From: Junio C Hamano <gitster@pobox•com>
To: "Nguyễn Thái Ngọc Duy" <pclouds@gmail•com>
Cc: git@vger•kernel.org
Subject: Re: [PATCH 01/12] Make starts_with() a wrapper of skip_prefix()
Date: Wed, 18 Dec 2013 10:16:17 -0800 [thread overview]
Message-ID: <xmqqppouhvny.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <xmqqa9fyjbg0.fsf@gitster.dls.corp.google.com> (Junio C. Hamano's message of "Wed, 18 Dec 2013 09:50:07 -0800")
Junio C Hamano <gitster@pobox•com> writes:
> Nguyễn Thái Ngọc Duy <pclouds@gmail•com> writes:
>
>> starts_with() started out as a copy of prefixcmp(). But if we don't
>> care about the sorting order, the logic looks closer to
>> skip_prefix(). This looks like a good thing to do.
>>
>> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail•com>
>> ---
>
> Sure, but the implementation of skip_prefix() scans the prefix
> string twice, while prefixcmp() aka starts_with() does it only once.
>
> I'd expect a later step in this series would rectify this micro
> regression in the performance, though ;-)
... and I did not see one, but it would be trivial on top.
git-compat-util.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/git-compat-util.h b/git-compat-util.h
index b72a80d..59265af 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -356,8 +356,11 @@ extern int suffixcmp(const char *str, const char *suffix);
static inline const char *skip_prefix_defval(const char *str, const char *prefix, const char *defval)
{
- size_t len = strlen(prefix);
- return strncmp(str, prefix, len) ? defval : str + len;
+ for ( ; ; str++, prefix++)
+ if (!*prefix)
+ return str;
+ else if (*str != *prefix)
+ return defval;
}
static inline const char *skip_prefix(const char *str, const char *prefix)
next prev parent reply other threads:[~2013-12-18 18:16 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-18 14:53 [PATCH 00/12] Hard coded string length cleanup Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 01/12] Make starts_with() a wrapper of skip_prefix() Nguyễn Thái Ngọc Duy
2013-12-18 17:50 ` Junio C Hamano
2013-12-18 18:16 ` Junio C Hamano [this message]
2013-12-18 14:53 ` [PATCH 02/12] Convert starts_with() to skip_prefix() for option parsing Nguyễn Thái Ngọc Duy
2013-12-20 6:51 ` Johannes Sixt
2013-12-20 7:04 ` Jeff King
2013-12-20 8:46 ` Christian Couder
2013-12-20 10:43 ` René Scharfe
2013-12-20 21:31 ` Junio C Hamano
2013-12-21 4:44 ` Duy Nguyen
2013-12-26 19:27 ` Junio C Hamano
2013-12-28 9:54 ` Jeff King
2013-12-18 14:53 ` [PATCH 03/12] Add and use skip_prefix_defval() Nguyễn Thái Ngọc Duy
2013-12-18 16:27 ` Kent R. Spillner
2013-12-18 17:51 ` Junio C Hamano
2013-12-18 14:53 ` [PATCH 04/12] Replace some use of starts_with() with skip_prefix() Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 05/12] Convert a lot of starts_with() to skip_prefix() Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 06/12] fetch.c: replace some use of starts_with() with skip_prefix() Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 07/12] connect.c: " Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 08/12] refs.c: " Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 09/12] diff.c: reduce code duplication in --stat-xxx parsing Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 10/12] environment.c: replace starts_with() in strip_namespace() with skip_prefix() Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 11/12] diff.c: convert diff_scoreopt_parse to use skip_prefix() Nguyễn Thái Ngọc Duy
2013-12-18 14:53 ` [PATCH 12/12] refs.c: use skip_prefix() in prune_ref() Nguyễn Thái Ngọc Duy
2013-12-18 18:06 ` [PATCH 00/12] Hard coded string length cleanup Junio C Hamano
2013-12-19 23:32 ` René Scharfe
2013-12-19 23:50 ` Duy Nguyen
2013-12-20 1:06 ` René Scharfe
2013-12-20 2:29 ` Duy Nguyen
2013-12-20 16:53 ` Junio C Hamano
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