WIP: pass Brandon's new conformance with ocimem piped through `ocis…

ociregistry/interface.go

@@ -99,6 +99,7 @@ type Reader interface {
 	// starting at offset0, up to but not including offset1.
 	// If offset1 is negative or exceeds the actual size of the blob, GetBlobRange will
 	// return all the data starting from offset0.
+	// If offset0 is negative, offset1 is the number of bytes to return from the end of the blob. (TODO https://github.com/cue-labs/oci/issues/47)
 	// The context also controls the lifetime of the returned BlobReader.
 	GetBlobRange(ctx context.Context, repo string, digest Digest, offset0, offset1 int64) (BlobReader, error)
 

ociregistry/internal/ocirequest/request.go

@@ -335,7 +335,10 @@ func Parse(method string, u *url.URL) (*Request, error) {
 		case ociref.IsValidTag(last):
 			rreq.Tag = last
 		default:
-			return nil, errNotFound
+			if strings.Contains(last, ":") {
+				return nil, errBadlyFormedDigest
+			}
+			return nil, errNotFound // TODO this probably shouldn't be 404 (more like 500 or just always errBadlyFormedDigest or maybe even "badly formed tag")
 		}
 		switch method {
 		case "GET":

ociregistry/ocimem/blob.go

@@ -20,8 +20,6 @@ import (
 	"fmt"
 	"sync"
 
-	"github.com/opencontainers/go-digest"
-
 	"cuelabs.dev/go/oci/ociregistry"
 )
 
@@ -178,8 +176,8 @@ func (b *Buffer) checkCommit(dig ociregistry.Digest) (err error) {
 			b.commitErr = err
 		}
 	}()
-	if digest.FromBytes(b.buf) != dig {
-		return fmt.Errorf("digest mismatch (sha256(%q) != %s): %w", b.buf, dig, ociregistry.ErrDigestInvalid)
+	if err := CheckDescriptor(ociregistry.Descriptor{Digest: dig, Size: int64(len(b.buf)), MediaType: "application/octet-stream"}, b.buf); err != nil { // TODO is it sane to abuse CheckDescriptor as "validate digest algorithm + validate digest" like this? it feels good to have that logic centralized
+		return err
 	}
 	b.desc = ociregistry.Descriptor{
 		MediaType: "application/octet-stream",

ociregistry/ocimem/lister.go

@@ -43,7 +43,9 @@ func (r *Registry) Referrers(_ context.Context, repoName string, digest ociregis
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	repo, err := r.repo(repoName)
-	if err != nil {
+	if err == ociregistry.ErrNameUnknown {
+		return ociregistry.SliceSeq([]ociregistry.Descriptor{}) // "Assuming a repository is found, this request MUST return a 200 OK response code. If the registry supports the referrers API, the registry MUST NOT return a 404 Not Found to a referrers API requests."
+	} else if err != nil {
 		return ociregistry.ErrorSeq[ociregistry.Descriptor](err)
 	}
 	var referrers []ociregistry.Descriptor

ociregistry/ocimem/reader.go

@@ -43,8 +43,12 @@ func (r *Registry) GetBlobRange(ctx context.Context, repoName string, dig ocireg
 	if o1 < 0 || o1 > int64(len(b.data)) {
 		o1 = int64(len(b.data))
 	}
+	if o0 < 0 { // TODO https://github.com/cue-labs/oci/issues/47
+		o0 = max(int64(len(b.data))-o1, 0)
+		o1 = int64(len(b.data))
+	}
 	if o0 < 0 || o0 > o1 {
-		return nil, fmt.Errorf("invalid range [%d, %d]; have [%d, %d]", o0, o1, 0, len(b.data))
+		return nil, fmt.Errorf("%w: [%d, %d]; have [%d, %d]", ociregistry.ErrRangeInvalid, o0, o1, 0, len(b.data))
 	}
 	return NewBytesReader(b.data[o0:o1], b.descriptor()), nil
 }

ociregistry/ocimem/registry.go

@@ -43,6 +43,7 @@ type repository struct {
 
 type blob struct {
 	mediaType string
+	digest    ociregistry.Digest
 	data      []byte
 	info      manifestInfo
 }
@@ -51,7 +52,7 @@ func (b *blob) descriptor() ociregistry.Descriptor {
 	return ociregistry.Descriptor{
 		MediaType:    b.mediaType,
 		Size:         int64(len(b.data)),
-		Digest:       digest.FromBytes(b.data),
+		Digest:       b.digest,
 		ArtifactType: b.info.artifactType,
 		Annotations:  b.info.annotations,
 	}
@@ -158,16 +159,12 @@ func CheckDescriptor(desc ociregistry.Descriptor, data []byte) error {
 	if err := desc.Digest.Validate(); err != nil {
 		return fmt.Errorf("invalid digest: %v", err)
 	}
-	if data != nil {
-		if digest.FromBytes(data) != desc.Digest {
-			return fmt.Errorf("digest mismatch")
-		}
+	if data != nil || desc.Size == 0 {
 		if desc.Size != int64(len(data)) {
-			return fmt.Errorf("size mismatch")
+			return ociregistry.ErrSizeInvalid // TODO include both sizes in the error?
 		}
-	} else {
-		if desc.Size == 0 && desc.Digest != emptyHash {
-			return fmt.Errorf("zero sized content with mismatching digest")
+		if desc.Digest.Algorithm().FromBytes(data) != desc.Digest {
+			return ociregistry.ErrDigestInvalid // TODO include both digests in the error?
 		}
 	}
 	if desc.MediaType == "" {

