view mercurial/win32.py @ 12727:52971985be14

backout: provide linear backout as a default (without --merge option)

This changes backouts changeset to retain linear history, .e. it is committed
as a child of the working directory parent, not the reverted changeset
parent.

The default behavior was previously to just commit a reverted change as a
child of the backed out changeset - thus creating a new head. Most of
the time, you would use the --merge option, as it does not make sense to
keep this dangling head as is.
The previous behavior could be obtained by using 'hg update --clean .' after a
'hg backout --merge'.

The --merge option itself is not affected by this change. There is also
still an autocommit of the backout if a merge is not needed, i.e. in case
the backout is the parent of the working directory.

Previously we had (pwd = parent of the working directory):
                  pwd     older
backout           auto    merge
backout --merge   auto    commit

With the new linear approach:
                  pwd     older
backout           auto    commit
backout --merge   auto    commit

auto: commit done by the backout command
merge: backout also already committed but explicit merge and commit needed
commit: user need to commit the update/merge

# win32.py - utility functions that use win32 API
#
# Copyright 2005-2009 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.

"""Utility functions that use win32 API.

Mark Hammond's win32all package allows better functionality on
Windows. This module overrides definitions in util.py. If not
available, import of this module will fail, and generic code will be
used.
"""

import win32api

import errno, os, sys, pywintypes, win32con, win32file, win32process
import winerror, win32gui, win32console
import osutil, encoding
from win32com.shell import shell, shellcon

def os_link(src, dst):
    try:
        win32file.CreateHardLink(dst, src)
    except pywintypes.error:
        raise OSError(errno.EINVAL, 'target implements hardlinks improperly')
    except NotImplementedError: # Another fake error win Win98
        raise OSError(errno.EINVAL, 'Hardlinking not supported')

def _getfileinfo(pathname):
    """Return number of hardlinks for the given file."""
    try:
        fh = win32file.CreateFile(pathname,
            win32file.GENERIC_READ, win32file.FILE_SHARE_READ,
            None, win32file.OPEN_EXISTING, 0, None)
    except pywintypes.error:
        raise OSError(errno.ENOENT, 'The system cannot find the file specified')
    try:
        return win32file.GetFileInformationByHandle(fh)
    finally:
        fh.Close()

def nlinks(pathname):
    """Return number of hardlinks for the given file."""
    links = _getfileinfo(pathname)[7]
    if links < 2:
        # Known to be wrong for most network drives
        dirname = os.path.dirname(pathname)
        if not dirname:
            dirname = '.'
        dt = win32file.GetDriveType(dirname + '\\')
        if dt == 4 or dt == 1:
            # Fake hardlink to force COW for network drives
            links = 2
    return links

def samefile(fpath1, fpath2):
    """Returns whether fpath1 and fpath2 refer to the same file. This is only
    guaranteed to work for files, not directories."""
    res1 = _getfileinfo(fpath1)
    res2 = _getfileinfo(fpath2)
    # Index 4 is the volume serial number, and 8 and 9 contain the file ID
    return res1[4] == res2[4] and res1[8] == res2[8] and res1[9] == res2[9]

def samedevice(fpath1, fpath2):
    """Returns whether fpath1 and fpath2 are on the same device. This is only
    guaranteed to work for files, not directories."""
    res1 = _getfileinfo(fpath1)
    res2 = _getfileinfo(fpath2)
    return res1[4] == res2[4]

def testpid(pid):
    '''return True if pid is still running or unable to
    determine, False otherwise'''
    try:
        handle = win32api.OpenProcess(
            win32con.PROCESS_QUERY_INFORMATION, False, pid)
        if handle:
            status = win32process.GetExitCodeProcess(handle)
            return status == win32con.STILL_ACTIVE
    except pywintypes.error, details:
        return details[0] != winerror.ERROR_INVALID_PARAMETER
    return True

def lookup_reg(key, valname=None, scope=None):
    ''' Look up a key/value name in the Windows registry.

