frostfs-s3-gw/api/layer/object.go
Denis Kirillov 55c99f6e30
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[#192] Fix frostfs dependencies
Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>
2023-01-12 16:47:04 +03:00

824 lines
21 KiB
Go

package layer
import (
"context"
"crypto/sha256"
"encoding/hex"
"errors"
"fmt"
"io"
"mime"
"path/filepath"
"sort"
"strconv"
"strings"
"sync"
"github.com/TrueCloudLab/frostfs-s3-gw/api"
"github.com/TrueCloudLab/frostfs-s3-gw/api/cache"
"github.com/TrueCloudLab/frostfs-s3-gw/api/data"
apiErrors "github.com/TrueCloudLab/frostfs-s3-gw/api/errors"
"github.com/TrueCloudLab/frostfs-sdk-go/client"
cid "github.com/TrueCloudLab/frostfs-sdk-go/container/id"
"github.com/TrueCloudLab/frostfs-sdk-go/object"
oid "github.com/TrueCloudLab/frostfs-sdk-go/object/id"
"github.com/minio/sio"
"github.com/panjf2000/ants/v2"
"go.uber.org/zap"
)
type (
getParams struct {
// payload range
off, ln uint64
oid oid.ID
bktInfo *data.BucketInfo
}
// ListObjectsParamsCommon contains common parameters for ListObjectsV1 and ListObjectsV2.
ListObjectsParamsCommon struct {
BktInfo *data.BucketInfo
Delimiter string
Encode string
MaxKeys int
Prefix string
}
// ListObjectsParamsV1 contains params for ListObjectsV1.
ListObjectsParamsV1 struct {
ListObjectsParamsCommon
Marker string
}
// ListObjectsParamsV2 contains params for ListObjectsV2.
ListObjectsParamsV2 struct {
ListObjectsParamsCommon
ContinuationToken string
StartAfter string
FetchOwner bool
}
allObjectParams struct {
Bucket *data.BucketInfo
Delimiter string
Prefix string
MaxKeys int
Marker string
ContinuationToken string
}
)
const (
continuationToken = "<continuation-token>"
)
func newAddress(cnr cid.ID, obj oid.ID) oid.Address {
var addr oid.Address
addr.SetContainer(cnr)
addr.SetObject(obj)
return addr
}
// objectHead returns all object's headers.
func (n *layer) objectHead(ctx context.Context, bktInfo *data.BucketInfo, idObj oid.ID) (*object.Object, error) {
prm := PrmObjectRead{
Container: bktInfo.CID,
Object: idObj,
WithHeader: true,
}
n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
res, err := n.frostFS.ReadObject(ctx, prm)
if err != nil {
return nil, err
}
return res.Head, nil
}
// initializes payload reader of the FrostFS object.
// Zero range corresponds to full payload (panics if only offset is set).
func (n *layer) initObjectPayloadReader(ctx context.Context, p getParams) (io.Reader, error) {
prm := PrmObjectRead{
Container: p.bktInfo.CID,
Object: p.oid,
WithPayload: true,
PayloadRange: [2]uint64{p.off, p.ln},
}
n.prepareAuthParameters(ctx, &prm.PrmAuth, p.bktInfo.Owner)
res, err := n.frostFS.ReadObject(ctx, prm)
if err != nil {
return nil, err
}
return res.Payload, nil
}
// objectGet returns an object with payload in the object.
func (n *layer) objectGet(ctx context.Context, bktInfo *data.BucketInfo, objID oid.ID) (*object.Object, error) {
prm := PrmObjectRead{
Container: bktInfo.CID,
Object: objID,
WithHeader: true,
WithPayload: true,
}
n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
res, err := n.frostFS.ReadObject(ctx, prm)
if err != nil {
return nil, err
}
return res.Head, nil
}
// MimeByFilePath detect mime type by file path extension.
