feat: add cached info

add cached layer info in a conversion.eg. converted image xxx(cached 10/13)

Signed-off-by: YuQiang <y_q_email@163.com>

pkg/cache/cache.go

@@ -67,6 +67,8 @@ type RemoteCache struct {
 	records map[digest.Digest]*Item
 	// size is the cache record capacity of target layers.
 	size int
+	// updateCount records the number of new caches added in one conversion.
+	updateCount int
 }
 
 func New(ctx context.Context, ref string, size int, pvd Provider) (context.Context, *RemoteCache) {
@@ -157,6 +159,9 @@ func Get(ctx context.Context, dgst digest.Digest) (*RemoteCache, *ocispec.Descri
 func Set(ctx context.Context, source, target ocispec.Descriptor) {
 	rc, ok := ctx.Value(cacheKey{}).(*RemoteCache)
 	if ok {
+		if rc.get(source.Digest) == nil {
+			rc.updateCount++
+		}
 		rc.set(source, target)
 	}
 }
@@ -456,3 +461,34 @@ func appendLayers(orgDescs, newDescs []ocispec.Descriptor, size int) []ocispec.D
 	}
 	return mergedLayers
 }
+
+// HitCount returns the hit info of cache layers in a conversion.
+func (rc *RemoteCache) HitInfo(ctx context.Context, desc ocispec.Descriptor, platform platforms.MatchComparer) (string, error) {
+	maniDescs := []ocispec.Descriptor{}
+	switch desc.MediaType {
+	case ocispec.MediaTypeImageManifest, images.MediaTypeDockerSchema2Manifest:
+		maniDescs = append(maniDescs, desc)
+	case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
+		descs, err := utils.GetManifests(ctx, rc.provider.ContentStore(), desc, platform)
+		if err != nil {
+			return "", err
+		}
+		maniDescs = append(maniDescs, descs...)
+	}
+	hitCount := 0
+	cacheCount := 0
+	for _, maniDesc := range maniDescs {
+		manifest := ocispec.Manifest{}
+		_, err := utils.ReadJSON(ctx, rc.provider.ContentStore(), &manifest, maniDesc)
+		if err != nil {
+			return "", errors.Wrap(err, "read manifest")
+		}
+		cacheCount += len(manifest.Layers)
+		for _, sourceLayer := range manifest.Layers {
+			if item := rc.get(sourceLayer.Digest); item != nil {
+				hitCount++
+			}
+		}
+	}
+	return fmt.Sprintf("%d/%d", (hitCount - rc.updateCount), cacheCount), nil
+}

pkg/converter/converter.go

@@ -142,7 +142,19 @@ func (cvt *Converter) Convert(ctx context.Context, source, target, cacheRef stri
 	if err := metric.SetSourceImageSize(ctx, cvt, source); err != nil {
 		return nil, errors.Wrap(err, "get source image size")
 	}
-	logger.Infof("pulled image %s, elapse %s", source, metric.SourcePullElapsed)
+	cacheHit := ""
+	if cache != nil {
+		sourceImage, err := cvt.provider.Image(ctx, source)
+		if err != nil {
+			return nil, errors.Wrap(err, "get source image")
+		}
+		hitInfo, err := cache.HitInfo(ctx, *sourceImage, cvt.platformMC)
+		if err != nil {
+			logger.Warnf("failed to get cache hit count: %s", err.Error())
+		}
+		cacheHit = fmt.Sprintf("(cached %s)", hitInfo)
+	}
+	logger.Infof("pulled image %s%s, elapse %s", source, cacheHit, metric.SourcePullElapsed)
 
 	logger.Infof("converting image %s", source)
 	start = time.Now()
@@ -158,7 +170,19 @@ func (cvt *Converter) Convert(ctx context.Context, source, target, cacheRef stri
 	if err := metric.SetTargetImageSize(ctx, cvt, desc); err != nil {
 		return nil, errors.Wrap(err, "get target image size")
 	}
-	logger.Infof("converted image %s, elapse %s", target, metric.ConversionElapsed)
+	cacheHit = ""
+	if cache != nil {
+		sourceImage, err := cvt.provider.Image(ctx, source)
+		if err != nil {
+			return nil, errors.Wrap(err, "get source image")
+		}
+		hitInfo, err := cache.HitInfo(ctx, *sourceImage, cvt.platformMC)
+		if err != nil {
+			logger.Warnf("failed to get cache hit count: %s", err.Error())
+		}
+		cacheHit = fmt.Sprintf("(cached %s)", hitInfo)
+	}
+	logger.Infof("converted image %s%s, elapse %s", target, cacheHit, metric.ConversionElapsed)
 
 	if cache != nil {
 		sourceImage, err := cvt.provider.Image(ctx, source)