mirror of https://github.com/aptly-dev/aptly
141 lines
2.7 KiB
Go
141 lines
2.7 KiB
Go
// Package database provides KV database for meta-information
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package database
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import (
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"bytes"
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"errors"
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"github.com/syndtr/goleveldb/leveldb"
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"github.com/syndtr/goleveldb/leveldb/filter"
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"github.com/syndtr/goleveldb/leveldb/opt"
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)
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// Errors for Storage
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var (
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ErrNotFound = errors.New("key not found")
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)
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// Storage is an interface to KV storage
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type Storage interface {
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Get(key []byte) ([]byte, error)
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Put(key []byte, value []byte) error
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Delete(key []byte) error
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KeysByPrefix(prefix []byte) [][]byte
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FetchByPrefix(prefix []byte) [][]byte
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Close() error
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StartBatch()
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FinishBatch() error
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}
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type levelDB struct {
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db *leveldb.DB
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batch *leveldb.Batch
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}
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// Check interface
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var (
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_ Storage = &levelDB{}
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)
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// OpenDB opens (creates) LevelDB database
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func OpenDB(path string) (Storage, error) {
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o := &opt.Options{
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Filter: filter.NewBloomFilter(10),
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}
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db, err := leveldb.OpenFile(path, o)
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if err != nil {
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return nil, err
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}
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return &levelDB{db: db}, nil
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}
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func (l *levelDB) Get(key []byte) ([]byte, error) {
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value, err := l.db.Get(key, nil)
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if err != nil {
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if err == leveldb.ErrNotFound {
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return nil, ErrNotFound
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}
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return nil, err
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}
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return value, nil
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}
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func (l *levelDB) Put(key []byte, value []byte) error {
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if l.batch != nil {
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l.batch.Put(key, value)
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return nil
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}
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old, err := l.db.Get(key, nil)
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if err != nil {
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if err != leveldb.ErrNotFound {
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return err
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}
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} else {
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if bytes.Compare(old, value) == 0 {
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return nil
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}
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}
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return l.db.Put(key, value, nil)
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}
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func (l *levelDB) Delete(key []byte) error {
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if l.batch != nil {
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l.batch.Delete(key)
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return nil
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}
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return l.db.Delete(key, nil)
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}
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func (l *levelDB) KeysByPrefix(prefix []byte) [][]byte {
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result := make([][]byte, 0, 20)
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iterator := l.db.NewIterator(nil, nil)
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defer iterator.Release()
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for ok := iterator.Seek(prefix); ok && bytes.HasPrefix(iterator.Key(), prefix); ok = iterator.Next() {
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key := iterator.Key()
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keyc := make([]byte, len(key))
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copy(keyc, key)
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result = append(result, keyc)
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}
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return result
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}
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func (l *levelDB) FetchByPrefix(prefix []byte) [][]byte {
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result := make([][]byte, 0, 20)
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iterator := l.db.NewIterator(nil, nil)
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defer iterator.Release()
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for ok := iterator.Seek(prefix); ok && bytes.HasPrefix(iterator.Key(), prefix); ok = iterator.Next() {
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val := iterator.Value()
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valc := make([]byte, len(val))
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copy(valc, val)
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result = append(result, valc)
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}
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return result
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}
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func (l *levelDB) Close() error {
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return l.db.Close()
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}
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func (l *levelDB) StartBatch() {
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if l.batch != nil {
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panic("batch already started")
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}
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l.batch = new(leveldb.Batch)
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}
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func (l *levelDB) FinishBatch() error {
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if l.batch == nil {
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panic("no batch")
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}
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err := l.db.Write(l.batch, nil)
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l.batch = nil
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return err
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}
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