VcsEventWidget + Slow Mercurial Log

[Fabian Wiesel]

Hi,

I have a small problem with how VcsEventWidget and Mercurial log interact
and I am not sure how to proceed.
It takes quite some time to get all the events and so the VcsEventWidget 
is stays empty.

One way to solve it, is in the plugin itself, by parsing the log 
incrementally and
to emit resultsReady() as I go.  Easy done. But I am not quite sure, how 
the GUI will then behave.
Also the process still takes quite some time for reading a lot of data 
people may not be interested in.
For the project I work on, that is about 30secs for about 5000 changesets.
How long would it take for a Mozilla-dev with almost 40k changesets? It 
seems to scale badly.

The other way to solve it would be in the VcsEventWidget (or the 
VcsEventModel):
Instead of loading the full log, one only loads the necessary parts.
Maybe the first 100 and the last one  and make a guesstimate about 
VcsItemEventModel::rowCount().
When GUI requests other parts of the VcsEventModel, one tries to find 
the correct blocks.
Similar problem, how does the GUI behave, if I change the rowCount() on 
the fly?
More work, quite a fair amount of more code, but definitely more 
scalable. But you could say it is a work-around.

Did I miss another possibility completely?

Fabian