contrib/python-hook-examples.py
author FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
Sun, 09 Oct 2016 01:03:16 +0900
changeset 30143 2d858c771760
parent 28562 2b585677220e
child 39895 1a184b727aff
permissions -rw-r--r--
perf: introduce safeattrsetter to replace direct attribute assignment Referring not-existing attribute immediately causes failure, but assigning a value to such attribute doesn't. For example, perf.py has code paths below, which assign a value to not-existing attribute. This causes incorrect performance measurement, but these code paths are executed successfully. - "repo._tags = None" in perftags() recent Mercurial has tags cache information in repo._tagscache - "branchmap.write = lambda repo: None" in perfbranchmap() branchmap cache is written out by branchcache.write() in branchmap.py "util.safehasattr() before assignment" can avoid this issue, but might increase mistake at "copy & paste" attribute name or so. To centralize (1) examining existence of, (2) assigning a value to, and (3) restoring an old value to the attribute, this patch introduces safeattrsetter(). This is used to replace direct attribute assignment in subsequent patches. Encapsulation of restoring is needed to completely remove direct attribute assignment from perf.py, even though restoring isn't needed so often.

'''
Examples of useful python hooks for Mercurial.
'''
from __future__ import absolute_import
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)))