cmd/rv/probe.go improved error handling

cmd/rv/main.go

@@ -148,7 +148,7 @@ func main() {
 
 	p, err := NewTurbidityProbe(*log, 60*time.Second)
 	if err != nil {
-		log.Log(logger.Error, "could not create new turbidity probe", "error", err.Error())
+		log.Log(logger.Fatal, "could not create new turbidity probe", "error", err.Error())
 	}
 
 	log.Log(logger.Debug, "initialising netsender client")

cmd/rv/probe.go

@@ -31,6 +31,8 @@ package main
 
 import (
 	"bytes"
+	"errors"
+	"fmt"
 	"os"
 	"time"
 
@@ -80,7 +82,7 @@ func NewTurbidityProbe(log logger.Logger, delay time.Duration) (*turbidityProbe,
 	template := gocv.IMRead("../../turbidity/images/template.jpg", gocv.IMReadGrayScale)
 	ts, err := turbidity.NewTurbiditySensor(template, standard, k1, k2, filterSize, scale, alpha, log)
 	if err != nil {
-		log.Error("failed create turbidity sensor", "error", err.Error())
+		return nil, fmt.Errorf("failed to create turbidity sensor: %w", err)
 	}
 	tp.ts = ts
 	return tp, nil
@@ -89,63 +91,58 @@ func NewTurbidityProbe(log logger.Logger, delay time.Duration) (*turbidityProbe,
 // Write, reads input h264 frames in the form of a byte stream and writes the the sharpness and contrast
 // scores of a video to the the turbidity probe.
 func (tp *turbidityProbe) Write(p []byte) (int, error) {
-	out := len(p)
 	if tp.buffer.Len() == 0 {
 		// The first entry in the buffer must be a keyframe to speed up decoding.
 		video, err := h264.Trim(p)
 		if err != nil {
-			tp.log.Log(logger.Debug, "no key frame detected", "error", err.Error())
-			return 0, nil
+			return 0, fmt.Errorf("could not trim h264: %w", err)
 		}
 		n, err := tp.buffer.Write(video)
 		if err != nil {
-			tp.log.Log(logger.Error, "could not write trimmed video to buffer", "error", err.Error())
 			tp.buffer.Reset()
-			return 0, nil
+			return 0, fmt.Errorf("could not write trimmed video to buffer: %w", err)
 		}
 		tp.log.Log(logger.Debug, "video trimmed, write keyframe complete", "size(bytes)", n)
 	} else if tp.buffer.Len() < bufferLimit {
 		// Buffer is limited to speed up decoding.
 		n, err := tp.buffer.Write(p)
 		if err != nil {
-			tp.log.Log(logger.Error, "could not write to buffer, reseting", "error", err.Error())
 			tp.buffer.Reset()
-			return 0, nil
+			return 0, fmt.Errorf("could not write to buffer: %w", err)
 		}
 		tp.log.Log(logger.Debug, "write to video buffer complete", "size(bytes)", n)
-	} else {
-		out = 0
 	}
 
 	select {
 	case <-tp.ticker.C:
 		tp.log.Log(logger.Debug, "beginning turbidity calculation")
 		startTime := time.Now()
-		tp.turbidityCalculation()
+		err := tp.turbidityCalculation()
+		if err != nil {
+			return 0, fmt.Errorf("could not calculate turbidity: %w", err)
+		}
 		tp.log.Log(logger.Debug, "finished turbidity calculation", "total duration (sec)", time.Since(startTime).Seconds())
 	default:
 	}
-	return out, nil
+	return len(p), nil
 }
 
