func (b *bridge) createManifestEvent(action string, repo distribution.Repository, sm *manifest.SignedManifest) (*Event, error) {
	event := b.createEvent(action)
	event.Target.MediaType = manifest.ManifestMediaType
	event.Target.Repository = repo.Name()

	p, err := sm.Payload()
	if err != nil {
		return nil, err
	}

	event.Target.Length = int64(len(p))

	event.Target.Digest, err = digest.FromBytes(p)
	if err != nil {
		return nil, err
	}

	// TODO(stevvooe): Currently, the is the "tag" url: once the digest url is
	// implemented, this should be replaced.
	event.Target.URL, err = b.ub.BuildManifestURL(sm.Name, sm.Tag)
	if err != nil {
		return nil, err
	}

	return event, nil
}

// calculateImageSize gets and updates size of each image layer. If manifest v2 is converted to v1,
// then it loses information about layers size. We have to get this information from server again.
func (isi *ImageStreamImporter) calculateImageSize(ctx gocontext.Context, repo distribution.Repository, image *api.Image) error {
	bs := repo.Blobs(ctx)

	layerSet := sets.NewString()
	size := int64(0)
	for i := range image.DockerImageLayers {
		layer := &image.DockerImageLayers[i]

		if layerSet.Has(layer.Name) {
			continue
		}
		layerSet.Insert(layer.Name)

		if layerSize, ok := isi.digestToLayerSizeCache[layer.Name]; ok {
			size += layerSize
			continue
		}

		desc, err := bs.Stat(ctx, digest.Digest(layer.Name))
		if err != nil {
			return err
		}

		isi.digestToLayerSizeCache[layer.Name] = desc.Size
		layer.LayerSize = desc.Size
		size += desc.Size
	}

	image.DockerImageMetadata.Size = size
	return nil
}

// blobSumAlreadyExists checks if the registry already know about any of the
// blobsums passed in the "blobsums" slice. If it finds one that the registry
// knows about, it returns the known digest and "true".
func blobSumAlreadyExists(ctx context.Context, blobsums []digest.Digest, repo distribution.Repository, layersPushed *pushMap) (digest.Digest, bool, error) {
	layersPushed.Lock()
	for _, dgst := range blobsums {
		if layersPushed.layersPushed[dgst] {
			// it is already known that the push is not needed and
			// therefore doing a stat is unnecessary
			layersPushed.Unlock()
			return dgst, true, nil
		}
	}
	layersPushed.Unlock()

	for _, dgst := range blobsums {
		_, err := repo.Blobs(ctx).Stat(ctx, dgst)
		switch err {
		case nil:
			return dgst, true, nil
		case distribution.ErrBlobUnknown:
			// nop
		default:
			return "", false, err
		}
	}
	return "", false, nil
}

// fetch downloads the blob to a tempfile, renames it to the expected name
func (r *blobRepo) fetch(ctx context.Context, repository distribution.Repository, dgst digest.Digest) (path string, err error) {
	defer apexctx.GetLogger(ctx).WithField("digest", dgst).Trace("fetch the blob").Stop(&err)
	tempFilePath := filepath.Join(r.SpoolPath, fmt.Sprintf("%s-%d", dgst.String(), rand.Int63()))
	f, err := os.Create(tempFilePath)
	if err != nil {
		return "", err
	}
	defer f.Close()
	defer os.Remove(tempFilePath)

	blob, err := repository.Blobs(ctx).Open(ctx, dgst)
	if err != nil {
		return "", err
	}
	defer blob.Close()

	if _, err = io.Copy(f, blob); err != nil {
		return "", err
	}
	f.Close()
	blob.Close()

	resultFilePath := filepath.Join(r.SpoolPath, dgst.String())
	if err = os.Rename(tempFilePath, resultFilePath); err != nil {
		return "", err
	}

	return resultFilePath, nil
}

// newRepositoryWithClient returns a new repository middleware.
func newRepositoryWithClient(registryClient client.Interface, quotaClient kclient.ResourceQuotasNamespacer, ctx context.Context, repo distribution.Repository, options map[string]interface{}) (distribution.Repository, error) {
	registryAddr := os.Getenv("DOCKER_REGISTRY_URL")
	if len(registryAddr) == 0 {
		return nil, errors.New("DOCKER_REGISTRY_URL is required")
	}

