From patchwork Tue May 20 11:42:53 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laszlo Ersek X-Patchwork-Id: 350659 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id B5A2C14007F for ; Tue, 20 May 2014 21:43:40 +1000 (EST) Received: from localhost ([::1]:52651 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmiSI-0006fZ-4K for incoming@patchwork.ozlabs.org; Tue, 20 May 2014 07:43:38 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52383) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmiRq-00061n-K1 for qemu-devel@nongnu.org; Tue, 20 May 2014 07:43:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WmiRk-0000bg-Qj for qemu-devel@nongnu.org; Tue, 20 May 2014 07:43:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58650) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmiRk-0000bc-JI for qemu-devel@nongnu.org; Tue, 20 May 2014 07:43:04 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4KBgutB031107 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 20 May 2014 07:42:57 -0400 Received: from lacos-laptop-7.usersys.redhat.com (ovpn-116-64.ams2.redhat.com [10.36.116.64]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s4KBgrjU013601; Tue, 20 May 2014 07:42:54 -0400 From: Laszlo Ersek To: qemu-devel@nongnu.org, Luiz Capitulino , Qiao Nuohan , Paolo Bonzini , Ekaterina Tumanova , Christian Borntraeger , "Aneesh Kumar K.V" Date: Tue, 20 May 2014 13:42:53 +0200 Message-Id: <1400586173-6481-1-git-send-email-lersek@redhat.com> In-Reply-To: <1400585987-6285-1-git-send-email-lersek@redhat.com> References: <1400585987-6285-1-git-send-email-lersek@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 7/7] dump: simplify get_len_buf_out() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org We can (and should) rely on the fact that s->flag_compress is exactly one of DUMP_DH_COMPRESSED_ZLIB, DUMP_DH_COMPRESSED_LZO, and DUMP_DH_COMPRESSED_SNAPPY. This is ensured by the QMP schema and dump_init() in combination. Suggested-by: Paolo Bonzini Signed-off-by: Laszlo Ersek --- dump.c | 44 +++++++++++++++----------------------------- 1 file changed, 15 insertions(+), 29 deletions(-) diff --git a/dump.c b/dump.c index b87045e..97d2c8d 100644 --- a/dump.c +++ b/dump.c @@ -1218,39 +1218,28 @@ static void free_data_cache(DataCache *data_cache) g_free(data_cache->buf); } static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress) { - size_t len_buf_out_zlib, len_buf_out_lzo, len_buf_out_snappy; - size_t len_buf_out; + switch (flag_compress) { + case DUMP_DH_COMPRESSED_ZLIB: + return compressBound(page_size); - /* init buf_out */ - len_buf_out_zlib = len_buf_out_lzo = len_buf_out_snappy = 0; - - /* buf size for zlib */ - len_buf_out_zlib = compressBound(page_size); - - /* buf size for lzo */ -#ifdef CONFIG_LZO - /* - * LZO will expand incompressible data by a little amount. please check the - * following URL to see the expansion calculation: - * http://www.oberhumer.com/opensource/lzo/lzofaq.php - */ - len_buf_out_lzo = page_size + page_size / 16 + 64 + 3; -#endif + case DUMP_DH_COMPRESSED_LZO: + /* + * LZO will expand incompressible data by a little amount. Please check + * the following URL to see the expansion calculation: + * http://www.oberhumer.com/opensource/lzo/lzofaq.php + */ + return page_size + page_size / 16 + 64 + 3; #ifdef CONFIG_SNAPPY - /* buf size for snappy */ - len_buf_out_snappy = snappy_max_compressed_length(page_size); + case DUMP_DH_COMPRESSED_SNAPPY: + return snappy_max_compressed_length(page_size); #endif - - /* get the biggest that can store all kinds of compressed page */ - len_buf_out = MAX(len_buf_out_zlib, - MAX(len_buf_out_lzo, len_buf_out_snappy)); - - return len_buf_out; + } + return 0; } /* * check if the page is all 0 */ @@ -1282,14 +1271,11 @@ static int write_dump_pages(DumpState *s) prepare_data_cache(&page_desc, s, offset_desc); prepare_data_cache(&page_data, s, offset_data); /* prepare buffer to store compressed data */ len_buf_out = get_len_buf_out(TARGET_PAGE_SIZE, s->flag_compress); - if (len_buf_out == 0) { - dump_error(s, "dump: failed to get length of output buffer.\n"); - goto out; - } + assert(len_buf_out != 0); #ifdef CONFIG_LZO wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS); #endif