 		}
-		fLine = fmt.Sprintf("%s%s %s:%03d %s %s %03d%s %s", colorStart, line.time.Format("060102 15:04:05.000"), line.file[fPartStart:], line.line, rightArrow, line.level.String(), counter, colorEnd, line.msg)
+		fLine = fmt.Sprintf("%s%s %s:%03d %s %s %03d%s%s %s", colorStart, line.time.Format("060102 15:04:05.000"), line.file[fPartStart:], line.line, rightArrow, line.level.String(), counter, formatDuplicates(duplicates), colorEnd, line.msg)
 	}
 
 	if counter >= maxCount {
@@ -56,3 +56,10 @@ func formatLine(line *logLine, useColor bool) string {
 
 	return fLine
 }
+
+func formatDuplicates(duplicates uint64) string {
+	if duplicates == 0 {
+		return ""
+	}
+	return fmt.Sprintf(" [%dx]", duplicates+1)
+}

log/logging.go

@@ -42,6 +42,20 @@ type logLine struct {
 	line  int
 }
 
+func (ll *logLine) Equal(ol *logLine) bool {
+	switch {
+	case ll.msg != ol.msg:
+		return false
+	case ll.file != ol.file:
+		return false
+	case ll.line != ol.line:
+		return false
+	case ll.level != ol.level:
+		return false
+	}
+	return true
+}
+
 const (
 	TraceLevel    severity = 1
 	DebugLevel    severity = 2

log/output.go

@@ -9,13 +9,10 @@ import (
 	"github.com/Safing/portbase/taskmanager"
 )
 
-func writeLine(line *logLine) {
+func writeLine(line *logLine, duplicates uint64) {
-
+	fmt.Println(formatLine(line, duplicates, true))
-	fmt.Println(formatLine(line, true))
-
 	// TODO: implement file logging and setting console/file logging
 	// TODO: use https://github.com/natefinch/lumberjack
-
 }
 
 func startWriter() {
@@ -26,10 +23,16 @@ func startWriter() {
 
 func writer() {
 	var line *logLine
+	var lastLine *logLine
+	var duplicates uint64
 	startedTask := false
 	defer shutdownWaitGroup.Done()
 
 	for {
+		// reset
+		line = nil
+		lastLine = nil
+		duplicates = 0
 
 		// wait until logs need to be processed
 		select {
@@ -47,7 +50,7 @@ func writer() {
 			for {
 				select {
 				case line = <-logBuffer:
-					writeLine(line)
+					writeLine(line, duplicates)
 				case <-time.After(10 * time.Millisecond):
 					fmt.Println(fmt.Sprintf("%s%s %s EOF%s", InfoLevel.color(), time.Now().Format("060102 15:04:05.000"), leftArrow, endColor()))
 					return
@@ -60,7 +63,33 @@ func writer() {
 		for {
 			select {
 			case line = <-logBuffer:
-				writeLine(line)
+
+				// look-ahead for deduplication (best effort)
+			dedupLoop:
+				for {
+					// check if there is another line waiting
+					select {
+					case nextLine := <-logBuffer:
+						lastLine = line
+						line = nextLine
+					default:
+						break dedupLoop
+					}
+
+					// deduplication
+					if !line.Equal(lastLine) {
+						// no duplicate
+						writeLine(lastLine, duplicates)
+						duplicates = 0
+					} else {
+						// duplicate
+						duplicates++
+					}
+				}
+
+				// write actual line
+				writeLine(line, duplicates)
+				duplicates = 0
 			default:
 				if startedTask {
 					taskmanager.EndMicroTask()
@@ -70,5 +99,11 @@ func writer() {
 			}
 		}
 
+		// back down a little
+		select {
+		case <-time.After(10 * time.Millisecond):
+		case <-shutdownSignal:
+		}
+
 	}
 }