/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *  * * * * * * * *
 * MeetiX OS By MeetiX OS Project [Marco Cicognani]                                    *
 *                                                                                     *
 *         DERIVED FROM THE GHOST OPERATING SYSTEM                                     *
 *         This software is derived from the Ghost operating system project,           *
 *         written by Max Schl√ºssel <lokoxe@gmail.com>. Copyright 2012-2017            *
 *         https://ghostkernel.org/                                                    *
 *         https://github.com/maxdev1/ghost                                            *
 *                                                                                     *
 * This program is free software; you can redistribute it and/or                       *
 * modify it under the terms of the GNU General Public License                         *
 * as published by the Free Software Foundation; either version 2                      *
 * of the License, or (char *argumentat your option) any later version.                *
 *                                                                                     *
 * This program is distributed in the hope that it will be useful,                     *
 * but WITHout ANY WARRANTY; without even the implied warranty of                      *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                       *
 * GNU General Public License for more details.                                        *
 *                                                                                     *
 * You should have received a copy of the GNU General Public License                   *
 * along with this program; if not, write to the Free Software                         *
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA      *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *  * * * * * * */

#include <logger/logger.hpp>
#include <memory/paging.hpp>
#include <memory/physical/PPreferenceTracker.hpp>

PPreferenceCountDirectory directory;

/**
 * increment the references to the provided address
 *
 * @param address:		the new address to add
 */
void PPreferenceTracker::increment(PhysAddr address) {
    uint32_t ti = TABLE_IN_DIRECTORY_INDEX(address);
    uint32_t pi = PAGE_IN_TABLE_INDEX(address);

    if ( !directory.tables[ti] ) {
        directory.tables[ti] = new PPreferenceCountTable();

        for ( uint32_t i = 0; i < 1024; i++ )
            directory.tables[ti]->referenceCount[i] = 0;
    }

    ++(directory.tables[ti]->referenceCount[pi]);
}

/**
 * decrement the references to the provided address
 *
 * @param address:		the physical address to be unreferenced
 * @return the number of references to the provided address
 */
int16_t PPreferenceTracker::decrement(PhysAddr address) {
    uint32_t ti = TABLE_IN_DIRECTORY_INDEX(address);
    uint32_t pi = PAGE_IN_TABLE_INDEX(address);

    if ( !directory.tables[ti] )
        return 0;
    return --(directory.tables[ti]->referenceCount[pi]);
}
