slicer: Skip object meta evaluation, if it is already done

Updated after benchmark. For the header object we already made flushObjectMetadata step in _writeChild and don't need to compute this data again.

                                                 │   old.txt    │              new.txt               │
                                                 │    sec/op    │   sec/op     vs base               │
SliceDataIntoObjects/slice_1-128/reader-16         116.55µ ± 1%   62.61µ ± 1%  -46.28% (p=0.002 n=6)
SliceDataIntoObjects/slice_1-128/writer-16         121.73µ ± 2%   64.94µ ± 1%  -46.65% (p=0.002 n=6)
SliceDataIntoObjects/slice_4-128/reader-16         111.50µ ± 3%   65.48µ ± 1%  -41.27% (p=0.002 n=6)
SliceDataIntoObjects/slice_4-128/writer-16         113.84µ ± 1%   67.38µ ± 2%  -40.81% (p=0.002 n=6)
SliceDataIntoObjects/slice_16-128/reader-16        110.43µ ± 1%   61.57µ ± 2%  -44.25% (p=0.002 n=6)
SliceDataIntoObjects/slice_16-128/writer-16        115.11µ ± 1%   63.93µ ± 1%  -44.46% (p=0.002 n=6)
SliceDataIntoObjects/slice_64-128/reader-16        109.10µ ± 1%   64.89µ ± 1%  -40.53% (p=0.002 n=6)
SliceDataIntoObjects/slice_64-128/writer-16        114.07µ ± 1%   67.24µ ± 1%  -41.05% (p=0.002 n=6)
SliceDataIntoObjects/slice_256-128/reader-16       108.68µ ± 1%   61.19µ ± 1%  -43.70% (p=0.002 n=6)
SliceDataIntoObjects/slice_256-128/writer-16        233.2µ ± 0%   236.2µ ± 2%        ~ (p=0.093 n=6)
SliceDataIntoObjects/slice_1024-128/reader-16      109.04µ ± 1%   64.34µ ± 1%  -41.00% (p=0.002 n=6)
SliceDataIntoObjects/slice_1024-128/writer-16       554.6µ ± 0%   569.6µ ± 2%   +2.71% (p=0.002 n=6)
SliceDataIntoObjects/slice_4096-128/reader-16      114.62µ ± 0%   63.45µ ± 1%  -44.65% (p=0.002 n=6)
SliceDataIntoObjects/slice_4096-128/writer-16       1.855m ± 2%   1.865m ± 1%        ~ (p=0.180 n=6)
SliceDataIntoObjects/slice_16384-128/reader-16     117.09µ ± 3%   67.15µ ± 0%  -42.65% (p=0.002 n=6)
SliceDataIntoObjects/slice_16384-128/writer-16      7.745m ± 2%   7.889m ± 1%   +1.86% (p=0.026 n=6)
SliceDataIntoObjects/slice_65536-128/reader-16     118.90µ ± 1%   67.12µ ± 1%  -43.55% (p=0.002 n=6)
SliceDataIntoObjects/slice_65536-128/writer-16      30.71m ± 1%   31.07m ± 0%   +1.20% (p=0.002 n=6)
SliceDataIntoObjects/slice_262144-128/reader-16    124.95µ ± 2%   72.49µ ± 1%  -41.98% (p=0.002 n=6)
SliceDataIntoObjects/slice_262144-128/writer-16     124.0m ± 1%   112.7m ± 0%   -9.15% (p=0.002 n=6)
SliceDataIntoObjects/slice_1048576-128/reader-16    184.8µ ± 2%   125.1µ ± 3%  -32.30% (p=0.002 n=6)
SliceDataIntoObjects/slice_1048576-128/writer-16    453.8m ± 1%   518.8m ± 2%  +14.32% (p=0.002 n=6)
geomean                                             461.0µ        318.0µ       -31.02%

