// Get gets a value for a given key
func (db *MDBM) Get(key []byte) (val []byte, err error) {
db.mutex.Lock()
defer db.mutex.Unlock()
var k, v C.datum
k.dptr = (*C.char)(unsafe.Pointer(&key[0]))
k.dsize = C.int(len(key))
C.mdbm_lock_smart(db.dbh, &k, 0)
defer C.mdbm_unlock_smart(db.dbh, &k, 0)
v, e := C.mdbm_fetch(db.dbh, k)
if e != nil {
return nil, errors.New("Cannot retrieve entry: " + e.Error())
}
return C.GoBytes(unsafe.Pointer(v.dptr), v.dsize), nil
}
// Delete deletes an entry given a key
func (db *MDBM) Delete(key []byte) error {
db.mutex.Lock()
defer db.mutex.Unlock()
var k C.datum
k.dptr = (*C.char)(unsafe.Pointer(&key[0]))
k.dsize = C.int(len(key))
// Same as storing. Lock is already done
// implicitly internally
C.mdbm_lock(db.dbh)
defer C.mdbm_unlock(db.dbh)
_, e := C.mdbm_delete(db.dbh, k)
if e != nil {
return errors.New("Cannot delete entry: " + e.Error())
}
return nil
}
// Put saves a key-value entry
func (db *MDBM) Put(key []byte, val []byte) error {
db.mutex.Lock()
defer db.mutex.Unlock()
var k, v C.datum
k.dptr = (*C.char)(unsafe.Pointer(&key[0]))
k.dsize = C.int(len(key))
v.dptr = (*C.char)(unsafe.Pointer(&val[0]))
v.dsize = C.int(len(val))
// Is locking here needed? storing/deleting implements
// implicit locking
C.mdbm_lock(db.dbh)
defer C.mdbm_unlock(db.dbh)
_, e := C.mdbm_store(db.dbh, k, v, C.MDBM_REPLACE)
if e != nil {
return errors.New("Cannot store entry: " + e.Error())
}
return nil
}