Re: [viewvc-dev] Re: SVN directory log performance

Jens Peters wrote:
> Hi Mike
> 
>> So, there are a number of interactions here.
>>
>> First, even though Subversion has a notion of --limit for 'svn log'
>> queries
>> (and the equivalent for the repository APIs), the vclib interface doesn't
>> expose it, so ViewVC doesn't use it.
>>
>> Secondly, remember that the items on the log view can be sorted by things
>> other than revision number.  So, while we could use --limit for log views
>> showing revision-sorted (or unsorted, which is the same thing in
>> Subversion)
>> output, we couldn't use that optimization for any other sorting style.
>>
> 
> Ok, I completely forgot the sorting feature. For that you would indeed
> need to fetch all revisions first. But do you think its worth to keep
> the sorting feature? (Actually I have stripped it from my template,
> because I never used it). I think for doing advanced queries with
> filtering and sorting you can better refer to the commit database.

Yeah, I'm torn about the sorting thing.  It seems fine for CVS views, but
for Subversion I just don't think it makes much sense.  And removing it
allows us all sorts of performance benefits.

> For the implementation details, I can see that in svn_ra you use
> svn_client_log which supports limit in a never version, but in svn (I
> think nearly everyone uses that) its svn_repos_history which does not
> support limits :(, so changing that seems indeed not that easy.

Well, there are other tricks we could use even with svn_repos_history(),
like fetching data in revision blocks (of, say, page_size * 4 revisions).
We might overfetch, but only by a relatively small margin, and certainly
cheaper than fetching the whole line of history.  (Ignoring the sort
problem, of course.)

> PS: I have one practical question: how do you develop viewvc? I have
> setup eclipse with pydev and I'm quite happy with that, especially able
> to debug is really cool. But whenever I do a change in a .py file I have
> to restart apache or the standalone.py, even if I delete the related
> .pyc files. Is there a way to tell python to watch the py/pyc files for
> changes?

I thought Python did that naturally, but maybe not.  I almost never have to
restart Apache for testing.  But then, I'm not using mod_python -- are you?

> PPS: Almost forgot again: Thanks a lot for your energy and motivation
> for developing ViewVC! Despite some performance issues, I haven't seen a
> better and more flexible version control web frontend... and its look &
> feel gets better and better :)

Thanks.  I'm only the guy who inherited the software -- much credit goes to
my predecessors.  But I enjoy it nonetheless.  :-)

-- 
C. Michael Pilato <[email protected]>
CollabNet   <>   www.collab.net   <>   Distributed Development On Demand

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