# win32.py - utility functions that use win32 API

#

# Copyright 2005-2009 Matt Mackall <mpm@selenic.com> 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 encoding

import ctypes, errno, os, struct, subprocess, random

_kernel32 = ctypes.windll.kernel32

_BOOL = ctypes.c_long

_WORD = ctypes.c_ushort

_DWORD = ctypes.c_ulong

_LPCSTR = _LPSTR = ctypes.c_char_p

_HANDLE = ctypes.c_void_p

_HWND = _HANDLE

_INVALID_HANDLE_VALUE = -1

# GetLastError

_ERROR_SUCCESS = 0

_ERROR_INVALID_PARAMETER = 87

_ERROR_INSUFFICIENT_BUFFER = 122

# WPARAM is defined as UINT_PTR (unsigned type)

# LPARAM is defined as LONG_PTR (signed type)

if ctypes.sizeof(ctypes.c_long) == ctypes.sizeof(ctypes.c_void_p):

    _WPARAM = ctypes.c_ulong

    _LPARAM = ctypes.c_long

elif ctypes.sizeof(ctypes.c_longlong) == ctypes.sizeof(ctypes.c_void_p):

    _WPARAM = ctypes.c_ulonglong

    _LPARAM = ctypes.c_longlong

class _FILETIME(ctypes.Structure):

    _fields_ = [('dwLowDateTime', _DWORD),

                ('dwHighDateTime', _DWORD)]

class _BY_HANDLE_FILE_INFORMATION(ctypes.Structure):

    _fields_ = [('dwFileAttributes', _DWORD),

                ('ftCreationTime', _FILETIME),

                ('ftLastAccessTime', _FILETIME),

                ('ftLastWriteTime', _FILETIME),

                ('dwVolumeSerialNumber', _DWORD),

                ('nFileSizeHigh', _DWORD),

                ('nFileSizeLow', _DWORD),

                ('nNumberOfLinks', _DWORD),

                ('nFileIndexHigh', _DWORD),

                ('nFileIndexLow', _DWORD)]

# CreateFile 

_FILE_SHARE_READ = 0x00000001

_FILE_SHARE_WRITE = 0x00000002

_FILE_SHARE_DELETE = 0x00000004

_OPEN_EXISTING = 3

# SetFileAttributes

_FILE_ATTRIBUTE_NORMAL = 0x80

_FILE_ATTRIBUTE_NOT_CONTENT_INDEXED = 0x2000

# Process Security and Access Rights

_PROCESS_QUERY_INFORMATION = 0x0400

# GetExitCodeProcess

_STILL_ACTIVE = 259

# registry

_HKEY_CURRENT_USER = 0x80000001L

_HKEY_LOCAL_MACHINE = 0x80000002L

_KEY_READ = 0x20019

_REG_SZ = 1

_REG_DWORD = 4

class _STARTUPINFO(ctypes.Structure):

    _fields_ = [('cb', _DWORD),

                ('lpReserved', _LPSTR),

                ('lpDesktop', _LPSTR),

                ('lpTitle', _LPSTR),

                ('dwX', _DWORD),

                ('dwY', _DWORD),

                ('dwXSize', _DWORD),

                ('dwYSize', _DWORD),

                ('dwXCountChars', _DWORD),

                ('dwYCountChars', _DWORD),

                ('dwFillAttribute', _DWORD),

                ('dwFlags', _DWORD),

                ('wShowWindow', _WORD),

                ('cbReserved2', _WORD),

                ('lpReserved2', ctypes.c_char_p),

                ('hStdInput', _HANDLE),

                ('hStdOutput', _HANDLE),

                ('hStdError', _HANDLE)]

class _PROCESS_INFORMATION(ctypes.Structure):

    _fields_ = [('hProcess', _HANDLE),

                ('hThread', _HANDLE),

                ('dwProcessId', _DWORD),

                ('dwThreadId', _DWORD)]

_DETACHED_PROCESS = 0x00000008

_STARTF_USESHOWWINDOW = 0x00000001

_SW_HIDE = 0

class _COORD(ctypes.Structure):

    _fields_ = [('X', ctypes.c_short),

                ('Y', ctypes.c_short)]

class _SMALL_RECT(ctypes.Structure):