                                                 │    old.txt    │               new.txt                │
                                                 │     B/op      │     B/op       vs base               │
SliceDataIntoObjects/slice_1-128/reader-16         16.880Ki ± 0%    9.453Ki ± 0%  -44.00% (p=0.002 n=6)
SliceDataIntoObjects/slice_1-128/writer-16         18.100Ki ± 0%    9.344Ki ± 0%  -48.38% (p=0.002 n=6)
SliceDataIntoObjects/slice_4-128/reader-16          14.75Ki ± 0%    10.33Ki ± 0%  -29.99% (p=0.002 n=6)
SliceDataIntoObjects/slice_4-128/writer-16          15.91Ki ± 0%    10.22Ki ± 0%  -35.77% (p=0.002 n=6)
SliceDataIntoObjects/slice_16-128/reader-16        14.504Ki ± 0%    8.984Ki ± 0%  -38.06% (p=0.002 n=6)
SliceDataIntoObjects/slice_16-128/writer-16        15.724Ki ± 0%    8.968Ki ± 0%  -42.97% (p=0.002 n=6)
SliceDataIntoObjects/slice_64-128/reader-16         13.63Ki ± 0%    10.33Ki ± 0%  -24.21% (p=0.002 n=6)
SliceDataIntoObjects/slice_64-128/writer-16         14.85Ki ± 0%    10.22Ki ± 0%  -31.17% (p=0.002 n=6)
SliceDataIntoObjects/slice_256-128/reader-16       14.005Ki ± 0%    8.985Ki ± 0%  -35.84% (p=0.002 n=6)
SliceDataIntoObjects/slice_256-128/writer-16        31.33Ki ± 0%    31.18Ki ± 0%   -0.47% (p=0.002 n=6)
SliceDataIntoObjects/slice_1024-128/reader-16      14.008Ki ± 0%    9.864Ki ± 0%  -29.58% (p=0.002 n=6)
SliceDataIntoObjects/slice_1024-128/writer-16       74.32Ki ± 0%    81.16Ki ± 0%   +9.21% (p=0.002 n=6)
SliceDataIntoObjects/slice_4096-128/reader-16      16.528Ki ± 0%    9.874Ki ± 0%  -40.26% (p=0.002 n=6)
SliceDataIntoObjects/slice_4096-128/writer-16       250.8Ki ± 0%    266.2Ki ± 0%   +6.13% (p=0.002 n=6)
SliceDataIntoObjects/slice_16384-128/reader-16      16.34Ki ± 0%    11.14Ki ± 0%  -31.82% (p=0.002 n=6)
SliceDataIntoObjects/slice_16384-128/writer-16      965.2Ki ± 0%   1038.0Ki ± 0%   +7.55% (p=0.002 n=6)
SliceDataIntoObjects/slice_65536-128/reader-16      17.27Ki ± 0%    10.97Ki ± 0%  -36.50% (p=0.002 n=6)
SliceDataIntoObjects/slice_65536-128/writer-16      3.711Mi ± 0%    3.981Mi ± 0%   +7.27% (p=0.002 n=6)
SliceDataIntoObjects/slice_262144-128/reader-16     16.04Ki ± 0%    11.41Ki ± 0%  -28.86% (p=0.002 n=6)
SliceDataIntoObjects/slice_262144-128/writer-16     14.88Mi ± 0%    15.53Mi ± 0%   +4.34% (p=0.002 n=6)
SliceDataIntoObjects/slice_1048576-128/reader-16    23.04Ki ± 1%    17.77Ki ± 3%  -22.87% (p=0.002 n=6)
SliceDataIntoObjects/slice_1048576-128/writer-16    57.72Mi ± 0%    63.79Mi ± 0%  +10.51% (p=0.002 n=6)
geomean                                             61.36Ki         46.61Ki       -24.04%

