func Open(path string) (*LevelDB, error) {
var err *C.char
db := &LevelDB{}
db.dbOpts = &DBOptions{C.leveldb_options_create()}
db.readOpts = &ReadOptions{C.leveldb_readoptions_create()}
db.writeOpts = &WriteOptions{C.leveldb_writeoptions_create()}
C.leveldb_options_set_create_if_missing(db.dbOpts.Opts, 1)
db.db = C.leveldb_open(db.dbOpts.Opts, C.CString(path), &err)
if db.db == nil {
e := &DBError{}
e.Err = "Open db failed"
return nil, e
}
if err != nil {
e := &DBError{}
e.Err = C.GoString(err)
return db, e
}
return db, nil
}
func OpenLeveldb(dir string) (*Leveldb, error) {
options := C.leveldb_options_create()
C.leveldb_options_set_create_if_missing(options, C.uchar(1))
cache := C.leveldb_cache_create_lru(levelCacheCap)
C.leveldb_options_set_cache(options, cache)
cDir := C.CString(dir)
defer C.free(unsafe.Pointer(cDir))
var err *C.char
db := C.leveldb_open(options, cDir, &err)
if err != nil {
return nil, errors.New(fmt.Sprintf("%s: %s", err, dir))
}
C.leveldb_free(unsafe.Pointer(err))
err = nil
leveldb := &Leveldb{
cdb: db,
read_options: C.leveldb_readoptions_create(),
write_options: C.leveldb_writeoptions_create(),
cache: cache,
}
return leveldb, nil
}
func (db *LevelDB) Get(key string) (value string, err error) {
opt := C.leveldb_readoptions_create() // write option
defer C.leveldb_free(unsafe.Pointer(opt))
k := C.CString(key) // copy
defer C.leveldb_free(unsafe.Pointer(k))
var vallen C.size_t
var cerr *C.char
cvalue := C.leveldb_get(db.CLevelDB, opt, k, C.size_t(len(key)), &vallen, &cerr)
if cerr != nil {
defer C.leveldb_free(unsafe.Pointer(cerr))
return "", errors.New(C.GoString(cerr))
}
if cvalue == nil {
return "", nil
}
defer C.leveldb_free(unsafe.Pointer(cvalue))
return C.GoString(cvalue), nil
}
// NewReadOptions allocates a new ReadOptions object.
//
// To prevent memory leaks, the *ReadOptions returned must have Close() called
// on it when it is no longer needed by the program.
func NewReadOptions() *ReadOptions {
opt := C.leveldb_readoptions_create()
return &ReadOptions{opt}
}
func Create_read_options() *Readoptions {
option := C.leveldb_readoptions_create()
return &Readoptions{option}
}