rust-index: use a `BitVec` instead of plain `Vec` for heads computation
The `Vec` method uses one byte per revision, this uses 1 per 8 revisions,
which improves our memory footprint. For large graphs (10+ millions), this
can make a measurable difference server-side.
I have seen no measurable impact on execution speed.
# Dummy extension that adds a delay after acquiring a lock.
#
# This extension can be used to test race conditions between lock acquisition.
import os
import time
def reposetup(ui, repo):
class delayedlockrepo(repo.__class__):
def lock(self, wait=True):
delay = float(os.environ.get('HGPRELOCKDELAY', '0.0'))
if delay:
time.sleep(delay)
res = super(delayedlockrepo, self).lock(wait=wait)
delay = float(os.environ.get('HGPOSTLOCKDELAY', '0.0'))
if delay:
time.sleep(delay)
return res
repo.__class__ = delayedlockrepo