Is it possible to find the most recent PUSH time for a mercurial repository from a pre-commit hook?

Question

I have a Mercurial repository, and I'm trying to create a commit hook that can reject a new incoming push if the previously most recent push has happened within the last 15 minutes (as a form of throttling, so we can make sure that our automated tests have time to finish before someone else lands on top of possibly broken code, with someone else now possibly landing on doubly broken code).

So I've set up my server-side hgrc file like this:

[hooks]
prechangegroup.throttlehook = python:path/to/throttlescript.py:hook

I'm using the prechangegroup hook because that gives me access to the repository as it exists without the incoming push's commits.

The hook works, in that the script's code runs and can reject an incoming push if I return a non-zero return code.

Where I'm running into difficulty is getting the most recent push's timestamp. In throttlescript.py, I have the following:

import time
def hook(ui, repo, **kwargs):
    difference = time.time() - repo['tip'].date()[0] # this should be the difference between the current time and the most recent push
    if difference < 900:
        print "You are pushing too soon after the most recent push. Please try again later."
        return 1
    return 0

But repo['tip'].date()[0] seems to be the timestamp of the most recent commit, which could have occurred long before it was pushed to the my canonical repository, so it probably can't be trusted as the most recent push's timestamp.

Is there some other place I can find the push's timestamp, rather than the commit's? Could I use the last modified time of some file within the repository's .hg folder?

Answer 1

Mercurial doesn't track pushes and pulls, only the changesets they bring. There is an extension called 'pushlog' written by the Mozilla folks that records all pushes and pulls to log, tough I don't think it's widely used.

If you're willing to get a little sleezy you could just check the last modified time on the .hg/store/00changelog.i file, which is written to on every successful push.

In bash you could do that pretty easily using find:

#!/bin/bash
if test -z $(find .hg/store/00changelog.i -newerct '15 minutes ago') ; then
    exit 0
fi
echo "You are pushing too soon after the most recent push. Please try again later."
exit 1

I predict though you'll just piss off your coworkers. :)