[#291] object: Use PayloadSizeLimiter from SDK

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

go.mod

@@ -5,7 +5,7 @@ go 1.18
 require (
 	git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.15.1-0.20230418080822-bd44a3f47b85
 	git.frostfs.info/TrueCloudLab/frostfs-contract v0.0.0-20230307110621-19a8ef2d02fb
-	git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20230418145405-db5b89496d68
+	git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20230503082209-d4fe9a193d1a
 	git.frostfs.info/TrueCloudLab/hrw v1.2.0
 	git.frostfs.info/TrueCloudLab/tzhash v1.8.0
 	github.com/cheggaaa/pb v1.0.29

pkg/services/object/put/distributed.go

@@ -10,10 +10,10 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
 	svcutil "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/placement"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/transformer"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/transformer"
 	"go.uber.org/zap"
 )
 
@@ -206,8 +206,9 @@ func (t *distributedTarget) iteratePlacement(ctx context.Context) (*transformer.
 
 	id, _ = t.obj.ID()
 
-	return new(transformer.AccessIdentifiers).
+	return &transformer.AccessIdentifiers{
-		WithSelfID(id), nil
+		SelfID: id,
+	}, nil
 }
 
 func (t *distributedTarget) iterateAddresses(ctx context.Context, traverser *placement.Traverser, addrs []placement.Node, resErr *atomic.Value) bool {

pkg/services/object/put/local.go

@@ -5,9 +5,9 @@ import (
 	"fmt"
 
 	objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/transformer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/transformer"
 )
 
 // ObjectStorage is an object storage interface.
@@ -61,6 +61,7 @@ func (t *localTarget) Close(ctx context.Context) (*transformer.AccessIdentifiers
 
 	id, _ := t.obj.ID()
 
-	return new(transformer.AccessIdentifiers).
+	return &transformer.AccessIdentifiers{
-		WithSelfID(id), nil
+		SelfID: id,
+	}, nil
 }

pkg/services/object/put/remote.go

@@ -10,9 +10,9 @@ import (
 	objectcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
 	internalclient "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/internal/client"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/transformer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/transformer"
 )
 
 type remoteTarget struct {
@@ -68,8 +68,7 @@ func (t *remoteTarget) Close(ctx context.Context) (*transformer.AccessIdentifier
 		return nil, fmt.Errorf("(%T) could not put object to %s: %w", t, t.nodeInfo.AddressGroup(), err)
 	}
 
-	return new(transformer.AccessIdentifiers).
+	return &transformer.AccessIdentifiers{SelfID: res.ID()}, nil
-		WithSelfID(res.ID()), nil
 }
 
 // NewRemoteSender creates, initializes and returns new RemoteSender instance.

pkg/services/object/put/streamer.go

@@ -10,9 +10,9 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/placement"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/transformer"
 	containerSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/transformer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
 )
 
@@ -126,18 +126,14 @@ func (p *Streamer) initTrustedTarget(prm *PutInitPrm) error {
 	p.sessionKey = sessionKey
 	p.target = &validatingTarget{
 		fmt: p.fmtValidator,
-		nextTarget: transformer.NewPayloadSizeLimiter(
+		nextTarget: transformer.NewPayloadSizeLimiter(transformer.Params{
-			p.maxPayloadSz,
+			Key:                    sessionKey,
-			containerSDK.IsHomomorphicHashingDisabled(prm.cnr),
+			NextTargetInit:         func() transformer.ObjectTarget { return p.newCommonTarget(prm) },
-			func() transformer.ObjectTarget {
+			NetworkState:           p.networkState,
-				return transformer.NewFormatTarget(&transformer.FormatterParams{
+			MaxSize:                p.maxPayloadSz,
-					Key:          sessionKey,
+			WithoutHomomorphicHash: containerSDK.IsHomomorphicHashingDisabled(prm.cnr),
-					NextTarget:   p.newCommonTarget(prm),
+			SessionToken:           sToken,
-					SessionToken: sToken,
+		}),
-					NetworkState: p.networkState,
-				})
-			},
-		),
 	}
 
 	return nil
@@ -273,7 +269,7 @@ func (p *Streamer) Close(ctx context.Context) (*PutResponse, error) {
 		return nil, fmt.Errorf("(%T) could not close object target: %w", p, err)
 	}
 
