fix

Signed-off-by: Sylvia Lei <lixlei@microsoft.com>

Author: Wwwsylvia

content.go

@@ -107,7 +107,7 @@ func resolve(ctx context.Context, target ReadOnlyTarget, proxy *cas.Proxy, refer
 }
 
 // DefaultFetchOptions provides the default FetchOptions.
-var DefaultFetchOptions = FetchOptions{}
+var DefaultFetchOptions FetchOptions
 
 // FetchOptions contains parameters for oras.Fetch.
 type FetchOptions struct {
@@ -150,32 +150,38 @@ func Fetch(ctx context.Context, target ReadOnlyTarget, reference string, opts Fe
 
 // DefaultFetchBytesOptions provides the default FetchBytesOptions.
 var DefaultFetchBytesOptions = FetchBytesOptions{
-	SizeLimit: int64(1 << 22), // 4 MiB
+	MaxBytes: defaultMaxBytes,
 }
 
+// defaultMaxBytes is the default value of MaxBytes.
+const defaultMaxBytes int64 = 4 * 1024 * 1024 // 4 MiB
+
 // FetchBytesOptions contains parameters for oras.FetchBytes.
 type FetchBytesOptions struct {
 	// FetchOptions contains parameters for fetching content.
 	FetchOptions
-	// SizeLimit limits the max size of the fetched content.
-	// If SizeLimit is not specified, or the specified value is less than or
-	// equal to 0, it will be considered as infinity.
-	SizeLimit int64
+	// MaxBytes limits the maximum size of the fetched content bytes.
+	// If less than or equal to 0, a default (currently 4 MiB) is used.
+	MaxBytes int64
 }
 
 // FetchBytes fetches the content bytes identified by the reference.
 func FetchBytes(ctx context.Context, target ReadOnlyTarget, reference string, opts FetchBytesOptions) (ocispec.Descriptor, []byte, error) {
+	if opts.MaxBytes <= 0 {
+		opts.MaxBytes = defaultMaxBytes
+	}
+
 	desc, rc, err := Fetch(ctx, target, reference, opts.FetchOptions)
 	if err != nil {
 		return ocispec.Descriptor{}, nil, err
 	}
 	defer rc.Close()
 
-	if opts.SizeLimit > 0 && desc.Size > opts.SizeLimit {
+	if desc.Size > opts.MaxBytes {
 		return ocispec.Descriptor{}, nil, fmt.Errorf(
-			"content size %v exceeds max size limit %v: %w",
+			"content size %v exceeds MaxBytes %v: %w",
 			desc.Size,
-			opts.SizeLimit,
+			opts.MaxBytes,
 			errdef.ErrSizeExceedsLimit)
 	}
 	bytes, err := content.ReadAll(rc, desc)

content_test.go

@@ -966,8 +966,8 @@ func TestFetchBytes_Memory(t *testing.T) {
 		t.Fatalf("oras.FetchBytes() error = %v, wantErr %v", err, errdef.ErrNotFound)
 	}
 
-	// test FetchBytes with SizeLimit = 1
-	_, _, err = oras.FetchBytes(ctx, target, manifestTag, oras.FetchBytesOptions{SizeLimit: 1})
+	// test FetchBytes with MaxBytes = 1
+	_, _, err = oras.FetchBytes(ctx, target, manifestTag, oras.FetchBytesOptions{MaxBytes: 1})
 	if !errors.Is(err, errdef.ErrSizeExceedsLimit) {
 		t.Fatalf("oras.FetchBytes() error = %v, wantErr %v", err, errdef.ErrSizeExceedsLimit)
 	}
@@ -994,7 +994,7 @@ func TestFetchBytes_Memory(t *testing.T) {
 		t.Errorf("oras.FetchBytes() = %v, want %v", gotBytes, blobs[3])
 	}
 
