Re: [Monotone-devel] Monotone performance degrades dramatically

[Steven Grimm]

Thomas Moschny wrote:
> This is a known problem. The commit command calls get_branch_heads() (at 
> least) two times; and get_branch_heads() execution time is directly dependent 
> on the number of revisions already in that branch. This is not directly a bug 
> of get_branch_heads(), but a problem of erase_bogus_certs() which validates  
> certificates over and over again. This is absolutely unnecessary, because the 
> validity of a cert (not to be confused with the trust in that cert) is a 
> constant. It could be verified once and for all and stored in the database 
> together with the cert.
>
> Simply no one has gotten around implementing that.
>   

Is this something that would be reasonably fixable by someone with no 
prior Monotone internals experience? I'm willing to have a whack at it 
but I have never done more than briefly glance at the insides of 
Monotone before. If this would be a change with far-reaching 
repercussions on the code's internal data flow, or one that would 
require lots of little tweaks in various non-obvious places, then I 
probably shouldn't touch it -- I have a list of other VCSes to evaluate 
and I can't afford to spend *too* much time getting up to speed enough 
to fix this.

But I am willing to spend *some* time; with this problem unfixed, 
Monotone is totally out of the running for our project (the full version 
of which gets a couple thousand new revisions a month) and I'd like to 
give it a fair shot since I actually like it a lot for my personal stuff.

-Steve