From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: [PATCH 03/14] strutil: add skip_prefix_icase Date: Tue, 29 Dec 2015 02:22:04 -0500 Message-ID: <20151229072204.GC8842@sigill.intra.peff.net> References: <20151229071847.GA8726@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Tue Dec 29 08:22:14 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aDobk-0000AM-Nx for gcvg-git-2@plane.gmane.org; Tue, 29 Dec 2015 08:22:13 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753189AbbL2HWI (ORCPT ); Tue, 29 Dec 2015 02:22:08 -0500 Received: from cloud.peff.net ([50.56.180.127]:46616 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753140AbbL2HWH (ORCPT ); Tue, 29 Dec 2015 02:22:07 -0500 Received: (qmail 17798 invoked by uid 102); 29 Dec 2015 07:22:07 -0000 Received: from Unknown (HELO peff.net) (10.0.1.1) by cloud.peff.net (qpsmtpd/0.84) with SMTP; Tue, 29 Dec 2015 01:22:07 -0600 Received: (qmail 19819 invoked by uid 107); 29 Dec 2015 07:22:19 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.84) with SMTP; Tue, 29 Dec 2015 02:22:19 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 29 Dec 2015 02:22:04 -0500 Content-Disposition: inline In-Reply-To: <20151229071847.GA8726@sigill.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Some sites that otherwise would use skip_prefix cannot do so, because it has no way to do case-insensitive comparisons. Such sites usually get around this by using strncasecmp, at the cost of having to use magic numbers. We can help them by providing a case-insensitive version of skip_prefix. Unfortunately, we don't share any code with the original skip_prefix. Since this is performance-sensitive code, we would not want to introduce an extra "do we are about case?" conditional into the middle of the loop. We could instead use macros or another technique to generate the almost-identical implementations, but the function simply isn't long enough to merit that confusing boilerplate. To show off the new function, we convert a simple case in log's add_header function. Signed-off-by: Jeff King --- builtin/log.c | 8 ++++---- strutil.h | 15 +++++++++++++++ 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/builtin/log.c b/builtin/log.c index 76823e6..44c6b26 100644 --- a/builtin/log.c +++ b/builtin/log.c @@ -677,10 +677,10 @@ static void add_header(const char *value) struct string_list_item *item; size_t len; - if (!strncasecmp(value, "to: ", 4)) - item = string_list_append(&extra_to, value + 4); - else if (!strncasecmp(value, "cc: ", 4)) - item = string_list_append(&extra_cc, value + 4); + if (skip_prefix_icase(value, "to: ", &value)) + item = string_list_append(&extra_to, value); + else if (skip_prefix_icase(value, "cc: ", &value)) + item = string_list_append(&extra_cc, value); else item = string_list_append(&extra_hdr, value); diff --git a/strutil.h b/strutil.h index 4fa2071..bb4c02d 100644 --- a/strutil.h +++ b/strutil.h @@ -32,6 +32,21 @@ static inline int skip_prefix(const char *str, const char *prefix, } /* + * Identical to skip_prefix, but compare characters case-insensitively. + */ +static inline int skip_prefix_icase(const char *str, const char *prefix, + const char **out) +{ + do { + if (!*prefix) { + *out = str; + return 1; + } + } while (tolower(*str++) == tolower(*prefix++)); + return 0; +} + +/* * If buf ends with suffix, return 1 and subtract the length of the suffix * from *len. Otherwise, return 0 and leave *len untouched. */ -- 2.7.0.rc3.367.g09631da