enable coloring by UIDs

internal/logging/logging.go

@@ -2,14 +2,20 @@ package logging
 
 import (
 	"fmt"
+	"hash/fnv"
 	"log"
 	"os"
+	"strconv"
 )
 
 const (
 	ColorNone = iota
 	ColorRed
 	ColorGreen
+	ColorYellow
+	ColorBlue
+	ColorPurple
+	ColorTeal
 )
 
 type Logger struct {
@@ -43,14 +49,15 @@ func (l *Logger) Errorf(debug bool, format string, v ...interface{}) {
 // Eventf writes an event with timestamp to stdout
 func (l *Logger) Eventf(color int, format string, v ...interface{}) {
 	msg := fmt.Sprintf(format, v...)
-
-	switch color {
-	case ColorRed:
-		msg = fmt.Sprintf("\x1b[31;1m%s\x1b[0m", msg)
-	case ColorGreen:
-		msg = fmt.Sprintf("\x1b[32;1m%s\x1b[0m", msg)
-	default:
+	if color != ColorNone {
+		msg = fmt.Sprintf("\x1b[%d;1m%s\x1b[0m", 30+color, msg)
 	}
 
 	l.eventLogger.Printf("%s", msg)
 }
+
+func GetColorByUID(uid int) int {
+	h := fnv.New32a()
+	h.Write([]byte(strconv.Itoa(uid)))
+	return (int(h.Sum32()) % (ColorTeal)) + 1
+}

internal/logging/logging_test.go

@@ -33,6 +33,7 @@ var logTests = []struct {
 func TestLogging(t *testing.T) {
 	for i, tt := range logTests {
 		actual := captureOutput(tt.logger, tt.test)
+		log.Printf("OUT: %s", actual)
 
 		// check colors and remove afterwards
 		colors := ansiMatcher.FindAll(actual, 2)
@@ -55,3 +56,46 @@ func captureOutput(logger *log.Logger, f func()) []byte {
 	f()
 	return buf.Bytes()
 }
+
+func TestGetColorByUID(t *testing.T) {
+	tests := []struct {
+		uid   int
+		color int
+	}{
+		{uid: 0, color: 4},
+		{uid: 1, color: 5},
+		{uid: 2, color: 2},
+		{uid: 3, color: 3},
+		{uid: 99999999999, color: 5},
+	}
+
+	for _, tt := range tests {
+		color := GetColorByUID(tt.uid)
+		if color != tt.color {
+			t.Errorf("GetColorByUID(%d)=%d but want %d", tt.uid, color, tt.color)
+		}
+	}
+
+	minColor := 9999999
+	maxColor := -9999999
+	for i := 0; i < 1000; i++ {
+		color := GetColorByUID(i)
+		if color < 1 || color > ColorTeal {
+			t.Fatalf("GetColorByUID(%d)=%d but this is out of range [%d, %d]", i, color, ColorRed, ColorTeal)
+		}
+
+		if color < minColor {
+			minColor = color
+		}
+		if color > maxColor {
+			maxColor = color
+		}
+	}
+
+	if minColor != 1 {
+		t.Errorf("GetColorByUID returned minimum color %d, not %d, on 1000 trials, which is extremely unlikely", minColor, 1)
+	}
+	if maxColor != ColorTeal {
+		t.Errorf("GetColorByUID returned maximum color %d, not %d, on 1000 trials, which is extremely unlikely", maxColor, ColorTeal)
+	}
+}

internal/pspy/pspy.go

@@ -57,7 +57,7 @@ func Start(cfg *config.Config, b *Bindings, sigCh chan os.Signal) chan struct{}
 
 func printOutput(cfg *config.Config, b *Bindings, chans *chans) chan struct{} {
 	exit := make(chan struct{})
-	fsEventColor, psEventColor := getColors(cfg.Colored)
+	// fsEventColor, psEventColor := getColors(cfg.Colored)
 
 	go func() {
 		for {
@@ -67,11 +67,15 @@ func printOutput(cfg *config.Config, b *Bindings, chans *chans) chan struct{} {
 				exit <- struct{}{}
 			case fe := <-chans.fsEventCh:
 				if cfg.LogFS {
-					b.Logger.Eventf(fsEventColor, "FS: %+v", fe)
+					b.Logger.Eventf(logging.ColorNone, "FS: %+v", fe)
 				}
 			case pe := <-chans.psEventCh:
 				if cfg.LogPS {
-					b.Logger.Eventf(psEventColor, "CMD: %+v", pe)
+					color := logging.ColorNone
+					if cfg.Colored {
+						color = logging.GetColorByUID(pe.UID)
+					}
+					b.Logger.Eventf(color, "CMD: %+v", pe)
 				}
 			}
 		}
@@ -79,17 +83,6 @@ func printOutput(cfg *config.Config, b *Bindings, chans *chans) chan struct{} {
 	return exit
 }
 
-func getColors(colored bool) (fsEventColor int, psEventColor int) {
-	if colored {
-		fsEventColor = logging.ColorGreen
-		psEventColor = logging.ColorRed
-	} else {
-		fsEventColor = logging.ColorNone
-		psEventColor = logging.ColorNone
-	}
-	return
-}
-
 func initFSW(fsw FSWatcher, rdirs, dirs []string, logger Logger) {
 	errCh, doneCh := fsw.Init(rdirs, dirs)
 	for {

internal/pspy/pspy_test.go

@@ -68,24 +68,6 @@ func TestStartPSS(t *testing.T) {
 	expectMessage(t, l.Error, "ERROR: error during refresh")
 }
 
-func TestGetColors(t *testing.T) {
-	tests := []struct {
-		colored      bool
-		fsEventColor int
-		psEventColor int
-	}{
-		{colored: true, fsEventColor: logging.ColorGreen, psEventColor: logging.ColorRed},
-		{colored: false, fsEventColor: logging.ColorNone, psEventColor: logging.ColorNone},
-	}
-
-	for _, tt := range tests {
-		c1, c2 := getColors(tt.colored)
-		if c1 != tt.fsEventColor || c2 != tt.psEventColor {
-			t.Errorf("Got wrong colors when colored=%t: expected %d, %d but got %d, %d", tt.colored, tt.fsEventColor, tt.psEventColor, c1, c2)
-		}
-	}
-}
-
 func TestStart(t *testing.T) {
 	drainFor := 10 * time.Millisecond
 	triggerEvery := 999 * time.Second
@@ -126,9 +108,9 @@ func TestStart(t *testing.T) {
 	<-time.After(2 * drainFor)
 	expectMessage(t, l.Info, "done")
 	expectTrigger(t, pss.runTriggerCh) // pss receives triggers from fsw
-	expectMessage(t, l.Event, fmt.Sprintf("%d CMD: UID=1000 PID=12345  | pss event", logging.ColorRed))
+	expectMessage(t, l.Event, fmt.Sprintf("%d CMD: UID=1000 PID=12345  | pss event", logging.ColorPurple))
 	expectMessage(t, l.Error, "ERROR: pss error")
-	expectMessage(t, l.Event, fmt.Sprintf("%d FS: fsw event", logging.ColorGreen))
+	expectMessage(t, l.Event, fmt.Sprintf("%d FS: fsw event", logging.ColorNone))
 	expectMessage(t, l.Error, "ERROR: fsw error")
 	expectMessage(t, l.Info, "Exiting program... (interrupt)")