contrib/python-hook-examples.py

sparse-revlog: introduce native (C) implementation of slicechunktodensity

This is a C implementation of `_slicechunktodensity` in the
`mercurial/revlogutils/deltas.py` file.

The algorithm involves a lot of integer manipulation and low-level access to
index data. Having a C implementation of it raises a large performance
improvement. See later changeset in this series for details.

'''
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.changelog.tip()
    else:
        last = node
    diff = patch.diff(repo, first, last)
    ui.write(patch.diffstat(util.iterlines(diff)))