    _fields_ = [('Left', ctypes.c_short),

                ('Top', ctypes.c_short),

                ('Right', ctypes.c_short),

                ('Bottom', ctypes.c_short)]

class _CONSOLE_SCREEN_BUFFER_INFO(ctypes.Structure):

    _fields_ = [('dwSize', _COORD),

                ('dwCursorPosition', _COORD),

                ('wAttributes', _WORD),

                ('srWindow', _SMALL_RECT),

                ('dwMaximumWindowSize', _COORD)]

_STD_ERROR_HANDLE = 0xfffffff4L # (DWORD)-12

def _raiseoserror(name):

    err = ctypes.WinError()

    raise OSError(err.errno, '%s: %s' % (name, err.strerror))

def _getfileinfo(name):

    fh = _kernel32.CreateFileA(name, 0,

            _FILE_SHARE_READ | _FILE_SHARE_WRITE | _FILE_SHARE_DELETE,

            None, _OPEN_EXISTING, 0, None)

    if fh == _INVALID_HANDLE_VALUE:

        _raiseoserror(name)

    try:

        fi = _BY_HANDLE_FILE_INFORMATION()

        if not _kernel32.GetFileInformationByHandle(fh, ctypes.byref(fi)):

            _raiseoserror(name)

        return fi

    finally:

        _kernel32.CloseHandle(fh)

def oslink(src, dst):

    try:

        if not _kernel32.CreateHardLinkA(dst, src, None):

            _raiseoserror(src)

    except AttributeError: # Wine doesn't support this function

        _raiseoserror(src)

def nlinks(name):

    '''return number of hardlinks for the given file'''

    return _getfileinfo(name).nNumberOfLinks

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)

    return (res1.dwVolumeSerialNumber == res2.dwVolumeSerialNumber

        and res1.nFileIndexHigh == res2.nFileIndexHigh

        and res1.nFileIndexLow == res2.nFileIndexLow)

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.dwVolumeSerialNumber == res2.dwVolumeSerialNumber

def testpid(pid):

    '''return True if pid is still running or unable to

    determine, False otherwise'''

    h = _kernel32.OpenProcess(_PROCESS_QUERY_INFORMATION, False, pid)

    if h:

        try:

            status = _DWORD()

            if _kernel32.GetExitCodeProcess(h, ctypes.byref(status)):

                return status.value == _STILL_ACTIVE

        finally:

            _kernel32.CloseHandle(h)

    return _kernel32.GetLastError() != _ERROR_INVALID_PARAMETER

def lookupreg(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).

    '''

    adv = ctypes.windll.advapi32

    byref = ctypes.byref

    if scope is None:

        scope = (_HKEY_CURRENT_USER, _HKEY_LOCAL_MACHINE)

    elif not isinstance(scope, (list, tuple)):

        scope = (scope,)

    for s in scope:

        kh = _HANDLE()

        res = adv.RegOpenKeyExA(s, key, 0, _KEY_READ, ctypes.byref(kh))

        if res != _ERROR_SUCCESS:

            continue

        try:

            size = _DWORD(600)

            type = _DWORD()

            buf = ctypes.create_string_buffer(size.value + 1)

            res = adv.RegQueryValueExA(kh.value, valname, None,

                                       byref(type), buf, byref(size))

            if res != _ERROR_SUCCESS:

                continue

            if type.value == _REG_SZ:

                # never let a Unicode string escape into the wild

                return encoding.tolocal(buf.value.encode('UTF-8'))

            elif type.value == _REG_DWORD:

                fmt = '<L'

                s = ctypes.string_at(byref(buf), struct.calcsize(fmt))

                return struct.unpack(fmt, s)[0]

        finally:

            adv.RegCloseKey(kh.value)

def executablepath():

    '''return full path of hg.exe'''

    size = 600

    buf = ctypes.create_string_buffer(size + 1)

    len = _kernel32.GetModuleFileNameA(None, ctypes.byref(buf), size)

    if len == 0:

        raise ctypes.WinError()

    elif len == size:

        raise ctypes.WinError(_ERROR_INSUFFICIENT_BUFFER)

    return buf.value

def getuser():

    '''return name of current user'''

    adv = ctypes.windll.advapi32

    size = _DWORD(300)

    buf = ctypes.create_string_buffer(size.value + 1)

    if not adv.GetUserNameA(ctypes.byref(buf), ctypes.byref(size)):

        raise ctypes.WinError()

    return buf.value

_SIGNAL_HANDLER = ctypes.WINFUNCTYPE(_BOOL, _DWORD)

_signalhandler = []

def setsignalhandler():

    '''Register a termination handler for console events including

    CTRL+C. python signal handlers do not work well with socket

    operations.