	pullthrough := false
	if value, ok := options["pullthrough"]; ok {
		if b, ok := value.(bool); ok {
			pullthrough = b
		}
	}

	nameParts := strings.SplitN(repo.Name(), "/", 2)
	if len(nameParts) != 2 {
		return nil, fmt.Errorf("invalid repository name %q: it must be of the format <project>/<name>", repo.Name())
	}

	return &repository{
		Repository: repo,

		ctx:            ctx,
		quotaClient:    quotaClient,
		registryClient: registryClient,
		registryAddr:   registryAddr,
		namespace:      nameParts[0],
		name:           nameParts[1],
		pullthrough:    pullthrough,
		cachedLayers:   cachedLayers,
	}, nil
}

// newRepository returns a new repository middleware.
func newRepository(ctx context.Context, repo distribution.Repository, options map[string]interface{}) (distribution.Repository, error) {
	registryAddr := os.Getenv("DOCKER_REGISTRY_URL")
	if len(registryAddr) == 0 {
		return nil, errors.New("DOCKER_REGISTRY_URL is required")
	}

	registryClient, err := NewRegistryOpenShiftClient()
	if err != nil {
		return nil, err
	}

	nameParts := strings.SplitN(repo.Name(), "/", 2)
	if len(nameParts) != 2 {
		return nil, fmt.Errorf("invalid repository name %q: it must be of the format <project>/<name>", repo.Name())
	}

	return &repository{
		Repository: repo,

		ctx:            ctx,
		registryClient: registryClient,
		registryAddr:   registryAddr,
		namespace:      nameParts[0],
		name:           nameParts[1],
	}, nil
}

func makeManifestService(t *testing.T, repository distribution.Repository) distribution.ManifestService {
	ctx := context.Background()

	manifestService, err := repository.Manifests(ctx)
	if err != nil {
		t.Fatalf("Failed to construct manifest store: %v", err)
	}
	return manifestService
}

func populateRepo(t *testing.T, ctx context.Context, repository distribution.Repository, name, tag string) (digest.Digest, error) {
	m := schema1.Manifest{
		Versioned: manifest.Versioned{
			SchemaVersion: 1,
		},
		Name: name,
		Tag:  tag,
	}

	for i := 0; i < 2; i++ {
		wr, err := repository.Blobs(ctx).Create(ctx)
		if err != nil {
			t.Fatalf("unexpected error creating test upload: %v", err)
		}

		rs, ts, err := testutil.CreateRandomTarFile()
		if err != nil {
			t.Fatalf("unexpected error generating test layer file")
		}
		dgst := digest.Digest(ts)
		if _, err := io.Copy(wr, rs); err != nil {
			t.Fatalf("unexpected error copying to upload: %v", err)
		}

		if _, err := wr.Commit(ctx, distribution.Descriptor{Digest: dgst}); err != nil {
			t.Fatalf("unexpected error finishing upload: %v", err)
		}
	}

	pk, err := libtrust.GenerateECP256PrivateKey()
	if err != nil {
		t.Fatalf("unexpected error generating private key: %v", err)
	}

	sm, err := schema1.Sign(&m, pk)
	if err != nil {
		t.Fatalf("error signing manifest: %v", err)
	}

	ms, err := repository.Manifests(ctx)
	if err != nil {
		t.Fatalf(err.Error())
	}
	ms.Put(sm)
	if err != nil {
		t.Fatalf("unexpected errors putting manifest: %v", err)
	}
	pl, err := sm.Payload()
	if err != nil {
		t.Fatal(err)
	}
	return digest.FromBytes(pl)
}

