[#539] getsvc: Write payload direct to out stream

To reduce memory allocations.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/services/object/get/assemble.go

@@ -113,9 +113,10 @@ func (r *request) HeadObject(ctx context.Context, id oid.ID) (*objectSDK.Object,
 	return w.Object(), nil
 }
 
-func (r *request) GetObject(ctx context.Context, id oid.ID, rng *objectSDK.Range, payloadBuffer []byte) (*objectSDK.Object, error) {
-	w := NewSimpleObjectWriter()
-	w.SetPayloadBuffer(payloadBuffer)
+func (r *request) GetObjectAndWritePayload(ctx context.Context, id oid.ID, rng *objectSDK.Range, writer ChunkWriter) (*objectSDK.Object, error) {
+	w := &payloadWriter{
+		origin: writer,
+	}
 
 	p := r.prm
 	p.common = p.common.WithLocalOnly(false)
@@ -128,7 +129,7 @@ func (r *request) GetObject(ctx context.Context, id oid.ID, rng *objectSDK.Range
 	if err := r.getObjectWithIndependentRequest(ctx, p); err != nil {
 		return nil, err
 	}
-	return w.Object(), nil
+	return w.obj, nil
 }
 
 func (r *request) getObjectWithIndependentRequest(ctx context.Context, prm RequestParameters) error {

pkg/services/object/get/assembler.go

@@ -10,7 +10,7 @@ import (
 )
 
 type objectGetter interface {
-	GetObject(ctx context.Context, id oid.ID, rng *objectSDK.Range, buffer []byte) (*objectSDK.Object, error)
+	GetObjectAndWritePayload(ctx context.Context, id oid.ID, rng *objectSDK.Range, writer ChunkWriter) (*objectSDK.Object, error)
 	HeadObject(ctx context.Context, id oid.ID) (*objectSDK.Object, error)
 }
 
@@ -77,10 +77,12 @@ func (a *assembler) getLastPartOrLinkObjectID() (oid.ID, bool) {
 }
 
 func (a *assembler) initializeFromSourceObjectID(ctx context.Context, id oid.ID) (*oid.ID, []oid.ID, error) {
-	sourceObject, err := a.getChildObject(ctx, id, nil, true, nil)
+	w := NewSimpleObjectWriter()
+	sourceObject, err := a.getChildObject(ctx, id, nil, true, w)
 	if err != nil {
 		return nil, nil, err
 	}
+	sourceObject.SetPayload(w.pld)
 
 	parentObject := sourceObject.Parent()
 	if parentObject == nil {
@@ -131,8 +133,8 @@ func (a *assembler) initializeFromSourceObjectID(ctx context.Context, id oid.ID)
 	return nil, sourceObject.Children(), nil
 }
 
-func (a *assembler) getChildObject(ctx context.Context, id oid.ID, rng *objectSDK.Range, verifyIsChild bool, payloadBuffer []byte) (*objectSDK.Object, error) {
-	obj, err := a.objGetter.GetObject(ctx, id, rng, payloadBuffer)
+func (a *assembler) getChildObject(ctx context.Context, id oid.ID, rng *objectSDK.Range, verifyIsChild bool, writer ChunkWriter) (*objectSDK.Object, error) {
+	obj, err := a.objGetter.GetObjectAndWritePayload(ctx, id, rng, writer)
 	if err != nil {
 		return nil, err
 	}
@@ -176,23 +178,16 @@ func (a *assembler) assemleObjectByPreviousIDInReverse(ctx context.Context, prev
 func (a *assembler) assemblePayloadByObjectIDs(ctx context.Context, writer ObjectWriter, partIDs []oid.ID, partRanges []objectSDK.Range, verifyIsChild bool) error {
 	withRng := len(partRanges) > 0 && a.rng != nil
 
-	var buffer []byte
 	for i := range partIDs {
 		var r *objectSDK.Range
 		if withRng {
 			r = &partRanges[i]
 		}
 
-		child, err := a.getChildObject(ctx, partIDs[i], r, verifyIsChild, buffer)
+		_, err := a.getChildObject(ctx, partIDs[i], r, verifyIsChild, writer)
 		if err != nil {
 			return err
 		}
-
-		if err := writer.WriteChunk(ctx, child.Payload()); err != nil {
-			return err
-		}
-
-		buffer = child.Payload()
 	}
 	return nil
 }

pkg/services/object/get/get_test.go

@@ -629,7 +629,6 @@ func TestGetRemoteSmall(t *testing.T) {
 
 		*c1, *c2 = *c2, *c1
 
-		w.SetPayloadBuffer(make([]byte, 0))
 		err = svc.Get(ctx, p)
 		require.NoError(t, err)
 		require.Equal(t, obj, w.Object())

pkg/services/object/get/writer.go

@@ -49,19 +49,9 @@ func NewSimpleObjectWriter() *SimpleObjectWriter {
 	}
 }
 
-func (s *SimpleObjectWriter) SetPayloadBuffer(buffer []byte) {
-	if buffer != nil {
-		s.pld = buffer[:0]
-	}
-}
-
 func (s *SimpleObjectWriter) WriteHeader(_ context.Context, obj *objectSDK.Object) error {
 	s.obj = obj
-
-	if s.pld == nil {
-		s.pld = make([]byte, 0, obj.PayloadSize())
-	}
-
+	s.pld = make([]byte, 0, obj.PayloadSize())
 	return nil
 }
 
@@ -90,3 +80,17 @@ func (h *hasherWrapper) WriteChunk(_ context.Context, p []byte) error {
 	_, err := h.hash.Write(p)
 	return err
 }
+
+type payloadWriter struct {
+	origin ChunkWriter
+	obj    *objectSDK.Object
+}
+
+func (w *payloadWriter) WriteChunk(ctx context.Context, p []byte) error {
+	return w.origin.WriteChunk(ctx, p)
+}
+
+func (w *payloadWriter) WriteHeader(_ context.Context, o *objectSDK.Object) error {
+	w.obj = o
+	return nil
+}