zmalloc.c

   1 /* zmalloc - total amount of allocated memory aware version of malloc()
   2  *
   3  * Copyright (c) 2006-2009, Salvatore Sanfilippo <antirez at gmail dot com>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  *   * Redistributions of source code must retain the above copyright notice,
  10  *     this list of conditions and the following disclaimer.
  11  *   * Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *   * Neither the name of Redis nor the names of its contributors may be used
  15  *     to endorse or promote products derived from this software without
  16  *     specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 static size_t used_memory = 0;
  35
  36 void *zmalloc(size_t size) {
  37     void *ptr = malloc(size+sizeof(size_t));
  38
  39     *((size_t*)ptr) = size;
  40     used_memory += size+sizeof(size_t);
  41     return (char*)ptr+sizeof(size_t);
  42 }
  43
  44 void *zrealloc(void *ptr, size_t size) {
  45     void *realptr;
  46     size_t oldsize;
  47     void *newptr;
  48
  49     if (ptr == NULL) return zmalloc(size);
  50     realptr = (char*)ptr-sizeof(size_t);
  51     oldsize = *((size_t*)realptr);
  52     newptr = realloc(realptr,size+sizeof(size_t));
  53     if (!newptr) return NULL;
  54
  55     *((size_t*)newptr) = size;
  56     used_memory -= oldsize;
  57     used_memory += size;
  58     return (char*)newptr+sizeof(size_t);
  59 }
  60
  61 void zfree(void *ptr) {
  62     void *realptr;
  63     size_t oldsize;
  64
  65     if (ptr == NULL) return;
  66     realptr = (char*)ptr-sizeof(size_t);
  67     oldsize = *((size_t*)realptr);
  68     used_memory -= oldsize+sizeof(size_t);
  69     free(realptr);
  70 }
  71
  72 char *zstrdup(const char *s) {
  73     size_t l = strlen(s)+1;
  74     char *p = zmalloc(l);
  75
  76     memcpy(p,s,l);
  77     return p;
  78 }
  79
  80 size_t zmalloc_used_memory(void) {
  81     return used_memory;
  82 }