func MimeByFilePath(path string) string {
ext := filepath.Ext(path)
if len(ext) == 0 {
return ""
}
return mime.TypeByExtension(ext)
}
func encryptionReader(r io.Reader, size uint64, key []byte) (io.Reader, uint64, error) {
encSize, err := sio.EncryptedSize(size)
if err != nil {
return nil, 0, fmt.Errorf("failed to compute enc size: %w", err)
}
r, err = sio.EncryptReader(r, sio.Config{MinVersion: sio.Version20, MaxVersion: sio.Version20, Key: key, CipherSuites: []byte{sio.AES_256_GCM}})
if err != nil {
return nil, 0, fmt.Errorf("couldn't create encrypter: %w", err)
}
return r, encSize, nil
}
func ParseCompletedPartHeader(hdr string) (*Part, error) {
// partInfo[0] -- part number, partInfo[1] -- part size, partInfo[2] -- checksum
partInfo := strings.Split(hdr, "-")
if len(partInfo) != 3 {
return nil, fmt.Errorf("invalid completed part header")
}
num, err := strconv.Atoi(partInfo[0])
if err != nil {
return nil, fmt.Errorf("invalid completed part number '%s': %w", partInfo[0], err)
}
size, err := strconv.Atoi(partInfo[1])
if err != nil {
return nil, fmt.Errorf("invalid completed part size '%s': %w", partInfo[1], err)
}
return &Part{
ETag: partInfo[2],
PartNumber: num,
Size: int64(size),
}, nil
}
// PutObject stores object into FrostFS, took payload from io.Reader.
func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.ExtendedObjectInfo, error) {
owner := n.Owner(ctx)
bktSettings, err := n.GetBucketSettings(ctx, p.BktInfo)
if err != nil {
return nil, fmt.Errorf("couldn't get versioning settings object: %w", err)
}
newVersion := &data.NodeVersion{
BaseNodeVersion: data.BaseNodeVersion{
FilePath: p.Object,
Size: p.Size,
},
IsUnversioned: !bktSettings.VersioningEnabled(),
}
r := p.Reader
if p.Encryption.Enabled() {
p.Header[AttributeDecryptedSize] = strconv.FormatInt(p.Size, 10)
if err = addEncryptionHeaders(p.Header, p.Encryption); err != nil {
return nil, fmt.Errorf("add encryption header: %w", err)
}
var encSize uint64
if r, encSize, err = encryptionReader(p.Reader, uint64(p.Size), p.Encryption.Key()); err != nil {
return nil, fmt.Errorf("create encrypter: %w", err)
}
p.Size = int64(encSize)
}
if r != nil {
if len(p.Header[api.ContentType]) == 0 {
if contentType := MimeByFilePath(p.Object); len(contentType) == 0 {
d := newDetector(r)
if contentType, err := d.Detect(); err == nil {
p.Header[api.ContentType] = contentType
}
r = d.MultiReader()
} else {
p.Header[api.ContentType] = contentType
}
}
}
prm := PrmObjectCreate{
Container: p.BktInfo.CID,
Creator: owner,
PayloadSize: uint64(p.Size),
Filepath: p.Object,
Payload: r,
CreationTime: TimeNow(ctx),
CopiesNumber: p.CopiesNumber,
}
prm.Attributes = make([][2]string, 0, len(p.Header))
for k, v := range p.Header {
prm.Attributes = append(prm.Attributes, [2]string{k, v})
}
id, hash, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
if err != nil {
return nil, err
}
reqInfo := api.GetReqInfo(ctx)
n.log.Debug("put object",
zap.String("reqId", reqInfo.RequestID),
zap.String("bucket", p.BktInfo.Name), zap.Stringer("cid", p.BktInfo.CID),
zap.String("object", p.Object), zap.Stringer("oid", id))
newVersion.OID = id
newVersion.ETag = hex.EncodeToString(hash)
if newVersion.ID, err = n.treeService.AddVersion(ctx, p.BktInfo, newVersion); err != nil {
return nil, fmt.Errorf("couldn't add new verion to tree service: %w", err)
}
if p.Lock != nil && (p.Lock.Retention != nil || p.Lock.LegalHold != nil) {
putLockInfoPrms := &PutLockInfoParams{
ObjVersion: &ObjectVersion{
BktInfo: p.BktInfo,
ObjectName: p.Object,
VersionID: id.EncodeToString(),
},
NewLock: p.Lock,
