diff --git a/lib/assets/Lib/tempfile.py b/lib/assets/Lib/tempfile.py new file mode 100644 --- /dev/null +++ b/lib/assets/Lib/tempfile.py @@ -0,0 +1,716 @@ +"""Temporary files. + +This module provides generic, low- and high-level interfaces for +creating temporary files and directories. The interfaces listed +as "safe" just below can be used without fear of race conditions. +Those listed as "unsafe" cannot, and are provided for backward +compatibility only. + +This module also provides some data items to the user: + + TMP_MAX - maximum number of names that will be tried before + giving up. + tempdir - If this is set to a string before the first use of + any routine from this module, it will be considered as + another candidate location to store temporary files. +""" + +__all__ = [ + "NamedTemporaryFile", "TemporaryFile", # high level safe interfaces + "SpooledTemporaryFile", "TemporaryDirectory", + "mkstemp", "mkdtemp", # low level safe interfaces + "mktemp", # deprecated unsafe interface + "TMP_MAX", "gettempprefix", # constants + "tempdir", "gettempdir" + ] + + +# Imports. + +import warnings as _warnings +import sys as _sys +import io as _io +import os as _os +import errno as _errno +from random import Random as _Random + +try: + import fcntl as _fcntl +except ImportError: + def _set_cloexec(fd): + pass +else: + def _set_cloexec(fd): + try: + flags = _fcntl.fcntl(fd, _fcntl.F_GETFD, 0) + except OSError: + pass + else: + # flags read successfully, modify + flags |= _fcntl.FD_CLOEXEC + _fcntl.fcntl(fd, _fcntl.F_SETFD, flags) + + +try: + import _thread +except ImportError: + import _dummy_thread as _thread +_allocate_lock = _thread.allocate_lock + +_text_openflags = _os.O_RDWR | _os.O_CREAT | _os.O_EXCL +if hasattr(_os, 'O_NOINHERIT'): + _text_openflags |= _os.O_NOINHERIT +if hasattr(_os, 'O_NOFOLLOW'): + _text_openflags |= _os.O_NOFOLLOW + +_bin_openflags = _text_openflags +if hasattr(_os, 'O_BINARY'): + _bin_openflags |= _os.O_BINARY + +if hasattr(_os, 'TMP_MAX'): + TMP_MAX = _os.TMP_MAX +else: + TMP_MAX = 10000 + +# Although it does not have an underscore for historical reasons, this +# variable is an internal implementation detail (see issue 10354). +template = "tmp" + +# Internal routines. + +_once_lock = _allocate_lock() + +if hasattr(_os, "lstat"): + _stat = _os.lstat +elif hasattr(_os, "stat"): + _stat = _os.stat +else: + # Fallback. All we need is something that raises OSError if the + # file doesn't exist. + def _stat(fn): + f = open(fn) + f.close() + +def _exists(fn): + try: + _stat(fn) + except OSError: + return False + else: + return True + +class _RandomNameSequence: + """An instance of _RandomNameSequence generates an endless + sequence of unpredictable strings which can safely be incorporated + into file names. Each string is six characters long. Multiple + threads can safely use the same instance at the same time. + + _RandomNameSequence is an iterator.""" + + characters = "abcdefghijklmnopqrstuvwxyz0123456789_" + + @property + def rng(self): + cur_pid = _os.getpid() + if cur_pid != getattr(self, '_rng_pid', None): + self._rng = _Random() + self._rng_pid = cur_pid + return self._rng + + def __iter__(self): + return self + + def __next__(self): + c = self.characters + choose = self.rng.choice + letters = [choose(c) for dummy in "123456"] + return ''.join(letters) + +def _candidate_tempdir_list(): + """Generate a list of candidate temporary directories which + _get_default_tempdir will try.""" + + dirlist = [] + + # First, try the environment. + for envname in 'TMPDIR', 'TEMP', 'TMP': + dirname = _os.getenv(envname) + if dirname: dirlist.append(dirname) + + # Failing that, try OS-specific locations. + if _os.name == 'nt': + dirlist.extend([ r'c:\temp', r'c:\tmp', r'\temp', r'\tmp' ]) + else: + dirlist.extend([ '/tmp', '/var/tmp', '/usr/tmp' ]) + + # As a last resort, the current directory. + try: + dirlist.append(_os.getcwd()) + except (AttributeError, OSError): + dirlist.append(_os.curdir) + + return dirlist + +def _get_default_tempdir(): + """Calculate the default directory to use for temporary files. + This routine should be called exactly once. + + We determine whether or not a candidate temp dir is usable by + trying to create and write to a file in that directory. If this + is successful, the test file is deleted. To prevent denial of + service, the name of the test file must be randomized.""" + + namer = _RandomNameSequence() + dirlist = _candidate_tempdir_list() + + for dir in dirlist: + if dir != _os.curdir: + dir = _os.path.normcase(_os.path.abspath(dir)) + # Try only a few names per directory. + for seq in range(100): + name = next(namer) + filename = _os.path.join(dir, name) + try: + fd = _os.open(filename, _bin_openflags, 0o600) + try: + try: + with _io.open(fd, 'wb', closefd=False) as fp: + fp.write(b'blat') + finally: + _os.close(fd) + finally: + _os.unlink(filename) + return dir + except FileExistsError: + pass + except OSError: + break # no point trying more names in this directory + raise FileNotFoundError(_errno.ENOENT, + "No usable temporary directory found in %s" % + dirlist) + +_name_sequence = None + +def _get_candidate_names(): + """Common setup sequence for all user-callable interfaces.""" + + global _name_sequence + if _name_sequence is None: + _once_lock.acquire() + try: + if _name_sequence is None: + _name_sequence = _RandomNameSequence() + finally: + _once_lock.release() + return _name_sequence + + +def _mkstemp_inner(dir, pre, suf, flags): + """Code common to mkstemp, TemporaryFile, and NamedTemporaryFile.""" + + names = _get_candidate_names() + + for seq in range(TMP_MAX): + name = next(names) + file = _os.path.join(dir, pre + name + suf) + try: + fd = _os.open(file, flags, 0o600) + _set_cloexec(fd) + return (fd, _os.path.abspath(file)) + except FileExistsError: + continue # try again + except PermissionError: + # This exception is thrown when a directory with the chosen name + # already exists on windows. + if _os.name == 'nt': + continue + else: + raise + + raise FileExistsError(_errno.EEXIST, + "No usable temporary file name found") + + +# User visible interfaces. + +def gettempprefix(): + """Accessor for tempdir.template.""" + return template + +tempdir = None + +def gettempdir(): + """Accessor for tempfile.tempdir.""" + global tempdir + if tempdir is None: + _once_lock.acquire() + try: + if tempdir is None: + tempdir = _get_default_tempdir() + finally: + _once_lock.release() + return tempdir + +def mkstemp(suffix="", prefix=template, dir=None, text=False): + """User-callable function to create and return a unique temporary + file. The return value is a pair (fd, name) where fd is the + file descriptor returned by os.open, and name is the filename. + + If 'suffix' is specified, the file name will end with that suffix, + otherwise there will be no suffix. + + If 'prefix' is specified, the file name will begin with that prefix, + otherwise a default prefix is used. + + If 'dir' is specified, the file will be created in that directory, + otherwise a default directory is used. + + If 'text' is specified and true, the file is opened in text + mode. Else (the default) the file is opened in binary mode. On + some operating systems, this makes no difference. + + The file is readable and writable only by the creating user ID. + If the operating system uses permission bits to indicate whether a + file is executable, the file is executable by no one. The file + descriptor is not inherited by children of this process. + + Caller is responsible for deleting the file when done with it. + """ + + if dir is None: + dir = gettempdir() + + if text: + flags = _text_openflags + else: + flags = _bin_openflags + + return _mkstemp_inner(dir, prefix, suffix, flags) + + +def mkdtemp(suffix="", prefix=template, dir=None): + """User-callable function to create and return a unique temporary + directory. The return value is the pathname of the directory. + + Arguments are as for mkstemp, except that the 'text' argument is + not accepted. + + The directory is readable, writable, and searchable only by the + creating user. + + Caller is responsible for deleting the directory when done with it. + """ + + if dir is None: + dir = gettempdir() + + names = _get_candidate_names() + + for seq in range(TMP_MAX): + name = next(names) + file = _os.path.join(dir, prefix + name + suffix) + try: + _os.mkdir(file, 0o700) + return file + except FileExistsError: + continue # try again + + raise FileExistsError(_errno.EEXIST, + "No usable temporary directory name found") + +def mktemp(suffix="", prefix=template, dir=None): + """User-callable function to return a unique temporary file name. The + file is not created. + + Arguments are as for mkstemp, except that the 'text' argument is + not accepted. + + This function is unsafe and should not be used. The file name + refers to a file that did not exist at some point, but by the time + you get around to creating it, someone else may have beaten you to + the punch. + """ + +## from warnings import warn as _warn +## _warn("mktemp is a potential security risk to your program", +## RuntimeWarning, stacklevel=2) + + if dir is None: + dir = gettempdir() + + names = _get_candidate_names() + for seq in range(TMP_MAX): + name = next(names) + file = _os.path.join(dir, prefix + name + suffix) + if not _exists(file): + return file + + raise FileExistsError(_errno.EEXIST, + "No usable temporary filename found") + + +class _TemporaryFileWrapper: + """Temporary file wrapper + + This class provides a wrapper around files opened for + temporary use. In particular, it seeks to automatically + remove the file when it is no longer needed. + """ + + def __init__(self, file, name, delete=True): + self.file = file + self.name = name + self.close_called = False + self.delete = delete + + def __getattr__(self, name): + # Attribute lookups are delegated to the underlying file + # and cached for non-numeric results + # (i.e. methods are cached, closed and friends are not) + file = self.