mercurial/windows.py

13774:1ce0e80799c0

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import osutil, error
import errno, msvcrt, os, re, sys, random, subprocess

nulldev = 'NUL:'
umask = 002

# wrap osutil.posixfile to provide friendlier exceptions

    try:
        _removedirs(os.path.dirname(f))
    except OSError:
        pass

def unlink(f):
    '''try to implement POSIX' unlink semantics on Windows'''

    # POSIX allows to unlink and rename open files. Windows has serious
    # problems with doing that:
    # - Calling os.unlink (or os.rename) on a file f fails if f or any
    #   hardlinked copy of f has been opened with Python's open(). There is no
    #   way such a file can be deleted or renamed on Windows (other than
    #   scheduling the delete or rename for the next reboot).
    # - Calling os.unlink on a file that has been opened with Mercurial's
    #   posixfile (or comparable methods) will delay the actual deletion of
    #   the file for as long as the file is held open. The filename is blocked
    #   during that time and cannot be used for recreating a new file under
    #   that same name ("zombie file"). Directories containing such zombie files
    #   cannot be removed or moved.
    # A file that has been opened with posixfile can be renamed, so we rename
    # f to a random temporary name before calling os.unlink on it. This allows
    # callers to recreate f immediately while having other readers do their
    # implicit zombie filename blocking on a temporary name.

    for tries in xrange(10):
        temp = '%s-%08x' % (f, random.randint(0, 0xffffffff))
        try:
            os.rename(f, temp)  # raises OSError EEXIST if temp exists
            break
        except OSError, e:
            if e.errno != errno.EEXIST:
                raise
    else:
        raise IOError, (errno.EEXIST, "No usable temporary filename found")

    try:
        os.unlink(temp)
    except:
        # Some very rude AV-scanners on Windows may cause this unlink to fail.
        # Not aborting here just leaks the temp file, whereas aborting at this
        # point may leave serious inconsistencies. Ideally, we would notify
        # the user in this case here.
        pass

def rename(src, dst):
    '''atomically rename file src to dst, replacing dst if it exists'''
    try:
        os.rename(src, dst)
    except OSError, e:

13775:930efdc6bfa4

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import osutil, error
import errno, msvcrt, os, re, sys, subprocess

nulldev = 'NUL:'
umask = 002

# wrap osutil.posixfile to provide friendlier exceptions

    try:
        _removedirs(os.path.dirname(f))
    except OSError:
        pass

def rename(src, dst):
    '''atomically rename file src to dst, replacing dst if it exists'''
    try:
        os.rename(src, dst)
    except OSError, e: