func (cursor Cursor) CursorGetRaw(flags DbFlag) ([]byte, []byte, error) {
key := C.DBT{flags: C.DB_DBT_REALLOC}
defer C.free(key.data)
val := C.DBT{flags: C.DB_DBT_REALLOC}
defer C.free(val.data)
err := Err(C.db_cursor_get(cursor.ptr, &key, &val, C.u_int32_t(flags)))
if err != nil {
return nil, nil, err
}
return cloneToBytes(&key), cloneToBytes(&val), ok
}
// Retrieve the first record with matching key from the database. If
// exact is false, the first record with a key greater than or equal
// to the given one is fetched; this operation mode only makes sense
// in combination with a B-tree database.
func (cur Cursor) Set(rec proto.Message, exact bool) (err error) {
var key, data C.DBT
var flags C.u_int32_t = 0
if exact {
key.flags |= C.DB_DBT_READONLY
flags |= C.DB_SET
} else {
key.flags |= C.DB_DBT_MALLOC
flags |= C.DB_SET_RANGE
}
data.flags |= C.DB_DBT_REALLOC
defer C.free(data.data)
err = cur.db.marshalKey(&key, rec)
if err == nil {
odata := key.data
defer func() {
if key.data != odata {
C.free(data.data)
}
}()
} else {
return
}
err = check(C.db_cursor_get(cur.ptr, &key, &data, flags))
if err != nil {
return
}
err = cur.db.unmarshalData(&data, rec)
if err != nil {
return
}
err = cur.db.unmarshalKey(&key, rec)
return
}
// Retrieve the previous record from the cursor.
func (cur Cursor) Prev(rec proto.Message) (err error) {
var key, data C.DBT
key.flags |= C.DB_DBT_REALLOC
defer C.free(key.data)
data.flags |= C.DB_DBT_REALLOC
defer C.free(data.data)
err = check(C.db_cursor_get(cur.ptr, &key, &data, C.DB_PREV))
if err != nil {
return
}
err = cur.db.unmarshalData(&data, rec)
if err != nil {
return
}
err = cur.db.unmarshalKey(&key, rec)
return
}