-	id := ids.ParentID()
+	id := ids.ParentID
 	if id != nil {
 		return &PutResponse{
 			id: *id,
@@ -281,6 +277,6 @@ func (p *Streamer) Close(ctx context.Context) (*PutResponse, error) {
 	}
 
 	return &PutResponse{
-		id: ids.SelfID(),
+		id: ids.SelfID,
 	}, nil
 }

pkg/services/object/put/validation.go

@@ -9,9 +9,9 @@ import (
 	"hash"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/transformer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/checksum"
 	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/transformer"
 	"git.frostfs.info/TrueCloudLab/tzhash/tz"
 )
 

pkg/services/object_manager/transformer/fmt.go

@@ -1,114 +0,0 @@
-package transformer
-
-import (
-	"context"
-	"crypto/ecdsa"
-	"fmt"
-
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
-	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/session"
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/version"
-)
-
-type formatter struct {
-	prm *FormatterParams
-
-	obj *object.Object
-
-	sz uint64
-}
-
-// FormatterParams groups NewFormatTarget parameters.
-type FormatterParams struct {
-	Key *ecdsa.PrivateKey
-
-	NextTarget ObjectTarget
-
-	SessionToken *session.Object
-
-	NetworkState netmap.State
-}
-
-// NewFormatTarget returns ObjectTarget instance that finalizes object structure
-// and writes it to the next target.
-//
-// Chunks must be written before the WriteHeader call.
-//
-// Object changes:
-// - sets version to current SDK version;
-// - sets payload size to the total length of all written chunks;
-// - sets session token;
-// - sets number of creation epoch;
-// - calculates and sets verification fields (ID, Signature).
-func NewFormatTarget(p *FormatterParams) ObjectTarget {
-	return &formatter{
-		prm: p,
-	}
-}
-
-func (f *formatter) WriteHeader(_ context.Context, obj *object.Object) error {
-	f.obj = obj
-
-	return nil
-}
-
-func (f *formatter) Write(ctx context.Context, p []byte) (n int, err error) {
-	n, err = f.prm.NextTarget.Write(ctx, p)
-
-	f.sz += uint64(n)
-
-	return
-}
-
-func (f *formatter) Close(ctx context.Context) (*AccessIdentifiers, error) {
-	curEpoch := f.prm.NetworkState.CurrentEpoch()
-	ver := version.Current()
-
-	f.obj.SetVersion(&ver)
-	f.obj.SetPayloadSize(f.sz)
-	f.obj.SetSessionToken(f.prm.SessionToken)
-	f.obj.SetCreationEpoch(curEpoch)
-
-	var (
-		parID  *oid.ID
-		parHdr *object.Object
-	)
-
-	if par := f.obj.Parent(); par != nil && par.Signature() == nil {
-		rawPar := object.NewFromV2(par.ToV2())
-
-		rawPar.SetSessionToken(f.prm.SessionToken)
-		rawPar.SetCreationEpoch(curEpoch)
-
-		if err := object.SetIDWithSignature(*f.prm.Key, rawPar); err != nil {
-			return nil, fmt.Errorf("could not finalize parent object: %w", err)
-		}
-
-		id, _ := rawPar.ID()
-		parID = &id
-		parHdr = rawPar
-
-		f.obj.SetParent(parHdr)
-	}
-
-	if err := object.SetIDWithSignature(*f.prm.Key, f.obj); err != nil {
-		return nil, fmt.Errorf("could not finalize object: %w", err)
-	}
-
-	if err := f.prm.NextTarget.WriteHeader(ctx, f.obj); err != nil {
-		return nil, fmt.Errorf("could not write header to next target: %w", err)
-	}
-
-	if _, err := f.prm.NextTarget.Close(ctx); err != nil {
-		return nil, fmt.Errorf("could not close next target: %w", err)
-	}
-
-	id, _ := f.obj.ID()
-
-	return new(AccessIdentifiers).
-		WithSelfID(id).
-		WithParentID(parID).
-		WithParent(parHdr), nil
-}