CopiesNumber: p.CopiesNumber,
NodeVersion: newVersion, // provide new version to make one less tree service call in PutLockInfo
}
if err = n.PutLockInfo(ctx, putLockInfoPrms); err != nil {
return nil, err
}
}
n.cache.CleanListCacheEntriesContainingObject(p.Object, p.BktInfo.CID)
objInfo := &data.ObjectInfo{
ID: id,
CID: p.BktInfo.CID,
Owner: owner,
Bucket: p.BktInfo.Name,
Name: p.Object,
Size: p.Size,
Created: prm.CreationTime,
Headers: p.Header,
ContentType: p.Header[api.ContentType],
HashSum: newVersion.ETag,
}
extendedObjInfo := &data.ExtendedObjectInfo{
ObjectInfo: objInfo,
NodeVersion: newVersion,
}
// todo filling api.AmzExpiration header
if err = n.putLifecycleObjects(ctx, p.BktInfo, objInfo, bktSettings.LifecycleConfig); err != nil {
return nil, fmt.Errorf("couldn't put expiration system objects: %w", err)
}
n.cache.PutObjectWithName(owner, extendedObjInfo)
return extendedObjInfo, nil
}
func (n *layer) headLastVersionIfNotDeleted(ctx context.Context, bkt *data.BucketInfo, objectName string) (*data.ExtendedObjectInfo, error) {
owner := n.Owner(ctx)
if extObjInfo := n.cache.GetLastObject(owner, bkt.Name, objectName); extObjInfo != nil {
return extObjInfo, nil
}
node, err := n.treeService.GetLatestVersion(ctx, bkt, objectName)
if err != nil {
if errors.Is(err, ErrNodeNotFound) {
return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchKey)
}
return nil, err
}
if node.IsDeleteMarker() {
return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchKey)
}
meta, err := n.objectHead(ctx, bkt, node.OID)
if err != nil {
return nil, err
}
objInfo := objectInfoFromMeta(bkt, meta)
extObjInfo := &data.ExtendedObjectInfo{
ObjectInfo: objInfo,
NodeVersion: node,
}
n.cache.PutObjectWithName(owner, extObjInfo)
return extObjInfo, nil
}
func (n *layer) headVersion(ctx context.Context, bkt *data.BucketInfo, p *HeadObjectParams) (*data.ExtendedObjectInfo, error) {
var err error
var foundVersion *data.NodeVersion
if p.VersionID == data.UnversionedObjectVersionID {
foundVersion, err = n.treeService.GetUnversioned(ctx, bkt, p.Object)
if err != nil {
if errors.Is(err, ErrNodeNotFound) {
return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchVersion)
}
return nil, err
}
} else {
versions, err := n.treeService.GetVersions(ctx, bkt, p.Object)
if err != nil {
return nil, fmt.Errorf("couldn't get versions: %w", err)
}
for _, version := range versions {
if version.OID.EncodeToString() == p.VersionID {
foundVersion = version
break
}
}
if foundVersion == nil {
return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchVersion)
}
}
owner := n.Owner(ctx)
if extObjInfo := n.cache.GetObject(owner, newAddress(bkt.CID, foundVersion.OID)); extObjInfo != nil {
return extObjInfo, nil
}
meta, err := n.objectHead(ctx, bkt, foundVersion.OID)
if err != nil {
if client.IsErrObjectNotFound(err) {
return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchVersion)
}
return nil, err
}
objInfo := objectInfoFromMeta(bkt, meta)
extObjInfo := &data.ExtendedObjectInfo{
ObjectInfo: objInfo,
NodeVersion: foundVersion,
}
n.cache.PutObject(owner, extObjInfo)
return extObjInfo, nil
}
// objectDelete puts tombstone object into frostfs.
func (n *layer) objectDelete(ctx context.Context, bktInfo *data.BucketInfo, idObj oid.ID) error {
prm := PrmObjectDelete{
Container: bktInfo.CID,
Object: idObj,
}
n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
n.cache.DeleteObject(newAddress(bktInfo.CID, idObj))
return n.frostFS.DeleteObject(ctx, prm)
}
// objectPutAndHash prepare auth parameters and invoke frostfs.CreateObject.
