shared/scratchbuf.c

   1 /*
   2  * kmod - interface to kernel module operations
   3  *
   4  * Copyright (C) 2016  Intel Corporation. All rights reserved.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include "scratchbuf.h"
  20
  21 #include <errno.h>
  22 #include <string.h>
  23
  24 void scratchbuf_init(struct scratchbuf *buf, char *stackbuf, size_t size)
  25 {
  26         buf->bytes = stackbuf;
  27         buf->size = size;
  28         buf->need_free = false;
  29 }
  30
  31 int scratchbuf_alloc(struct scratchbuf *buf, size_t size)
  32 {
  33         char *tmp;
  34
  35         if (size <= buf->size)
  36                 return 0;
  37
  38         if (buf->need_free) {
  39                 tmp = realloc(buf->bytes, size);
  40                 if (tmp == NULL)
  41                         return -ENOMEM;
  42         } else {
  43                 tmp = malloc(size);
  44                 if (tmp == NULL)
  45                         return -ENOMEM;
  46                 memcpy(tmp, buf->bytes, buf->size);
  47         }
  48
  49         buf->size = size;
  50         buf->bytes = tmp;
  51         buf->need_free = true;
  52
  53         return 0;
  54 }
  55
  56 void scratchbuf_release(struct scratchbuf *buf)
  57 {
  58         if (buf->need_free)
  59                 free(buf->bytes);
  60 }