On Sun, Dec 30, 2007 at 01:02:28PM +0000, Marco Costalba wrote:
> Subject: [PATCH] Certain codepaths (notably "git log --pretty=format...") use
>
> prefixcmp() extensively, with very short prefixes. In those cases,
> calling strlen() is a wasteful operation, so avoid it.
>
> Initial patch by Johannes Schindelin.
>
> Signed-off-by: Marco Costalba <mcostalba@xxxxxxxxx>
> ---
> git-compat-util.h | 11 ++++++++++-
> 1 files changed, 10 insertions(+), 1 deletions(-)
>
> diff --git a/git-compat-util.h b/git-compat-util.h
> index 79eb10e..843a8f5 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -398,7 +398,16 @@ static inline int sane_case(int x, int high)
>
> static inline int prefixcmp(const char *str, const char *prefix)
> {
> - return strncmp(str, prefix, strlen(prefix));
> + do {
> + if (*str != *prefix)
> + return *(unsigned const char *)prefix - *(unsigned const char *)str;
> +
> + if (!*(++prefix))
> + return 0;
> +
> + str++;
> +
> + } while (1);
This code doesn't work if prefix is "". You want something like:
for (; *prefix; prefix++, str++) {
if (*str != *prefix)
return *(unsigned const char *)prefix - *(unsigned const char *)str;
}
return 0;
--
·O· Pierre Habouzit
··O madcoder@xxxxxxxxxx
OOO http://www.madism.org
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