ociregistry/ocimem/writer.go

@@ -33,7 +33,7 @@ func (r *Registry) PushBlob(ctx context.Context, repoName string, desc ociregist
 		return ociregistry.Descriptor{}, fmt.Errorf("cannot read content: %v", err)
 	}
 	if err := CheckDescriptor(desc, data); err != nil {
-		return ociregistry.Descriptor{}, fmt.Errorf("invalid descriptor: %v", err)
+		return ociregistry.Descriptor{}, fmt.Errorf("invalid descriptor: %w", err)
 	}
 
 	r.mu.Lock()
@@ -42,7 +42,7 @@ func (r *Registry) PushBlob(ctx context.Context, repoName string, desc ociregist
 	if err != nil {
 		return ociregistry.Descriptor{}, err
 	}
-	repo.blobs[desc.Digest] = &blob{mediaType: desc.MediaType, data: data}
+	repo.blobs[desc.Digest] = &blob{mediaType: desc.MediaType, digest: desc.Digest, data: data}
 	return desc, nil
 }
 
@@ -69,7 +69,7 @@ func (r *Registry) PushBlobChunkedResume(ctx context.Context, repoName, id strin
 			r.mu.Lock()
 			defer r.mu.Unlock()
 			desc, data, _ := b.GetBlob()
-			repo.blobs[desc.Digest] = &blob{mediaType: desc.MediaType, data: data}
+			repo.blobs[desc.Digest] = &blob{mediaType: desc.MediaType, digest: desc.Digest, data: data}
 			return nil
 		}, id)
 		repo.uploads[b.ID()] = b
@@ -129,7 +129,7 @@ func (r *Registry) PushManifest(ctx context.Context, repoName string, tag string
 	// make a copy of the data to avoid potential corruption.
 	data = slices.Clone(data)
 	if err := CheckDescriptor(desc, data); err != nil {
-		return ociregistry.Descriptor{}, fmt.Errorf("invalid descriptor: %v", err)
+		return ociregistry.Descriptor{}, fmt.Errorf("invalid descriptor: %w", err)
 	}
 	info, err := r.checkManifestReferences(repoName, desc.MediaType, data)
 	if err != nil {
@@ -138,6 +138,7 @@ func (r *Registry) PushManifest(ctx context.Context, repoName string, tag string
 
 	repo.manifests[dig] = &blob{
 		mediaType: mediaType,
+		digest:    dig,
 		data:      data,
 		info:      info,
 	}
@@ -166,7 +167,7 @@ func (r *Registry) checkManifestReferences(repoName string, mediaType string, da
 		}
 		switch info.kind {
 		case kindBlob:
-			if repo.blobs[info.desc.Digest] == nil {
+			if repo.blobs[info.desc.Digest] == nil && len(info.desc.URLs) == 0 { // TODO should the "urls" half of this check be optional?
 				return manifestInfo{}, fmt.Errorf("blob for %s not found", info.name)
 			}
 		case kindManifest:

ociregistry/ociserver/range.go

@@ -29,6 +29,7 @@ import (
 
 // httpRange specifies a byte range as requested by a client.
 // If end is negative, it represents the end of the file.
+// If start is negative, end represents the number of bytes to return from the end of the file. (TODO https://github.com/cue-labs/oci/issues/47)
 type httpRange struct {
 	start, end int64
 }
@@ -63,7 +64,13 @@ func parseRange(s string) ([]httpRange, error) {
 			if end == "" || end[0] == '-' {
 				return nil, errors.New("invalid range")
 			}
-			return nil, errors.New("end-relative range not supported")
+			// TODO https://github.com/cue-labs/oci/issues/47
+			r.start = -1
+			i, err := strconv.ParseInt(end, 10, 64)
+			if err != nil {
+				return nil, errors.New("invalid range")
+			}
+			r.end = i
 		} else {
 			i, err := strconv.ParseInt(start, 10, 64)
 			if err != nil || i < 0 {

ociregistry/ociserver/reader.go

@@ -93,6 +93,10 @@ func (r *registry) handleBlobGet(ctx context.Context, resp http.ResponseWriter,
 		if rng.end == -1 || rng.end > desc.Size {
 			rng.end = desc.Size
 		}
+		if rng.start == -1 { // TODO https://github.com/cue-labs/oci/issues/47
+			rng.start = desc.Size - rng.end
+			rng.end = desc.Size
+		}
 		if rng.start > desc.Size {
 			return withHTTPCode(http.StatusRequestedRangeNotSatisfiable, fmt.Errorf("range starts after end of blob"))
 		}

ociregistry/ociserver/writer.go

@@ -138,7 +138,7 @@ func (r *registry) handleBlobCompleteUpload(ctx context.Context, resp http.Respo
 	defer w.Close()
 
 	if _, err := io.Copy(w, req.Body); err != nil {
-		return fmt.Errorf("failed to copy data to %T: %v", w, err)
+		return fmt.Errorf("failed to copy data to %T: %w", w, err)
 	}
 	desc, err := w.Commit(ociregistry.Digest(rreq.Digest))
 	if err != nil {
@@ -154,7 +154,7 @@ func (r *registry) handleBlobCompleteUpload(ctx context.Context, resp http.Respo
 func (r *registry) handleBlobMount(ctx context.Context, resp http.ResponseWriter, req *http.Request, rreq *ocirequest.Request) error {
 	desc, err := r.backend.MountBlob(ctx, rreq.FromRepo, rreq.Repo, ociregistry.Digest(rreq.Digest))
 	if err != nil {
-		return err
+		return r.handleBlobStartUpload(ctx, resp, req, rreq) // TODO debug log?  only do this on 404?
 	}
 	if err := r.setLocationHeader(resp, true, desc, "/v2/"+rreq.Repo+"/blobs/"+rreq.Digest); err != nil {
 		return err