PlexKodiConnect/resources/lib/watchdog/observers/winapi.py

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2018-04-28 17:12:29 +10:00
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# winapi.py: Windows API-Python interface (removes dependency on pywin32)
#
# Copyright (C) 2007 Thomas Heller <theller@ctypes.org>
# Copyright (C) 2010 Will McGugan <will@willmcgugan.com>
# Copyright (C) 2010 Ryan Kelly <ryan@rfk.id.au>
# Copyright (C) 2010 Yesudeep Mangalapilly <yesudeep@gmail.com>
# Copyright (C) 2014 Thomas Amland
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and / or other materials provided with the distribution.
# * Neither the name of the organization nor the names of its contributors may
# be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# Portions of this code were taken from pyfilesystem, which uses the above
# new BSD license.
from __future__ import with_statement
import ctypes.wintypes
import struct
from functools import reduce
try:
LPVOID = ctypes.wintypes.LPVOID
except AttributeError:
# LPVOID wasn't defined in Py2.5, guess it was introduced in Py2.6
LPVOID = ctypes.c_void_p
# Invalid handle value.
INVALID_HANDLE_VALUE = ctypes.c_void_p(-1).value
# File notification contants.
FILE_NOTIFY_CHANGE_FILE_NAME = 0x01
FILE_NOTIFY_CHANGE_DIR_NAME = 0x02
FILE_NOTIFY_CHANGE_ATTRIBUTES = 0x04
FILE_NOTIFY_CHANGE_SIZE = 0x08
FILE_NOTIFY_CHANGE_LAST_WRITE = 0x010
FILE_NOTIFY_CHANGE_LAST_ACCESS = 0x020
FILE_NOTIFY_CHANGE_CREATION = 0x040
FILE_NOTIFY_CHANGE_SECURITY = 0x0100
FILE_FLAG_BACKUP_SEMANTICS = 0x02000000
FILE_FLAG_OVERLAPPED = 0x40000000
FILE_LIST_DIRECTORY = 1
FILE_SHARE_READ = 0x01
FILE_SHARE_WRITE = 0x02
FILE_SHARE_DELETE = 0x04
OPEN_EXISTING = 3
# File action constants.
FILE_ACTION_CREATED = 1
FILE_ACTION_DELETED = 2
FILE_ACTION_MODIFIED = 3
FILE_ACTION_RENAMED_OLD_NAME = 4
FILE_ACTION_RENAMED_NEW_NAME = 5
FILE_ACTION_OVERFLOW = 0xFFFF
# Aliases
FILE_ACTION_ADDED = FILE_ACTION_CREATED
FILE_ACTION_REMOVED = FILE_ACTION_DELETED
THREAD_TERMINATE = 0x0001
# IO waiting constants.
WAIT_ABANDONED = 0x00000080
WAIT_IO_COMPLETION = 0x000000C0
WAIT_OBJECT_0 = 0x00000000
WAIT_TIMEOUT = 0x00000102
# Error codes
ERROR_OPERATION_ABORTED = 995
class OVERLAPPED(ctypes.Structure):
_fields_ = [('Internal', LPVOID),
('InternalHigh', LPVOID),
('Offset', ctypes.wintypes.DWORD),
('OffsetHigh', ctypes.wintypes.DWORD),
('Pointer', LPVOID),
('hEvent', ctypes.wintypes.HANDLE),
]
def _errcheck_bool(value, func, args):
if not value:
raise ctypes.WinError()
return args
def _errcheck_handle(value, func, args):
if not value:
raise ctypes.WinError()
if value == INVALID_HANDLE_VALUE:
raise ctypes.WinError()
return args
def _errcheck_dword(value, func, args):
if value == 0xFFFFFFFF:
raise ctypes.WinError()
return args
ReadDirectoryChangesW = ctypes.windll.kernel32.ReadDirectoryChangesW
ReadDirectoryChangesW.restype = ctypes.wintypes.BOOL
ReadDirectoryChangesW.errcheck = _errcheck_bool
ReadDirectoryChangesW.argtypes = (
ctypes.wintypes.HANDLE, # hDirectory
LPVOID, # lpBuffer
ctypes.wintypes.DWORD, # nBufferLength
ctypes.wintypes.BOOL, # bWatchSubtree
ctypes.wintypes.DWORD, # dwNotifyFilter
ctypes.POINTER(ctypes.wintypes.DWORD), # lpBytesReturned
