From 4a5f2ee492b938832c34819f768da2770788a64d Mon Sep 17 00:00:00 2001
From: Evgenii Baidakov <evgenii@nspcc.io>
Date: Thu, 27 Jul 2023 15:57:52 +0400
Subject: [PATCH] slicer: Reuse stub object

Updated after benchmark. During object slicing we recreate object on each part, we may reuse it, just reset some fields.

Signed-off-by: Evgenii Baidakov <evgenii@nspcc.io>
---
 object/object.go        | 17 +++++++++++++++++
 object/slicer/slicer.go | 32 ++++++++++++++++++++------------
 2 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/object/object.go b/object/object.go
index c956bad6..db0fe1e0 100644
--- a/object/object.go
+++ b/object/object.go
@@ -111,6 +111,14 @@ func (o *Object) SetID(v oid.ID) {
 		SetObjectID(&v2)
 }
 
+// ResetID removes object identifier.
+//
+// See also [Object.SetID].
+func (o *Object) ResetID() {
+	(*object.Object)(o).
+		SetObjectID(nil)
+}
+
 // Signature returns signature of the object identifier.
 //
 // See also [Object.SetSignature].
@@ -536,6 +544,15 @@ func (o *Object) SetParentID(v oid.ID) {
 	})
 }
 
+// ResetParentID removes identifier of the parent object.
+//
+// See also [Object.SetParentID].
+func (o *Object) ResetParentID() {
+	o.setSplitFields(func(split *object.SplitHeader) {
+		split.SetParent(nil)
+	})
+}
+
 // Parent returns parent object w/o payload.
 //
 // See also [Object.SetParent].
diff --git a/object/slicer/slicer.go b/object/slicer/slicer.go
index f560950a..46daa76e 100644
--- a/object/slicer/slicer.go
+++ b/object/slicer/slicer.go
@@ -233,6 +233,14 @@ func initPayloadStream(ctx context.Context, ow ObjectWriter, header object.Objec
 	currentVersion := version.Current()
 	header.SetVersion(&currentVersion)
 
+	var stubObject object.Object
+	stubObject.SetVersion(&currentVersion)
+	stubObject.SetContainerID(containerID)
+	stubObject.SetCreationEpoch(opts.currentNeoFSEpoch)
+	stubObject.SetType(object.TypeRegular)
+	stubObject.SetOwnerID(&owner)
+	stubObject.SetSessionToken(opts.sessionToken)
+
 	res := &PayloadWriter{
 		ctx:               ctx,
 		isHeaderWriteStep: true,
@@ -246,6 +254,7 @@ func initPayloadStream(ctx context.Context, ow ObjectWriter, header object.Objec
 		rootMeta:          newDynamicObjectMetadata(opts.withHomoChecksum),
 		childMeta:         newDynamicObjectMetadata(opts.withHomoChecksum),
 		prmObjectPutInit:  prm,
+		stubObject:        &stubObject,
 	}
 
 	maxObjSize := childPayloadSizeLimit(opts)
@@ -284,6 +293,7 @@ type PayloadWriter struct {
 
 	writtenChildren  []oid.ID
 	prmObjectPutInit client.PrmObjectPutInit
+	stubObject       *object.Object
 }
 
 // Write writes next chunk of the object data. Concatenation of all chunks forms
@@ -365,19 +375,14 @@ func (x *PayloadWriter) writeLastChild(ctx context.Context, meta dynamicObjectMe
 }
 
 func (x *PayloadWriter) _writeChild(ctx context.Context, meta dynamicObjectMetadata, last bool, rootIDHandler func(id oid.ID)) error {
-	currentVersion := version.Current()
-
-	fCommon := func(obj *object.Object) {
-		obj.SetVersion(&currentVersion)
-		obj.SetContainerID(x.container)
-		obj.SetCreationEpoch(x.currentEpoch)
-		obj.SetType(object.TypeRegular)
-		obj.SetOwnerID(&x.owner)
-		obj.SetSessionToken(x.sessionToken)
-	}
+	obj := *x.stubObject
+	obj.SetSplitID(nil)
+	obj.ResetPreviousID()
+	obj.SetParent(nil)
+	obj.ResetParentID()
+	obj.SetSignature(nil)
+	obj.ResetID()
 
-	var obj object.Object
-	fCommon(&obj)
 	if x.withSplit {
 		obj.SetSplitID(x.splitID)
 	}
@@ -421,6 +426,9 @@ func (x *PayloadWriter) _writeChild(ctx context.Context, meta dynamicObjectMetad
 		meta.reset()
 		obj.ResetPreviousID()
 		obj.SetChildren(x.writtenChildren...)
+		// we reuse already written object, we should reset these fields, to eval them one more time in writeInMemObject.
+		obj.ResetID()
+		obj.SetSignature(nil)
 
 		_, err = writeInMemObject(ctx, x.signer, x.stream, obj, nil, meta, x.prmObjectPutInit)
 		if err != nil {