From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56492) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZyNXF-0003N0-Jj for qemu-devel@nongnu.org; Mon, 16 Nov 2015 12:25:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZyNXA-0000PX-Lc for qemu-devel@nongnu.org; Mon, 16 Nov 2015 12:25:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52751) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZyNXA-0000Oy-FJ for qemu-devel@nongnu.org; Mon, 16 Nov 2015 12:25:40 -0500 From: Gerd Hoffmann Date: Mon, 16 Nov 2015 18:25:16 +0100 Message-Id: <1447694735-3420-2-git-send-email-kraxel@redhat.com> In-Reply-To: <1447694735-3420-1-git-send-email-kraxel@redhat.com> References: <1447694735-3420-1-git-send-email-kraxel@redhat.com> Subject: [Qemu-devel] [PULL 01/20] buffer: make the Buffer capacity increase in powers of two List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Lieven , Gerd Hoffmann From: Peter Lieven This makes sure the number of reallocs is in O(log N). Signed-off-by: Peter Lieven Reviewed-by: Daniel P. Berrange Signed-off-by: Gerd Hoffmann Message-id: 1446203414-4013-2-git-send-email-kraxel@redhat.com [ rebased to util/buffer.c ] Signed-off-by: Gerd Hoffmann --- util/buffer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/util/buffer.c b/util/buffer.c index cedd055..7ddd693 100644 --- a/util/buffer.c +++ b/util/buffer.c @@ -20,10 +20,13 @@ #include "qemu/buffer.h" +#define BUFFER_MIN_INIT_SIZE 4096 + void buffer_reserve(Buffer *buffer, size_t len) { if ((buffer->capacity - buffer->offset) < len) { - buffer->capacity += (len + 1024); + buffer->capacity = pow2ceil(buffer->offset + len); + buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE); buffer->buffer = g_realloc(buffer->buffer, buffer->capacity); } } -- 1.8.3.1