Пример #1
0
func main() {

	ro := &opt.ReadOptions{}
	wo := &opt.WriteOptions{}
	opts := &opt.Options{}

	ldb, err := leveldb.OpenFile("dbfile", opts)
	if err != nil {
		fmt.Printf("db open failed %v\n", err)
		return
	}

	batch := new(leveldb.Batch)
	for _, datum := range dataset {
		key := fmt.Sprintf("%v", datum.key)
		batch.Put([]byte(key), []byte(datum.value))
	}
	err = ldb.Write(batch, wo)

	for _, datum := range dataset {
		key := fmt.Sprintf("%v", datum.key)
		data, err := ldb.Get([]byte(key), ro)

		if err != nil {
			fmt.Printf("db read failed %v\n", err)
		}

		if string(data) != datum.value {
			fmt.Printf("mismatched data from db key %v val %v db %v", key, datum.value, data)
		}
	}
	fmt.Printf("completed\n")
	ldb.Close()
}
Пример #2
0
func openDB(dbpath string, create bool) (pbdb database.Db, err error) {
	var db LevelDb
	var tlDb *leveldb.DB
	var dbversion int32

	defer func() {
		if err == nil {
			db.lDb = tlDb

			db.txUpdateMap = map[btcwire.ShaHash]*txUpdateObj{}
			db.txSpentUpdateMap = make(map[btcwire.ShaHash]*spentTxUpdate)

			pbdb = &db
		}
	}()

	if create == true {
		err = os.Mkdir(dbpath, 0750)
		if err != nil {
			log.Errorf("mkdir failed %v %v", dbpath, err)
			return
		}
	} else {
		_, err = os.Stat(dbpath)
		if err != nil {
			err = database.ErrDbDoesNotExist
			return
		}
	}

	needVersionFile := false
	verfile := dbpath + ".ver"
	fi, ferr := os.Open(verfile)
	if ferr == nil {
		defer fi.Close()

		ferr = binary.Read(fi, binary.LittleEndian, &dbversion)
		if ferr != nil {
			dbversion = ^0
		}
	} else {
		if create == true {
			needVersionFile = true
			dbversion = CurrentDBVersion
		}
	}

	opts := &opt.Options{
		BlockCacher:     opt.DefaultBlockCacher,
		Compression:     opt.NoCompression,
		OpenFilesCacher: opt.DefaultOpenFilesCacher,
	}

	switch dbversion {
	case 0:
		opts = &opt.Options{}
	case 1:
		// uses defaults from above
	default:
		err = fmt.Errorf("unsupported db version %v", dbversion)
		return
	}

	tlDb, err = leveldb.OpenFile(dbpath, opts)
	if err != nil {
		return
	}

	// If we opened the database successfully on 'create'
	// update the
	if needVersionFile {
		fo, ferr := os.Create(verfile)
		if ferr != nil {
			// TODO(design) close and delete database?
			err = ferr
			return
		}
		defer fo.Close()
		err = binary.Write(fo, binary.LittleEndian, dbversion)
		if err != nil {
			return
		}
	}

	return
}