-	// test FetchBytes with TargetPlatform and SizeLimit = 1
+	// test FetchBytes with TargetPlatform and MaxBytes = 1
 	// should return size exceed error
 	opts = oras.FetchBytesOptions{
 		FetchOptions: oras.FetchOptions{
@@ -1005,7 +1005,7 @@ func TestFetchBytes_Memory(t *testing.T) {
 				},
 			},
 		},
-		SizeLimit: 1,
+		MaxBytes: 1,
 	}
 	_, _, err = oras.FetchBytes(ctx, target, manifestTag, opts)
 	if !errors.Is(err, errdef.ErrSizeExceedsLimit) {
@@ -1192,8 +1192,8 @@ func TestFetchBytes_Repository(t *testing.T) {
 		t.Errorf("oras.FetchBytes() = %v, want %v", gotBytes, blob)
 	}
 
-	// test FetchBytes with SizeLimit = 1
-	_, _, err = oras.FetchBytes(ctx, repo, ref, oras.FetchBytesOptions{SizeLimit: 1})
+	// test FetchBytes with MaxBytes = 1
+	_, _, err = oras.FetchBytes(ctx, repo, ref, oras.FetchBytesOptions{MaxBytes: 1})
 	if !errors.Is(err, errdef.ErrSizeExceedsLimit) {
 		t.Fatalf("oras.FetchBytes() error = %v, wantErr %v", err, errdef.ErrSizeExceedsLimit)
 	}
@@ -1227,7 +1227,7 @@ func TestFetchBytes_Repository(t *testing.T) {
 		t.Errorf("oras.FetchBytes() = %v, want %v", gotBytes, manifest)
 	}
 
-	// test FetchBytes with TargetPlatform and SizeLimit = 1
+	// test FetchBytes with TargetPlatform and MaxBytes = 1
 	// should return size exceed error
 	opts = oras.FetchBytesOptions{
 		FetchOptions: oras.FetchOptions{
@@ -1238,7 +1238,7 @@ func TestFetchBytes_Repository(t *testing.T) {
 				},
 			},
 		},
-		SizeLimit: 1,
+		MaxBytes: 1,
 	}
 	_, _, err = oras.FetchBytes(ctx, repo, ref, opts)
 	if !errors.Is(err, errdef.ErrSizeExceedsLimit) {

copy.go

@@ -77,7 +77,7 @@ func (opts *CopyOptions) WithTargetPlatform(p *ocispec.Platform) {
 // CopyGraphOptions contains parameters for oras.CopyGraph.
 type CopyGraphOptions struct {
 	// Concurrency limits the maximum number of concurrent copy tasks.
-	// If Concurrency is not specified, or the specified value is less
+	// If Concurrency is not specified, or the specified value is less than
 	// or equal to 0, the concurrency limit will be considered as infinity.
 	Concurrency int64
 	// PreCopy handles the current descriptor before copying it.

extendedcopy.go

@@ -51,8 +51,8 @@ type ExtendedCopyGraphOptions struct {
 	CopyGraphOptions
 	// Depth limits the maximum depth of the directed acyclic graph (DAG) that
 	// will be extended-copied.
-	// If Depth is no specified, or the specified value is less or equal than 0,
-	// the depth limit will be considered as infinity.
+	// If Depth is no specified, or the specified value is less than or
+	// equal to 0, the depth limit will be considered as infinity.
 	Depth int
 	// FindPredecessors finds the predecessors of the current node.
 	// If FindPredecessors is nil, src.Predecessors will be adapted and used.

registry/remote/repository.go

@@ -98,7 +98,7 @@ type Repository struct {
 	// MaxMetadataBytes specifies a limit on how many response bytes are allowed
 	// in the server's response to the metadata APIs, such as catalog list, tag
 	// list, and referrers list.
-	// If zero, a default (currently 4MiB) is used.
+	// If less than or equal to zero, a default (currently 4MiB) is used.
 	MaxMetadataBytes int64
 }
 

registry/remote/utils.go

@@ -58,9 +58,9 @@ func parseLink(resp *http.Response) (string, error) {
 }
 
 // limitReader returns a Reader that reads from r but stops with EOF after n
-// bytes. If n is zero, defaultMaxMetadataBytes is used.
+// bytes. If n is less than or equal to zero, defaultMaxMetadataBytes is used.
 func limitReader(r io.Reader, n int64) io.Reader {
-	if n == 0 {
+	if n <= 0 {
 		n = defaultMaxMetadataBytes
 	}
 	return io.LimitReader(r, n)