[Svnmerge] [PATCH] Bidirectional patch take 2

[Giovanni Bajo]

Blair Zajac <blair at orcaware.com> wrote:

>> Please run timing tests with and without the --bidirectional flags,
>> especially if you are using a repository that does not do
>> bidirectional merges.
>> The optimization in the patched svnmerge.py should show
>> almost no speed loss.
>>
>> If people cannot show a speed hit for enabling this feature by
>> default, I'll
>> plan on doing so.

$ echo $GCCREPO
svn+ssh://giovannibajo@gcc.gnu.org/svn/gcc

$ time svn log --quiet -r100000:110000 $GCCREPO/trunk 2>&1 >/dev/null
real    0m21.590s
user    0m0.188s
sys     0m0.044s

$ time svn log --quiet -r100000:110000 $GCCREPO/trunk 2>&1 >/dev/null
real    0m22.816s
user    0m0.192s
sys     0m0.040s

$ time svn log --quiet -r100000:110000 $GCCREPO/trunk 2>&1 >/dev/null
real    0m21.248s
user    0m0.180s
sys     0m0.092s



$ time svn log --verbose --quiet -r100000:110000 $GCCREPO/trunk 2>&1 >/dev/null
real    0m42.020s
user    0m0.688s
sys     0m0.108s

$ time svn log --verbose --quiet -r100000:110000 $GCCREPO/trunk 2>&1 >/dev/null
real    0m44.731s
user    0m0.652s
sys     0m0.088s

$ time svn log --verbose --quiet -r100000:110000 $GCCREPO/trunk 2>&1 >/dev/null
real    0m52.781s
user    0m0.668s
sys     0m0.108s


So, logging is basically twice as slower. Even if the merge time dominates, I'm
unsure whether we want to add this gratuitous overhead for users not doing
bidirectional merges.

I'll review the patch later today, thanks!

Giovanni Bajo