// Returns object ID and payload sha256 hash.
func (n *layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktInfo *data.BucketInfo) (oid.ID, []byte, error) {
n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
hash := sha256.New()
prm.Payload = wrapReader(prm.Payload, 64*1024, func(buf []byte) {
hash.Write(buf)
})
id, err := n.frostFS.CreateObject(ctx, prm)
if err != nil {
return oid.ID{}, nil, err
}
return id, hash.Sum(nil), nil
}
// ListObjectsV1 returns objects in a bucket for requests of Version 1.
func (n *layer) ListObjectsV1(ctx context.Context, p *ListObjectsParamsV1) (*ListObjectsInfoV1, error) {
var result ListObjectsInfoV1
prm := allObjectParams{
Bucket: p.BktInfo,
Delimiter: p.Delimiter,
Prefix: p.Prefix,
MaxKeys: p.MaxKeys,
Marker: p.Marker,
}
objects, next, err := n.getLatestObjectsVersions(ctx, prm)
if err != nil {
return nil, err
}
if next != nil {
result.IsTruncated = true
result.NextMarker = objects[len(objects)-1].Name
}
result.Prefixes, result.Objects = triageObjects(objects)
return &result, nil
}
// ListObjectsV2 returns objects in a bucket for requests of Version 2.
func (n *layer) ListObjectsV2(ctx context.Context, p *ListObjectsParamsV2) (*ListObjectsInfoV2, error) {
var result ListObjectsInfoV2
prm := allObjectParams{
Bucket: p.BktInfo,
Delimiter: p.Delimiter,
Prefix: p.Prefix,
MaxKeys: p.MaxKeys,
Marker: p.StartAfter,
ContinuationToken: p.ContinuationToken,
}
objects, next, err := n.getLatestObjectsVersions(ctx, prm)
if err != nil {
return nil, err
}
if next != nil {
result.IsTruncated = true
result.NextContinuationToken = next.ID.EncodeToString()
}
result.Prefixes, result.Objects = triageObjects(objects)
return &result, nil
}
type logWrapper struct {
log *zap.Logger
}
func (l *logWrapper) Printf(format string, args ...interface{}) {
l.log.Info(fmt.Sprintf(format, args...))
}
func (n *layer) getLatestObjectsVersions(ctx context.Context, p allObjectParams) (objects []*data.ObjectInfo, next *data.ObjectInfo, err error) {
if p.MaxKeys == 0 {
return nil, nil, nil
}
owner := n.Owner(ctx)
cacheKey := cache.CreateObjectsListCacheKey(p.Bucket.CID, p.Prefix, true)
nodeVersions := n.cache.GetList(owner, cacheKey)
if nodeVersions == nil {
nodeVersions, err = n.treeService.GetLatestVersionsByPrefix(ctx, p.Bucket, p.Prefix)
if err != nil {
return nil, nil, err
}
n.cache.PutList(owner, cacheKey, nodeVersions)
}
if len(nodeVersions) == 0 {
return nil, nil, nil
}
sort.Slice(nodeVersions, func(i, j int) bool {
return nodeVersions[i].FilePath < nodeVersions[j].FilePath
})
poolCtx, cancel := context.WithCancel(ctx)
defer cancel()
objOutCh, err := n.initWorkerPool(poolCtx, 2, p, nodesGenerator(poolCtx, p, nodeVersions))
if err != nil {
return nil, nil, fmt.Errorf("failed to init worker pool: %w", err)
}
objects = make([]*data.ObjectInfo, 0, p.MaxKeys)
for obj := range objOutCh {
objects = append(objects, obj)
}
sort.Slice(objects, func(i, j int) bool {
return objects[i].Name < objects[j].Name
})
if len(objects) > p.MaxKeys {
next = objects[p.MaxKeys]
objects = objects[:p.MaxKeys]
}
return
}
func nodesGenerator(ctx context.Context, p allObjectParams, nodeVersions []*data.NodeVersion) <-chan *data.NodeVersion {
nodeCh := make(chan *data.NodeVersion)
existed := make(map[string]struct{}, len(nodeVersions)) // to squash the same directories
go func() {
var generated int
LOOP:
for _, node := range nodeVersions {
if shouldSkip(node, p, existed) {
continue
}
select {
case <-ctx.Done():
break LOOP
case nodeCh <- node:
generated++
if generated == p.MaxKeys+1 { // we use maxKeys+1 to be able to know nextMarker/nextContinuationToken
break LOOP
}
}
}
close(nodeCh)
}()
return nodeCh
}
func (n *layer) initWorkerPool(ctx context.Context, size int, p allObjectParams, input <-chan *data.NodeVersion) (<-chan *data.ObjectInfo, error) {
pool, err := ants.NewPool(size, ants.WithLogger(&logWrapper{n.log}))
if err != nil {
return nil, fmt.Errorf("coudln't init go pool for listing: %w", err)
}
objCh := make(chan *data.ObjectInfo)
go func() {
var wg sync.WaitGroup
LOOP:
for node := range input {
select {
case <-ctx.Done():
break LOOP
default:
}
// We have to make a copy of pointer to data.NodeVersion
// to get correct value in submitted task function.
