chore(storage): fix gRPC reader size/remain logic

storage/integration_test.go

@@ -793,13 +793,19 @@ func TestIntegration_ObjectReadGRPC(t *testing.T) {
 
 	obj := gc.Bucket(grpcBucketName).Object(name)
 
-	// Using a negative length to indicate reading to the end.
-	r, err := obj.NewRangeReader(ctx, 0, -1)
+	r, err := obj.NewReader(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer r.Close()
 
+	if size := r.Size(); size != int64(len(content)) {
+		t.Errorf("got size = %v, want %v", size, len(content))
+	}
+	if rem := r.Remain(); rem != int64(len(content)) {
+		t.Errorf("got %v bytes remaining, want %v", rem, len(content))
+	}
+
 	b := new(bytes.Buffer)
 	b.Grow(len(content))
 
@@ -816,6 +822,10 @@ func TestIntegration_ObjectReadGRPC(t *testing.T) {
 	if diff := cmp.Diff(got, want); diff != "" {
 		t.Errorf("got(-),want(+):\n%s", diff)
 	}
+
+	if rem := r.Remain(); rem != 0 {
+		t.Errorf("got %v bytes remaining, want 0", rem)
+	}
 }
 
 func TestIntegration_ObjectReadChunksGRPC(t *testing.T) {
@@ -850,6 +860,13 @@ func TestIntegration_ObjectReadChunksGRPC(t *testing.T) {
 	}
 	defer r.Close()
 
+	if size := r.Size(); size != int64(len(content)) {
+		t.Errorf("got size = %v, want %v", size, len(content))
+	}
+	if rem := r.Remain(); rem != int64(len(content)) {
+		t.Errorf("got %v bytes remaining, want %v", rem, len(content))
+	}
+
 	bufSize := len(content)
 	buf := make([]byte, bufSize)
 
@@ -868,6 +885,10 @@ func TestIntegration_ObjectReadChunksGRPC(t *testing.T) {
 		offset += n
 	}
 
+	if rem := r.Remain(); rem != 0 {
+		t.Errorf("got %v bytes remaining, want 0", rem)
+	}
+
 	// TODO: Verify content with the checksums.
 }
 
@@ -905,6 +926,13 @@ func TestIntegration_ObjectReadRelativeToEndGRPC(t *testing.T) {
 	}
 	defer r.Close()
 
+	if size := r.Size(); size != int64(len(content)) {
+		t.Errorf("got size = %v, want %v", size, len(content))
+	}
+	if rem := r.Remain(); rem != int64(offset) {
+		t.Errorf("got %v bytes remaining, want %v", rem, offset)
+	}
+
 	b := new(bytes.Buffer)
 	b.Grow(offset)
 
@@ -921,6 +949,10 @@ func TestIntegration_ObjectReadRelativeToEndGRPC(t *testing.T) {
 	if diff := cmp.Diff(got, want); diff != "" {
 		t.Errorf("got(-),want(+):\n%s", diff)
 	}
+
+	if rem := r.Remain(); rem != 0 {
+		t.Errorf("got %v bytes remaining, want 0", rem)
+	}
 }
 
 func TestIntegration_ObjectReadPartialContentGRPC(t *testing.T) {

storage/reader.go

@@ -233,6 +233,8 @@ func (o *ObjectHandle) NewRangeReader(ctx context.Context, offset, length int64)
 		if !strings.HasPrefix(cr, "bytes ") || !strings.Contains(cr, "/") {
 			return nil, fmt.Errorf("storage: invalid Content-Range %q", cr)
 		}
+		// Content range is formatted <first byte>-<last byte>/<total size>. We take
+		// the total size.
 		size, err = strconv.ParseInt(cr[strings.LastIndex(cr, "/")+1:], 10, 64)
 		if err != nil {
 			return nil, fmt.Errorf("storage: invalid Content-Range %q", cr)
@@ -514,9 +516,8 @@ func (o *ObjectHandle) newRangeReaderWithGRPC(ctx context.Context, offset, lengt
 	// object metadata.
 	msg := res.response
 	obj := msg.GetMetadata()
-	// This is the size of the content the Reader will convey. It can be the
-	// entire object, or just the size of the request range.
-	size := msg.GetContentRange().GetCompleteLength()
+	// This is the size of the entire object, even if only a range was requested.
+	size := obj.GetSize()
 
 	r.Attrs = ReaderObjectAttrs{
 		Size:            size,
@@ -527,9 +528,16 @@ func (o *ObjectHandle) newRangeReaderWithGRPC(ctx context.Context, offset, lengt
 		Metageneration:  obj.GetMetageneration(),
 		Generation:      obj.GetGeneration(),
 	}
-	if cr := msg.GetContentRange(); cr != nil {
+
+	r.size = size
+	cr := msg.GetContentRange()
+	if cr != nil {
 		r.Attrs.StartOffset = cr.GetStart()
+		r.remain = cr.GetEnd() - cr.GetStart() + 1
+	} else {
+		r.remain = size
 	}
+
 	// Only support checksums when reading an entire object, not a range.
 	if msg.GetObjectChecksums().Crc32C != nil && offset == 0 && length == 0 {
 		r.wantCRC = msg.GetObjectChecksums().GetCrc32C()
@@ -539,8 +547,6 @@ func (o *ObjectHandle) newRangeReaderWithGRPC(ctx context.Context, offset, lengt
 	// Store the content from the first Recv in the client buffer for reading
 	// later.
 	r.leftovers = msg.GetChecksummedData().GetContent()
-	r.remain = size
-	r.size = size
 
 	return r, nil
 }