dmmlib/src/realloc.c

/*
 *   Copyright Institute of Communication and Computer Systems (ICCS) 
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */

/**
 * @file   realloc.c
 * @author Ioannis Koutras (joko@microlab.ntua.gr)
 * @date   September 2012
 *
 * @brief  Implementation of realloc() call.
 */

#include "dmmlib/dmmlib.h"

#include <stdbool.h>
#ifdef BITMAP_RB_ONLY
#include "bitmap/bitmap.h"
#include "bitmap/bitmap_rb.h"
#endif /* BITMAP_RB_ONLY */
#include "release_memory.h"

void * realloc(void *ptr, size_t size) {
    raw_block_header_t *current_raw_block;
    bool found;

    if(ptr == NULL) {
        return malloc(size);
    }

    if(size == 0) {
        free(ptr);
#ifdef BITMAP_RB_ONLY
        return malloc(CHUNK_HDR_SIZE + 32); // FIXME 32 <- minimum size
#endif /* BITMAP_RB_ONLY */
#ifdef FL_RB_ONLY
        return malloc((size_t) 32); // FIXME 32 <- minimum size
#endif /* FL_RB_ONLY */
    }

    found = false;

    current_raw_block = systemallocator.raw_block_head;
    while(current_raw_block) {
        if(((char *)ptr > (char *)current_raw_block) &&
                ((char *)ptr < (char *)(current_raw_block) +
                 current_raw_block->size)) {
            found = true;
            break;
        }
        current_raw_block = current_raw_block->next_raw_block;
    }

    if(found == true) {
#ifdef BITMAP_RB_ONLY
        bitmap_rb_t *bitmap_rb;
        bitmap_rb = (bitmap_rb_t *)((char *)current_raw_block +
                sizeof(raw_block_header_t));
        return bitmap_realloc(bitmap_rb, ptr, size);
#endif /* BITMAP_RB_ONLY */
#ifdef FL_RB_ONLY
        return freelist_realloc(current_raw_block, ptr, size);
#endif /* FL_RB_ONLY */
    } else {
        return NULL; // FIXME what about big blocks?
    }
}