contrib/casesmash.py

dirstate-v2: Reuse existing nodes when appending to a data file

When writing a dirstate in v2 format by appending to an existing data file,
nodes that are still "unparsed" from the previous on-disk representation
have been unchanged and can therefore be reused.

This makes the new data point to previously-existing data for tree nodes.

Differential Revision: https://phab.mercurial-scm.org/D11095

from __future__ import absolute_import
import __builtin__
import os
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:
            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')