025905fcdf
Switch the database from LevelDB to SQLite, for greater stability and simpler code. Co-authored-by: Tommy van der Vorst <tommy@pixelspark.nl> Co-authored-by: bt90 <btom1990@googlemail.com>
114 lines
2.8 KiB
Go
114 lines
2.8 KiB
Go
// Copyright (C) 2018 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at https://mozilla.org/MPL/2.0/.
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package backend
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import (
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"github.com/syndtr/goleveldb/leveldb"
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"github.com/syndtr/goleveldb/leveldb/iterator"
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"github.com/syndtr/goleveldb/leveldb/util"
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)
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// leveldbBackend implements Backend on top of a leveldb
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type leveldbBackend struct {
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ldb *leveldb.DB
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closeWG *closeWaitGroup
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location string
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}
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func newLeveldbBackend(ldb *leveldb.DB, location string) *leveldbBackend {
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return &leveldbBackend{
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ldb: ldb,
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closeWG: &closeWaitGroup{},
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location: location,
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}
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}
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func (b *leveldbBackend) NewReadTransaction() (ReadTransaction, error) {
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return b.newSnapshot()
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}
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func (b *leveldbBackend) newSnapshot() (leveldbSnapshot, error) {
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rel, err := newReleaser(b.closeWG)
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if err != nil {
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return leveldbSnapshot{}, err
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}
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snap, err := b.ldb.GetSnapshot()
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if err != nil {
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rel.Release()
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return leveldbSnapshot{}, wrapLeveldbErr(err)
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}
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return leveldbSnapshot{
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snap: snap,
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rel: rel,
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}, nil
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}
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func (b *leveldbBackend) Close() error {
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b.closeWG.CloseWait()
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return wrapLeveldbErr(b.ldb.Close())
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}
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func (b *leveldbBackend) Get(key []byte) ([]byte, error) {
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val, err := b.ldb.Get(key, nil)
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return val, wrapLeveldbErr(err)
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}
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func (b *leveldbBackend) NewPrefixIterator(prefix []byte) (Iterator, error) {
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return &leveldbIterator{b.ldb.NewIterator(util.BytesPrefix(prefix), nil)}, nil
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}
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func (b *leveldbBackend) NewRangeIterator(first, last []byte) (Iterator, error) {
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return &leveldbIterator{b.ldb.NewIterator(&util.Range{Start: first, Limit: last}, nil)}, nil
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}
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func (b *leveldbBackend) Location() string {
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return b.location
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}
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// leveldbSnapshot implements backend.ReadTransaction
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type leveldbSnapshot struct {
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snap *leveldb.Snapshot
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rel *releaser
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}
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func (l leveldbSnapshot) Get(key []byte) ([]byte, error) {
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val, err := l.snap.Get(key, nil)
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return val, wrapLeveldbErr(err)
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}
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func (l leveldbSnapshot) NewPrefixIterator(prefix []byte) (Iterator, error) {
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return l.snap.NewIterator(util.BytesPrefix(prefix), nil), nil
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}
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func (l leveldbSnapshot) NewRangeIterator(first, last []byte) (Iterator, error) {
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return l.snap.NewIterator(&util.Range{Start: first, Limit: last}, nil), nil
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}
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func (l leveldbSnapshot) Release() {
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l.snap.Release()
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l.rel.Release()
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}
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type leveldbIterator struct {
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iterator.Iterator
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}
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func (it *leveldbIterator) Error() error {
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return wrapLeveldbErr(it.Iterator.Error())
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}
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// wrapLeveldbErr wraps errors so that the backend package can recognize them
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func wrapLeveldbErr(err error) error {
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switch err {
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case leveldb.ErrClosed:
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return errClosed
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case leveldb.ErrNotFound:
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return errNotFound
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}
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return err
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}
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