[RFI] Annotations cache & progressive display of annotations

[Stefan Monnier]

> bzr annotate --show-ids will give you the revision ids which introduced
> a given line. (at the cost of annotating the whole file)

Performance is the key problem.

> I'm not really sure why you couldn't just do "bzr log -p FILE" and then
> filter out the diffs that did not affect the lines you cared about.
> (Given that that is all that --lines NN..MM would really be doing.)

Yes, that's the way to do it, but you need to update the NN..MM range
after every hunk.  It's again a performance problem: bzr could do it
internally much more efficiently.

I'm not saying it can't be done outside of Bzr.  I'm saying that I think
it would be a great feature for Bzr to support and that by doing it
within Bzr, it can be made a lot more efficient.
Just like "annotate" could be implemented on top of "bzr log -p" but it's
considered an important feature worth optimizing.


        Stefan