GNU bug report logs - #16893
[PATCH] Avoid matching line-by-line for case-insensitive with grep

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From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: Paul Eggert <eggert <at> cs.ucla.edu>
Cc: tracker <at> debbugs.gnu.org
Subject: bug#16893: closed ([PATCH] Avoid matching line-by-line for
 case-insensitive with grep)
Date: Sat, 01 Mar 2014 06:27:02 +0000

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Your message dated Fri, 28 Feb 2014 22:26:36 -0800
with message-id <53117D9C.6030309 <at> cs.ucla.edu>
and subject line Re: bug#16893: [PATCH] Avoid matching line-by-line for case-insensitive with grep
has caused the debbugs.gnu.org bug report #16893,
regarding [PATCH] Avoid matching line-by-line for case-insensitive with grep
to be marked as done.

(If you believe you have received this mail in error, please contact
help-debbugs <at> gnu.org.)


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16893: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=16893
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From: Norihiro Tanaka <noritnk <at> kcn.ne.jp>
To: submit <at> debbugs.gnu.org
Subject: [PATCH] Avoid matching line-by-line for case-insensitive with grep
Date: Fri, 28 Feb 2014 01:02:40 +0900

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Now grep and awk matchers doesn't waste buffer in case-sensisitive matching.
So I think that we can avoid line-by-line matching for them.

It enable to speed up case-sensitive matching with grep or awk matcher
without trivial_case_ignore as fast as when with it.

In bug#16232:
> The following times 2.16, 2.17 and 2.17+patch two ways:
> 
> $ yes jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj | head -10000000 > k
> $ for i in 16 17 18; do echo $i; env LC_ALL=en_US.UTF-8 time
> /p/p/grep-2.$i/bin/grep -i foobar k; done
> 16
>        15.96 real        14.57 user         0.12 sys
> 17
>         1.13 real         1.07 user         0.06 sys
> 18
>         1.96 real         1.89 user         0.06 sys
> 
> The above search takes more than 70% longer with the proposed patch.

Therefore, I think 30% slow-down is caused by the line-by-line matching
for them.

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From: Paul Eggert <eggert <at> cs.ucla.edu>
To: 16893-done <at> debbugs.gnu.org
Subject: Re: bug#16893: [PATCH] Avoid matching line-by-line for
 case-insensitive with grep
Date: Fri, 28 Feb 2014 22:26:36 -0800

Thanks, I applied that.  It simplifies another patch I've been meaning 
to put in, yay!

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