[#441] Don't produce extra object.Head request at regular object upload

Hash can be calculated locally in S3 gateway.
Creation epoch used for versioning and will be
fetched during get and list requests. To avoid
conflicts, put method do not update cache anymore.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

api/layer/object.go

@@ -2,6 +2,7 @@ package layer
 
 import (
 	"context"
+	"crypto/sha256"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -199,7 +200,7 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Object
 		}
 	}
 
-	id, err := n.objectPut(ctx, prm)
+	id, hash, err := n.objectPutAndHash(ctx, prm)
 	if err != nil {
 		return nil, err
 	}
@@ -219,15 +220,6 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Object
 		}
 	}
 
-	meta, err := n.objectHead(ctx, p.BktInfo.CID, *id)
-	if err != nil {
-		return nil, err
-	}
-
-	if err = n.objCache.Put(*meta); err != nil {
-		n.log.Error("couldn't cache an object", zap.Error(err))
-	}
-
 	n.listsCache.CleanCacheEntriesContainingObject(p.Object, p.BktInfo.CID)
 
 	for _, id := range idsToDeleteArr {
@@ -247,8 +239,6 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Object
 		}
 	}
 
-	payloadChecksum, _ := meta.PayloadChecksum()
-
 	return &data.ObjectInfo{
 		ID:  id,
 		CID: p.BktInfo.CID,
@@ -258,10 +248,9 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Object
 		Name:        p.Object,
 		Size:        p.Size,
 		Created:     time.Now(),
-		CreationEpoch: meta.CreationEpoch(),
 		Headers:     p.Header,
 		ContentType: p.Header[api.ContentType],
-		HashSum:       hex.EncodeToString(payloadChecksum.Value()),
+		HashSum:     hex.EncodeToString(hash),
 	}, nil
 }
 
@@ -463,6 +452,18 @@ func (n *layer) objectPut(ctx context.Context, prm neofs.PrmObjectCreate) (*oid.
 	return id, n.transformNeofsError(ctx, err)
 }
 
+// objectPutAndHash prepare auth parameters and invoke neofs.CreateObject.
+// Returns object ID and payload sha256 hash.
+func (n *layer) objectPutAndHash(ctx context.Context, prm neofs.PrmObjectCreate) (*oid.ID, []byte, error) {
+	n.prepareAuthParameters(ctx, &prm.PrmAuth)
+	hash := sha256.New()
+	prm.Payload = wrapReader(prm.Payload, 64*1024, func(buf []byte) {
+		hash.Write(buf)
+	})
+	id, err := n.neoFS.CreateObject(ctx, prm)
+	return id, hash.Sum(nil), n.transformNeofsError(ctx, err)
+}
+
 // ListObjectsV1 returns objects in a bucket for requests of Version 1.
 func (n *layer) ListObjectsV1(ctx context.Context, p *ListObjectsParamsV1) (*ListObjectsInfoV1, error) {
 	var (
@@ -712,3 +713,22 @@ func (n *layer) transformNeofsError(ctx context.Context, err error) error {
 
 	return err
 }
+
+func wrapReader(input io.Reader, bufSize int, f func(buf []byte)) io.Reader {
+	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
+}

api/layer/object_test.go

@@ -1,8 +1,10 @@
 package layer
 
 import (
+	"bytes"
 	"crypto/rand"
 	"crypto/sha256"
+	"io/ioutil"
 	"testing"
 
 	"github.com/nspcc-dev/neofs-s3-gw/api/data"
@@ -112,3 +114,21 @@ func TestTrimAfterObjectID(t *testing.T) {
 		require.Nil(t, actual)
 	})
 }
+
+func TestWrapReader(t *testing.T) {
+	src := make([]byte, 1024*1024+1)
+	_, err := rand.Read(src)
+	require.NoError(t, err)
+	h := sha256.Sum256(src)
+
+	streamHash := sha256.New()
+	reader := bytes.NewReader(src)
+	wrappedReader := wrapReader(reader, 64*1024, func(buf []byte) {
+		streamHash.Write(buf)
+	})
+
+	dst, err := ioutil.ReadAll(wrappedReader)
+	require.NoError(t, err)
+	require.Equal(t, src, dst)
+	require.Equal(t, h[:], streamHash.Sum(nil))
+}