go-ethereum/triedb/pathdb/history_indexer.go

// Copyright 2024 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 pathdb

import (
	"errors"
	"sync"
	"sync/atomic"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/log"
)

const historyReadBatch = 1000 // The batch size for reading state history

type historyIndexer struct {
	disk    ethdb.KeyValueStore
	freezer ethdb.AncientStore
	headCh  chan uint64
	closeCh chan struct{}
	wg      sync.WaitGroup
}

func newHistoryIndexer(disk ethdb.KeyValueStore, freezer ethdb.AncientStore, head uint64) *historyIndexer {
	indexer := &historyIndexer{
		disk:    disk,
		freezer: freezer,
		headCh:  make(chan uint64),
		closeCh: make(chan struct{}),
	}
	indexer.wg.Add(1)
	go indexer.loop(head)
	return indexer
}

func (i *historyIndexer) close() {
	select {
	case <-i.closeCh:
		return
	default:
		close(i.closeCh)
		i.wg.Wait()
	}
}

func (i *historyIndexer) notify(head uint64) error {
	select {
	case <-i.closeCh:
		return errors.New("closed")
	case i.headCh <- head:
	}
	return nil
}

func (i *historyIndexer) process(w *historyWriter, h *history, id uint64) error {
	for _, account := range h.accountList {
		w.addAccount(account, id)
		for _, slot := range h.storageList[account] {
			w.addSlot(account, slot, id)
		}
	}
	return w.finish(i.disk, false, id)
}

func (i *historyIndexer) next() (uint64, error) {
	tail, err := i.freezer.Tail()
	if err != nil {
		return 0, err
	}
	tailID := tail + 1 // compute the real history id

	// Start indexing from scratch if nothing has been indexed
	head := rawdb.ReadStateHistoryIndexHead(i.disk)
	if head == nil {
		return tailID, nil
	}
	// Resume indexing from the last interrupted position
	if *head+1 >= tailID {
		return *head + 1, nil
	}
	// History has been shortened without indexing. Discard the gapped segment
	// in the history and shift to the first available element.
	//
	// The missing indexes corresponding to the gapped histories won't be visible.
	// It's fine to leave them unindexed.
	log.Info("History gap detected, discard old segment", "oldHead", *head, "newHead", tailID)
	return tailID, nil
}

func (i *historyIndexer) run(done chan struct{}, head uint64, interrupt *atomic.Int32) {
	defer close(done)

	begin, err := i.next()
	if err != nil {
		log.Error("Failed to find next state history for indexing", "err", err)
		return
	}
	// TODO what if head is lower than the index head. It can
	// happen if the entire state history freezer is reset.
	//if begin > head {
	//
	//}
	log.Info("Start history indexing", "begin", begin, "head", head)

	var (
		current = begin
		writer  = newHistoryWriter()
		start   = time.Now()
		logged  = time.Now()
	)
	for current <= head {
		count := head - current + 1
		if count > historyReadBatch {
			count = historyReadBatch
		}
		s := time.Now()
		result, err := readHistories(i.freezer, current, count)
		if err != nil {
			log.Error("Failed to read history", "err", err)
			return
		}
		log.Debug("Loaded histories", "number", len(result), "elapsed", common.PrettyDuration(time.Since(s)))

		for _, h := range result {
			if err := i.process(writer, h, current); err != nil {
				log.Error("Failed to index history", "err", err)
				return
			}
			current += 1

			if time.Since(logged) > time.Second*8 {
				logged = time.Now()

				var (
					left  = head - current
					done  = current - begin
					speed = done/uint64(time.Since(start)/time.Millisecond+1) + 1 // +1s to avoid division by zero
				)
				// Override the ETA if larger than the largest until now
				eta := time.Duration(left/speed) * time.Millisecond
				log.Info("Indexing state history", "processed", current-begin+1, "remain", head-current, "eta", common.PrettyDuration(eta))
			}
		}
		// Check interruption signal and abort process if it's fired
		if interrupt != nil {
			if signal := interrupt.Load(); signal != 0 {
				if err := writer.finish(i.disk, true, current-1); err != nil {
					log.Error("Failed to flush index", "err", err)
				}
				log.Info("State indexing interrupted")
				return
			}
		}
	}
	if err := writer.finish(i.disk, true, head); err != nil {
		log.Error("Failed to flush index", "err", err)
	}
	log.Info("Indexed state history", "from", begin, "to", head, "elapsed", common.PrettyDuration(time.Since(start)))
}

func (i *historyIndexer) loop(head uint64) {
	defer i.wg.Done()

	// Launch background indexing thread
	done, interrupt := make(chan struct{}), new(atomic.Int32)
	go i.run(done, head, interrupt)

	for {
		select {
		case newHead := <-i.headCh:
			if newHead <= head {
				// TODO, reorg??
				continue
			}
			head = newHead

			if done == nil {
				done, interrupt = make(chan struct{}), new(atomic.Int32)
				go i.run(done, head, interrupt)
			}
		case <-done:
			done, interrupt = nil, nil

		case <-i.closeCh:
			if done != nil {
				interrupt.Store(1)
				log.Info("Waiting background history indexer to exit")
				<-done
			}
			return
		}
	}
}