contrib/python-hook-examples.py

purge: avoid full walks when directories aren't purged

If match.traversedir is not None, we're forced to do full walks. However when
we aren't purging directories we don't need to set match.traversedir to
anything.

This speeds up non-full walks such as the one hgwatchman makes possible. For
mozilla-central with hgwatchman enabled, 'hg purge --files' goes from 0.88
seconds to 0.22.

'''
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)))