[FFmpeg-devel,v3] avutil/avstring: improve av_strreplace implement

Message ID	20170402224444.57210-1-lq@chinaffmpeg.org
State	Accepted
Commit	44cd7502c739a97f9b37319f208e1bcc5b1899fd
Headers	show Delivered-To: ffmpegpatchwork@gmail.com 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; From: Steven Liu <lq@chinaffmpeg.org> To: ffmpeg-devel@ffmpeg.org Date: Mon, 3 Apr 2017 06:44:44 +0800 Message-Id: <20170402224444.57210-1-lq@chinaffmpeg.org> In-Reply-To: <alpine.LNX.2.00.1704022100380.19160@iq.passwd.hu> References: <alpine.LNX.2.00.1704022100380.19160@iq.passwd.hu> Subject: [FFmpeg-devel] [PATCH v3] avutil/avstring: improve av_strreplace implement Precedence: list Reply-To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> Cc: Steven Liu <lq@chinaffmpeg.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" <ffmpeg-devel-bounces@ffmpeg.org>

diff --git a/libavutil/avstring.c b/libavutil/avstring.c index 52e6e6cd13..f03dd25141 100644 --- a/libavutil/avstring.c +++ b/libavutil/avstring.c @@ -231,80 +231,26 @@ int av_strncasecmp(const char *a, const char *b, size_t n) return c1 - c2; } -char *av_strreplace(const char *str, const char *from, const char *to) +char *av_strireplace(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); + av_bprint_append_data(&pbuf, pstr, strlen(pstr)); + if (!av_bprint_is_complete(&pbuf)) { + av_bprint_finalize(&pbuf, NULL); } 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_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; } diff --git a/libavutil/avstring.h b/libavutil/avstring.h index 33be8bf484..04d2695640 100644 --- a/libavutil/avstring.h +++ b/libavutil/avstring.h @@ -270,7 +270,7 @@ int av_strncasecmp(const char *a, const char *b, size_t n); * Locale-independent strings replace. * @note This means only ASCII-range characters are replace */ -char *av_strreplace(const char *str, const char *from, const char *to); +char *av_strireplace(const char *str, const char *from, const char *to); /** * Thread safe basename. diff --git a/libavutil/tests/avstring.c b/libavutil/tests/avstring.c index 14bc7ffcea..887bd25a12 100644 --- a/libavutil/tests/avstring.c +++ b/libavutil/tests/avstring.c @@ -93,6 +93,22 @@ int main(void) TEST_STRNSTR(haystack, needle [2], strlen(haystack), NULL ); TEST_STRNSTR(haystack, strings[1], strlen(haystack), haystack ); + /*Testing av_strireplace()*/ + #define TEST_STRIREPLACE(haystack, needle, expected) \ + ptr = av_strireplace(haystack, needle, "instead"); \ + if (ptr == NULL) { \ + printf("error, received null pointer!\n"); \ + } else { \ + if (strcmp(ptr, expected) != 0) \ + printf( "expected: %s, received: %s\n", expected, ptr); \ + av_free(ptr); \ + } + + TEST_STRIREPLACE(haystack, needle [0], "Education consists mainly in what we have uninstead"); + TEST_STRIREPLACE(haystack, needle [1], "Education consists mainly in what we have instead"); + TEST_STRIREPLACE(haystack, needle [2], "Education consists mainly in what we have instead."); + TEST_STRIREPLACE(haystack, needle [1], "Education consists mainly in what we have instead"); + /*Testing av_d2str()*/ #define TEST_D2STR(value, expected) \ if((ptr = av_d2str(value)) == NULL){ \

[FFmpeg-devel,v3] avutil/avstring: improve av_strreplace implement

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