pkg/object: add copy interface (#3581)

pkg/object/interface.go

@@ -84,6 +84,8 @@ type ObjectStorage interface {
 	Get(key string, off, limit int64) (io.ReadCloser, error)
 	// Put data read from a reader to an object specified by key.
 	Put(key string, in io.Reader) error
+	// Copy an object from src to dst.
+	Copy(dst, src string) error
 	// Delete a object.
 	Delete(key string) error
 

pkg/object/object_storage.go

@@ -124,6 +124,10 @@ func (s DefaultObjectStorage) Head(key string) (Object, error) {
 	return nil, notSupported
 }
 
+func (s DefaultObjectStorage) Copy(dst, src string) error {
+	return notSupported
+}
+
 func (s DefaultObjectStorage) CreateMultipartUpload(key string) (*MultipartUpload, error) {
 	return nil, notSupported
 }

pkg/object/object_storage_test.go

@@ -122,7 +122,8 @@ func testStorage(t *testing.T, s ObjectStorage) {
 	if err := s.Create(); err != nil {
 		t.Fatalf("err should be nil when creating a bucket with the same name")
 	}
-	s = WithPrefix(s, "unit-test/")
+	prefix := "unit-test/"
+	s = WithPrefix(s, prefix)
 	defer func() {
 		if err := s.Delete("test"); err != nil {
 			t.Fatalf("delete failed: %s", err)
@@ -371,6 +372,20 @@ func testStorage(t *testing.T, s ObjectStorage) {
 		t.Fatalf("storage class should be %s but got %s", sc, o.StorageClass())
 	}
 
+	dstKey := "test-copy"
+	defer s.Delete(dstKey)
+	err = s.Copy(fmt.Sprintf("%s%s", prefix, dstKey), fmt.Sprintf("%stest", prefix))
+	if err != nil && err != notSupported {
+		t.Fatalf("copy failed: %s", err.Error())
+	}
+	if err == nil {
+		if o, err := s.Head(dstKey); err != nil {
+			t.Fatalf("check exists failed: %s", err.Error())
+		} else if sc != "" && o.StorageClass() != sc {
+			t.Fatalf("storage class should be %s but got %s", sc, o.StorageClass())
+		}
+	}
+
 	if err := s.Delete("test"); err != nil {
 		t.Fatalf("delete failed: %s", err)
 	}

pkg/object/prefix.go

@@ -117,6 +117,10 @@ func (p *withPrefix) Put(key string, in io.Reader) error {
 	return p.os.Put(p.prefix+key, in)
 }
 
+func (p *withPrefix) Copy(dst, src string) error {
+	return p.os.Copy(dst, src)
+}
+
 func (p *withPrefix) Delete(key string) error {
 	return p.os.Delete(p.prefix + key)
 }

pkg/object/sharding.go

@@ -69,6 +69,10 @@ func (s *sharded) Put(key string, body io.Reader) error {
 	return s.pick(key).Put(key, body)
 }
 
+func (s *sharded) Copy(dst, src string) error {
+	return notSupported
+}
+
 func (s *sharded) Delete(key string) error {
 	return s.pick(key).Delete(key)
 }