mercurial/scmposix.py

revset: make use of natively-computed set for 'draft()' and 'secret()'

If the computation of a set for each phase (done in C) is available,
we use it directly instead of applying a simple filter. This give a
massive speed-up in the vast majority of cases.

On my mercurial repo with about 15000 out of 40000 draft changesets:

revset: draft()
   plain         min           first         last
0) 0.011201      0.019950      0.009844      0.000074
1) 0.000284   2% 0.000312   1% 0.000314   3% 0.000315 x4.3

Bad performance for "last" come from the handling of the 15000 elements set
(memory allocation, filtering hidden changesets (99% of it) etc. compared to
applying the filter only on a handfuld of revisions (the first draft changesets
being close of tip).

This is not seen as an issue since:

* Timing is still pretty good and in line with all the other one,
* Current user of Vanilla Mercurial will not have 1/3 of their repo draft,

This bad effect disappears when phase's set is smaller. (about 200 secrets):

revset: secret()
   plain         min           first         last
0) 0.011181      0.022228      0.010851      0.000452
1) 0.000058   0% 0.000084   0% 0.000087   0% 0.000087  19%

import sys, os
import osutil

def _rcfiles(path):
    rcs = [os.path.join(path, 'hgrc')]
    rcdir = os.path.join(path, 'hgrc.d')
    try:
        rcs.extend([os.path.join(rcdir, f)
                    for f, kind in osutil.listdir(rcdir)
                    if f.endswith(".rc")])
    except OSError:
        pass
    return rcs

def systemrcpath():
    path = []
    if sys.platform == 'plan9':
        root = 'lib/mercurial'
    else:
        root = 'etc/mercurial'
    # old mod_python does not set sys.argv
    if len(getattr(sys, 'argv', [])) > 0:
        p = os.path.dirname(os.path.dirname(sys.argv[0]))
        if p != '/':
            path.extend(_rcfiles(os.path.join(p, root)))
    path.extend(_rcfiles('/' + root))
    return path

def userrcpath():
    if sys.platform == 'plan9':
        return [os.environ['home'] + '/lib/hgrc']
    else:
        return [os.path.expanduser('~/.hgrc')]