prysm-pulse/beacon-chain/state/stateutil/historical_summaries_root.go
terencechain 179252faea
Address historical summaries feedback (#11864)
* Address historical summaries feedback

* Fix build

* Fix test

* Move historicalSummaries

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
2023-01-16 12:44:40 +00:00

50 lines
1.5 KiB
Go

package stateutil
import (
"bytes"
"encoding/binary"
"fmt"
"github.com/pkg/errors"
fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
"github.com/prysmaticlabs/prysm/v3/crypto/hash"
"github.com/prysmaticlabs/prysm/v3/encoding/ssz"
ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
)
func HistoricalSummariesRoot(summaries []*ethpb.HistoricalSummary) ([32]byte, error) {
max := uint64(fieldparams.HistoricalRootsLength)
if uint64(len(summaries)) > max {
return [32]byte{}, fmt.Errorf("historical summary exceeds max length %d", max)
}
hasher := hash.CustomSHA256Hasher()
roots := make([][32]byte, len(summaries))
for i := 0; i < len(summaries); i++ {
r, err := summaries[i].HashTreeRoot()
if err != nil {
return [32]byte{}, errors.Wrap(err, "could not merkleize historical summary")
}
roots[i] = r
}
summariesRoot, err := ssz.BitwiseMerkleize(
hasher,
roots,
uint64(len(roots)),
fieldparams.HistoricalRootsLength,
)
if err != nil {
return [32]byte{}, errors.Wrap(err, "could not compute historical summaries merkleization")
}
summariesLenBuf := new(bytes.Buffer)
if err := binary.Write(summariesLenBuf, binary.LittleEndian, uint64(len(summaries))); err != nil {
return [32]byte{}, errors.Wrap(err, "could not marshal historical summary length")
}
// We need to mix in the length of the slice.
summariesLenRoot := make([]byte, 32)
copy(summariesLenRoot, summariesLenBuf.Bytes())
res := ssz.MixInLength(summariesRoot, summariesLenRoot)
return res, nil
}