contrib/python-hook-examples.py

revset: fast implementation for fullreposet.__and__

"And" operation with something that contains the whole repo should be super
cheap. Check method docstring for details.

This provide massive boost to simple revset that use `subset & xxx`

revset #0: p1(20000)
0) wall 0.002447 comb 0.010000 user 0.010000 sys 0.000000 (best of 767)
1) wall 0.000529 comb 0.000000 user 0.000000 sys 0.000000 (best of 3947)

revset #1: p2(10000)
0) wall 0.002464 comb 0.000000 user 0.000000 sys 0.000000 (best of 913)
1) wall 0.000530 comb 0.000000 user 0.000000 sys 0.000000 (best of 4226)

No other regression spotted.

More performance improvements are expected in the future as more
revset predicate are converted to use `subset & xxx`

The relaxed way `fullreposet` handles "&" operation may cause some trouble for
people comparing smartset from different filter levels. I'm not sure such people
exist and we can improve that aspect in later patches.

'''
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)))