    '''

    def handler(event):

        _kernel32.ExitProcess(1)

    if _signalhandler:

        return # already registered

    h = _SIGNAL_HANDLER(handler)

    _signalhandler.append(h) # needed to prevent garbage collection

    if not _kernel32.SetConsoleCtrlHandler(h, True):

        raise ctypes.WinError()

_WNDENUMPROC = ctypes.WINFUNCTYPE(_BOOL, _HWND, _LPARAM)

def hidewindow():

    user32 = ctypes.windll.user32

    def callback(hwnd, pid):

        wpid = _DWORD()

        user32.GetWindowThreadProcessId(hwnd, ctypes.byref(wpid))

        if pid == wpid.value:

            user32.ShowWindow(hwnd, _SW_HIDE)

            return False # stop enumerating windows

        return True

    pid = _kernel32.GetCurrentProcessId()

    user32.EnumWindows(_WNDENUMPROC(callback), pid)

def termwidth():

    # cmd.exe does not handle CR like a unix console, the CR is

    # counted in the line length. On 80 columns consoles, if 80

    # characters are written, the following CR won't apply on the

    # current line but on the new one. Keep room for it.

    width = 79

    # Query stderr to avoid problems with redirections

    screenbuf = _kernel32.GetStdHandle(

                  _STD_ERROR_HANDLE) # don't close the handle returned

    if screenbuf is None or screenbuf == _INVALID_HANDLE_VALUE:

        return width

    csbi = _CONSOLE_SCREEN_BUFFER_INFO()

    if not _kernel32.GetConsoleScreenBufferInfo(

                        screenbuf, ctypes.byref(csbi)):

        return width

    width = csbi.srWindow.Right - csbi.srWindow.Left

    return width

def spawndetached(args):

    # No standard library function really spawns a fully detached

    # process under win32 because they allocate pipes or other objects

    # to handle standard streams communications. Passing these objects

    # to the child process requires handle inheritance to be enabled

    # which makes really detached processes impossible.

    si = _STARTUPINFO()

    si.cb = ctypes.sizeof(_STARTUPINFO)

    si.dwFlags = _STARTF_USESHOWWINDOW

    si.wShowWindow = _SW_HIDE

    pi = _PROCESS_INFORMATION()

    env = ''

    for k in os.environ:

        env += "%s=%s\0" % (k, os.environ[k])

    if not env:

        env = '\0'

    env += '\0'

    args = subprocess.list2cmdline(args)

    # Not running the command in shell mode makes python26 hang when

    # writing to hgweb output socket.

    comspec = os.environ.get("COMSPEC", "cmd.exe")

    args = comspec + " /c " + args

    res = _kernel32.CreateProcessA(

        None, args, None, None, False, _DETACHED_PROCESS,

        env, os.getcwd(), ctypes.byref(si), ctypes.byref(pi))

    if not res:

        raise ctypes.WinError()

    return pi.dwProcessId

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 OSError:

        # The unlink might have failed because the READONLY attribute may heave

        # been set on the original file. Rename works fine with READONLY set,

        # but not os.unlink. Reset all attributes and try again.

        _kernel32.SetFileAttributesA(temp, _FILE_ATTRIBUTE_NORMAL)

        try:

            os.unlink(temp)

        except OSError:

            # The unlink might have failed due to some very rude AV-Scanners.

            # Leaking a tempfile is the lesser evil than aborting here and

            # leaving some potentially serious inconsistencies.

            pass

def makedir(path, notindexed):

    os.mkdir(path)

    if notindexed:

        _kernel32.SetFileAttributesA(path, _FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)