 func (tp *turbidityProbe) Close() error {
 	return nil
 }
 
-func (tp *turbidityProbe) turbidityCalculation() {
+func (tp *turbidityProbe) turbidityCalculation() error {
 	var imgs []gocv.Mat
 	img := gocv.NewMat()
 	// Write byte array to a temp file.
 	file, err := os.CreateTemp("temp", "video*.h264")
 	if err != nil {
-		tp.log.Error("failed to create temp file", "error", err.Error())
-		return
+		return fmt.Errorf("failed to create temp file: %w", err)
 	}
 	tp.log.Log(logger.Debug, "writing to file", "buffer size(bytes)", tp.buffer.Len())
 	_, err = file.Write(tp.buffer.Bytes())
 	if err != nil {
-		tp.log.Error("failed to write to temporary file", "error", err.Error())
-		return
+		return fmt.Errorf("failed to write to temporary file: %w", err)
 	}
 	tp.log.Log(logger.Debug, "write to file success", "buffer size(bytes)", tp.buffer.Len())
 	tp.buffer.Reset()
@@ -154,37 +151,48 @@ func (tp *turbidityProbe) turbidityCalculation() {
 	startTime := time.Now()
 	vc, err := gocv.VideoCaptureFile(file.Name())
 	if err != nil {
-		tp.log.Error("failed to open video file", "error", err.Error())
-		return
+		return fmt.Errorf("failed to open video file: %w", err)
 	}
 	tp.log.Log(logger.Debug, "video capture open", "total duration (sec)", time.Since(startTime).Seconds())
 
-	// Store each frame untill max.
+	// Store each frame until maximum amount is reached.
 	startTime = time.Now()
 	for vc.Read(&img) && len(imgs) < maxImages {
 		imgs = append(imgs, img.Clone())
 	}
 	if len(imgs) <= 0 {
-		tp.log.Log(logger.Warning, "no frames found")
-		return
+		return errors.New("no frames found")
 	}
 	tp.log.Log(logger.Debug, "read time", "total duration (sec)", time.Since(startTime).Seconds())
 
 	// Process video data to get saturation and contrast scores.
 	res, err := tp.ts.Evaluate(imgs)
 	if err != nil {
-		tp.log.Error("evaluate failed", "error", err.Error())
-	} else {
-		tp.contrast = stat.Mean(res.Contrast, nil)
-		tp.sharpness = stat.Mean(res.Sharpness, nil)
+		err_ := cleanUp(file.Name(), vc)
+		if err_ != nil {
+			return fmt.Errorf("could not clean up after evaluation error: %w", err_)
+		}
+		return fmt.Errorf("evaluation error: %w", err)
 	}
 
-	err = os.Remove(file.Name())
+	tp.contrast = stat.Mean(res.Contrast, nil)
+	tp.sharpness = stat.Mean(res.Sharpness, nil)
+
+	err = cleanUp(file.Name(), vc)
 	if err != nil {
-		tp.log.Error("could not remove file", "error", err.Error())
+		return fmt.Errorf("could not clean up: %w", err)
+	}
+	return nil
+}
+
+func cleanUp(file string, vc *gocv.VideoCapture) error {
+	err := os.Remove(file)
+	if err != nil {
+		return fmt.Errorf("could not remove temp file: %w", err)
 	}
 	err = vc.Close()
 	if err != nil {
-		tp.log.Error("could not close video capture", "error", err.Error())
+		return fmt.Errorf("could not close video capture device: %w", err)
 	}
+	return nil
 }

codec/h264/parse.go

@@ -79,7 +79,7 @@ func (s *frameScanner) readByte() (b byte, ok bool) {
 	return b, true
 }
 
-// Trim, will trim down a given byte stream of video data so that a key frame appears first.
+// Trim will trim down a given byte stream of video data so that a key frame appears first.
 func Trim(n []byte) ([]byte, error) {
 	sc := frameScanner{buf: n}
 	for {

turbidity/turbidity.go

@@ -48,11 +48,11 @@ type TurbiditySensor struct {
 	standard, standardCorners gocv.Mat
 	k1, k2, sobelFilterSize   int
 	scale, alpha              float64
-	logger                    logger.Logger
+	log                       logger.Logger
 }
 
