mercurial/pure/osutil.py

strip: enhance repair.strip to receive a list of nodes (issue3299)

Originally, mq.strip called repair.strip a single rev at a time.
repair.strip stores in a backup bundle any revision greater than
the revision being stripped, strips, then restores the backup with
repo.addchangegroup. So, when stripping revisions on more than one
topological branch, some could end up being restored from the backup
bundle, only to be later removed by a subsequent repair.strip call.

But repo.addchangegroup calls hooks for all those restore operations.
And 9df9444e96ec changed it to delay all hook calls until the
repository lock were released - by mq.strip, after stripping all
revisions. Thus, the hooks could be called over revisions already
removed from the repository at that point.

By generating the revision lists at once inside repo.strip, we avoid
calling addchangegroup for temporary restores. Incidentally, this
also avoids creating many backup files for a single strip command.

# osutil.py - pure Python version of osutil.c
#
#  Copyright 2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import os
import stat as statmod

def _mode_to_kind(mode):
    if statmod.S_ISREG(mode):
        return statmod.S_IFREG
    if statmod.S_ISDIR(mode):
        return statmod.S_IFDIR
    if statmod.S_ISLNK(mode):
        return statmod.S_IFLNK
    if statmod.S_ISBLK(mode):
        return statmod.S_IFBLK
    if statmod.S_ISCHR(mode):
        return statmod.S_IFCHR
    if statmod.S_ISFIFO(mode):
        return statmod.S_IFIFO
    if statmod.S_ISSOCK(mode):
        return statmod.S_IFSOCK
    return mode

def listdir(path, stat=False, skip=None):
    '''listdir(path, stat=False) -> list_of_tuples

    Return a sorted list containing information about the entries
    in the directory.

    If stat is True, each element is a 3-tuple:

      (name, type, stat object)

    Otherwise, each element is a 2-tuple:

      (name, type)
    '''
    result = []
    prefix = path
    if not prefix.endswith(os.sep):
        prefix += os.sep
    names = os.listdir(path)
    names.sort()
    for fn in names:
        st = os.lstat(prefix + fn)
        if fn == skip and statmod.S_ISDIR(st.st_mode):
            return []
        if stat:
            result.append((fn, _mode_to_kind(st.st_mode), st))
        else:
            result.append((fn, _mode_to_kind(st.st_mode)))
    return result

if os.name != 'nt':
    posixfile = open
else:
    import ctypes, ctypes.util

    _kernel32 = ctypes.windll.kernel32

    _DWORD = ctypes.c_ulong
    _LPCSTR = _LPSTR = ctypes.c_char_p
    _HANDLE = ctypes.c_void_p

    _INVALID_HANDLE_VALUE = _HANDLE(-1).value

    def _crtname():
        try:
            # find_msvcrt was introduced in Python 2.6
            return ctypes.util.find_msvcrt()
        except AttributeError:
            return 'msvcr71.dll' # CPython 2.5 and 2.4

    _crt = ctypes.PyDLL(_crtname())

    # CreateFile 
    _FILE_SHARE_READ = 0x00000001
    _FILE_SHARE_WRITE = 0x00000002
    _FILE_SHARE_DELETE = 0x00000004

    _CREATE_ALWAYS = 2
    _OPEN_EXISTING = 3
    _OPEN_ALWAYS = 4

    _GENERIC_READ = 0x80000000
    _GENERIC_WRITE = 0x40000000

    _FILE_ATTRIBUTE_NORMAL = 0x80

    # _open_osfhandle
    _O_RDONLY = 0x0000
    _O_RDWR = 0x0002
    _O_APPEND = 0x0008

    _O_TEXT = 0x4000
    _O_BINARY = 0x8000

    # types of parameters of C functions used (required by pypy)

    _kernel32.CreateFileA.argtypes = [_LPCSTR, _DWORD, _DWORD, ctypes.c_void_p,
        _DWORD, _DWORD, _HANDLE]
    _kernel32.CreateFileA.restype = _HANDLE

    _crt._open_osfhandle.argtypes = [_HANDLE, ctypes.c_int]
    _crt._open_osfhandle.restype = ctypes.c_int

    def _raiseioerror(name):
        err = ctypes.WinError()
        raise IOError(err.errno, '%s: %s' % (name, err.strerror))

    class posixfile(object):
        '''a file object aiming for POSIX-like semantics

        CPython's open() returns a file that was opened *without* setting the
        _FILE_SHARE_DELETE flag, which causes rename and unlink to abort.
        This even happens if any hardlinked copy of the file is in open state.
        We set _FILE_SHARE_DELETE here, so files opened with posixfile can be
        renamed and deleted while they are held open.
        Note that if a file opened with posixfile is unlinked, the file
        remains but cannot be opened again or be recreated under the same name,
        until all reading processes have closed the file.'''

        def __init__(self, name, mode='r', bufsize=-1):
            if 'b' in mode:
                flags = _O_BINARY
            else:
                flags = _O_TEXT

            m0 = mode[0]
            if m0 == 'r' and not '+' in mode:
                flags |= _O_RDONLY
                access = _GENERIC_READ
            else:
                # work around http://support.microsoft.com/kb/899149 and
                # set _O_RDWR for 'w' and 'a', even if mode has no '+'
                flags |= _O_RDWR
                access = _GENERIC_READ | _GENERIC_WRITE

            if m0 == 'r':
                creation = _OPEN_EXISTING
            elif m0 == 'w':
                creation = _CREATE_ALWAYS
            elif m0 == 'a':
                creation = _OPEN_ALWAYS
                flags |= _O_APPEND
            else:
                raise ValueError("invalid mode: %s" % mode)

            fh = _kernel32.CreateFileA(name, access,
                    _FILE_SHARE_READ | _FILE_SHARE_WRITE | _FILE_SHARE_DELETE,
                    None, creation, _FILE_ATTRIBUTE_NORMAL, None)
            if fh == _INVALID_HANDLE_VALUE:
                _raiseioerror(name)

            # for CPython we must use the same CRT as Python uses,
            # or the os.fdopen call below will abort with
            #   "OSError: [Errno 9] Bad file descriptor"
            fd = _crt._open_osfhandle(fh, flags)
            if fd == -1:
                _kernel32.CloseHandle(fh)
                _raiseioerror(name)

            f = os.fdopen(fd, mode, bufsize)
            # unfortunately, f.name is '<fdopen>' at this point -- so we store
            # the name on this wrapper. We cannot just assign to f.name,
            # because that attribute is read-only.
            object.__setattr__(self, 'name', name)
            object.__setattr__(self, '_file', f)

        def __iter__(self):
            return self._file

        def __getattr__(self, name):
            return getattr(self._file, name)

        def __setattr__(self, name, value):
            '''mimics the read-only attributes of Python file objects
            by raising 'TypeError: readonly attribute' if someone tries:
              f = posixfile('foo.txt')
              f.name = 'bla'  '''
            return self._file.__setattr__(name, value)