plugeth/les/pruner.go

100 lines
2.9 KiB
Go

// Copyright 2020 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 les
import (
"sync"
"time"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
)
// pruner is responsible for pruning historical light chain data.
type pruner struct {
db ethdb.Database
indexers []*core.ChainIndexer
closeCh chan struct{}
wg sync.WaitGroup
}
// newPruner returns a light chain pruner instance.
func newPruner(db ethdb.Database, indexers ...*core.ChainIndexer) *pruner {
pruner := &pruner{
db: db,
indexers: indexers,
closeCh: make(chan struct{}),
}
pruner.wg.Add(1)
go pruner.loop()
return pruner
}
// close notifies all background goroutines belonging to pruner to exit.
func (p *pruner) close() {
close(p.closeCh)
p.wg.Wait()
}
// loop periodically queries the status of chain indexers and prunes useless
// historical chain data. Notably, whenever Geth restarts, it will iterate
// all historical sections even they don't exist at all(below checkpoint) so
// that light client can prune cached chain data that was ODRed after pruning
// that section.
func (p *pruner) loop() {
defer p.wg.Done()
// cleanTicker is the ticker used to trigger a history clean 2 times a day.
var cleanTicker = time.NewTicker(12 * time.Hour)
defer cleanTicker.Stop()
// pruning finds the sections that have been processed by all indexers
// and deletes all historical chain data.
// Note, if some indexers don't support pruning(e.g. eth.BloomIndexer),
// pruning operations can be silently ignored.
pruning := func() {
min := uint64(math.MaxUint64)
for _, indexer := range p.indexers {
sections, _, _ := indexer.Sections()
if sections < min {
min = sections
}
}
// Always keep the latest section data in database.
if min < 2 || len(p.indexers) == 0 {
return
}
for _, indexer := range p.indexers {
if err := indexer.Prune(min - 2); err != nil {
log.Debug("Failed to prune historical data", "err", err)
return
}
}
p.db.Compact(nil, nil) // Compact entire database, ensure all removed data are deleted.
}
for {
pruning()
select {
case <-cleanTicker.C:
case <-p.closeCh:
return
}
}
}