Function fdb_status fdb_iterator_prev

src/iterator.cc:2015–2060

}

LIBFDB_API
fdb_status fdb_iterator_prev(fdb_iterator *iterator)
{
    if (!iterator) {
        return FDB_RESULT_INVALID_HANDLE;
    }

    fdb_status result = FDB_RESULT_SUCCESS;

    if (!atomic_cas_uint8_t(&iterator->handle->handle_busy, 0, 1)) {
        return FDB_RESULT_HANDLE_BUSY;
    }

    if (iterator->hbtrie_iterator) {
        while ((result = _fdb_iterator_prev(iterator)) ==
                FDB_RESULT_KEY_NOT_FOUND);
    } else {
        while ((result = _fdb_iterator_seq_prev(iterator)) ==
                FDB_RESULT_KEY_NOT_FOUND);
    }
    if (result == FDB_RESULT_SUCCESS) {
        iterator->direction = FDB_ITR_REVERSE;
    } else {
        iterator->_dhandle = NULL; // fail fdb_iterator_get also
        if (iterator->direction != FDB_ITR_DIR_NONE) {
            iterator->direction = FDB_ITR_DIR_NONE;
            if ((iterator->seqtree_iterator || iterator->seqtrie_iterator) &&
                    iterator->status == FDB_ITR_IDX) {
                iterator->_offset = BLK_NOT_FOUND;
            }
            if (iterator->tree_cursor) {
                iterator->tree_cursor = avl_next(iterator->tree_cursor);
                if (iterator->tree_cursor &&
                        iterator->status == FDB_ITR_WAL) {
                    // if the last document was returned from WAL,
                    // shift again, past curkey into next
                    iterator->tree_cursor = avl_next(iterator->tree_cursor);
                }
            }
        }
    }

    atomic_cas_uint8_t(&iterator->handle->handle_busy, 1, 0);
    atomic_incr_uint64_t(&iterator->handle->op_stats->num_iterator_moves);
    return result;
}

LIBFDB_API
fdb_status fdb_iterator_next(fdb_iterator *iterator)