func(node *data.NodeVersion) {
wg.Add(1)
err = pool.Submit(func() {
defer wg.Done()
oi := n.objectInfoFromObjectsCacheOrFrostFS(ctx, p.Bucket, node, p.Prefix, p.Delimiter)
if oi == nil {
// try to get object again
if oi = n.objectInfoFromObjectsCacheOrFrostFS(ctx, p.Bucket, node, p.Prefix, p.Delimiter); oi == nil {
// form object info with data that the tree node contains
oi = getPartialObjectInfo(p.Bucket, node)
}
}
select {
case <-ctx.Done():
case objCh <- oi:
}
})
if err != nil {
wg.Done()
n.log.Warn("failed to submit task to pool", zap.Error(err))
}
}(node)
}
wg.Wait()
close(objCh)
pool.Release()
}()
return objCh, nil
}
// getPartialObjectInfo form data.ObjectInfo using data available in data.NodeVersion.
func getPartialObjectInfo(bktInfo *data.BucketInfo, node *data.NodeVersion) *data.ObjectInfo {
return &data.ObjectInfo{
ID: node.OID,
CID: bktInfo.CID,
Bucket: bktInfo.Name,
Name: node.FilePath,
Size: node.Size,
HashSum: node.ETag,
}
}
func (n *layer) bucketNodeVersions(ctx context.Context, bkt *data.BucketInfo, prefix string) ([]*data.NodeVersion, error) {
var err error
owner := n.Owner(ctx)
cacheKey := cache.CreateObjectsListCacheKey(bkt.CID, prefix, false)
nodeVersions := n.cache.GetList(owner, cacheKey)
if nodeVersions == nil {
nodeVersions, err = n.treeService.GetAllVersionsByPrefix(ctx, bkt, prefix)
if err != nil {
return nil, fmt.Errorf("get all versions from tree service: %w", err)
}
n.cache.PutList(owner, cacheKey, nodeVersions)
}
return nodeVersions, nil
}
func (n *layer) getAllObjectsVersions(ctx context.Context, bkt *data.BucketInfo, prefix, delimiter string) (map[string][]*data.ExtendedObjectInfo, error) {
nodeVersions, err := n.bucketNodeVersions(ctx, bkt, prefix)
if err != nil {
return nil, err
}
versions := make(map[string][]*data.ExtendedObjectInfo, len(nodeVersions))
for _, nodeVersion := range nodeVersions {
oi := &data.ObjectInfo{}
if nodeVersion.IsDeleteMarker() { // delete marker does not match any object in FrostFS
oi.ID = nodeVersion.OID
oi.Name = nodeVersion.FilePath
oi.Owner = nodeVersion.DeleteMarker.Owner
oi.Created = nodeVersion.DeleteMarker.Created
oi.IsDeleteMarker = true
} else {
if oi = n.objectInfoFromObjectsCacheOrFrostFS(ctx, bkt, nodeVersion, prefix, delimiter); oi == nil {
continue
}
}
eoi := &data.ExtendedObjectInfo{
ObjectInfo: oi,
NodeVersion: nodeVersion,
}
objVersions, ok := versions[oi.Name]
if !ok {
objVersions = []*data.ExtendedObjectInfo{eoi}
} else if !oi.IsDir {
objVersions = append(objVersions, eoi)
}
versions[oi.Name] = objVersions
}
return versions, nil
}
func IsSystemHeader(key string) bool {
_, ok := api.SystemMetadata[key]
return ok || strings.HasPrefix(key, api.FrostFSSystemMetadataPrefix)
}
func shouldSkip(node *data.NodeVersion, p allObjectParams, existed map[string]struct{}) bool {
if node.IsDeleteMarker() {
return true
}
