1 files changed, 99 insertions, 0 deletions
diff --git a/libexif/exif-mem.c b/libexif/exif-mem.c
new file mode 100644
index 0000000..b4d7ece
--- /dev/null
+++ b/libexif/exif-mem.c
@@ -0,0 +1,99 @@
+#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);
+}