plugeth/core/state/snapshot/holdable_iterator.go
rjl493456442 59ac229f87
core/state/snapshot: detect and clean up dangling storage snapshot in generation (#24811)
* core/state/snapshot: check dangling storages when generating snapshot

* core/state/snapshot: polish

* core/state/snapshot: wipe the last part of the dangling storages

* core/state/snapshot: fix and add tests

* core/state/snapshot: fix comment

* README: remove mentions of fast sync (#24656)

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>

* core, cmd: expose dangling storage detector for wider usage

* core/state/snapshot: rename variable

* core, ethdb: use global iterators for snapshot generation

* core/state/snapshot: polish

* cmd, core/state/snapshot: polish

* core/state/snapshot: polish

* Update core/state/snapshot/generate.go

Co-authored-by: Martin Holst Swende <martin@swende.se>

* ethdb: extend db test suite and fix memorydb iterator

* ethdb/dbtest: rollback changes

* ethdb/memorydb: simplify iteration

* core/state/snapshot: update dangling counter

* core/state/snapshot: release iterators

* core/state/snapshot: update metrics

* core/state/snapshot: update time metrics

* metrics/influxdb: temp solution to present counter meaningfully, remove it

* add debug log, revert later

* core/state/snapshot: fix iterator panic

* all: customized snapshot iterator for backward iteration

* core, ethdb: polish

* core/state/snapshot: remove debug log

* core/state/snapshot: address comments from peter

* core/state/snapshot: reopen the iterator at the next position

* ethdb, core/state/snapshot: address comment from peter

* core/state/snapshot: reopen exhausted iterators

Co-authored-by: Tbnoapi <63448616+nuoomnoy02@users.noreply.github.com>
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Martin Holst Swende <martin@swende.se>
2022-05-23 13:26:22 +03:00

98 lines
3.0 KiB
Go

// Copyright 2022 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 snapshot
import (
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/ethdb"
)
// holdableIterator is a wrapper of underlying database iterator. It extends
// the basic iterator interface by adding Hold which can hold the element
// locally where the iterator is currently located and serve it up next time.
type holdableIterator struct {
it ethdb.Iterator
key []byte
val []byte
atHeld bool
}
// newHoldableIterator initializes the holdableIterator with the given iterator.
func newHoldableIterator(it ethdb.Iterator) *holdableIterator {
return &holdableIterator{it: it}
}
// Hold holds the element locally where the iterator is currently located which
// can be served up next time.
func (it *holdableIterator) Hold() {
if it.it.Key() == nil {
return // nothing to hold
}
it.key = common.CopyBytes(it.it.Key())
it.val = common.CopyBytes(it.it.Value())
it.atHeld = false
}
// Next moves the iterator to the next key/value pair. It returns whether the
// iterator is exhausted.
func (it *holdableIterator) Next() bool {
if !it.atHeld && it.key != nil {
it.atHeld = true
} else if it.atHeld {
it.atHeld = false
it.key = nil
it.val = nil
}
if it.key != nil {
return true // shifted to locally held value
}
return it.it.Next()
}
// Error returns any accumulated error. Exhausting all the key/value pairs
// is not considered to be an error.
func (it *holdableIterator) Error() error { return it.it.Error() }
// Release releases associated resources. Release should always succeed and can
// be called multiple times without causing error.
func (it *holdableIterator) Release() {
it.atHeld = false
it.key = nil
it.val = nil
it.it.Release()
}
// Key returns the key of the current key/value pair, or nil if done. The caller
// should not modify the contents of the returned slice, and its contents may
// change on the next call to Next.
func (it *holdableIterator) Key() []byte {
if it.key != nil {
return it.key
}
return it.it.Key()
}
// Value returns the value of the current key/value pair, or nil if done. The
// caller should not modify the contents of the returned slice, and its contents
// may change on the next call to Next.
func (it *holdableIterator) Value() []byte {
if it.val != nil {
return it.val
}
return it.it.Value()
}