// Copyright 2019 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 rawdb
import (
"errors"
"fmt"
"math"
"os"
"path/filepath"
"sync"
"sync/atomic"
"time"
"github.com/ava-labs/coreth/params"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/metrics"
"github.com/prometheus/tsdb/fileutil"
)
var (
// errUnknownTable is returned if the user attempts to read from a table that is
// not tracked by the freezer.
errUnknownTable = errors.New("unknown table")
// errOutOrderInsertion is returned if the user attempts to inject out-of-order
// binary blobs into the freezer.
errOutOrderInsertion = errors.New("the append operation is out-order")
// errSymlinkDatadir is returned if the ancient directory specified by user
// is a symbolic link.
errSymlinkDatadir = errors.New("symbolic link datadir is not supported")
)
const (
// freezerRecheckInterval is the frequency to check the key-value database for
// chain progression that might permit new blocks to be frozen into immutable
// storage.
freezerRecheckInterval = time.Minute
// freezerBatchLimit is the maximum number of blocks to freeze in one batch
// before doing an fsync and deleting it from the key-value store.
freezerBatchLimit = 30000
)
// freezer is an memory mapped append-only database to store immutable chain data
// into flat files:
//
// - The append only nature ensures that disk writes are minimized.
// - The memory mapping ensures we can max out system memory for caching without
// reserving it for go-ethereum. This would also reduce the memory requirements
// of Geth, and thus also GC overhead.
type freezer struct {
// WARNING: The `frozen` field is accessed atomically. On 32 bit platforms, only
// 64-bit aligned fields can be atomic. The struct is guaranteed to be so aligned,
// so take advantage of that (https://golang.org/pkg/sync/atomic/#pkg-note-BUG).
frozen uint64 // Number of blocks already frozen
threshold uint64 // Number of recent blocks not to freeze (params.FullImmutabilityThreshold apart from tests)
tables map[string]*freezerTable // Data tables for storing everything
instanceLock fileutil.Releaser // File-system lock to prevent double opens
trigger chan chan struct{} // Manual blocking freeze trigger, test determinism
quit chan struct{}
closeOnce sync.Once
}
// newFreezer creates a chain freezer that moves ancient chain data into
// append-only flat file containers.
func newFreezer(datadir string, namespace string) (*freezer, error) {
// Create the initial freezer object
var (
readMeter = metrics.NewRegisteredMeter(namespace+"ancient/read", nil)
writeMeter = metrics.NewRegisteredMeter(namespace+"ancient/write", nil)
sizeGauge = metrics.NewRegisteredGauge(namespace+"ancient/size", nil)
)
// Ensure the datadir is not a symbolic link if it exists.
if info, err := os.Lstat(datadir); !os.IsNotExist(err) {
if info.Mode()&os.ModeSymlink != 0 {
log.Warn("Symbolic link ancient database is not supported", "path", datadir)
return nil, errSymlinkDatadir
}
}
// Leveldb uses LOCK as the filelock filename. To prevent the
// name collision, we use FLOCK as the lock name.
lock, _, err := fileutil.Flock(filepath.Join(datadir, "FLOCK"))
if err != nil {
return nil, err
}
// Open all the supported data tables
freezer := &freezer{
threshold: params.FullImmutabilityThreshold,
tables: make(map[string]*freezerTable