view contrib/casesmash.py @ 18091:f7f8159caad3

ancestor: add lazy membership testing to lazyancestors

This also makes the perfancestorset command use lazy membership testing. In a
linear repository with over 400,000 commits, without this patch, hg
perfancestorset takes 0.80 seconds no matter how far behind we're looking.
With this patch, hg perfancestorset -- X takes:

    Rev X       Time
       -1      0.00s
    -4000      0.01s
   -20000      0.04s
   -80000      0.17s
  -200000      0.43s
  -300000      0.69s
        0      0.88s

Thus, for revisions close to tip, we're up to several orders of magnitude
faster. At 0 we're around 10% slower.

import sys, os, __builtin__
from mercurial import util

def lowerwrap(scope, funcname):
    f = getattr(scope, funcname)
    def wrap(fname, *args, **kwargs):
        d, base = os.path.split(fname)
        try:
            files = os.listdir(d or '.')
        except OSError, inst:
            files = []
        if base in files:
            return f(fname, *args, **kwargs)
        for fn in files:
            if fn.lower() == base.lower():
                return f(os.path.join(d, fn), *args, **kwargs)
        return f(fname, *args, **kwargs)
    scope.__dict__[funcname] = wrap

def normcase(path):
    return path.lower()

os.path.normcase = normcase

for f in 'file open'.split():
    lowerwrap(__builtin__, f)

for f in "chmod chown open lstat stat remove unlink".split():
    lowerwrap(os, f)

for f in "exists lexists".split():
    lowerwrap(os.path, f)

lowerwrap(util, 'posixfile')