Merge pull request #1264 from aaronlehmann/hash-errors

Simplify digest.FromBytes calling convention

digest/digest.go

@@ -1,7 +1,6 @@
 package digest
 
 import (
-	"bytes"
 	"fmt"
 	"hash"
 	"io"
@@ -99,8 +98,19 @@ func FromTarArchive(rd io.Reader) (Digest, error) {
 }
 
 // FromBytes digests the input and returns a Digest.
-func FromBytes(p []byte) (Digest, error) {
-	return FromReader(bytes.NewReader(p))
+func FromBytes(p []byte) Digest {
+	digester := Canonical.New()
+
+	if _, err := digester.Hash().Write(p); err != nil {
+		// Writes to a Hash should never fail. None of the existing
+		// hash implementations in the stdlib or hashes vendored
+		// here can return errors from Write. Having a panic in this
+		// condition instead of having FromBytes return an error value
+		// avoids unnecessary error handling paths in all callers.
+		panic("write to hash function returned error: " + err.Error())
+	}
+
+	return digester.Digest()
 }
 
 // Validate checks that the contents of d is a valid digest, returning an

digest/verifiers_test.go

@@ -15,10 +15,7 @@ import (
 func TestDigestVerifier(t *testing.T) {
 	p := make([]byte, 1<<20)
 	rand.Read(p)
-	digest, err := FromBytes(p)
-	if err != nil {
-		t.Fatalf("unexpected error digesting bytes: %#v", err)
-	}
+	digest := FromBytes(p)
 
 	verifier, err := NewDigestVerifier(digest)
 	if err != nil {

notifications/bridge.go

@@ -98,10 +98,7 @@ func (b *bridge) createManifestEvent(action string, repo string, sm *schema1.Sig
 
 	event.Target.Length = int64(len(p))
 	event.Target.Size = int64(len(p))
-	event.Target.Digest, err = digest.FromBytes(p)
-	if err != nil {
-		return nil, err
-	}
+	event.Target.Digest = digest.FromBytes(p)
 
 	event.Target.URL, err = b.ub.BuildManifestURL(sm.Name, event.Target.Digest.String())
 	if err != nil {

notifications/bridge_test.go

@@ -90,10 +90,7 @@ func createTestEnv(t *testing.T, fn testSinkFn) Listener {
 		t.Fatalf("error getting manifest payload: %v", err)
 	}
 
-	dgst, err = digest.FromBytes(payload)
-	if err != nil {
-		t.Fatalf("error digesting manifest payload: %v", err)
-	}
+	dgst = digest.FromBytes(payload)
 
 	return NewBridge(ub, source, actor, request, fn)
 }

notifications/listener_test.go

@@ -167,11 +167,7 @@ func checkExerciseRepository(t *testing.T, repository distribution.Repository) {
 		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)
-	}
-
+	dgst := digest.FromBytes(p)
 	fetchedByManifest, err := manifests.Get(dgst)
 	if err != nil {
 		t.Fatalf("unexpected error fetching manifest: %v", err)

registry/client/repository_test.go

@@ -38,12 +38,7 @@ func newRandomBlob(size int) (digest.Digest, []byte) {
 		panic("unable to read enough bytes")
 	}
 
-	dgst, err := digest.FromBytes(b)
-	if err != nil {
-		panic(err)
-	}
-
-	return dgst, b
+	return digest.FromBytes(b), b
 }
 
 func addTestFetch(repo string, dgst digest.Digest, content []byte, m *testutil.RequestResponseMap) {
@@ -509,16 +504,11 @@ func newRandomSchemaV1Manifest(name, tag string, blobCount int) (*schema1.Signed
 		panic(err)
 	}
 
-	dgst, err := digest.FromBytes(p)
-	if err != nil {
-		panic(err)
-	}
-
-	return sm, dgst, p
+	return sm, digest.FromBytes(p), p
 }
 
 func addTestManifestWithEtag(repo, reference string, content []byte, m *testutil.RequestResponseMap, dgst string) {
-	actualDigest, _ := digest.FromBytes(content)
+	actualDigest := digest.FromBytes(content)
 	getReqWithEtag := testutil.Request{
 		Method: "GET",
 		Route:  "/v2/" + repo + "/manifests/" + reference,

registry/handlers/api_test.go

@@ -880,8 +880,7 @@ func testManifestAPI(t *testing.T, env *testEnv, args manifestArgs) (*testEnv, m
 	payload, err := signedManifest.Payload()
 	checkErr(t, err, "getting manifest payload")
 
-	dgst, err := digest.FromBytes(payload)
-	checkErr(t, err, "digesting manifest")
+	dgst := digest.FromBytes(payload)
 
 	args.signedManifest = signedManifest
 	args.dgst = dgst
@@ -1487,8 +1486,7 @@ func createRepository(env *testEnv, t *testing.T, imageName string, tag string)
 	payload, err := signedManifest.Payload()
 	checkErr(t, err, "getting manifest payload")
 