// newRepositoryWithClient returns a new repository middleware.
func newRepositoryWithClient(
	registryOSClient client.Interface,
	quotaClient kcoreclient.ResourceQuotasGetter,
	limitClient kcoreclient.LimitRangesGetter,
	ctx context.Context,
	repo distribution.Repository,
	options map[string]interface{},
) (distribution.Repository, error) {
	registryAddr := os.Getenv(DockerRegistryURLEnvVar)
	if len(registryAddr) == 0 {
		return nil, fmt.Errorf("%s is required", DockerRegistryURLEnvVar)
	}

	acceptschema2, err := getBoolOption(AcceptSchema2EnvVar, "acceptschema2", false, options)
	if err != nil {
		context.GetLogger(ctx).Error(err)
	}
	blobrepositorycachettl, err := getDurationOption(BlobRepositoryCacheTTLEnvVar, "blobrepositorycachettl", defaultBlobRepositoryCacheTTL, options)
	if err != nil {
		context.GetLogger(ctx).Error(err)
	}
	pullthrough, err := getBoolOption(PullthroughEnvVar, "pullthrough", true, options)
	if err != nil {
		context.GetLogger(ctx).Error(err)
	}
	mirrorPullthrough, err := getBoolOption(MirrorPullthroughEnvVar, "mirrorpullthrough", true, options)
	if err != nil {
		context.GetLogger(ctx).Error(err)
	}

	nameParts := strings.SplitN(repo.Named().Name(), "/", 2)
	if len(nameParts) != 2 {
		return nil, fmt.Errorf("invalid repository name %q: it must be of the format <project>/<name>", repo.Named().Name())
	}

	return &repository{
		Repository: repo,

		ctx:                    ctx,
		quotaClient:            quotaClient,
		limitClient:            limitClient,
		registryOSClient:       registryOSClient,
		registryAddr:           registryAddr,
		namespace:              nameParts[0],
		name:                   nameParts[1],
		acceptschema2:          acceptschema2,
		blobrepositorycachettl: blobrepositorycachettl,
		pullthrough:            pullthrough,
		mirrorPullthrough:      mirrorPullthrough,
		cachedLayers:           cachedLayers,
	}, nil
}

// MakeSchema2Manifest constructs a schema 2 manifest from a given list of digests and returns
// the digest of the manifest
func MakeSchema2Manifest(repository distribution.Repository, digests []digest.Digest) (distribution.Manifest, error) {
	ctx := context.Background()
	blobStore := repository.Blobs(ctx)
	builder := schema2.NewManifestBuilder(blobStore, []byte{})
	for _, digest := range digests {
		builder.AppendReference(distribution.Descriptor{Digest: digest})
	}

	manifest, err := builder.Build(ctx)
	if err != nil {
		return nil, fmt.Errorf("unexpected error generating manifest: %v", err)
	}

	return manifest, nil
}

// blobSumAlreadyExists checks if the registry already know about any of the
// blobsums passed in the "blobsums" slice. If it finds one that the registry
// knows about, it returns the known digest and "true".
func blobSumAlreadyExists(ctx context.Context, blobsums []digest.Digest, repo distribution.Repository, pushState *pushState) (distribution.Descriptor, bool, error) {
	for _, dgst := range blobsums {
		descriptor, err := repo.Blobs(ctx).Stat(ctx, dgst)
		switch err {
		case nil:
			descriptor.MediaType = schema2.MediaTypeLayer
			return descriptor, true, nil
		case distribution.ErrBlobUnknown:
			// nop
		default:
			return distribution.Descriptor{}, false, err
		}
	}
	return distribution.Descriptor{}, false, nil
}

// UploadBlobs lets you upload blobs to a repository
func UploadBlobs(repository distribution.Repository, layers map[digest.Digest]io.ReadSeeker) error {
	ctx := context.Background()
	for digest, rs := range layers {
		wr, err := repository.Blobs(ctx).Create(ctx)
		if err != nil {
			return fmt.Errorf("unexpected error creating upload: %v", err)
		}

		if _, err := io.Copy(wr, rs); err != nil {
			return fmt.Errorf("unexpected error copying to upload: %v", err)
		}

		if _, err := wr.Commit(ctx, distribution.Descriptor{Digest: digest}); err != nil {
			return fmt.Errorf("unexpected error committinng upload: %v", err)
		}
	}
	return nil
}

