1 files changed, 93 insertions, 0 deletions
diff --git a/src/lib/memarea.c b/src/lib/memarea.c
new file mode 100644
index 0000000..747ea8b
--- /dev/null
+++ b/src/lib/memarea.c
@@ -0,0 +1,93 @@
+/* Copyright (c) 2017-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "memarea.h"
+
+struct memarea {
+	const void *data;
+	size_t size;
+
+	memarea_free_callback_t *callback;
+	void *context;
+
+	int refcount;
+};
+
+static struct memarea memarea_empty = {
+	.refcount = 1,
+};
+
+#undef memarea_init
+struct memarea *
+memarea_init(const void *data, size_t size,
+	     memarea_free_callback_t *callback, void *context)
+{
+	struct memarea *area;
+
+	i_assert(callback != NULL);
+
+	area = i_new(struct memarea, 1);
+	area->data = data;
+	area->size = size;
+	area->callback = callback;
+	area->context = context;
+	area->refcount = 1;
+	return area;
+}
+
+struct memarea *memarea_init_empty(void)
+{
+	i_assert(memarea_empty.refcount > 0);
+	memarea_empty.refcount++;
+	return &memarea_empty;
+}
+
+void memarea_ref(struct memarea *area)
+{
+	i_assert(area->refcount > 0);
+	area->refcount++;
+}
+
+void memarea_unref(struct memarea **_area)
+{
+	struct memarea *area = *_area;
+
+	*_area = NULL;
+	i_assert(area->refcount > 0);
+
+	if (--area->refcount > 0)
+		return;
+	i_assert(area != &memarea_empty);
+	area->callback(area->context);
+	i_free(area);
+}
+
+void memarea_free_without_callback(struct memarea **_area)
+{
+	struct memarea *area = *_area;
+
+	*_area = NULL;
+	i_assert(memarea_get_refcount(area) == 1);
+	i_free(area);
+}
+
+unsigned int memarea_get_refcount(struct memarea *area)
+{
+	i_assert(area->refcount > 0);
+	return area->refcount;
+}
+
+const void *memarea_get(struct memarea *area, size_t *size_r)
+{
+	*size_r = area->size;
+	return area->data;
+}
+
+size_t memarea_get_size(struct memarea *area)
+{
+	return area->size;
+}
+
+void memarea_free_callback_noop(void *context ATTR_UNUSED)
+{
+}