Golang C.leveldb_create_iterator类(方法)实例源码

func (db *DB) NewIterator() driver.IIterator {
	it := new(Iterator)

	it.it = C.leveldb_create_iterator(db.db, db.iteratorOpts.Opt)

	return it
}

func (s *Snapshot) NewIterator() *Iterator {
	it := new(Iterator)

	it.it = C.leveldb_create_iterator(s.db.db, s.iteratorOpts.Opt)

	return it
}

func (self *Leveldb) Iter(fun func(string, Getter) bool) {
	iterator := C.leveldb_create_iterator(self.cdb, self.read_options)
	defer C.leveldb_iter_destroy(iterator)
	var keyLen C.size_t
	var keyValue *C.char
	var valueLen C.size_t
	var valueValue *C.char
	var ret bool
	for C.leveldb_iter_seek_to_first(iterator); C.leveldb_iter_valid(iterator) != levelFalse; C.leveldb_iter_next(iterator) {
		keyValue = C.leveldb_iter_key(iterator, &keyLen)
		key := string(C.GoBytes(unsafe.Pointer(keyValue), C.int(keyLen)))
		valueValue = C.leveldb_iter_value(iterator, &valueLen)
		value := C.GoBytes(unsafe.Pointer(valueValue), C.int(valueLen))
		r := bytes.NewReader(value)
		ret = fun(key, func(e interface{}) error {
			return decode(r, e)
		})
		if ret == false {
			break
		}
	}
}

// NewIterator returns an Iterator over the the database that uses the
// ReadOptions given.
//
// Often, this is used for large, offline bulk reads while serving live
// traffic. In that case, it may be wise to disable caching so that the data
// processed by the returned Iterator does not displace the already cached
// data. This can be done by calling SetFillCache(false) on the ReadOptions
// before passing it here.
//
// Similiarly, ReadOptions.SetSnapshot is also useful.
func (db *DB) NewIterator(ro *ReadOptions) *Iterator {
	it := C.leveldb_create_iterator(db.Ldb, ro.Opt)
	return &Iterator{Iter: it}
}