func (b *bridge) createLayerEvent(action string, repo distribution.Repository, layer distribution.Layer) (*Event, error) {
	event := b.createEvent(action)
	event.Target.MediaType = layerMediaType
	event.Target.Repository = repo.Name()

	event.Target.Length = layer.Length()

	dgst := layer.Digest()
	event.Target.Digest = dgst

	var err error
	event.Target.URL, err = b.ub.BuildBlobURL(repo.Name(), dgst)
	if err != nil {
		return nil, err
	}

	return event, nil
}

// layerAlreadyExists checks if the registry already know about any of the
// metadata passed in the "metadata" slice. If it finds one that the registry
// knows about, it returns the known digest and "true".
func layerAlreadyExists(ctx context.Context, metadata []metadata.V2Metadata, repoInfo reference.Named, repo distribution.Repository, pushState *pushState) (distribution.Descriptor, bool, error) {
	for _, meta := range metadata {
		// Only check blobsums that are known to this repository or have an unknown source
		if meta.SourceRepository != "" && meta.SourceRepository != repoInfo.FullName() {
			continue
		}
		descriptor, err := repo.Blobs(ctx).Stat(ctx, meta.Digest)
		switch err {
		case nil:
			descriptor.MediaType = schema2.MediaTypeLayer
			return descriptor, true, nil
		case distribution.ErrBlobUnknown:
			// nop
		default:
			return distribution.Descriptor{}, false, err
		}
	}
	return distribution.Descriptor{}, false, nil
}

// newRepositoryWithClient returns a new repository middleware.
func newRepositoryWithClient(
	registryOSClient client.Interface,
	quotaClient kclient.ResourceQuotasNamespacer,
	limitClient kclient.LimitRangesNamespacer,
	ctx context.Context,
	repo distribution.Repository,
	options map[string]interface{},
) (distribution.Repository, error) {
	registryAddr := os.Getenv(DockerRegistryURLEnvVar)
	if len(registryAddr) == 0 {
		return nil, fmt.Errorf("%s is required", DockerRegistryURLEnvVar)
	}

	pullthrough := getBoolOption("pullthrough", false, options)

	acceptschema2 := false

	if os.Getenv(AcceptSchema2EnvVar) != "" {
		acceptschema2 = os.Getenv(AcceptSchema2EnvVar) == "true"
	} else {
		acceptschema2 = getBoolOption("acceptschema2", false, options)
	}

	nameParts := strings.SplitN(repo.Named().Name(), "/", 2)
	if len(nameParts) != 2 {
		return nil, fmt.Errorf("invalid repository name %q: it must be of the format <project>/<name>", repo.Named().Name())
	}

	return &repository{
		Repository: repo,

		ctx:              ctx,
		quotaClient:      quotaClient,
		limitClient:      limitClient,
		registryOSClient: registryOSClient,
		registryAddr:     registryAddr,
		namespace:        nameParts[0],
		name:             nameParts[1],
		pullthrough:      pullthrough,
		acceptschema2:    acceptschema2,
		cachedLayers:     cachedLayers,
	}, nil
}

func pushManifest(ctx context.Context, m *schema1.Manifest,
	privateKey libtrust.PrivateKey,
	repository distribution.Repository) (string, error) {
	signed, err := schema1.Sign(m, privateKey)
	if err != nil {
		return "", err
	}

	manifestDigest, err := digestFromManifest(signed)
	if err != nil {
		return "", err
	}

	manifests, err := repository.Manifests(ctx)
	if err != nil {
		return "", err
	}

	log.Printf("manifest: digest: %s", manifestDigest)

	return string(manifestDigest), manifests.Put(signed)
}

// Push pushes a plugin to a registry.
func Push(name string, rs registry.Service, metaHeader http.Header, authConfig *types.AuthConfig, config io.ReadCloser, layers io.ReadCloser) (digest.Digest, error) {
	ref, err := reference.ParseNamed(name)
	if err != nil {
		return "", err
	}

	repoInfo, err := rs.ResolveRepository(ref)
	if err != nil {
		return "", err
	}

	if err := dockerdist.ValidateRepoName(repoInfo.Name()); err != nil {
		return "", err
	}