 // NewTurbiditySensor returns a new TurbiditySensor.
-func NewTurbiditySensor(template, standard gocv.Mat, k1, k2, sobelFilterSize int, scale, alpha float64, logger logger.Logger) (*TurbiditySensor, error) {
+func NewTurbiditySensor(template, standard gocv.Mat, k1, k2, sobelFilterSize int, scale, alpha float64, log logger.Logger) (*TurbiditySensor, error) {
 	ts := new(TurbiditySensor)
 	templateCorners := gocv.NewMat()
 	standardCorners := gocv.NewMat()
@@ -79,7 +79,7 @@ func NewTurbiditySensor(template, standard gocv.Mat, k1, k2, sobelFilterSize int
 
 	ts.k1, ts.k2, ts.sobelFilterSize = k1, k2, sobelFilterSize
 	ts.alpha, ts.scale = alpha, scale
-	ts.logger = logger
+	ts.log = log
 	return ts, nil
 }
 
@@ -97,18 +97,18 @@ func (ts TurbiditySensor) Evaluate(imgs []gocv.Mat) (*Results, error) {
 			return nil, fmt.Errorf("could not transform image: %d: %w", i, err)
 		}
 
-		ts.logger.Log(logger.Debug, "transform successful", "transform duration (sec)", time.Since(timer).Seconds())
+		ts.log.Log(logger.Debug, "transform successful", "transform duration (sec)", time.Since(timer).Seconds())
 
 		timer = time.Now()
 		edge := ts.sobel(marker)
-		ts.logger.Log(logger.Debug, "sobel filter successful", "sobel duration", time.Since(timer).Seconds())
+		ts.log.Log(logger.Debug, "sobel filter successful", "sobel duration", time.Since(timer).Seconds())
 
 		timer = time.Now()
 		sharpScore, contScore, err := ts.EvaluateImage(marker, edge)
 		if err != nil {
 			return result, err
 		}
-		ts.logger.Log(logger.Debug, "sharpness and contrast evaluation successful", "evaluation duration", time.Since(timer).Seconds())
+		ts.log.Log(logger.Debug, "sharpness and contrast evaluation successful", "evaluation duration", time.Since(timer).Seconds())
 		result.Update(sharpScore, contScore, float64(i), i)
 	}
 	return result, nil

turbidity/turbidity_test.go

@@ -74,7 +74,7 @@ func TestImages(t *testing.T) {
 		MaxBackups: logMaxBackup,
 		MaxAge:     logMaxAge,
 	}
-	log := logger.New(logVerbosity, io.MultiWriter(fileLog), logSuppress)
+	log := *logger.New(logVerbosity, io.MultiWriter(fileLog), logSuppress)
 
 	template := gocv.IMRead("images/template.jpg", gocv.IMReadGrayScale)
 	standard := gocv.IMRead("images/default.jpg", gocv.IMReadGrayScale)
@@ -89,7 +89,7 @@ func TestImages(t *testing.T) {
 		}
 	}
 
-	ts, err := NewTurbiditySensor(template, standard, k1, k2, filterSize, scale, alpha, *log)
+	ts, err := NewTurbiditySensor(template, standard, k1, k2, filterSize, scale, alpha, log)
 	if err != nil {
 		t.Fatalf("could not create turbidity sensor: %v", err)
 	}
@@ -111,7 +111,7 @@ func TestImages(t *testing.T) {
 		results.Update(stat.Mean(sample_result.Sharpness, nil), stat.Mean(sample_result.Contrast, nil), float64(i)*increment, i)
 	}
 
-	err = plotResults(results.Turbidity, normalize(results.Sharpness), normalize(results.Contrast))
+	err = plotResults(results.Turbidity, results.Sharpness, results.Contrast)
 	if err != nil {
 		t.Fatalf("plotting Failed: %v", err)
 	}