beacon/light: attempt at refactoring

beacon/light/canonicalstore.go

@@ -0,0 +1,252 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package light
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/beacon/types"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/lru"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+func determineRange(db ethdb.Iteratee, keyPrefix []byte) Range {
+	var (
+		iter      = db.NewIterator(keyPrefix, nil)
+		keyLength = len(keyPrefix)
+		p         Range
+	)
+	defer iter.Release()
+	for iter.Next() {
+		if len(iter.Key()) != keyLength+8 {
+			log.Warn("Invalid key length in the canonical chain database", "key", fmt.Sprintf("%#x", iter.Key()))
+			continue
+		}
+		period := binary.BigEndian.Uint64(iter.Key()[keyLength : keyLength+8])
+		if p.Start == 0 {
+			p.Start = period
+		} else if p.End != period {
+			log.Warn("Gap in the canonical chain database")
+			break // continuity guaranteed
+		}
+		p.End = period + 1
+	}
+	return p
+}
+
+// fixedCommitteeRootsStore stores fixedCommitteeRoots
+type fixedCommitteeRootsStore struct {
+	periods Range
+	cache   *lru.Cache[uint64, common.Hash]
+}
+
+// newFixedCommitteeRootsStore creates a new fixedCommitteeRootsStore and
+// verifies the continuity of the range in database.
+func newFixedCommitteeRootsStore(db ethdb.Iteratee) *fixedCommitteeRootsStore {
+	return &fixedCommitteeRootsStore{
+		cache:   lru.NewCache[uint64, common.Hash](100),
+		periods: determineRange(db, rawdb.FixedCommitteeRootKey),
+	}
+}
+
+// databaseKey returns the database key belonging to the given period.
+func (cs *fixedCommitteeRootsStore) databaseKey(period uint64) []byte {
+	return binary.BigEndian.AppendUint64(rawdb.FixedCommitteeRootKey, period)
+}
+
+// add adds the given item to the database. It also ensures that the range remains
+// continuous. Can be used either with a batch or database backend.
+func (cs *fixedCommitteeRootsStore) add(backend ethdb.KeyValueWriter, period uint64, value common.Hash) error {
+	if !cs.periods.CanExpand(period) {
+		return fmt.Errorf("period expansion is not allowed, first: %d, next: %d, period: %d", cs.periods.Start, cs.periods.End, period)
+	}
+	if err := backend.Put(cs.databaseKey(period), value[:]); err != nil {
+		return err
+	}
+	cs.cache.Add(period, value)
+	cs.periods.Expand(period)
+	return nil
+}
+
+// deleteFrom removes items starting from the given period.
+func (cs *fixedCommitteeRootsStore) deleteFrom(db ethdb.KeyValueWriter, fromPeriod uint64) (deleted Range) {
+	keepRange, deleteRange := cs.periods.Split(fromPeriod)
+	deleteRange.Each(func(period uint64) {
+		db.Delete(cs.databaseKey(period))
+		cs.cache.Remove(period)
+	})
+	cs.periods = keepRange
+	return deleteRange
+}
+
+// get returns the item at the given period or the null value of the given type
+// if no item is present.
+// Note: get is thread safe in itself and therefore can be called either with
+// locked or unlocked chain mutex.
+func (cs *fixedCommitteeRootsStore) get(backend ethdb.KeyValueReader, period uint64) (value common.Hash, ok bool) {
+	if value, ok = cs.cache.Get(period); ok {
+		return
+	}
+	enc, err := backend.Get(cs.databaseKey(period))
+	if err != nil {
+		return common.Hash{}, false
+	}
+	if len(enc) != common.HashLength {
+		log.Error("Error decoding canonical store value", "error", "incorrect length for committee root entry in the database")
+	}
+	return common.BytesToHash(enc), true
+}
+
+// serializedSyncCommitteeStore stores SerializedSyncCommittee
+type serializedSyncCommitteeStore struct {
+	periods Range
+	cache   *lru.Cache[uint64, *types.SerializedSyncCommittee]
+}
+
+// newSerializedSyncCommitteSTore creates a new serializedSyncCommitteeStore and
+// verifies the continuity of the range in database.
+func newSerializedSyncCommitteSTore(db ethdb.Iteratee) *serializedSyncCommitteeStore {
+	return &serializedSyncCommitteeStore{
+		cache:   lru.NewCache[uint64, *types.SerializedSyncCommittee](100),
+		periods: determineRange(db, rawdb.SyncCommitteeKey),
+	}
+}
+
+// databaseKey returns the database key belonging to the given period.
+func (cs *serializedSyncCommitteeStore) databaseKey(period uint64) []byte {
+	return binary.BigEndian.AppendUint64(rawdb.SyncCommitteeKey, period)
+}
+
+// add adds the given item to the database. It also ensures that the range remains
+// continuous. Can be used either with a batch or database backend.