	endpoints, err := rs.LookupPushEndpoints(repoInfo.Hostname())
	if err != nil {
		return "", err
	}

	var confirmedV2 bool
	var repository distribution.Repository
	for _, endpoint := range endpoints {
		if confirmedV2 && endpoint.Version == registry.APIVersion1 {
			logrus.Debugf("Skipping v1 endpoint %s because v2 registry was detected", endpoint.URL)
			continue
		}
		repository, confirmedV2, err = dockerdist.NewV2Repository(context.Background(), repoInfo, endpoint, metaHeader, authConfig, "push", "pull")
		if err != nil {
			return "", err
		}
		if !confirmedV2 {
			return "", ErrUnSupportedRegistry
		}
		logrus.Debugf("Trying to push %s to %s %s", repoInfo.Name(), endpoint.URL, endpoint.Version)
		// This means that we found an endpoint. and we are ready to push
		break
	}

	// Returns a reference to the repository's blob service.
	blobs := repository.Blobs(context.Background())

	// Descriptor = {mediaType, size, digest}
	var descs []distribution.Descriptor

	for i, f := range []io.ReadCloser{config, layers} {
		bw, err := blobs.Create(context.Background())
		if err != nil {
			logrus.Debugf("Error in blobs.Create: %v", err)
			return "", err
		}
		h := sha256.New()
		r := io.TeeReader(f, h)
		_, err = io.Copy(bw, r)
		if err != nil {
			logrus.Debugf("Error in io.Copy: %v", err)
			return "", err
		}
		f.Close()
		mt := MediaTypeLayer
		if i == 0 {
			mt = MediaTypeConfig
		}
		// Commit completes the write process to the BlobService.
		// The descriptor arg to Commit is called the "provisional" descriptor and
		// used for validation.
		// The returned descriptor should be the one used. Its called the "Canonical"
		// descriptor.
		desc, err := bw.Commit(context.Background(), distribution.Descriptor{
			MediaType: mt,
			// XXX: What about the Size?
			Digest: digest.NewDigest("sha256", h),
		})
		if err != nil {
			logrus.Debugf("Error in bw.Commit: %v", err)
			return "", err
		}
		// The canonical descriptor is set the mediatype again, just in case.
		// Dont touch the digest or the size here.
		desc.MediaType = mt
		logrus.Debugf("pushed blob: %s %s", desc.MediaType, desc.Digest)
		descs = append(descs, desc)
	}

	// XXX: schema2.Versioned needs a MediaType as well.
	// "application/vnd.docker.distribution.manifest.v2+json"
	m, err := schema2.FromStruct(schema2.Manifest{Versioned: schema2.SchemaVersion, Config: descs[0], Layers: descs[1:]})
	if err != nil {
		logrus.Debugf("error in schema2.FromStruct: %v", err)
		return "", err
	}

	msv, err := repository.Manifests(context.Background())
	if err != nil {
		logrus.Debugf("error in repository.Manifests: %v", err)
		return "", err
	}

	_, pl, err := m.Payload()
//.........这里部分代码省略.........

// checkExerciseRegistry takes the registry through all of its operations,
// carrying out generic checks.
func checkExerciseRepository(t *testing.T, repository distribution.Repository) {
	// TODO(stevvooe): This would be a nice testutil function. Basically, it
	// takes the registry through a common set of operations. This could be
	// used to make cross-cutting updates by changing internals that affect
	// update counts. Basically, it would make writing tests a lot easier.
	ctx := context.Background()
	tag := "thetag"
	m := manifest.Manifest{
		Versioned: manifest.Versioned{
			SchemaVersion: 1,
		},
		Name: repository.Name(),
		Tag:  tag,
	}

	blobs := repository.Blobs(ctx)
	for i := 0; i < 2; i++ {
		rs, ds, err := testutil.CreateRandomTarFile()
		if err != nil {
			t.Fatalf("error creating test layer: %v", err)
		}
		dgst := digest.Digest(ds)

		wr, err := blobs.Create(ctx)
		if err != nil {
			t.Fatalf("error creating layer upload: %v", err)
		}

