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Re: svn commit: r1483532 - in /subversion/trunk/subversion: include/ libsvn_client/ libsvn_fs_base/ libsvn_fs_fs/ libsvn_ra/ libsvn_ra_local/ libsvn_ra_svn/ libsvn_repos/ libsvn_subr/ libsvn_wc/ mod_dav_svn/ svndumpfilter/ svnmucc/ svnrdump/ svnserve/ svns...

From: Stefan Fuhrmann <stefan.fuhrmann_at_wandisco.com>
Date: Thu, 16 May 2013 23:40:33 +0200

On Thu, May 16, 2013 at 11:14 PM, Ivan Zhakov <ivan_at_visualsvn.com> wrote:

> On Thu, May 16, 2013 at 11:48 PM, <stefan2_at_apache.org> wrote:
> > Author: stefan2
> > Date: Thu May 16 19:48:47 2013
> > New Revision: 1483532
> >
> > URL: http://svn.apache.org/r1483532
> > Log:
> > We frequently use property name constants in conjunction with hash
> containers.
> > Provide new wrappers around apr_hash_get and apr_hash_set that accept
> such
> > string constants and statically determine their size. That minimizes the
> > hash access costs.
> >
> > Mass change hash get and set calls for SVN_PROP_* constants.
> >
> Hi Stefan,
>
> Is the performance gain costs code complexity? Please understand my
> correctly: it's great improve Subversion speed. I just don't like the
> idea getting code more complicated to win just several cycles.
>

It is not essential to use these wrappers in all places. I did that for
symmetry.
As for the complexity: The patch should not add any significant maintenance
costs - no extra parameters etc.

Not using the new wrappers doesn't break anything. Using them
inappropriately,
e.g. on a const char *, will break result in data not being found in the
hash
(keys would effectively be truncated to 4 or 8 bytes) or even a segfault in
all
uses of that code. So, these cases would caught early on.

-- Stefan^2.

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Received on 2013-05-16 23:41:06 CEST

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