From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16609 invoked by alias); 28 Sep 2010 01:29:09 -0000 Received: (qmail 16591 invoked by uid 9447); 28 Sep 2010 01:29:08 -0000 Date: Tue, 28 Sep 2010 01:29:00 -0000 Message-ID: <20100928012908.16589.qmail@sourceware.org> From: agk@sourceware.org To: lvm-devel@redhat.com, lvm2-cvs@sourceware.org Subject: LVM2 ./WHATS_NEW lib/misc/lvm-string.c Mailing-List: contact lvm2-cvs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: lvm2-cvs-owner@sourceware.org X-SW-Source: 2010-09/txt/msg00015.txt.bz2 CVSROOT: /cvs/lvm2 Module name: LVM2 Changes by: agk@sourceware.org 2010-09-28 01:29:07 Modified files: . : WHATS_NEW lib/misc : lvm-string.c Log message: Speed up unquoting of quoted double quotes and backslashes. Patches: http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.1737&r2=1.1738 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/misc/lvm-string.c.diff?cvsroot=lvm2&r1=1.22&r2=1.23 --- LVM2/WHATS_NEW 2010/09/27 19:09:34 1.1737 +++ LVM2/WHATS_NEW 2010/09/28 01:29:06 1.1738 @@ -1,5 +1,6 @@ Version 2.02.75 - ===================================== + Speed up unquoting of quoted double quotes and backslashes. Speed up CRC32 calculations by using a larger lookup table. Version 2.02.74 - 24th September 2010 --- LVM2/lib/misc/lvm-string.c 2010/09/23 12:02:34 1.22 +++ LVM2/lib/misc/lvm-string.c 2010/09/28 01:29:07 1.23 @@ -108,33 +108,64 @@ } } +static void _unquote_one_character(char *src, const char orig_char, + const char quote_char) +{ + char *out; + char s, n; + + /* Optimise for the common case where no changes are needed. */ + while ((s = *src++)) { + if (s == quote_char && + ((n = *src) == orig_char || n == quote_char)) { + out = src++; + *(out - 1) = n; + + while ((s = *src++)) { + if (s == quote_char && + ((n = *src) == orig_char || n == quote_char)) { + s = n; + src++; + } + *out = s; + out++; + } + + *out = '\0'; + return; + } + } +} + /* * Unquote each character given in orig_char array and unquote quote_char - * as well. The array ends up with '\0' character. Also save the first - * occurence of each character from orig_char that was found unquoted in - * arr_substr_first_unquoted array. This way we can process several - * characters in one go. + * as well. Also save the first occurrence of each character from orig_char + * that was found unquoted in arr_substr_first_unquoted array. This way we can + * process several characters in one go. */ -static void _unquote_characters(char *src, const int orig_chars[], - const int quote_char, +static void _unquote_characters(char *src, const char *orig_chars, + const int num_orig_chars, + const char quote_char, char *arr_substr_first_unquoted[]) { char *out = src; - int c; - int i; + char c, s, n; + unsigned i; - while (*src) { - for (i = 0; (c = orig_chars[i]); i++) { - if (*src == quote_char && - (*(src + 1) == c || *(src + 1) == quote_char)) { + while ((s = *src++)) { + for (i = 0; i < num_orig_chars; i++) { + c = orig_chars[i]; + if (s == quote_char && + ((n = *src) == c || n == quote_char)) { + s = n; src++; break; } - else if (arr_substr_first_unquoted && (*src == c) && - !arr_substr_first_unquoted[i]) + if (arr_substr_first_unquoted && (s == c) && + !arr_substr_first_unquoted[i]) arr_substr_first_unquoted[i] = out; - } - *out++ = *src++; + }; + *out++ = s; } *out = '\0'; @@ -229,9 +260,7 @@ */ void unescape_double_quotes(char *src) { - const int orig_chars[] = {'\"', '\0'}; - - _unquote_characters(src, orig_chars, '\\', NULL); + _unquote_one_character(src, '\"', '\\'); } /* @@ -244,10 +273,10 @@ char **substr_first_unquoted_colon, char **substr_first_unquoted_at_sign) { - const int orig_chars[] = {':', '@', '\0'}; + const char *orig_chars = ":@"; char *arr_substr_first_unquoted[] = {NULL, NULL, NULL}; - _unquote_characters(src, orig_chars, '\\', arr_substr_first_unquoted); + _unquote_characters(src, orig_chars, 2, '\\', arr_substr_first_unquoted); if (substr_first_unquoted_colon) *substr_first_unquoted_colon = arr_substr_first_unquoted[0];