~vkolesnikov/pbxt/pbxt-index-selectivity-backscan

xtPublic void xt_idx_delete_current(XTOpenTablePtr ot, XTIndexPtr ind)

{

        XTIdxKeyValueRec        key_value;

        xtWord1                         key_buf[XT_INDEX_MAX_KEY_SIZE + XT_MAX_RECORD_REF_SIZE];

        XTIdxItemRec            tmp_state;

 

        retry_after_oom:

#ifdef XT_TRACK_INDEX_UPDATES

        ot->ot_ind_changed = 0;

#endif

 

        key_value.sv_flags = XT_SEARCH_WHOLE_KEY;

        xt_get_record_ref(&ot->ot_ind_rbuf.tb_data[ot->ot_ind_state.i_item_offset + ot->ot_ind_state.i_item_size - XT_RECORD_REF_SIZE], &key_value.sv_rec_id, &key_value.sv_row_id);

        key_value.sv_length = ot->ot_ind_state.i_item_size - XT_RECORD_REF_SIZE;

        key_value.sv_key = key_buf;

        memcpy(key_buf, &ot->ot_ind_rbuf.tb_data[ot->ot_ind_state.i_item_offset], key_value.sv_length);

        tmp_state = ot->ot_ind_state;

 

        if (!idx_delete(ot, ind, &key_value)) {

                if (idx_out_of_memory_failure(ot))

                        goto retry_after_oom;

                xt_log_and_clear_exception_ns();

        }

 

        /* Setup things so that next or prev will work!

         * This basically means that we must force a search

         * for the next key value.

         *

         * I assume that what I am trying to do is restore

         * the search value, to that which we had before the

         * delete.

         *

         * The problem is, key_buf can be changed by idx_delete().

         *

         * However, I am assuming that ot_ind_rbuf does not

         * change so we can just restore the state?

        ot->ot_ind_state.i_node_ref_size = XT_NODE_REF_SIZE;

        ot->ot_ind_state.i_item_offset = 0;

        ot->ot_ind_state.i_item_size = key_value.sv_length + XT_RECORD_REF_SIZE;

        xt_set_val_record_ref(&ot->ot_ind_rbuf.tb_data[key_value.sv_length], &key_value);

        memcpy(ot->ot_ind_rbuf.tb_data, key_buf, key_value.sv_length);

         */

        ot->ot_ind_state = tmp_state;

        /* This will force search, because it says that this is not a leaf

         * node. Only leaf nodes can be stepped!

         */

        ot->ot_ind_state.i_node_ref_size = XT_NODE_REF_SIZE;

}