		// Use the resumes, as well!
		wr, err = blobs.Resume(ctx, wr.ID())
		if err != nil {
			t.Fatalf("error resuming layer upload: %v", err)
		}

		io.Copy(wr, rs)

		if _, err := wr.Commit(ctx, distribution.Descriptor{Digest: dgst}); err != nil {
			t.Fatalf("unexpected error finishing upload: %v", err)
		}

		m.FSLayers = append(m.FSLayers, manifest.FSLayer{
			BlobSum: dgst,
		})

		// Then fetch the blobs
		if rc, err := blobs.Open(ctx, dgst); err != nil {
			t.Fatalf("error fetching layer: %v", err)
		} else {
			defer rc.Close()
		}
	}

	pk, err := libtrust.GenerateECP256PrivateKey()
	if err != nil {
		t.Fatalf("unexpected error generating key: %v", err)
	}

	sm, err := manifest.Sign(&m, pk)
	if err != nil {
		t.Fatalf("unexpected error signing manifest: %v", err)
	}

	manifests, err := repository.Manifests(ctx)
	if err != nil {
		t.Fatal(err.Error())
	}

	if err = manifests.Put(sm); err != nil {
		t.Fatalf("unexpected error putting the manifest: %v", err)
	}

	p, err := sm.Payload()
	if err != nil {
		t.Fatalf("unexpected error getting manifest payload: %v", err)
	}

	dgst, err := digest.FromBytes(p)
	if err != nil {
		t.Fatalf("unexpected error digesting manifest payload: %v", err)
	}

	fetchedByManifest, err := manifests.Get(dgst)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest: %v", err)
	}

	if fetchedByManifest.Tag != sm.Tag {
		t.Fatalf("retrieved unexpected manifest: %v", err)
	}

	fetched, err := manifests.GetByTag(tag)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest: %v", err)
	}

	if fetched.Tag != fetchedByManifest.Tag {
		t.Fatalf("retrieved unexpected manifest: %v", err)
	}
//.........这里部分代码省略.........

// Pull downloads the plugin from Store
func Pull(name string, rs registry.Service, metaheader http.Header, authConfig *types.AuthConfig) (PullData, error) {
	ref, err := reference.ParseNamed(name)
	if err != nil {
		logrus.Debugf("pull.go: error in ParseNamed: %v", err)
		return nil, err
	}

	repoInfo, err := rs.ResolveRepository(ref)
	if err != nil {
		logrus.Debugf("pull.go: error in ResolveRepository: %v", err)
		return nil, err
	}

	if err := dockerdist.ValidateRepoName(repoInfo.Name()); err != nil {
		logrus.Debugf("pull.go: error in ValidateRepoName: %v", err)
		return nil, err
	}

	endpoints, err := rs.LookupPullEndpoints(repoInfo.Hostname())
	if err != nil {
		logrus.Debugf("pull.go: error in LookupPullEndpoints: %v", err)
		return nil, err
	}

	var confirmedV2 bool
	var repository distribution.Repository

	for _, endpoint := range endpoints {
		if confirmedV2 && endpoint.Version == registry.APIVersion1 {
			logrus.Debugf("Skipping v1 endpoint %s because v2 registry was detected", endpoint.URL)
			continue
		}

		// TODO: reuse contexts
		repository, confirmedV2, err = dockerdist.NewV2Repository(context.Background(), repoInfo, endpoint, metaheader, authConfig, "pull")
		if err != nil {
			logrus.Debugf("pull.go: error in NewV2Repository: %v", err)
			return nil, err
		}
		if !confirmedV2 {
			logrus.Debugf("pull.go: !confirmedV2")
			return nil, ErrUnSupportedRegistry
		}
		logrus.Debugf("Trying to pull %s from %s %s", repoInfo.Name(), endpoint.URL, endpoint.Version)
		break
	}

	tag := DefaultTag
	if ref, ok := ref.(reference.NamedTagged); ok {
		tag = ref.Tag()
	}

