From patchwork Sun Apr 2 14:49:09 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Steven X-Patchwork-Id: 3242 Delivered-To: ffmpegpatchwork@gmail.com Received: by 10.103.44.195 with SMTP id s186csp2831164vss; Sun, 2 Apr 2017 07:49:38 -0700 (PDT) X-Received: by 10.28.148.195 with SMTP id w186mr5910002wmd.35.1491144578447; Sun, 02 Apr 2017 07:49:38 -0700 (PDT) Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id s11si16216888wra.190.2017.04.02.07.49.37; Sun, 02 Apr 2017 07:49:38 -0700 (PDT) Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Authentication-Results: mx.google.com; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 1A32B6883DE; Sun, 2 Apr 2017 17:49:33 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from smtpproxy19.qq.com (smtpproxy19.qq.com [184.105.206.84]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 9FCFB688380 for ; Sun, 2 Apr 2017 17:49:23 +0300 (EEST) X-QQ-mid: bizesmtp2t1491144558ts02v5o9o Received: from localhost (unknown [221.222.200.46]) by esmtp4.qq.com (ESMTP) with id ; Sun, 02 Apr 2017 22:49:17 +0800 (CST) X-QQ-SSF: 01100000002000F0FF30000A0000000 X-QQ-FEAT: DW7AxydIg/vRjBWKgJEQtrdw0BMWF+e/zollQgdRGh3UT/qEsTZB9gq0L1oTQ LtR4TErPTcPKBaQPwpytiuo5c3Cx00xJT2Z257pg24/vNA2fSAsHb2Ltj95TQxO1YaYw7pm RuFkEigu4R/gRGgIMepBNXeOPD5xb+G3nZ0wiVRZYlMJdO7SUATlML2ufP+gg5qYGTnPlJj kXYwM9yFBAdDQx5+DbzjTKBqjAAUxb1osjkf2MgA4cE9QthXhEHn5BMdrJ7aKSQt4XfX8aL Muiw== X-QQ-GoodBg: 0 From: Steven Liu To: ffmpeg-devel@ffmpeg.org Date: Sun, 2 Apr 2017 22:49:09 +0800 Message-Id: <20170402144909.51374-1-lq@chinaffmpeg.org> X-Mailer: git-send-email 2.11.0 (Apple Git-81) X-QQ-SENDSIZE: 520 X-QQ-Bgrelay: 1 Subject: [FFmpeg-devel] [PATCH] avutil/avstring: improve av_strreplace implement X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Cc: Steven Liu MIME-Version: 1.0 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Use AVBprint to implementing av_strreplace Signed-off-by: Steven Liu --- libavutil/avstring.c | 74 ++++++---------------------------------------------- 1 file changed, 8 insertions(+), 66 deletions(-) diff --git a/libavutil/avstring.c b/libavutil/avstring.c index 52e6e6cd13..55f3bee94c 100644 --- a/libavutil/avstring.c +++ b/libavutil/avstring.c @@ -233,78 +233,20 @@ int av_strncasecmp(const char *a, const char *b, size_t n) char *av_strreplace(const char *str, const char *from, const char *to) { - /* Adjust each of the below values to suit your needs. */ - /* Increment positions cache size initially by this number. */ - size_t cache_sz_inc = 16; - /* Thereafter, each time capacity needs to be increased, - * multiply the increment by this factor. */ - const size_t cache_sz_inc_factor = 3; - /* But never increment capacity by more than this number. */ - const size_t cache_sz_inc_max = 1048576; - - char *pret, *ret = NULL; + char *ret = NULL; const char *pstr2, *pstr = str; - size_t i, count = 0; - uintptr_t *pos_cache_tmp, *pos_cache = NULL; - size_t cache_sz = 0; - size_t cpylen, orglen, retlen, tolen, fromlen = strlen(from); + size_t tolen = strlen(to), fromlen = strlen(from); + AVBPrint pbuf; - /* Find all matches and cache their positions. */ + av_bprint_init(&pbuf, 1, AV_BPRINT_SIZE_UNLIMITED); while ((pstr2 = av_stristr(pstr, from))) { - count++; - /* Increase the cache size when necessary. */ - if (cache_sz < count) { - cache_sz += cache_sz_inc; - pos_cache_tmp = av_realloc(pos_cache, sizeof(*pos_cache) * cache_sz); - if (!pos_cache_tmp) { - goto end_strreplace; - } else pos_cache = pos_cache_tmp; - cache_sz_inc *= cache_sz_inc_factor; - if (cache_sz_inc > cache_sz_inc_max) { - cache_sz_inc = cache_sz_inc_max; - } - } - - pos_cache[count-1] = pstr2 - str; + av_bprint_append_data(&pbuf, pstr, pstr2 - pstr); pstr = pstr2 + fromlen; + av_bprint_append_data(&pbuf, to, tolen); } - orglen = pstr - str + strlen(pstr); - /* Allocate memory for the post-replacement string. */ - if (count > 0) { - tolen = strlen(to); - retlen = orglen + (tolen - fromlen) * count; - } else { - retlen = orglen; - } - ret = av_malloc(retlen + 1); - if (!ret) { - goto end_strreplace; - } - - if (!count) { - /* If no matches, then just duplicate the string. */ - av_strlcpy(ret, str, retlen + 1); - } else { - /* Otherwise, duplicate the string whilst performing - * the replacements using the position cache. */ - pret = ret; - memcpy(pret, str, pos_cache[0]); - pret += pos_cache[0]; - for (i = 0; i < count; i++) { - memcpy(pret, to, tolen); - pret += tolen; - pstr = str + pos_cache[i] + fromlen; - cpylen = (i == count-1 ? orglen : pos_cache[i+1]) - pos_cache[i] - fromlen; - memcpy(pret, pstr, cpylen); - pret += cpylen; - } - ret[retlen] = '\0'; - } + av_bprint_append_data(&pbuf, pstr, strlen(pstr)); + av_bprint_finalize(&pbuf, &ret); -end_strreplace: - /* Free the cache and return the post-replacement string, - * which will be NULL in the event of an error. */ - av_free(pos_cache); return ret; }