Refactor encoding.Convert

Signed-off-by: Shiming Zhang <[email protected]>
etcd-io · May 10, 2024 · 1eda7c0 · 1eda7c0
1 parent 8149bb3
commit 1eda7c0
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Showing 5 changed files with 42 additions and 40 deletions.
diff --git a/cmd/decode.go b/cmd/decode.go
@@ -151,12 +151,11 @@ func runInBatchMode(metaOnly bool, outMediaType string, out io.Writer) (err erro
 			continue
 		}
 
-		buf := bytes.NewBufferString("")
-		_, err = encoding.Convert(scheme.Codecs, inMediaType, outMediaType, decodedinput, buf)
+		buf, _, err := encoding.Convert(scheme.Codecs, inMediaType, outMediaType, decodedinput)
 		if err != nil {
 			fmt.Fprintf(out, "ERROR:%v|\n", err)
 		} else {
-			fmt.Fprintf(out, "OK|%s\n", buf.String())
+			fmt.Fprintf(out, "OK|%s\n", string(buf))
 		}
 
 		lineNum++
@@ -174,7 +173,12 @@ func run(metaOnly bool, outMediaType string, in []byte, out io.Writer) error {
 		return encoding.DecodeSummary(inMediaType, in, out)
 	}
 
-	_, err = encoding.Convert(scheme.Codecs, inMediaType, outMediaType, in, out)
+	buf, _, err := encoding.Convert(scheme.Codecs, inMediaType, outMediaType, in)
+	if err != nil {
+		return err
+	}
+
+	_, err = out.Write(buf)
 	return err
 }
 

diff --git a/cmd/encode.go b/cmd/encode.go
@@ -81,6 +81,10 @@ func encodeValidateAndRun() error {
 
 // encodeRun runs the encode command.
 func encodeRun(inMediaType string, in []byte, out io.Writer) error {
-	_, err := encoding.Convert(scheme.Codecs, inMediaType, encoding.StorageBinaryMediaType, in, out)
+	buf, _, err := encoding.Convert(scheme.Codecs, inMediaType, encoding.StorageBinaryMediaType, in)
+	if err != nil {
+		return err
+	}
+	_, err = out.Write(buf)
 	return err
 }
diff --git a/cmd/extract.go b/cmd/extract.go
@@ -222,7 +222,11 @@ func printValue(filename string, key string, version string, raw bool, outMediaT
 		fmt.Fprintf(out, "%s\n", string(in))
 		return nil
 	}
-	_, err = encoding.DetectAndConvert(scheme.Codecs, outMediaType, in, out)
+	buf, _, err := encoding.DetectAndConvert(scheme.Codecs, outMediaType, in)
+	if err != nil {
+		return err
+	}
+	_, err = out.Write(buf)
 	return err
 }
 
@@ -244,7 +248,11 @@ func printLeafItemSummary(kv *mvccpb.KeyValue, out io.Writer) error {
 
 // printLeafItemValue prints an etcd value for a given boltdb leaf item.
 func printLeafItemValue(kv *mvccpb.KeyValue, outMediaType string, out io.Writer) error {
-	_, err := encoding.DetectAndConvert(scheme.Codecs, outMediaType, kv.Value, out)
+	buf, _, err := encoding.DetectAndConvert(scheme.Codecs, outMediaType, kv.Value)
+	if err != nil {
+		return err
+	}
+	_, err = out.Write(buf)
 	return err
 }
 

diff --git a/pkg/data/data.go b/pkg/data/data.go
@@ -228,12 +228,12 @@ func ListKeySummaries(codecs serializer.CodecFactory, filename string, filters [
 		if prefixAllowed {
 			ks, ok := m[string(kv.Key)]
 			if !ok {
-				buf := new(bytes.Buffer)
+				var buf []byte
 				var valJson string
 				var typeMeta *runtime.TypeMeta
 				var err error
-				if typeMeta, err = encoding.DetectAndConvert(codecs, encoding.JsonMediaType, kv.Value, buf); err == nil {
-					valJson = strings.TrimSpace(buf.String())
+				if buf, typeMeta, err = encoding.DetectAndConvert(codecs, encoding.JsonMediaType, kv.Value); err == nil {
+					valJson = strings.TrimSpace(string(buf))
 				}
 				var key string
 				var value map[string]interface{}