ctypes.POINTER(OVERLAPPED), # lpOverlapped
LPVOID # FileIOCompletionRoutine # lpCompletionRoutine
)
CreateFileW = ctypes.windll.kernel32.CreateFileW
CreateFileW.restype = ctypes.wintypes.HANDLE
CreateFileW.errcheck = _errcheck_handle
CreateFileW.argtypes = (
ctypes.wintypes.LPCWSTR, # lpFileName
ctypes.wintypes.DWORD, # dwDesiredAccess
ctypes.wintypes.DWORD, # dwShareMode
LPVOID, # lpSecurityAttributes
ctypes.wintypes.DWORD, # dwCreationDisposition
ctypes.wintypes.DWORD, # dwFlagsAndAttributes
ctypes.wintypes.HANDLE # hTemplateFile
)
CloseHandle = ctypes.windll.kernel32.CloseHandle
CloseHandle.restype = ctypes.wintypes.BOOL
CloseHandle.argtypes = (
ctypes.wintypes.HANDLE, # hObject
)
CancelIoEx = ctypes.windll.kernel32.CancelIoEx
CancelIoEx.restype = ctypes.wintypes.BOOL
CancelIoEx.errcheck = _errcheck_bool
CancelIoEx.argtypes = (
ctypes.wintypes.HANDLE, # hObject
ctypes.POINTER(OVERLAPPED) # lpOverlapped
)
CreateEvent = ctypes.windll.kernel32.CreateEventW
CreateEvent.restype = ctypes.wintypes.HANDLE
CreateEvent.errcheck = _errcheck_handle
CreateEvent.argtypes = (
LPVOID, # lpEventAttributes
ctypes.wintypes.BOOL, # bManualReset
ctypes.wintypes.BOOL, # bInitialState
ctypes.wintypes.LPCWSTR, # lpName
)
SetEvent = ctypes.windll.kernel32.SetEvent
SetEvent.restype = ctypes.wintypes.BOOL
SetEvent.errcheck = _errcheck_bool
SetEvent.argtypes = (
ctypes.wintypes.HANDLE, # hEvent
)
WaitForSingleObjectEx = ctypes.windll.kernel32.WaitForSingleObjectEx
WaitForSingleObjectEx.restype = ctypes.wintypes.DWORD
WaitForSingleObjectEx.errcheck = _errcheck_dword
WaitForSingleObjectEx.argtypes = (
ctypes.wintypes.HANDLE, # hObject
ctypes.wintypes.DWORD, # dwMilliseconds
ctypes.wintypes.BOOL, # bAlertable
)
CreateIoCompletionPort = ctypes.windll.kernel32.CreateIoCompletionPort
CreateIoCompletionPort.restype = ctypes.wintypes.HANDLE
CreateIoCompletionPort.errcheck = _errcheck_handle
CreateIoCompletionPort.argtypes = (
ctypes.wintypes.HANDLE, # FileHandle
ctypes.wintypes.HANDLE, # ExistingCompletionPort
LPVOID, # CompletionKey
ctypes.wintypes.DWORD, # NumberOfConcurrentThreads
)
GetQueuedCompletionStatus = ctypes.windll.kernel32.GetQueuedCompletionStatus
GetQueuedCompletionStatus.restype = ctypes.wintypes.BOOL
GetQueuedCompletionStatus.errcheck = _errcheck_bool
GetQueuedCompletionStatus.argtypes = (
ctypes.wintypes.HANDLE, # CompletionPort
LPVOID, # lpNumberOfBytesTransferred
LPVOID, # lpCompletionKey
ctypes.POINTER(OVERLAPPED), # lpOverlapped
ctypes.wintypes.DWORD, # dwMilliseconds
)
PostQueuedCompletionStatus = ctypes.windll.kernel32.PostQueuedCompletionStatus
PostQueuedCompletionStatus.restype = ctypes.wintypes.BOOL
PostQueuedCompletionStatus.errcheck = _errcheck_bool
PostQueuedCompletionStatus.argtypes = (
ctypes.wintypes.HANDLE, # CompletionPort
ctypes.wintypes.DWORD, # lpNumberOfBytesTransferred
ctypes.wintypes.DWORD, # lpCompletionKey
ctypes.POINTER(OVERLAPPED), # lpOverlapped
)
class FILE_NOTIFY_INFORMATION(ctypes.Structure):
_fields_ = [("NextEntryOffset", ctypes.wintypes.DWORD),
("Action", ctypes.wintypes.DWORD),
("FileNameLength", ctypes.wintypes.DWORD),
#("FileName", (ctypes.wintypes.WCHAR * 1))]
("FileName", (ctypes.c_char * 1))]
LPFNI = ctypes.POINTER(FILE_NOTIFY_INFORMATION)
