tests/lockdelay.py

snapshot: extract parent chain computation

The final step of this series is to include chain related to "prev" in the
search. Before adding that code we do some simple code movement to clarify the
next diff.

# Dummy extension that adds a delay after acquiring a lock.
#
# This extension can be used to test race conditions between lock acquisition.

from __future__ import absolute_import

import os
import time

def reposetup(ui, repo):

    class delayedlockrepo(repo.__class__):
        def lock(self):
            delay = float(os.environ.get('HGPRELOCKDELAY', '0.0'))
            if delay:
                time.sleep(delay)
            res = super(delayedlockrepo, self).lock()
            delay = float(os.environ.get('HGPOSTLOCKDELAY', '0.0'))
            if delay:
                time.sleep(delay)
            return res
    repo.__class__ = delayedlockrepo