pkg/services/object_manager/transformer/transformer.go

@@ -1,294 +0,0 @@
-package transformer
-
-import (
-	"context"
-	"crypto/sha256"
-	"fmt"
-	"hash"
-
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/checksum"
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
-	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
-	"git.frostfs.info/TrueCloudLab/tzhash/tz"
-)
-
-type payloadSizeLimiter struct {
-	maxSize, written uint64
-
-	withoutHomomorphicHash bool
-
-	targetInit func() ObjectTarget
-
-	target ObjectTarget
-
-	current, parent *object.Object
-
-	currentHashers, parentHashers []*payloadChecksumHasher
-
-	previous []oid.ID
-
-	chunkWriter writer
-
-	splitID *object.SplitID
-
-	parAttrs []object.Attribute
-}
-
-type payloadChecksumHasher struct {
-	hasher hash.Hash
-
-	checksumWriter func([]byte)
-}
-
-// NewPayloadSizeLimiter returns ObjectTarget instance that restricts payload length
-// of the writing object and writes generated objects to targets from initializer.
-//
-// Calculates and adds homomorphic hash to resulting objects only if withoutHomomorphicHash
-// is false.
-//
-// Objects w/ payload size less or equal than max size remain untouched.
-func NewPayloadSizeLimiter(maxSize uint64, withoutHomomorphicHash bool, targetInit TargetInitializer) ObjectTarget {
-	return &payloadSizeLimiter{
-		maxSize:                maxSize,
-		withoutHomomorphicHash: withoutHomomorphicHash,
-		targetInit:             targetInit,
-		splitID:                object.NewSplitID(),
-	}
-}
-
-func (s *payloadSizeLimiter) WriteHeader(_ context.Context, hdr *object.Object) error {
-	s.current = fromObject(hdr)
-
-	s.initialize()
-
-	return nil
-}
-
-func (s *payloadSizeLimiter) Write(ctx context.Context, p []byte) (int, error) {
-	if err := s.writeChunk(ctx, p); err != nil {
-		return 0, err
-	}
-
-	return len(p), nil
-}
-
-func (s *payloadSizeLimiter) Close(ctx context.Context) (*AccessIdentifiers, error) {
-	return s.release(ctx, true)
-}
-
-func (s *payloadSizeLimiter) initialize() {
-	// if it is an object after the 1st
-	if ln := len(s.previous); ln > 0 {
-		// initialize parent object once (after 1st object)
-		if ln == 1 {
-			s.detachParent()
-		}
-
-		// set previous object to the last previous identifier
-		s.current.SetPreviousID(s.previous[ln-1])
-	}
-
-	s.initializeCurrent()
-}
-
-func fromObject(obj *object.Object) *object.Object {
-	cnr, _ := obj.ContainerID()
-
-	res := object.New()
-	res.SetContainerID(cnr)
-	res.SetOwnerID(obj.OwnerID())
-	res.SetAttributes(obj.Attributes()...)
-	res.SetType(obj.Type())
-
-	// obj.SetSplitID creates splitHeader but we don't need to do it in case
-	// of small objects, so we should make nil check.
-	if obj.SplitID() != nil {
-		res.SetSplitID(obj.SplitID())
-	}
-
-	return res
-}
-
-func (s *payloadSizeLimiter) initializeCurrent() {
-	// initialize current object target
-	s.target = s.targetInit()
-
-	// create payload hashers
-	s.currentHashers = payloadHashersForObject(s.current, s.withoutHomomorphicHash)
-
-	// compose multi-writer from target and all payload hashers
-	ws := make([]writer, 0, 1+len(s.currentHashers)+len(s.parentHashers))
-
-	ws = append(ws, s.target)
-
-	for i := range s.currentHashers {
-		ws = append(ws, newWriter(s.currentHashers[i].hasher))
-	}
-
-	for i := range s.parentHashers {
-		ws = append(ws, newWriter(s.parentHashers[i].hasher))
-	}
-
-	s.chunkWriter = newMultiWriter(ws...)
-}
-
-func payloadHashersForObject(obj *object.Object, withoutHomomorphicHash bool) []*payloadChecksumHasher {
-	hashers := make([]*payloadChecksumHasher, 0, 2)
-
-	hashers = append(hashers, &payloadChecksumHasher{
-		hasher: sha256.New(),
-		checksumWriter: func(binChecksum []byte) {
-			if ln := len(binChecksum); ln != sha256.Size {
-				panic(fmt.Sprintf("wrong checksum length: expected %d, has %d", sha256.Size, ln))
-			}
-
-			csSHA := [sha256.Size]byte{}