__dict__['file'] + a = getattr(file, name) + if not isinstance(a, int): + setattr(self, name, a) + return a + + # The underlying __enter__ method returns the wrong object + # (self.file) so override it to return the wrapper + def __enter__(self): + self.file.__enter__() + return self + + # iter() doesn't use __getattr__ to find the __iter__ method + def __iter__(self): + return iter(self.file) + + # NT provides delete-on-close as a primitive, so we don't need + # the wrapper to do anything special. We still use it so that + # file.name is useful (i.e. not "(fdopen)") with NamedTemporaryFile. + if _os.name != 'nt': + # Cache the unlinker so we don't get spurious errors at + # shutdown when the module-level "os" is None'd out. Note + # that this must be referenced as self.unlink, because the + # name TemporaryFileWrapper may also get None'd out before + # __del__ is called. + unlink = _os.unlink + + def close(self): + if not self.close_called: + self.close_called = True + self.file.close() + if self.delete: + self.unlink(self.name) + + def __del__(self): + self.close() + + # Need to trap __exit__ as well to ensure the file gets + # deleted when used in a with statement + def __exit__(self, exc, value, tb): + result = self.file.__exit__(exc, value, tb) + self.close() + return result + else: + def __exit__(self, exc, value, tb): + self.file.__exit__(exc, value, tb) + + +def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, + newline=None, suffix="", prefix=template, + dir=None, delete=True): + """Create and return a temporary file. + Arguments: + 'prefix', 'suffix', 'dir' -- as for mkstemp. + 'mode' -- the mode argument to io.open (default "w+b"). + 'buffering' -- the buffer size argument to io.open (default -1). + 'encoding' -- the encoding argument to io.open (default None) + 'newline' -- the newline argument to io.open (default None) + 'delete' -- whether the file is deleted on close (default True). + The file is created as mkstemp() would do it. + + Returns an object with a file-like interface; the name of the file + is accessible as file.name. The file will be automatically deleted + when it is closed unless the 'delete' argument is set to False. + """ + + if dir is None: + dir = gettempdir() + + flags = _bin_openflags + + # Setting O_TEMPORARY in the flags causes the OS to delete + # the file when it is closed. This is only supported by Windows. + if _os.name == 'nt' and delete: + flags |= _os.O_TEMPORARY + + (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) + file = _io.open(fd, mode, buffering=buffering, + newline=newline, encoding=encoding) + + return _TemporaryFileWrapper(file, name, delete) + +if _os.name != 'posix' or _os.sys.platform == 'cygwin': + # On non-POSIX and Cygwin systems, assume that we cannot unlink a file + # while it is open. + TemporaryFile = NamedTemporaryFile + +else: + def TemporaryFile(mode='w+b', buffering=-1, encoding=None, + newline=None, suffix="", prefix=template, + dir=None): + """Create and return a temporary file. + Arguments: + 'prefix', 'suffix', 'dir' -- as for mkstemp. + 'mode' -- the mode argument to io.open (default "w+b"). + 'buffering' -- the buffer size argument to io.open (default -1). + 'encoding' -- the encoding argument to io.open (default None) + 'newline' -- the newline argument to io.open (default None) + The file is created as mkstemp() would do it. + + Returns an object with a file-like interface. The file has no + name, and will cease to exist when it is closed. + """ + + if dir is None: + dir = gettempdir() + + flags = _bin_openflags + + (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) + try: + _os.unlink(name) + return _io.open(fd, mode, buffering=buffering, + newline=newline, encoding=encoding) + except: + _os.close(fd) + raise + +class SpooledTemporaryFile: + """Temporary file wrapper, specialized to switch from BytesIO + or StringIO to a real file when it exceeds a certain size or + when a fileno is needed. + """ + _rolled = False + + def __init__(self, max_size=0, mode='w+b', buffering=-1, + encoding=None, newline=None, + suffix="", prefix=template, dir=None): + if 'b' in mode: + self._file = _io.BytesIO() + else: + # Setting newline="\n" avoids newline translation; + # this is important because otherwise on Windows we'd + # hget double newline translation upon rollover(). + self._file = _io.StringIO(newline="\n") + self._max_size = max_size + self._rolled = False + self._TemporaryFileArgs = {'mode': mode, 'buffering': buffering, + 'suffix': suffix, 'prefix': prefix, + 'encoding': encoding, 'newline': newline, + 