+func (cs *serializedSyncCommitteeStore) add(db ethdb.KeyValueWriter, period uint64, value *types.SerializedSyncCommittee) error {
+	if !cs.periods.CanExpand(period) {
+		return fmt.Errorf("period expansion is not allowed, first: %d, next: %d, period: %d", cs.periods.Start, cs.periods.End, period)
+	}
+	if err := db.Put(cs.databaseKey(period), value[:]); err != nil {
+		return err
+	}
+	cs.cache.Add(period, value)
+	cs.periods.Expand(period)
+	return nil
+}
+
+// deleteFrom removes items starting from the given period.
+func (cs *serializedSyncCommitteeStore) deleteFrom(db ethdb.KeyValueWriter, fromPeriod uint64) (deleted Range) {
+	keepRange, deleteRange := cs.periods.Split(fromPeriod)
+	deleteRange.Each(func(period uint64) {
+		db.Delete(cs.databaseKey(period))
+		cs.cache.Remove(period)
+	})
+	cs.periods = keepRange
+	return deleteRange
+}
+
+// get returns the item at the given period or the null value of the given type
+// if no item is present.
+// Note: get is thread safe in itself and therefore can be called either with
+// locked or unlocked chain mutex.
+func (cs *serializedSyncCommitteeStore) get(db ethdb.KeyValueReader, period uint64) (value *types.SerializedSyncCommittee, ok bool) {
+	if value, ok = cs.cache.Get(period); ok {
+		return
+	}
+	enc, err := db.Get(cs.databaseKey(period))
+	if err != nil {
+		return nil, false
+	}
+	if len(enc) != types.SerializedSyncCommitteeSize {
+		log.Error("Error decoding canonical store value", "error", "incorrect length for serialized committee entry in the database")
+		return nil, false
+	}
+	committee := new(types.SerializedSyncCommittee)
+	copy(committee[:], enc)
+	return committee, true
+}
+
+// updatesStore stores lightclient updates
+type updatesStore struct {
+	periods Range
+	cache   *lru.Cache[uint64, *types.LightClientUpdate]
+}
+
+// newUpdatesStore creates a new updatesStore and
+// verifies the continuity of the range in database.
+func newUpdatesStore(db ethdb.Iteratee) *updatesStore {
+	return &updatesStore{
+		cache:   lru.NewCache[uint64, *types.LightClientUpdate](100),
+		periods: determineRange(db, rawdb.BestUpdateKey),
+	}
+}
+
+// databaseKey returns the database key belonging to the given period.
+func (cs *updatesStore) databaseKey(period uint64) []byte {
+	return binary.BigEndian.AppendUint64(rawdb.BestUpdateKey, period)
+}
+
+// add adds the given item to the database. It also ensures that the range remains
+// continuous. Can be used either with a batch or database backend.
+func (cs *updatesStore) add(db ethdb.KeyValueWriter, period uint64, update *types.LightClientUpdate) error {
+	if !cs.periods.CanExpand(period) {
+		return fmt.Errorf("period expansion is not allowed, first: %d, next: %d, period: %d", cs.periods.Start, cs.periods.End, period)
+	}
+	enc, err := rlp.EncodeToBytes(update)
+	if err != nil {
+		return err
+	}
+	if err := db.Put(cs.databaseKey(period), enc); err != nil {
+		return err
+	}
+	cs.cache.Add(period, update)
+	cs.periods.Expand(period)
+	return nil
+}
+
+// deleteFrom removes items starting from the given period.
+func (cs *updatesStore) deleteFrom(db ethdb.KeyValueWriter, fromPeriod uint64) (deleted Range) {
+	keepRange, deleteRange := cs.periods.Split(fromPeriod)
+	deleteRange.Each(func(period uint64) {
+		db.Delete(cs.databaseKey(period))
+		cs.cache.Remove(period)
+	})
+	cs.periods = keepRange
+	return deleteRange
+}
+
+// get returns the item at the given period or the null value of the given type
+// if no item is present.
+// Note: get is thread safe in itself and therefore can be called either with
+// locked or unlocked chain mutex.
+func (cs *updatesStore) get(db ethdb.KeyValueReader, period uint64) (value *types.LightClientUpdate, ok bool) {
+	if value, ok = cs.cache.Get(period); ok {
+		return
+	}
+	enc, err := db.Get(cs.databaseKey(period))
+	if err != nil {
+		return nil, false
+	}
+	update := new(types.LightClientUpdate)
+	if err := rlp.DecodeBytes(enc, update); err != nil {
+		log.Error("Error decoding canonical store value", "error", err)
+		return nil, false
+	}
+	return update, true
+}