-			copy(csSHA[:], binChecksum)
-
-			var cs checksum.Checksum
-			cs.SetSHA256(csSHA)
-
-			obj.SetPayloadChecksum(cs)
-		},
-	})
-
-	if !withoutHomomorphicHash {
-		hashers = append(hashers, &payloadChecksumHasher{
-			hasher: tz.New(),
-			checksumWriter: func(binChecksum []byte) {
-				if ln := len(binChecksum); ln != tz.Size {
-					panic(fmt.Sprintf("wrong checksum length: expected %d, has %d", tz.Size, ln))
-				}
-
-				csTZ := [tz.Size]byte{}
-				copy(csTZ[:], binChecksum)
-
-				var cs checksum.Checksum
-				cs.SetTillichZemor(csTZ)
-
-				obj.SetPayloadHomomorphicHash(cs)
-			},
-		})
-	}
-
-	return hashers
-}
-
-func (s *payloadSizeLimiter) release(ctx context.Context, finalize bool) (*AccessIdentifiers, error) {
-	// Arg finalize is true only when called from Close method.
-	// We finalize parent and generate linking objects only if it is more
-	// than 1 object in split-chain.
-	withParent := finalize && len(s.previous) > 0
-
-	if withParent {
-		writeHashes(s.parentHashers)
-		s.parent.SetPayloadSize(s.written)
-		s.current.SetParent(s.parent)
-	}
-
-	// release current object
-	writeHashes(s.currentHashers)
-
-	// release current, get its id
-	if err := s.target.WriteHeader(ctx, s.current); err != nil {
-		return nil, fmt.Errorf("could not write header: %w", err)
-	}
-
-	ids, err := s.target.Close(ctx)
-	if err != nil {
-		return nil, fmt.Errorf("could not close target: %w", err)
-	}
-
-	// save identifier of the released object
-	s.previous = append(s.previous, ids.SelfID())
-
-	if withParent {
-		// generate and release linking object
-		s.initializeLinking(ids.Parent())
-		s.initializeCurrent()
-
-		if _, err := s.release(ctx, false); err != nil {
-			return nil, fmt.Errorf("could not release linking object: %w", err)
-		}
-	}
-
-	return ids, nil
-}
-
-func writeHashes(hashers []*payloadChecksumHasher) {
-	for i := range hashers {
-		hashers[i].checksumWriter(hashers[i].hasher.Sum(nil))
-	}
-}
-
-func (s *payloadSizeLimiter) initializeLinking(parHdr *object.Object) {
-	s.current = fromObject(s.current)
-	s.current.SetParent(parHdr)
-	s.current.SetChildren(s.previous...)
-	s.current.SetSplitID(s.splitID)
-}
-
-func (s *payloadSizeLimiter) writeChunk(ctx context.Context, chunk []byte) error {
-	// statement is true if the previous write of bytes reached exactly the boundary.
-	if s.written > 0 && s.written%s.maxSize == 0 {
-		if s.written == s.maxSize {
-			s.prepareFirstChild()
-		}
-
-		// we need to release current object
-		if _, err := s.release(ctx, false); err != nil {
-			return fmt.Errorf("could not release object: %w", err)
-		}
-
-		// initialize another object
-		s.initialize()
-	}
-
-	var (
-		ln         = uint64(len(chunk))
-		cut        = ln
-		leftToEdge = s.maxSize - s.written%s.maxSize
-	)
-
-	// write bytes no further than the boundary of the current object
-	if ln > leftToEdge {
-		cut = leftToEdge
-	}
-
-	if _, err := s.chunkWriter.Write(ctx, chunk[:cut]); err != nil {
-		return fmt.Errorf("could not write chunk to target: %w", err)
-	}
-
-	// increase written bytes counter
-	s.written += cut
-
-	// if there are more bytes in buffer we call method again to start filling another object
-	if ln > leftToEdge {
-		return s.writeChunk(ctx, chunk[cut:])
-	}
-
-	return nil
-}
-
-func (s *payloadSizeLimiter) prepareFirstChild() {
-	// initialize split header with split ID on first object in chain
-	s.current.InitRelations()
-	s.current.SetSplitID(s.splitID)
-
-	// cut source attributes
-	s.parAttrs = s.current.Attributes()
-	s.current.SetAttributes()
-
-	// attributes will be added to parent in detachParent
-}
-
-func (s *payloadSizeLimiter) detachParent() {
-	s.parent = s.current
-	s.current = fromObject(s.parent)
-	s.parent.ResetRelations()
-	s.parent.SetSignature(nil)
-	s.parentHashers = s.currentHashers
-
-	// return source attributes
-	s.parent.SetAttributes(s.parAttrs...)
-}

