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bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA af
From: |
Norihiro Tanaka |
Subject: |
bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset |
Date: |
Tue, 29 Apr 2014 21:03:05 +0900 |
The previous version of 2nd patch wasn't so better still, because it was
slow for below in order that it never fills beg == prev_beg.
$ yes 'abcdabc
jjjjjjj' | head -50000000 >k
$ env LC_ALL=C time -p src/grep abcd.bd k
Accordingly, I have fixed it. It works below if dfafast is true.
- If `beg - prev_beg' is small, overhead by calls of KWset and DFA is
high. So use constant 64 as minimum shift of the `end' pointer.
- If ratio of `match - beg' to `beg - prev_beg' is large, KWset isn't
effective. So consider it.
As far as I have tested, It improves the performance of the worst cases
with little slowdown to others.
Thanks,
Norihiro
patch.txt
Description: Text document
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Norihiro Tanaka, 2014/04/26
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Paul Eggert, 2014/04/26
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Norihiro Tanaka, 2014/04/27
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Norihiro Tanaka, 2014/04/27
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Paul Eggert, 2014/04/28
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Norihiro Tanaka, 2014/04/28
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset,
Norihiro Tanaka <=
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Paul Eggert, 2014/04/30
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Norihiro Tanaka, 2014/04/30
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Paul Eggert, 2014/04/30
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Norihiro Tanaka, 2014/04/30
- bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset, Paul Eggert, 2014/04/30