comparison mercurial/win32.py @ 35510:2062f7c2ac83

win32: implement util.getfstype()

This will allow NTFS to be added to the hardlink whitelist, and resume creating
hardlinks in transactions (which was disabled globally in 07a92bbd02e5; see also
e5ce49a30146).  I opted to report "cifs" for remote volumes because this shows
in `hg debugfs`, which also reports that hardlinks are supported for these
volumes.  So being able to distinguish it from "unknown" seems useful.

The documentation [1] seems to indicate that SMB isn't supported by these
functions, but experimenting shows that mapped drives are reported as "NTFS" on
Windows 7.  I don't have a second Windows machine, but instead shared a temp
directory on C:\.  In this setup, both of the following were detected as 'cifs'
with the explicit GetDriveType() check:

  Z:\repo>hg ci -A

  C:\>hg -R \\hostname\temp\repo ci -A   # (without Z:\ being mapped)

It looks like this is called 6 times to add and commit a single new file, so I'm
a little surprised this isn't cached.

[1] https://msdn.microsoft.com/en-us/library/windows/desktop/aa364993(v=vs.85).aspx

35509:beede158ea8a

    pass

_kernel32.SetFileAttributesA.argtypes = [_LPCSTR, _DWORD]
_kernel32.SetFileAttributesA.restype = _BOOL

_kernel32.OpenProcess.argtypes = [_DWORD, _BOOL, _DWORD]
_kernel32.OpenProcess.restype = _HANDLE

_kernel32.GetExitCodeProcess.argtypes = [_HANDLE, ctypes.c_void_p]
_kernel32.GetExitCodeProcess.restype = _BOOL

    if len == 0:
        raise ctypes.WinError() # Note: WinError is a function
    elif len == size:
        raise ctypes.WinError(_ERROR_INSUFFICIENT_BUFFER)
    return buf.value

def getuser():
    '''return name of current user'''
    size = _DWORD(300)
    buf = ctypes.create_string_buffer(size.value + 1)

35510:2062f7c2ac83

    pass

_kernel32.SetFileAttributesA.argtypes = [_LPCSTR, _DWORD]
_kernel32.SetFileAttributesA.restype = _BOOL

_DRIVE_UNKNOWN = 0
_DRIVE_NO_ROOT_DIR = 1
_DRIVE_REMOVABLE = 2
_DRIVE_FIXED = 3
_DRIVE_REMOTE = 4
_DRIVE_CDROM = 5
_DRIVE_RAMDISK = 6

_kernel32.GetDriveTypeA.argtypes = [_LPCSTR]
_kernel32.GetDriveTypeA.restype = _UINT

_kernel32.GetVolumeInformationA.argtypes = [_LPCSTR, ctypes.c_void_p, _DWORD,
    ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, _DWORD]
_kernel32.GetVolumeInformationA.restype = _BOOL

_kernel32.GetVolumePathNameA.argtypes = [_LPCSTR, ctypes.c_void_p, _DWORD]
_kernel32.GetVolumePathNameA.restype = _BOOL

_kernel32.OpenProcess.argtypes = [_DWORD, _BOOL, _DWORD]
_kernel32.OpenProcess.restype = _HANDLE

_kernel32.GetExitCodeProcess.argtypes = [_HANDLE, ctypes.c_void_p]
_kernel32.GetExitCodeProcess.restype = _BOOL

    if len == 0:
        raise ctypes.WinError() # Note: WinError is a function
    elif len == size:
        raise ctypes.WinError(_ERROR_INSUFFICIENT_BUFFER)
    return buf.value

def getfstype(path):
    """Get the filesystem type name from a directory or file (best-effort)

    Returns None if we are unsure. Raises OSError on ENOENT, EPERM, etc.
    """
    # realpath() calls GetFullPathName()
    realpath = os.path.realpath(path)

    size = len(realpath) + 1
    buf = ctypes.create_string_buffer(size)

    if not _kernel32.GetVolumePathNameA(realpath, ctypes.byref(buf), size):
        raise ctypes.WinError() # Note: WinError is a function

    t = _kernel32.GetDriveTypeA(buf.value)

    if t == _DRIVE_REMOTE:
        return 'cifs'
    elif t not in (_DRIVE_REMOVABLE, _DRIVE_FIXED, _DRIVE_CDROM,
                   _DRIVE_RAMDISK):
        return None

    size = 256
    name = ctypes.create_string_buffer(size)

    if not _kernel32.GetVolumeInformationA(buf.value, None, 0, None, None, None,
                                           ctypes.byref(name), size):
        raise ctypes.WinError() # Note: WinError is a function

    return name.value

def getuser():
    '''return name of current user'''
    size = _DWORD(300)
    buf = ctypes.create_string_buffer(size.value + 1)