contrib/python-hook-examples.py

repository: define manifest interfaces

The long march towards declaring interfaces for repository
primitives continues.

This commit essentially defines interfaces based on the following
types:

* manifest.manifestdict -> imanifestdict
* manifest.manifestlog -> imanifestlog
* manifest.memmanifestctx -> imanifestrevisionwritable
* manifest.manifestctx -> imanifestrevisionstored
* manifest.memtreemanifestctx -> imanifestrevisionwritable
* manifest.treemanifestctx -> imanifestrevisionstored
* util.dirs -> idirs

The interfaces are thoroughly documented. Their documentation is
now better than the documentation in manifest.py in many cases.

With the exception of util.dirs, classes have been annotated with
their interfaces. (I didn't feel like util.dirs needed the
proper interface treatment.)

Tests have been added demonstrating that all classes and instances
conform to their interfaces.

This work was much easier than filelogs. That's because Durham
did an excellent job formalizing the manifest API a while back.

There are still some minor kludges with the interfaces that should
probably be addressed. But the primary goal with interface
declarations is getting something established. Once we have an
interface, we can modify it later easily enough.

Differential Revision: https://phab.mercurial-scm.org/D3869

'''
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)))