view contrib/python-hook-examples.py @ 33799:05264fc9d8d6

util: make nogc effective for CPython

279cd80059d4 made `util.nogc` a no-op. It was to optimize PyPy. But it slows
down CPython if many objects (like 300k+) are created.

For example, running `hg log -r .` without extensions in `hg-committed` with
14k+ obsmarkers have the following times:

  before        | after
  hg    | chg   | hg    | chg
  -----------------------------
  1.262 | 0.860 | 1.077 | 0.619 (seconds, best of 20 runs)

Therefore let's re-enable nogc for CPython.

Differential Revision: https://phab.mercurial-scm.org/D402

'''
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)))