-	dgst, err := digest.FromBytes(payload)
-	checkErr(t, err, "digesting manifest")
+	dgst := digest.FromBytes(payload)
 
 	manifestDigestURL, err := env.builder.BuildManifestURL(imageName, dgst.String())
 	checkErr(t, err, "building manifest url")

registry/handlers/images.go

@@ -250,11 +250,5 @@ func digestManifest(ctx context.Context, sm *schema1.SignedManifest) (digest.Dig
 		p = sm.Raw
 	}
 
-	dgst, err := digest.FromBytes(p)
-	if err != nil {
-		ctxu.GetLogger(ctx).Errorf("error digesting manifest: %v", err)
-		return "", err
-	}
-
-	return dgst, err
+	return digest.FromBytes(p), nil
 }

registry/proxy/proxyblobstore_test.go

@@ -298,10 +298,7 @@ func testProxyStoreServe(t *testing.T, te *testEnv, numClients int) {
 				}
 
 				bodyBytes := w.Body.Bytes()
-				localDigest, err := digest.FromBytes(bodyBytes)
-				if err != nil {
-					t.Fatalf("Error making digest from blob")
-				}
+				localDigest := digest.FromBytes(bodyBytes)
 				if localDigest != remoteBlob.Digest {
 					t.Fatalf("Mismatching blob fetch from proxy")
 				}
@@ -335,10 +332,7 @@ func testProxyStoreServe(t *testing.T, te *testEnv, numClients int) {
 			t.Fatalf(err.Error())
 		}
 
-		dl, err := digest.FromBytes(w.Body.Bytes())
-		if err != nil {
-			t.Fatalf("Error making digest from blob")
-		}
+		dl := digest.FromBytes(w.Body.Bytes())
 		if dl != dr.Digest {
 			t.Errorf("Mismatching blob fetch from proxy")
 		}

registry/proxy/proxymanifeststore.go

@@ -137,12 +137,7 @@ func manifestDigest(sm *schema1.SignedManifest) (digest.Digest, error) {
 
 	}
 
-	dgst, err := digest.FromBytes(payload)
-	if err != nil {
-		return "", err
-	}
-
-	return dgst, nil
+	return digest.FromBytes(payload), nil
 }
 
 func (pms proxyManifestStore) Put(manifest *schema1.SignedManifest) error {

registry/proxy/proxymanifeststore_test.go

@@ -177,7 +177,7 @@ func populateRepo(t *testing.T, ctx context.Context, repository distribution.Rep
 	if err != nil {
 		t.Fatal(err)
 	}
-	return digest.FromBytes(pl)
+	return digest.FromBytes(pl), nil
 }
 
 // TestProxyManifests contains basic acceptance tests

registry/storage/blob_test.go

@@ -176,10 +176,7 @@ func TestSimpleBlobUpload(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Error reading all of blob %s", err.Error())
 	}
-	expectedDigest, err := digest.FromBytes(randomBlob)
-	if err != nil {
-		t.Fatalf("Error getting digest from bytes: %s", err)
-	}
+	expectedDigest := digest.FromBytes(randomBlob)
 	simpleUpload(t, bs, randomBlob, expectedDigest)
 
 	d, err = bs.Stat(ctx, expectedDigest)

registry/storage/blobstore.go

@@ -56,12 +56,7 @@ func (bs *blobStore) Open(ctx context.Context, dgst digest.Digest) (distribution
 // content is already present, only the digest will be returned. This should
 // only be used for small objects, such as manifests. This implemented as a convenience for other Put implementations
 func (bs *blobStore) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
-	dgst, err := digest.FromBytes(p)
-	if err != nil {
-		context.GetLogger(ctx).Errorf("blobStore: error digesting content: %v, %s", err, string(p))
-		return distribution.Descriptor{}, err
-	}
-
+	dgst := digest.FromBytes(p)
 	desc, err := bs.statter.Stat(ctx, dgst)
 	if err == nil {
 		// content already present

registry/storage/linkedblobstore.go

@@ -75,10 +75,7 @@ func (lbs *linkedBlobStore) ServeBlob(ctx context.Context, w http.ResponseWriter
 }
 
 func (lbs *linkedBlobStore) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
-	dgst, err := digest.FromBytes(p)
-	if err != nil {
-		return distribution.Descriptor{}, err
-	}
+	dgst := digest.FromBytes(p)
 	// Place the data in the blob store first.
 	desc, err := lbs.blobStore.Put(ctx, mediaType, p)
 	if err != nil {

registry/storage/manifeststore_test.go

@@ -185,11 +185,7 @@ func TestManifestStorage(t *testing.T) {
 
 	// Now that we have a payload, take a moment to check that the manifest is
 	// return by the payload digest.
-	dgst, err := digest.FromBytes(payload)
-	if err != nil {
-		t.Fatalf("error getting manifest digest: %v", err)
-	}
-
+	dgst := digest.FromBytes(payload)
 	exists, err = ms.Exists(dgst)
 	if err != nil {
 		t.Fatalf("error checking manifest existence by digest: %v", err)