'dir': dir} + + def _check(self, file): + if self._rolled: return + max_size = self._max_size + if max_size and file.tell() > max_size: + self.rollover() + + def rollover(self): + if self._rolled: return + file = self._file + newfile = self._file = TemporaryFile(**self._TemporaryFileArgs) + del self._TemporaryFileArgs + + newfile.write(file.getvalue()) + newfile.seek(file.tell(), 0) + + self._rolled = True + + # The method caching trick from NamedTemporaryFile + # won't work here, because _file may change from a + # BytesIO/StringIO instance to a real file. So we list + # all the methods directly. + + # Context management protocol + def __enter__(self): + if self._file.closed: + raise ValueError("Cannot enter context with closed file") + return self + + def __exit__(self, exc, value, tb): + self._file.close() + + # file protocol + def __iter__(self): + return self._file.__iter__() + + def close(self): + self._file.close() + + @property + def closed(self): + return self._file.closed + + @property + def encoding(self): + try: + return self._file.encoding + except AttributeError: + if 'b' in self._TemporaryFileArgs['mode']: + raise + return self._TemporaryFileArgs['encoding'] + + def fileno(self): + self.rollover() + return self._file.fileno() + + def flush(self): + self._file.flush() + + def isatty(self): + return self._file.isatty() + + @property + def mode(self): + try: + return self._file.mode + except AttributeError: + return self._TemporaryFileArgs['mode'] + + @property + def name(self): + try: + return self._file.name + except AttributeError: + return None + + @property + def newlines(self): + try: + return self._file.newlines + except AttributeError: + if 'b' in self._TemporaryFileArgs['mode']: + raise + return self._TemporaryFileArgs['newline'] + + def read(self, *args): + return self._file.read(*args) + + def readline(self, *args): + return self._file.readline(*args) + + def readlines(self, *args): + return self._file.readlines(*args) + + def seek(self, *args): + self._file.seek(*args) + + @property + def softspace(self): + return self._file.softspace + + def tell(self): + return self._file.tell() + + def truncate(self, size=None): + if size is None: + self._file.truncate() + else: + if size > self._max_size: + self.rollover() + self._file.truncate(size) + + def write(self, s): + file = self._file + rv = file.write(s) + self._check(file) + return rv + + def writelines(self, iterable): + file = self._file + rv = file.writelines(iterable) + self._check(file) + return rv + + +class TemporaryDirectory(object): + """Create and return a temporary directory. This has the same + behavior as mkdtemp but can be used as a context manager. For + example: + + with TemporaryDirectory() as tmpdir: + ... + + Upon exiting the context, the directory and everything contained + in it are removed. + """ + + def __init__(self, suffix="", prefix=template, dir=None): + self._closed = False + self.name = None # Handle mkdtemp raising an exception + self.name = mkdtemp(suffix, prefix, dir) + + def __repr__(self): + return "<{} {!r}>".format(self.__class__.__name__, self.name) + + def __enter__(self): + return self.name + + def cleanup(self, _warn=False): + if self.name and not self._closed: + try: + self._rmtree(self.name) + except (TypeError, AttributeError) as ex: + # Issue #10188: Emit a warning on stderr + # if the directory could not be cleaned + # up due to missing globals + if "None" not in str(ex): + raise + print("ERROR: {!r} while cleaning up {!r}".format(ex, self,), + file=_sys.stderr) + return + self._closed = True + if _warn: + self._warn("Implicitly cleaning up {!r}".format(self), + ResourceWarning) + + def __exit__(self, exc, value, tb): + self.cleanup() + + def __del__(self): + # Issue a ResourceWarning if implicit cleanup needed + self.cleanup(_warn=True) + + # XXX (ncoghlan): The following code attempts to make + # this class tolerant of the module nulling out process + # that happens during CPython interpreter shutdown + # Alas, it doesn't actually manage it. See issue #10188 + _listdir = staticmethod(_os.listdir) + _path_join = staticmethod(_os.path.join) + _isdir = staticmethod(_os.path.isdir) + _islink = staticmethod(_os.path.islink) + _remove = staticmethod(_os.remove) + _rmdir = staticmethod(_os.rmdir) + _os_error = OSError + _warn = _warnings.warn + + def _rmtree(self, path): + # Essentially a stripped down version of shutil.rmtree. We can't + # use globals because they may be None'ed out at shutdown. + for name in self._listdir(path): + fullname = self._path_join(path, name) + try: + isdir = self._isdir(fullname) and not self._islink(fullname) + except self._os_error: + isdir = False + if isdir: + self._rmtree(fullname) + else: + try: + self._remove(fullname) + except self._os_error: + pass + try: + self._rmdir(path) + except self._os_error: + pass