From 82282810cd1209496183ccadfdaf0dba7d7621e8 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 7 Nov 2014 17:18:13 +0100 Subject: [PATCH 26/41] dump: simplify get_len_buf_out() Message-id: <1415380693-16593-27-git-send-email-lersek@redhat.com> Patchwork-id: 62209 O-Subject: [RHEL-7.1 qemu-kvm PATCH 26/26] dump: simplify get_len_buf_out() Bugzilla: 1157798 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Luiz Capitulino RH-Acked-by: dgibson 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 Reviewed-by: Paolo Bonzini Signed-off-by: Luiz Capitulino (cherry picked from commit b87ef3518b2eeb9a57ee0d06d7e82a07ab5e4ffd) Signed-off-by: Miroslav Rezanina --- dump.c | 46 ++++++++++++++++------------------------------ 1 file changed, 16 insertions(+), 30 deletions(-) diff --git a/dump.c b/dump.c index f980354..e9bd237 100644 --- a/dump.c +++ b/dump.c @@ -1226,35 +1226,24 @@ static void free_data_cache(DataCache *data_cache) 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; - - /* 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 + switch (flag_compress) { + case DUMP_DH_COMPRESSED_ZLIB: + return compressBound(page_size); + + 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; } /* @@ -1290,10 +1279,7 @@ static int write_dump_pages(DumpState *s) /* 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); -- 1.8.3.1