diff --git a/pkg/encoding/encoding.go b/pkg/encoding/encoding.go
@@ -60,28 +60,32 @@ func ToMediaType(out string) (string, error) {
 // DetectAndConvert first detects the media type of the in param data and then converts it from
 // the kv store encoded data to the given output format using kubernetes' api machinery to
 // perform the conversion.
-func DetectAndConvert(codecs serializer.CodecFactory, outMediaType string, in []byte, out io.Writer) (*runtime.TypeMeta, error) {
+func DetectAndConvert(codecs serializer.CodecFactory, outMediaType string, in []byte) ([]byte, *runtime.TypeMeta, error) {
 	inMediaType, in, err := DetectAndExtract(in)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	return Convert(codecs, inMediaType, outMediaType, in, out)
+	return Convert(codecs, inMediaType, outMediaType, in)
 }
 
 // Convert from kv store encoded data to the given output format using kubernetes' api machinery to
 // perform the conversion.
-func Convert(codecs serializer.CodecFactory, inMediaType, outMediaType string, in []byte, out io.Writer) (*runtime.TypeMeta, error) {
+func Convert(codecs serializer.CodecFactory, inMediaType, outMediaType string, in []byte) ([]byte, *runtime.TypeMeta, error) {
 	if inMediaType == StorageBinaryMediaType && outMediaType == ProtobufMediaType {
-		return nil, DecodeRaw(in, out)
+		unknown, err := DecodeUnknown(in)
+		if err != nil {
+			return nil, nil, err
+		}
+		return unknown.Raw, &unknown.TypeMeta, nil
 	}
 
 	if inMediaType == ProtobufMediaType && outMediaType == StorageBinaryMediaType {
-		return nil, fmt.Errorf("unsupported conversion: protobuf to kubernetes binary storage representation")
+		return nil, nil, fmt.Errorf("unsupported conversion: protobuf to kubernetes binary storage representation")
 	}
 
 	typeMeta, err := decodeTypeMeta(inMediaType, in)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	var encoded []byte
@@ -94,29 +98,25 @@ func Convert(codecs serializer.CodecFactory, inMediaType, outMediaType string, i
 	} else {
 		inCodec, err := newCodec(codecs, typeMeta, inMediaType)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 		outCodec, err := newCodec(codecs, typeMeta, outMediaType)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 
 		obj, err := runtime.Decode(inCodec, in)
 		if err != nil {
-			return nil, fmt.Errorf("error decoding from %s: %s", inMediaType, err)
+			return nil, nil, fmt.Errorf("error decoding from %s: %s", inMediaType, err)
 		}
 
 		encoded, err = runtime.Encode(outCodec, obj)
 		if err != nil {
-			return nil, fmt.Errorf("error encoding to %s: %s", outMediaType, err)
+			return nil, nil, fmt.Errorf("error encoding to %s: %s", outMediaType, err)
 		}
 	}
 
-	_, err = out.Write(encoded)
-	if err != nil {
-		return nil, err
-	}
-	return typeMeta, nil
+	return encoded, typeMeta, nil
 }
 
 // DetectAndExtract searches the the start of either json of protobuf data, and, if found, returns the mime type and data.
@@ -165,20 +165,6 @@ func tryFindJson(in []byte) (*json.RawMessage, bool) {
 	return nil, false
 }
 
-// DecodeRaw decodes the raw payload bytes contained within the 'Unknown' protobuf envelope of
-// the given storage data.
-func DecodeRaw(in []byte, out io.Writer) error {
-	unknown, err := DecodeUnknown(in)
-	if err != nil {
-		return err
-	}
-	_, err = out.Write(unknown.Raw)
-	if err != nil {
-		return fmt.Errorf("failed to write output: %v", err)
-	}
-	return nil
-}
-
 // DecodeSummary decodes the TypeMeta, ContentEncoding and ContentType fields from the 'Unknown'
 // protobuf envelope of the given storage data.
 func DecodeSummary(inMediaType string, in []byte, out io.Writer) error {