Re: [PATCH 01/12] Make starts_with() a wrapper of skip_prefix()
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Dec 18, 2013, 17:50 UTC
- Message-ID
- <xmqqa9fyjbg0.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <1387378437-20646-2-git-send-email-pclouds@gmail.com>
Nguyễn Thái Ngọc Duy <pclouds@gmail.com> writes:
Show 6 quoted lines
> 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 ;-)
Show 48 quoted lines
> git-compat-util.h | 6 +++++-
> strbuf.c | 9 ---------
> 2 files changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/git-compat-util.h b/git-compat-util.h
> index b73916b..84f1078 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -350,7 +350,6 @@ extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_lis
> extern void set_error_routine(void (*routine)(const char *err, va_list params));
> extern void set_die_is_recursing_routine(int (*routine)(void));
>
> -extern int starts_with(const char *str, const char *prefix);
> extern int prefixcmp(const char *str, const char *prefix);
> extern int ends_with(const char *str, const char *suffix);
> extern int suffixcmp(const char *str, const char *suffix);
> @@ -361,6 +360,11 @@ static inline const char *skip_prefix(const char *str, const char *prefix)
> return strncmp(str, prefix, len) ? NULL : str + len;
> }
>
> +static inline int starts_with(const char *str, const char *prefix)
> +{
> + return skip_prefix(str, prefix) != NULL;
> +}
> +
> #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
>
> #ifndef PROT_READ
> diff --git a/strbuf.c b/strbuf.c
> index 83caf4a..bd4c0d8 100644
> --- a/strbuf.c
> +++ b/strbuf.c
> @@ -1,15 +1,6 @@
> #include "cache.h"
> #include "refs.h"
>
> -int starts_with(const char *str, const char *prefix)
> -{
> - for (; ; str++, prefix++)
> - if (!*prefix)
> - return 1;
> - else if (*str != *prefix)
> - return 0;
> -}
> -
> int prefixcmp(const char *str, const char *prefix)
> {
> for (; ; str++, prefix++)