pkg/services/object_manager/transformer/types.go

@@ -1,111 +0,0 @@
-package transformer
-
-import (
-	"context"
-
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
-	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
-)
-
-// AccessIdentifiers represents group of the object identifiers
-// that are returned after writing the object.
-// Consists of the ID of the stored object and the ID of the parent object.
-type AccessIdentifiers struct {
-	par *oid.ID
-
-	self oid.ID
-
-	parHdr *object.Object
-}
-
-// ObjectTarget is an interface of the object writer.
-type ObjectTarget interface {
-	// WriteHeader writes object header w/ payload part.
-	// The payload of the object may be incomplete.
-	//
-	// Must be called exactly once. Control remains with the caller.
-	// Missing a call or re-calling can lead to undefined behavior
-	// that depends on the implementation.
-	//
-	// Must not be called after Close call.
-	WriteHeader(context.Context, *object.Object) error
-
-	// Write writes object payload chunk.
-	//
-	// Can be called multiple times.
-	//
-	// Must not be called after Close call.
-	Write(ctx context.Context, p []byte) (n int, err error)
-
-	// Close is used to finish object writing.
-	//
-	// Close must return access identifiers of the object
-	// that has been written.
-	//
-	// Must be called no more than once. Control remains with the caller.
-	// Re-calling can lead to undefined behavior
-	// that depends on the implementation.
-	Close(ctx context.Context) (*AccessIdentifiers, error)
-}
-
-// TargetInitializer represents ObjectTarget constructor.
-type TargetInitializer func() ObjectTarget
-
-// SelfID returns identifier of the written object.
-func (a AccessIdentifiers) SelfID() oid.ID {
-	return a.self
-}
-
-// WithSelfID returns AccessIdentifiers with passed self identifier.
-func (a *AccessIdentifiers) WithSelfID(v oid.ID) *AccessIdentifiers {
-	res := a
-	if res == nil {
-		res = new(AccessIdentifiers)
-	}
-
-	res.self = v
-
-	return res
-}
-
-// ParentID return identifier of the parent of the written object.
-func (a *AccessIdentifiers) ParentID() *oid.ID {
-	if a != nil {
-		return a.par
-	}
-
-	return nil
-}
-
-// WithParentID returns AccessIdentifiers with passed parent identifier.
-func (a *AccessIdentifiers) WithParentID(v *oid.ID) *AccessIdentifiers {
-	res := a
-	if res == nil {
-		res = new(AccessIdentifiers)
-	}
-
-	res.par = v
-
-	return res
-}
-
-// Parent return identifier of the parent of the written object.
-func (a *AccessIdentifiers) Parent() *object.Object {
-	if a != nil {
-		return a.parHdr
-	}
-
-	return nil
-}
-
-// WithParent returns AccessIdentifiers with passed parent identifier.
-func (a *AccessIdentifiers) WithParent(v *object.Object) *AccessIdentifiers {
-	res := a
-	if res == nil {
-		res = new(AccessIdentifiers)
-	}
-
-	res.parHdr = v
-
-	return res
-}

pkg/services/object_manager/transformer/writer.go

@@ -1,52 +0,0 @@
-package transformer
-
-import (
-	"context"
-	"io"
-)
-
-type writer interface {
-	Write(ctx context.Context, p []byte) (n int, err error)
-}
-
-type multiWriter struct {
-	writers []writer
-}
-
-func (t *multiWriter) Write(ctx context.Context, p []byte) (n int, err error) {
-	for _, w := range t.writers {
-		n, err = w.Write(ctx, p)
-		if err != nil {
-			return
-		}
-		if n != len(p) {
-			err = io.ErrShortWrite
-			return
-		}
-	}
-	return len(p), nil
-}
-
-func newMultiWriter(writers ...writer) writer {
-	allWriters := make([]writer, 0, len(writers))
-	for _, w := range writers {
-		if mw, ok := w.(*multiWriter); ok {
-			allWriters = append(allWriters, mw.writers...)
-		} else {
-			allWriters = append(allWriters, w)
-		}
-	}
-	return &multiWriter{allWriters}
-}
-
-type writerWrapper struct {
-	Writer io.Writer
-}
-
-func (w *writerWrapper) Write(_ context.Context, p []byte) (n int, err error) {
-	return w.Writer.Write(p)
-}
-
-func newWriter(w io.Writer) writer {
-	return &writerWrapper{Writer: w}
-}