Add BLI_buffer, an alternative to BLI_array

BLI_buffer is a dynamic homogeneous array similar to BLI_array, but it
allocates a structure that can be passed around making it possible to
resize the array outside the function it was declared in.

1 files changed, 58 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/buffer.c b/source/blender/blenlib/intern/buffer.c
new file mode 100644
index 00000000000..98151c8eebf
--- /dev/null
+++ b/source/blender/blenlib/intern/buffer.c
@@ -0,0 +1,58 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_buffer.h"
+#include "BLI_utildefines.h"
+
+#include <string.h>
+
+void BLI_buffer_resize(BLI_Buffer *buffer, int new_count)
+{
+	if (new_count > buffer->alloc_count) {
+		if (buffer->using_static) {
+			void *orig = buffer->data;
+			buffer->data = MEM_callocN(buffer->elem_size * new_count,
+									   "BLI_Buffer.data");
+			memcpy(buffer->data, orig, buffer->elem_size * buffer->count);
+			buffer->alloc_count = new_count;
+			buffer->using_static = FALSE;
+		}
+		else {
+			if (new_count < buffer->alloc_count * 2)
+				buffer->alloc_count *= 2;
+			else
+				buffer->alloc_count = new_count;
+			buffer->data = MEM_reallocN(buffer->data,
+										(buffer->elem_size *
+										 buffer->alloc_count));
+		}
+	}
+
+	buffer->count = new_count;
+}
+
+void BLI_buffer_free(BLI_Buffer *buffer)
+{
+	if (!buffer->using_static)
+		MEM_freeN(buffer->data);
+	memset(buffer, 0, sizeof(*buffer));
+}