	// tags := repository.Tags(context.Background())
	// desc, err := tags.Get(context.Background(), tag)
	// 	if err != nil {
	// 		return nil, err
	// 	}
	//
	msv, err := repository.Manifests(context.Background())
	if err != nil {
		logrus.Debugf("pull.go: error in repository.Manifests: %v", err)
		return nil, err
	}
	manifest, err := msv.Get(context.Background(), "", distribution.WithTag(tag))
	if err != nil {
		// TODO: change 401 to 404
		logrus.Debugf("pull.go: error in msv.Get(): %v", err)
		return nil, err
	}

	_, pl, err := manifest.Payload()
	if err != nil {
		logrus.Debugf("pull.go: error in manifest.Payload(): %v", err)
		return nil, err
	}
	var m schema2.Manifest
	if err := json.Unmarshal(pl, &m); err != nil {
		logrus.Debugf("pull.go: error in json.Unmarshal(): %v", err)
		return nil, err
	}

	pd := &pullData{
		repository: repository,
		manifest:   m,
	}

	logrus.Debugf("manifest: %s", pl)
	return pd, nil
}

// checkExerciseRegistry takes the registry through all of its operations,
// carrying out generic checks.
func checkExerciseRepository(t *testing.T, repository distribution.Repository) {
	// TODO(stevvooe): This would be a nice testutil function. Basically, it
	// takes the registry through a common set of operations. This could be
	// used to make cross-cutting updates by changing internals that affect
	// update counts. Basically, it would make writing tests a lot easier.

	ctx := context.Background()
	tag := "thetag"
	// todo: change this to use Builder

	m := schema1.Manifest{
		Versioned: manifest.Versioned{
			SchemaVersion: 1,
		},
		Name: repository.Named().Name(),
		Tag:  tag,
	}

	var blobDigests []digest.Digest
	blobs := repository.Blobs(ctx)
	for i := 0; i < 2; i++ {
		rs, ds, err := testutil.CreateRandomTarFile()
		if err != nil {
			t.Fatalf("error creating test layer: %v", err)
		}
		dgst := digest.Digest(ds)
		blobDigests = append(blobDigests, dgst)

		wr, err := blobs.Create(ctx)
		if err != nil {
			t.Fatalf("error creating layer upload: %v", err)
		}

		// Use the resumes, as well!
		wr, err = blobs.Resume(ctx, wr.ID())
		if err != nil {
			t.Fatalf("error resuming layer upload: %v", err)
		}

		io.Copy(wr, rs)

		if _, err := wr.Commit(ctx, distribution.Descriptor{Digest: dgst}); err != nil {
			t.Fatalf("unexpected error finishing upload: %v", err)
		}

		m.FSLayers = append(m.FSLayers, schema1.FSLayer{
			BlobSum: dgst,
		})
		m.History = append(m.History, schema1.History{
			V1Compatibility: "",
		})

		// Then fetch the blobs
		if rc, err := blobs.Open(ctx, dgst); err != nil {
			t.Fatalf("error fetching layer: %v", err)
		} else {
			defer rc.Close()
		}
	}

	pk, err := libtrust.GenerateECP256PrivateKey()
	if err != nil {
		t.Fatalf("unexpected error generating key: %v", err)
	}

	sm, err := schema1.Sign(&m, pk)
	if err != nil {
		t.Fatalf("unexpected error signing manifest: %v", err)
	}

	manifests, err := repository.Manifests(ctx)
	if err != nil {
		t.Fatal(err.Error())
	}

	var digestPut digest.Digest
	if digestPut, err = manifests.Put(ctx, sm); err != nil {
		t.Fatalf("unexpected error putting the manifest: %v", err)
	}

	dgst := digest.FromBytes(sm.Canonical)
	if dgst != digestPut {
		t.Fatalf("mismatching digest from payload and put")
	}

	_, err = manifests.Get(ctx, dgst)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest: %v", err)
	}

	err = manifests.Delete(ctx, dgst)
	if err != nil {
		t.Fatalf("unexpected error deleting blob: %v", err)
	}

	for _, d := range blobDigests {
		err = blobs.Delete(ctx, d)
		if err != nil {
//.........这里部分代码省略.........