filePath := node.FilePath
if dirName := tryDirectoryName(node, p.Prefix, p.Delimiter); len(dirName) != 0 {
filePath = dirName
}
if _, ok := existed[filePath]; ok {
return true
}
if filePath <= p.Marker {
return true
}
if p.ContinuationToken != "" {
if _, ok := existed[continuationToken]; !ok {
if p.ContinuationToken != node.OID.EncodeToString() {
return true
}
existed[continuationToken] = struct{}{}
}
}
existed[filePath] = struct{}{}
return false
}
func triageObjects(allObjects []*data.ObjectInfo) (prefixes []string, objects []*data.ObjectInfo) {
for _, ov := range allObjects {
if ov.IsDir {
prefixes = append(prefixes, ov.Name)
} else {
objects = append(objects, ov)
}
}
return
}
func triageExtendedObjects(allObjects []*data.ExtendedObjectInfo) (prefixes []string, objects []*data.ExtendedObjectInfo) {
for _, ov := range allObjects {
if ov.ObjectInfo.IsDir {
prefixes = append(prefixes, ov.ObjectInfo.Name)
} else {
objects = append(objects, ov)
}
}
return
}
func (n *layer) objectInfoFromObjectsCacheOrFrostFS(ctx context.Context, bktInfo *data.BucketInfo, node *data.NodeVersion, prefix, delimiter string) (oi *data.ObjectInfo) {
if oiDir := tryDirectory(bktInfo, node, prefix, delimiter); oiDir != nil {
return oiDir
}
owner := n.Owner(ctx)
if extInfo := n.cache.GetObject(owner, newAddress(bktInfo.CID, node.OID)); extInfo != nil {
return extInfo.ObjectInfo
}
meta, err := n.objectHead(ctx, bktInfo, node.OID)
if err != nil {
n.log.Warn("could not fetch object meta", zap.Error(err))
return nil
}
oi = objectInfoFromMeta(bktInfo, meta)
n.cache.PutObject(owner, &data.ExtendedObjectInfo{ObjectInfo: oi, NodeVersion: node})
return oi
}
func tryDirectory(bktInfo *data.BucketInfo, node *data.NodeVersion, prefix, delimiter string) *data.ObjectInfo {
dirName := tryDirectoryName(node, prefix, delimiter)
if len(dirName) == 0 {
return nil
}
return &data.ObjectInfo{
ID: node.OID, // to use it as continuation token
CID: bktInfo.CID,
IsDir: true,
IsDeleteMarker: node.IsDeleteMarker(),
Bucket: bktInfo.Name,
Name: dirName,
}
}
// tryDirectoryName forms directory name by prefix and delimiter.
// If node isn't a directory empty string is returned.
// This function doesn't check if node has a prefix. It must do a caller.
func tryDirectoryName(node *data.NodeVersion, prefix, delimiter string) string {
if len(delimiter) == 0 {
return ""
}
tail := strings.TrimPrefix(node.FilePath, prefix)
index := strings.Index(tail, delimiter)
if index >= 0 {
return prefix + tail[:index+1]
}
return ""
}
func wrapReader(input io.Reader, bufSize int, f func(buf []byte)) io.Reader {
if input == nil {
return nil
}
r, w := io.Pipe()
go func() {
var buf = make([]byte, bufSize)
for {
n, err := input.Read(buf)
if n > 0 {
f(buf[:n])
_, _ = w.Write(buf[:n]) // ignore error, input is not ReadCloser
}
if err != nil {
_ = w.CloseWithError(err)
break
}
}
}()
return r
}