graphmod: restore generator nature of dagwalker
9966c95b8c4f introduced the ability to walk the DAG
given arbitrary revisions, but changed the behaviour of
it to return a list of all nodes (and create a changectx
for each one) rather than doing it lazily.
This has a pretty significant impact on performance for large
repositories (tested on CPython repo, with output disabled):
$ time hg glog
real 0m2.642s
user 0m2.560s
sys 0m0.080s
Before 9966c95b8c4f:
$ time hg glog
real 0m0.143s
user 0m0.112s
sys 0m0.032s
And after this fix:
$ time hg glog
real 0m0.213s
user 0m0.184s
sys 0m0.028s
'''
Examples of useful python hooks for Mercurial.
'''
from mercurial import patch, util
def diffstat(ui, repo, **kwargs):
'''Example usage:
[hooks]
commit.diffstat = python:/path/to/this/file.py:diffstat
changegroup.diffstat = python:/path/to/this/file.py:diffstat
'''
if kwargs.get('parent2'):
return
node = kwargs['node']
first = repo[node].p1().node()
if 'url' in kwargs:
last = repo['tip'].node()
else:
last = node
diff = patch.diff(repo, first, last)
ui.write(patch.diffstat(util.iterlines(diff)))