                                                 │   old.txt   │               new.txt               │
                                                 │  allocs/op  │  allocs/op    vs base               │
SliceDataIntoObjects/slice_1-128/reader-16          254.0 ± 0%     149.0 ± 0%  -41.34% (p=0.002 n=6)
SliceDataIntoObjects/slice_1-128/writer-16          276.0 ± 0%     148.0 ± 0%  -46.38% (p=0.002 n=6)
SliceDataIntoObjects/slice_4-128/reader-16          223.0 ± 0%     161.0 ± 0%  -27.80% (p=0.002 n=6)
SliceDataIntoObjects/slice_4-128/writer-16          244.0 ± 0%     160.0 ± 0%  -34.43% (p=0.002 n=6)
SliceDataIntoObjects/slice_16-128/reader-16         218.0 ± 0%     142.0 ± 0%  -34.86% (p=0.002 n=6)
SliceDataIntoObjects/slice_16-128/writer-16         240.0 ± 0%     143.0 ± 0%  -40.42% (p=0.002 n=6)
SliceDataIntoObjects/slice_64-128/reader-16         204.0 ± 0%     161.0 ± 0%  -21.08% (p=0.002 n=6)
SliceDataIntoObjects/slice_64-128/writer-16         226.0 ± 0%     160.0 ± 0%  -29.20% (p=0.002 n=6)
SliceDataIntoObjects/slice_256-128/reader-16        211.0 ± 0%     142.0 ± 0%  -32.70% (p=0.002 n=6)
SliceDataIntoObjects/slice_256-128/writer-16        472.0 ± 0%     478.0 ± 0%   +1.27% (p=0.002 n=6)
SliceDataIntoObjects/slice_1024-128/reader-16       211.0 ± 0%     155.0 ± 0%  -26.54% (p=0.002 n=6)
SliceDataIntoObjects/slice_1024-128/writer-16      1.140k ± 0%    1.283k ± 0%  +12.54% (p=0.002 n=6)
SliceDataIntoObjects/slice_4096-128/reader-16       247.0 ± 0%     155.0 ± 0%  -37.25% (p=0.002 n=6)
SliceDataIntoObjects/slice_4096-128/writer-16      3.884k ± 0%    4.237k ± 0%   +9.10% (p=0.002 n=6)
SliceDataIntoObjects/slice_16384-128/reader-16      243.0 ± 0%     172.0 ± 0%  -29.22% (p=0.002 n=6)
SliceDataIntoObjects/slice_16384-128/writer-16     14.91k ± 0%    16.51k ± 0%  +10.70% (p=0.002 n=6)
SliceDataIntoObjects/slice_65536-128/reader-16      259.0 ± 0%     169.0 ± 0%  -34.75% (p=0.002 n=6)
SliceDataIntoObjects/slice_65536-128/writer-16     58.73k ± 0%    64.87k ± 0%  +10.47% (p=0.002 n=6)
SliceDataIntoObjects/slice_262144-128/reader-16     240.0 ± 0%     178.0 ± 1%  -25.83% (p=0.002 n=6)
SliceDataIntoObjects/slice_262144-128/writer-16    233.8k ± 0%    252.3k ± 0%   +7.92% (p=0.002 n=6)
SliceDataIntoObjects/slice_1048576-128/reader-16    340.5 ± 1%     279.5 ± 3%  -17.91% (p=0.002 n=6)
SliceDataIntoObjects/slice_1048576-128/writer-16   909.8k ± 0%   1032.7k ± 0%  +13.51% (p=0.002 n=6)
geomean                                             930.0          732.6       -21.23%

Signed-off-by: Evgenii Baidakov <[email protected]>

object/slicer/slicer.go

@@ -469,9 +469,19 @@ func flushObjectMetadata(signer neofscrypto.Signer, meta dynamicObjectMetadata,
 }
 
 func writeInMemObject(ctx context.Context, signer user.Signer, w ObjectWriter, header object.Object, payload []byte, meta dynamicObjectMetadata, session *session.Object) (oid.ID, error) {
-	id, err := flushObjectMetadata(signer, meta, &header)
-	if err != nil {
-		return id, err
+	var (
+		id    oid.ID
+		err   error
+		isSet bool
+	)
+
+	id, isSet = header.ID()
+	if !isSet || header.Signature() == nil {
+		id, err = flushObjectMetadata(signer, meta, &header)
+
+		if err != nil {
+			return id, err
+		}
 	}
 
 	var prm client.PrmObjectPutInit