    valname: value name. If unspecified, the default value for the key
    is used.
    scope: optionally specify scope for registry lookup, this can be
    a sequence of scopes to look up in order. Default (CURRENT_USER,
    LOCAL_MACHINE).
    '''
    try:
        from _winreg import HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, \
            QueryValueEx, OpenKey
    except ImportError:
        return None

    if scope is None:
        scope = (HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE)
    elif not isinstance(scope, (list, tuple)):
        scope = (scope,)
    for s in scope:
        try:
            val = QueryValueEx(OpenKey(s, key), valname)[0]
            # never let a Unicode string escape into the wild
            return encoding.tolocal(val.encode('UTF-8'))
        except EnvironmentError:
            pass

def system_rcpath_win32():
    '''return default os-specific hgrc search path'''
    proc = win32api.GetCurrentProcess()
    try:
        # This will fail on windows < NT
        filename = win32process.GetModuleFileNameEx(proc, 0)
    except:
        filename = win32api.GetModuleFileName(0)
    # Use mercurial.ini found in directory with hg.exe
    progrc = os.path.join(os.path.dirname(filename), 'mercurial.ini')
    if os.path.isfile(progrc):
        return [progrc]
    # Use hgrc.d found in directory with hg.exe
    progrcd = os.path.join(os.path.dirname(filename), 'hgrc.d')
    if os.path.isdir(progrcd):
        rcpath = []
        for f, kind in osutil.listdir(progrcd):
            if f.endswith('.rc'):
                rcpath.append(os.path.join(progrcd, f))
        return rcpath
    # else look for a system rcpath in the registry
    try:
        value = win32api.RegQueryValue(
                win32con.HKEY_LOCAL_MACHINE, 'SOFTWARE\\Mercurial')
        rcpath = []
        for p in value.split(os.pathsep):
            if p.lower().endswith('mercurial.ini'):
                rcpath.append(p)
            elif os.path.isdir(p):
                for f, kind in osutil.listdir(p):
                    if f.endswith('.rc'):
                        rcpath.append(os.path.join(p, f))
        return rcpath
    except pywintypes.error:
        return []

def user_rcpath_win32():
    '''return os-specific hgrc search path to the user dir'''
    userdir = os.path.expanduser('~')
    if sys.getwindowsversion()[3] != 2 and userdir == '~':
        # We are on win < nt: fetch the APPDATA directory location and use
        # the parent directory as the user home dir.
        appdir = shell.SHGetPathFromIDList(
            shell.SHGetSpecialFolderLocation(0, shellcon.CSIDL_APPDATA))
        userdir = os.path.dirname(appdir)
    return [os.path.join(userdir, 'mercurial.ini'),
            os.path.join(userdir, '.hgrc')]

def getuser():
    '''return name of current user'''
    return win32api.GetUserName()

def set_signal_handler_win32():
    """Register a termination handler for console events including
    CTRL+C. python signal handlers do not work well with socket
    operations.
    """
    def handler(event):
        win32process.ExitProcess(1)
    win32api.SetConsoleCtrlHandler(handler)

def hidewindow():
    def callback(*args, **kwargs):
        hwnd, pid = args
        wpid = win32process.GetWindowThreadProcessId(hwnd)[1]
        if pid == wpid:
            win32gui.ShowWindow(hwnd, win32con.SW_HIDE)

    pid =  win32process.GetCurrentProcessId()
    win32gui.EnumWindows(callback, pid)

def termwidth():
    try:
        # Query stderr to avoid problems with redirections
        screenbuf = win32console.GetStdHandle(win32console.STD_ERROR_HANDLE)
        try:
            window = screenbuf.GetConsoleScreenBufferInfo()['Window']
            width = window.Right - window.Left
            return width
        finally:
            screenbuf.Detach()
    except pywintypes.error:
        return 79