1 files changed, 44 insertions, 0 deletions
diff --git a/libmisc/high_water_alloc.c b/libmisc/high_water_alloc.c
new file mode 100644
index 0000000..c127dc1
--- /dev/null
+++ b/libmisc/high_water_alloc.c
@@ -0,0 +1,44 @@
+/*
+  File: high_water_alloc.c
+
+  Copyright (C) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
+
+  This program 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 2.1 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 Lesser General Public
+  License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "misc.h"
+
+int high_water_alloc(void **buf, size_t *bufsize, size_t newsize)
+{
+#define CHUNK_SIZE	256
+	/*
+	 * Goal here is to avoid unnecessary memory allocations by
+	 * using static buffers which only grow when necessary.
+	 * Size is increased in fixed size chunks (CHUNK_SIZE).
+	 */
+	if (*bufsize < newsize) {
+		void *newbuf;
+
+		newsize = (newsize + CHUNK_SIZE-1) & ~(CHUNK_SIZE-1);
+		newbuf = realloc(*buf, newsize);
+		if (!newbuf)
+			return 1;
+
+		*buf = newbuf;
+		*bufsize = newsize;
+	}
+	return 0;
+}