Various adjustments to digest package for govet/golint

digest/digest.go

@@ -75,8 +75,8 @@ func ParseDigest(s string) (Digest, error) {
 	return Digest(s), nil
 }
 
-// DigestReader returns the most valid digest for the underlying content.
+// FromReader returns the most valid digest for the underlying content.
-func DigestReader(rd io.Reader) (Digest, error) {
+func FromReader(rd io.Reader) (Digest, error) {
 
 	// TODO(stevvooe): This is pretty inefficient to always be calculating a
 	// sha256 hash to provide fallback, but it provides some nice semantics in
@@ -114,8 +114,9 @@ func DigestReader(rd io.Reader) (Digest, error) {
 	return d, nil
 }
 
-func DigestBytes(p []byte) (Digest, error) {
+// FromBytes digests the input and returns a Digest.
-	return DigestReader(bytes.NewReader(p))
+func FromBytes(p []byte) (Digest, error) {
+	return FromReader(bytes.NewReader(p))
 }
 
 // Algorithm returns the algorithm portion of the digest. This will panic if

digest/doc.go

@@ -1,4 +1,4 @@
-// This package provides a generalized type to opaquely represent message
+// Package digest provides a generalized type to opaquely represent message
 // digests and their operations within the registry. The Digest type is
 // designed to serve as a flexible identifier in a content-addressable system.
 // More importantly, it provides tools and wrappers to work with tarsums and

digest/verifiers.go

@@ -11,6 +11,10 @@ import (
 	"github.com/docker/docker/pkg/tarsum"
 )
 
+// Verifier presents a general verification interface to be used with message
+// digests and other byte stream verifications. Users instantiate a Verifier
+// from one of the various methods, write the data under test to it then check
+// the result with the Verified method.
 type Verifier interface {
 	io.Writer
 
@@ -23,7 +27,9 @@ type Verifier interface {
 	// Reset()
 }
 
-func DigestVerifier(d Digest) Verifier {
+// NewDigestVerifier returns a verifier that compares the written bytes
+// against a passed in digest.
+func NewDigestVerifier(d Digest) Verifier {
 	alg := d.Algorithm()
 	switch alg {
 	case "md5", "sha1", "sha256":
@@ -62,13 +68,11 @@ func DigestVerifier(d Digest) Verifier {
 			pw:     pw,
 		}
 	}
-
-	panic("unsupported digest: " + d)
 }
 
-// LengthVerifier returns a verifier that returns true when the number of read
+// NewLengthVerifier returns a verifier that returns true when the number of
-// bytes equals the expected parameter.
+// read bytes equals the expected parameter.
-func LengthVerifier(expected int64) Verifier {
+func NewLengthVerifier(expected int64) Verifier {
 	return &lengthVerifier{
 		expected: expected,
 	}

digest/verifiers_test.go

@@ -13,12 +13,12 @@ import (
 func TestDigestVerifier(t *testing.T) {
 	p := make([]byte, 1<<20)
 	rand.Read(p)
-	digest, err := DigestBytes(p)
+	digest, err := FromBytes(p)
 	if err != nil {
 		t.Fatalf("unexpected error digesting bytes: %#v", err)
 	}
 
-	verifier := DigestVerifier(digest)
+	verifier := NewDigestVerifier(digest)
 	io.Copy(verifier, bytes.NewReader(p))
 
 	if !verifier.Verified() {
@@ -30,7 +30,7 @@ func TestDigestVerifier(t *testing.T) {
 		t.Fatalf("error creating tarfile: %v", err)
 	}
 
-	digest, err = DigestReader(tf)
+	digest, err = FromReader(tf)
 	if err != nil {
 		t.Fatalf("error digesting tarsum: %v", err)
 	}
@@ -45,8 +45,8 @@ func TestDigestVerifier(t *testing.T) {
 	// This is the most relevant example for the registry application. It's
 	// effectively a read through pipeline, where the final sink is the digest
 	// verifier.
-	verifier = DigestVerifier(digest)
+	verifier = NewDigestVerifier(digest)
-	lengthVerifier := LengthVerifier(expectedSize)
+	lengthVerifier := NewLengthVerifier(expectedSize)
 	rd := io.TeeReader(tf, lengthVerifier)
 	io.Copy(verifier, rd)
 

storage/layerupload.go

@@ -241,8 +241,8 @@ func (luc *layerUploadController) validateLayer(fp layerFile, size int64, dgst d
 		return "", ErrLayerTarSumVersionUnsupported
 	}
 
-	digestVerifier := digest.DigestVerifier(dgst)
+	digestVerifier := digest.NewDigestVerifier(dgst)
-	lengthVerifier := digest.LengthVerifier(size)
+	lengthVerifier := digest.NewLengthVerifier(size)
 
 	// First, seek to the end of the file, checking the size is as expected.
 	end, err := fp.Seek(0, os.SEEK_END)
@@ -267,7 +267,7 @@ func (luc *layerUploadController) validateLayer(fp layerFile, size int64, dgst d
 	// sink. Instead, its read driven. This migth be okay.
 
 	// Calculate an updated digest with the latest version.
-	dgst, err = digest.DigestReader(tr)
+	dgst, err = digest.FromReader(tr)
 	if err != nil {
 		return "", err
 	}

storage/paths.go

@@ -1,12 +1,12 @@
 package storage
 
 import (
-	"strings"
-	"github.com/docker/docker-registry/digest"
 	"fmt"
 	"path"
+	"strings"
 
 	"github.com/docker/docker-registry/common"
+	"github.com/docker/docker-registry/digest"
 )
 
 const storagePathVersion = "v2"