exif-mem.c

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/* exif-mem.c
 *
 * Copyright (c) 2004 Lutz Mueller <lutz@users.sourceforge.net>
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA.
 *
 * SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
#include <libexif/exif-mem.h>
 
#include <stdlib.h>
 
struct _ExifMem {
        unsigned int ref_count;
        ExifMemAllocFunc alloc_func;
        ExifMemReallocFunc realloc_func;
        ExifMemFreeFunc free_func;
};
 
static void *
exif_mem_alloc_func (ExifLong ds)
{
        return calloc ((size_t) ds, 1);
}
 
static void *
exif_mem_realloc_func (void *d, ExifLong ds)
{
        return realloc (d, (size_t) ds);
}
 
static void
exif_mem_free_func (void *d)
{
        free (d);
}
 
ExifMem *
exif_mem_new (ExifMemAllocFunc alloc_func, ExifMemReallocFunc realloc_func,
              ExifMemFreeFunc free_func)
{
        ExifMem *mem;
 
        if (!alloc_func && !realloc_func) 
                return NULL;
        mem = alloc_func ? alloc_func (sizeof (ExifMem)) :
                           realloc_func (NULL, sizeof (ExifMem));
        if (!mem) return NULL;
        mem->ref_count = 1;
 
        mem->alloc_func   = alloc_func;
        mem->realloc_func = realloc_func;
        mem->free_func    = free_func;
 
        return mem;
}
 
void
exif_mem_ref (ExifMem *mem)
{
        if (!mem) return;
        mem->ref_count++;
}
 
void
exif_mem_unref (ExifMem *mem)
{
        if (!mem) return;
        if (!--mem->ref_count)
                exif_mem_free (mem, mem);
}
 
void
exif_mem_free (ExifMem *mem, void *d)
{
        if (!mem) return;
        if (mem->free_func) {
                mem->free_func (d);
                return;
        }
}
 
void *
exif_mem_alloc (ExifMem *mem, ExifLong ds)
{
        if (!mem) return NULL;
        if (mem->alloc_func || mem->realloc_func)
                return mem->alloc_func ? mem->alloc_func (ds) :
                                         mem->realloc_func (NULL, ds);
        return NULL;
}
 
void *
exif_mem_realloc (ExifMem *mem, void *d, ExifLong ds)
{
        return (mem && mem->realloc_func) ? mem->realloc_func (d, ds) : NULL;
}
 
ExifMem *
exif_mem_new_default (void)
{
        return exif_mem_new (exif_mem_alloc_func, exif_mem_realloc_func,
                             exif_mem_free_func);
}