/* * 
 * This file is part of bufferpool
 *
 * Copyright (C) 2007 by LScube team <team@streaming.polito.it>
 * See AUTHORS for more details
 * 
 * bufferpool is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * bufferpool 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with bufferpool; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 
 *
 */



#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>

#include <sys/mman.h>

#include <bufferpool.h>

#ifndef BPBUFF_REALLOC



/*@brief internal function used to add a slot or, in case of shared memory, a page of slots
 * (of BPBUFF_SHM_PAGE size).
 * WARNING: the function assumes that the caller (bp_write or bp_getslot) locked the buffer mutex
 * @return the first BPSlot of new added page of slots.
 * */
BPSlot *bp_slotadd(BPBuffer * buffer, BPSlot * prev)
{
    BPSlot *added;
    BPSlotPtr prev_diff;

    switch (buffer->type) {
    case buff_shm:
        prev_diff = BPtoSlotPtr(buffer, prev);
        added = bp_shm_addpage(buffer);
        prev = &buffer->slots[prev_diff];

        buffer->slots[buffer->known_slots - 1].next = prev->next;    // last added slot in shm new page is linked to the prev->next in old queue

        bp_log(FNC_LOG_DEBUG, "BPSlots page added in SHM memory\n");
        break;
    case buff_local:
    default:
        if (!(added = calloc(1, sizeof(BPSlotAdded))))
            return NULL;
        ((BPSlotAdded *) added)->next_added = buffer->added_slots;
        buffer->added_slots = (BPSlotAdded *) added;

        added->next = prev->next;
        bp_log(FNC_LOG_DEBUG, "slot added\n");
        break;
    }

    prev->next = BPtoSlotPtr(buffer, added);

    return added;
}
#endif                // BPBUFF_REALLOC