Add libexif to deps/third_party.

libexif/sources/libexif/exif-mem.c

+ /* exif-mem.c
+  *
+  * Copyright (c) 2003 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.
+  */
+
+#include <libexif/exif-mem.h>
+
+#include <stdlib.h>
+
+struct _ExifMem {
+        unsigned int ref_count;
+        ExifMemAllocFunc alloc_func;
+        ExifMemReallocFunc realloc_func;
+        ExifMemFreeFunc free_func;
+};
+
+/*! Default memory allocation function. */
+static void *
+exif_mem_alloc_func (ExifLong ds)
+{
+        return calloc ((size_t) ds, 1);
+}
+
+/*! Default memory reallocation function. */
+static void *
+exif_mem_realloc_func (void *d, ExifLong ds)
+{
+        return realloc (d, (size_t) ds);
+}
+
+/*! Default memory free function. */
+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);
+}