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Re: [PATCH] import memmem() with linear complexity from Gnulib

From
Mike Hommey <mh@glandium.org>
Date
Feb 28, 2009, 22:44 UTC
Message-ID
<20090228224401.GA27262@glandium.org>
In-Reply-To
<1235848615.7043.30.camel@ubuntu.ubuntu-domain>
On Sat, Feb 28, 2009 at 08:16:55PM +0100, René Scharfe wrote:
Show 25 quoted lines
> Gnulib and glibc have gained a memmem() implementation using the Two-Way
> algorithm, which needs constant space and linear time.  Import it to
> compat/ in order to replace the simple quadratic implementation there.
> 
> memmem.c and str-two-way.h are copied verbatim from the repository at
> git://git.savannah.gnu.org/gnulib.git, with the following changes to
> memmem.c to make it fit into git's build environment:
> 
> 	21,23c21
> 	< #ifndef _LIBC
> 	< # include <config.h>
> 	< #endif
> 	---
> 	> #include "../git-compat-util.h"
> 	40c38
> 	< memmem (const void *haystack_start, size_t haystack_len,
> 	---
> 	> gitmemmem(const void *haystack_start, size_t haystack_len,
> 
> Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
> ---
>  Makefile             |    1 +
>  compat/memmem.c      |  103 +++++++++----
>  compat/str-two-way.h |  429 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 504 insertions(+), 29 deletions(-)
Seeing how much memmem is being used in the codebase, is it really worth?
Mike
Previous: René ScharfeNext: Jeff King
Message 14 of 23 in “Pickaxe search clean-up and optimization”
  1. 0/4 Pickaxe search clean-up and optimizationJunio C Hamano, Feb 26, 2009
  2. 1/4 diffcore-pickaxe: refactor diffcore_pickaxe()Junio C Hamano, Feb 26, 2009
  3. René ScharfeFeb 27, 2009
  4. 2/4 diffcore-pickaxe: micro-optimize has_match() functionJunio C Hamano, Feb 26, 2009
  5. 3/4 diffcore-pickaxe: further refactor count_match()Junio C Hamano, Feb 26, 2009
  6. Kjetil BarvikFeb 26, 2009
  7. René ScharfeFeb 28, 2009
  8. Junio C HamanoFeb 28, 2009
  9. Junio C HamanoFeb 28, 2009
  10. René ScharfeFeb 28, 2009
  11. Junio C HamanoFeb 28, 2009
  12. René ScharfeFeb 28, 2009
  13. import memmem() with linear complexity from GnulibRené Scharfe, Feb 28, 2009
  14. Mike HommeyFeb 28, 2009
  15. Jeff KingMar 1, 2009
  16. René ScharfeMar 1, 2009
  17. René ScharfeMar 1, 2009
  18. Junio C HamanoMar 1, 2009
  19. René ScharfeMar 1, 2009
  20. 4/4 diffcore-pickaxe: optimize by trimming common initial and trailing partsJunio C Hamano, Feb 26, 2009
  21. Junio C HamanoFeb 26, 2009
  22. 1/2 diffcore-pickaxe: use memmem()René Scharfe, Mar 2, 2009
  23. 2/2 optimize compat/ memmem()René Scharfe, Mar 2, 2009

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