Re: [PATCH] svn-fast-time-from-cstring.patch

Isn't this a repost of your earlier patch? I thought we'd applied that one.

Brandon Ehle wrote:

> * subversion/libsvn_subr/time.c(svn_time_from_cstring):
> Unroll the sscanf when converting time from a string for
> better performance.
>
> Index: subversion/libsvn_subr/time.c
> ===================================================================
> --- subversion/libsvn_subr/time.c (revision 3971)
> +++ subversion/libsvn_subr/time.c (working copy)
> @@ -142,44 +142,53 @@
> return -1;
> }
>
> -
> svn_error_t *
> svn_time_from_cstring(apr_time_t *when, const char *data, apr_pool_t
> *pool)
> {
> apr_time_exp_t exploded_time;
> apr_status_t apr_err;
> char wday[4], month[4];
> + const char *c = data;
>
> - /* First try the new timestamp format. */
> - if (sscanf (data,
> - timestamp_format,
> - &exploded_time.tm_year,
> - &exploded_time.tm_mon,
> - &exploded_time.tm_mday,
> - &exploded_time.tm_hour,
> - &exploded_time.tm_min,
> - &exploded_time.tm_sec,
> - &exploded_time.tm_usec) == 7)
> - {
> - exploded_time.tm_year -= 1900;
> - exploded_time.tm_mon -= 1;
> - exploded_time.tm_wday = 0;
> - exploded_time.tm_yday = 0;
> - exploded_time.tm_isdst = 0;
> - exploded_time.tm_gmtoff = 0;
> - - apr_err = apr_implode_gmt (when, &exploded_time);
> - if(apr_err != APR_SUCCESS)
> - {
> - return svn_error_createf (SVN_ERR_BAD_DATE, apr_err, NULL,
> - "Date conversion failed.");
> - }
> - - return SVN_NO_ERROR;
> - }
> - /* Then try the compatibility option. */
> - else if (sscanf (data,
> - old_timestamp_format,
> + /* Open-code parsing of the new timestamp format, as this
> + is a hot path for reading the entries file.
> + + This format looks like:
> + "2001-08-31T04:24:14.966996Z" */
> + exploded_time.tm_year = strtoul(c, (char**)&c, 10);
> + if (*c++ != '-') goto fail;
> + exploded_time.tm_mon = strtoul(c, (char**)&c, 10);
> + if (*c++ != '-') goto fail;
> + exploded_time.tm_mday = strtoul(c, (char**)&c, 10);
> + if (*c++ != 'T') goto fail;
> + exploded_time.tm_hour = strtoul(c, (char**)&c, 10);
> + if (*c++ != ':') goto fail;
> + exploded_time.tm_min = strtoul(c, (char**)&c, 10);
> + if (*c++ != ':') goto fail;
> + exploded_time.tm_sec = strtoul(c, (char**)&c, 10);
> + if (*c++ != '.') goto fail;
> + exploded_time.tm_usec = strtoul(c, (char**)&c, 10);
> + if (*c++ != 'Z') goto fail;
> +
> + exploded_time.tm_year -= 1900;
> + exploded_time.tm_mon -= 1;
> + exploded_time.tm_wday = 0;
> + exploded_time.tm_yday = 0;
> + exploded_time.tm_isdst = 0;
> + exploded_time.tm_gmtoff = 0;
> +
> + apr_err = apr_implode_gmt(when, &exploded_time);
> + if (apr_err == APR_SUCCESS)
> + return SVN_NO_ERROR;
> +
> + return svn_error_createf(SVN_ERR_BAD_DATE, apr_err, NULL,
> + "Date conversion failed.");
> +
> +fail:
> + /* Try the compatibility option. This does not need to be fast,
> + as this format is no longer generated and the client will convert
> + an old-format entries file the first time it reads it. */
> + if (sscanf(data, old_timestamp_format,
> wday,
> &exploded_time.tm_mday,
> month,
>
>
>
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-- 
Brane Čibej   <brane_at_xbc.nu>   http://www.xbc.nu/brane/
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