source: mainline/uspace/srv/devman/match.c@ 38b3baf

/*
 * Copyright (c) 2010 Lenka Trochtova
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup devman
 * @{
 */

#include <str.h>

#include "devman.h"

int get_match_score(driver_t *drv, node_t *dev)
{
        link_t *drv_head = &drv->match_ids.ids;
        link_t *dev_head = &dev->match_ids.ids;
        
        if (list_empty(drv_head) || list_empty(dev_head))
                return 0;
        
        link_t *drv_link = drv->match_ids.ids.next;
        link_t *dev_link = dev->match_ids.ids.next;
        
        match_id_t *drv_id = list_get_instance(drv_link, match_id_t, link);
        match_id_t *dev_id = list_get_instance(dev_link, match_id_t, link);
        
        int score_next_drv = 0;
        int score_next_dev = 0;
        
        do {
                match_id_t *tmp_ma_id;
        
                if (0 == str_cmp(drv_id->id, dev_id->id)) {
                        /*
                         * We found a match.
                         * Return the score of the match.
                         */
                        return drv_id->score * dev_id->score;
                }
                
                /*
                 * Compute the next score we get, if we advance in the driver's
                 * list of match ids.
                 */
                if (drv_head != drv_link->next) {
                        tmp_ma_id = list_get_instance(drv_link->next,
                            match_id_t, link);
                        score_next_drv = dev_id->score * tmp_ma_id->score;
                } else {
                        score_next_drv = 0;
                }
                
                /*
                 * Compute the next score we get, if we advance in the device's
                 * list of match ids.
                 */
                if (dev_head != dev_link->next) {
                        tmp_ma_id = list_get_instance(dev_link->next,
                            match_id_t, link);
                        score_next_dev = drv_id->score * tmp_ma_id->score;
                } else {
                        score_next_dev = 0;
                }
                
                /*
                 * Advance in one of the two lists, so we get the next highest
                 * score.
                 */
                if (score_next_drv > score_next_dev) {
                        drv_link = drv_link->next;
                        drv_id = list_get_instance(drv_link, match_id_t, link);
                } else {
                        dev_link = dev_link->next;
                        dev_id = list_get_instance(dev_link, match_id_t, link);
                }
                
        } while (drv_head != drv_link->next && dev_head != dev_link->next);
        
        return 0;
}

/** @}
 */