# We don't need to recalculate these flags every time a call is made to
# the win32 API functions.
WATCHDOG_FILE_FLAGS = FILE_FLAG_BACKUP_SEMANTICS
WATCHDOG_FILE_SHARE_FLAGS = reduce(
lambda x, y: x | y, [
FILE_SHARE_READ,
FILE_SHARE_WRITE,
FILE_SHARE_DELETE,
])
WATCHDOG_FILE_NOTIFY_FLAGS = reduce(
lambda x, y: x | y, [
FILE_NOTIFY_CHANGE_FILE_NAME,
FILE_NOTIFY_CHANGE_DIR_NAME,
FILE_NOTIFY_CHANGE_ATTRIBUTES,
FILE_NOTIFY_CHANGE_SIZE,
FILE_NOTIFY_CHANGE_LAST_WRITE,
FILE_NOTIFY_CHANGE_SECURITY,
FILE_NOTIFY_CHANGE_LAST_ACCESS,
FILE_NOTIFY_CHANGE_CREATION,
])
BUFFER_SIZE = 2048
def _parse_event_buffer(readBuffer, nBytes):
results = []
while nBytes > 0:
fni = ctypes.cast(readBuffer, LPFNI)[0]
ptr = ctypes.addressof(fni) + FILE_NOTIFY_INFORMATION.FileName.offset
#filename = ctypes.wstring_at(ptr, fni.FileNameLength)
filename = ctypes.string_at(ptr, fni.FileNameLength)
results.append((fni.Action, filename.decode('utf-16')))
numToSkip = fni.NextEntryOffset
if numToSkip <= 0:
break
readBuffer = readBuffer[numToSkip:]
nBytes -= numToSkip # numToSkip is long. nBytes should be long too.
return results
def get_directory_handle(path):
"""Returns a Windows handle to the specified directory path."""
return CreateFileW(path, FILE_LIST_DIRECTORY, WATCHDOG_FILE_SHARE_FLAGS,
None, OPEN_EXISTING, WATCHDOG_FILE_FLAGS, None)
def close_directory_handle(handle):
try:
CancelIoEx(handle, None) # force ReadDirectoryChangesW to return
CloseHandle(handle) # close directory handle
except WindowsError:
try:
CloseHandle(handle) # close directory handle
except:
return
def read_directory_changes(handle, recursive):
"""Read changes to the directory using the specified directory handle.
http://timgolden.me.uk/pywin32-docs/win32file__ReadDirectoryChangesW_meth.html
"""
event_buffer = ctypes.create_string_buffer(BUFFER_SIZE)
nbytes = ctypes.wintypes.DWORD()
try:
ReadDirectoryChangesW(handle, ctypes.byref(event_buffer),
len(event_buffer), recursive,
WATCHDOG_FILE_NOTIFY_FLAGS,
ctypes.byref(nbytes), None, None)
except WindowsError as e:
if e.winerror == ERROR_OPERATION_ABORTED:
return [], 0
raise e
# Python 2/3 compat
try:
int_class = long
except NameError:
int_class = int
return event_buffer.raw, int_class(nbytes.value)
class WinAPINativeEvent(object):
def __init__(self, action, src_path):
self.action = action
self.src_path = src_path
@property
def is_added(self):
return self.action == FILE_ACTION_CREATED
@property
def is_removed(self):
return self.action == FILE_ACTION_REMOVED
@property
def is_modified(self):
return self.action == FILE_ACTION_MODIFIED
@property
def is_renamed_old(self):
return self.action == FILE_ACTION_RENAMED_OLD_NAME
@property
def is_renamed_new(self):
return self.action == FILE_ACTION_RENAMED_NEW_NAME
def __repr__(self):
return ("<WinAPINativeEvent: action=%d, src_path=%r>" % (self.action, self.src_path))
def read_events(handle, recursive):
buf, nbytes = read_directory_changes(handle, recursive)
events = _parse_event_buffer(buf, nbytes)
return [WinAPINativeEvent(action, path) for action, path in events]