refactor(model): name the artwork mime lookup for what it is keyed by

GetAllMimes reads as a collection of mime types; it returns a hash -> mime index
over every stored artwork. GetMimeByHash names the key, matching the convention
the other map-returning repository methods already follow (CountBySuffix,
CountByClient).

core/artwork/prune.go

@@ -44,7 +44,7 @@ func prune(ctx context.Context, ds model.DataStore, store *ImageStore) error {
 	}
 
 	// Read after the delete, so the sweep below reclaims the files of the rows just removed.
-	mimes, err := repo.GetAllMimes()
+	mimes, err := repo.GetMimeByHash()
 	if err != nil {
 		return err
 	}

core/artwork/prune_test.go

@@ -18,7 +18,7 @@ type flakyGetArtworkRepo struct {
 	*tests.MockArtworkRepo
 }
 
-func (f *flakyGetArtworkRepo) GetAllMimes() (map[string]string, error) {
+func (f *flakyGetArtworkRepo) GetMimeByHash() (map[string]string, error) {
 	return nil, errors.New("db locked")
 }
 

model/artwork.go

@@ -106,8 +106,8 @@ type ArtworkRepository interface {
 	DeleteForItems(kind Kind, ids []string) error
 	// GetInfoForItems hydrates a page in one batched query.
 	GetInfoForItems(kind Kind, ids []string) (map[string]ItemArtworkInfo, error)
-	// GetAllMimes returns hash -> current mime for every stored artwork.
-	GetAllMimes() (map[string]string, error)
+	// GetMimeByHash returns hash -> current mime for every stored artwork.
+	GetMimeByHash() (map[string]string, error)
 	// PurgeDanglingItemArtwork removes state rows whose entity no longer exists.
 	PurgeDanglingItemArtwork() (int64, error)
 }

persistence/artwork_repository.go

@@ -56,7 +56,7 @@ func (r *artworkRepository) PutImage(a *model.Artwork) error {
 	return err
 }
 
-func (r *artworkRepository) GetAllMimes() (map[string]string, error) {
+func (r *artworkRepository) GetMimeByHash() (map[string]string, error) {
 	sel := Select("hash", "mime").From(r.tableName)
 	var rows []struct {
 		Hash string

persistence/artwork_repository_test.go

@@ -89,7 +89,7 @@ var _ = Describe("ArtworkRepository", func() {
 		It("returns every stored hash with its current mime", func() {
 			Expect(repo.PutImage(&model.Artwork{Hash: "all1", Mime: "image/jpeg"})).To(Succeed())
 			Expect(repo.PutImage(&model.Artwork{Hash: "all2", Mime: "image/png"})).To(Succeed())
-			mimes, err := repo.GetAllMimes()
+			mimes, err := repo.GetMimeByHash()
 			Expect(err).ToNot(HaveOccurred())
 			Expect(mimes).To(HaveKeyWithValue("all1", "image/jpeg"))
 			Expect(mimes).To(HaveKeyWithValue("all2", "image/png"))

tests/mock_artwork_repo.go

@@ -50,7 +50,7 @@ func (m *MockArtworkRepo) PutImage(a *model.Artwork) error {
 	return nil
 }
 
-func (m *MockArtworkRepo) GetAllMimes() (map[string]string, error) {
+func (m *MockArtworkRepo) GetMimeByHash() (map[string]string, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	if m.Err != nil {