diff options
Diffstat (limited to 'Lib/tempfile.py')
| -rw-r--r-- | Lib/tempfile.py | 143 |
1 files changed, 116 insertions, 27 deletions
diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 0537228ba5..2f1f9fda78 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -6,6 +6,14 @@ provided by this module can be used without fear of race conditions except for 'mktemp'. 'mktemp' is subject to race conditions and should not be used; it is provided for backward compatibility only. +The default path names are returned as str. If you supply bytes as +input, all return values will be in bytes. Ex: + + >>> tempfile.mkstemp() + (4, '/tmp/tmptpu9nin8') + >>> tempfile.mkdtemp(suffix=b'') + b'/tmp/tmppbi8f0hy' + This module also provides some data items to the user: TMP_MAX - maximum number of names that will be tried before @@ -21,7 +29,8 @@ __all__ = [ "mkstemp", "mkdtemp", # low level safe interfaces "mktemp", # deprecated unsafe interface "TMP_MAX", "gettempprefix", # constants - "tempdir", "gettempdir" + "tempdir", "gettempdir", + "gettempprefixb", "gettempdirb", ] @@ -55,8 +64,10 @@ if hasattr(_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). +# This variable _was_ unused for legacy reasons, see issue 10354. +# But as of 3.5 we actually use it at runtime so changing it would +# have a possibly desirable side effect... But we do not want to support +# that as an API. It is undocumented on purpose. Do not depend on this. template = "tmp" # Internal routines. @@ -82,6 +93,46 @@ def _exists(fn): else: return True + +def _infer_return_type(*args): + """Look at the type of all args and divine their implied return type.""" + return_type = None + for arg in args: + if arg is None: + continue + if isinstance(arg, bytes): + if return_type is str: + raise TypeError("Can't mix bytes and non-bytes in " + "path components.") + return_type = bytes + else: + if return_type is bytes: + raise TypeError("Can't mix bytes and non-bytes in " + "path components.") + return_type = str + if return_type is None: + return str # tempfile APIs return a str by default. + return return_type + + +def _sanitize_params(prefix, suffix, dir): + """Common parameter processing for most APIs in this module.""" + output_type = _infer_return_type(prefix, suffix, dir) + if suffix is None: + suffix = output_type() + if prefix is None: + if output_type is str: + prefix = template + else: + prefix = _os.fsencode(template) + if dir is None: + if output_type is str: + dir = gettempdir() + else: + dir = gettempdirb() + return prefix, suffix, dir, output_type + + class _RandomNameSequence: """An instance of _RandomNameSequence generates an endless sequence of unpredictable strings which can safely be incorporated @@ -195,17 +246,18 @@ def _get_candidate_names(): return _name_sequence -def _mkstemp_inner(dir, pre, suf, flags): +def _mkstemp_inner(dir, pre, suf, flags, output_type): """Code common to mkstemp, TemporaryFile, and NamedTemporaryFile.""" names = _get_candidate_names() + if output_type is bytes: + names = map(_os.fsencode, 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) - return (fd, _os.path.abspath(file)) except FileExistsError: continue # try again except PermissionError: @@ -216,6 +268,7 @@ def _mkstemp_inner(dir, pre, suf, flags): continue else: raise + return (fd, _os.path.abspath(file)) raise FileExistsError(_errno.EEXIST, "No usable temporary file name found") @@ -224,9 +277,13 @@ def _mkstemp_inner(dir, pre, suf, flags): # User visible interfaces. def gettempprefix(): - """Accessor for tempdir.template.""" + """The default prefix for temporary directories.""" return template +def gettempprefixb(): + """The default prefix for temporary directories as bytes.""" + return _os.fsencode(gettempprefix()) + tempdir = None def gettempdir(): @@ -241,7 +298,11 @@ def gettempdir(): _once_lock.release() return tempdir -def mkstemp(suffix="", prefix=template, dir=None, text=False): +def gettempdirb(): + """A bytes version of tempfile.gettempdir().""" + return _os.fsencode(gettempdir()) + +def mkstemp(suffix=None, prefix=None, 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. @@ -259,6 +320,10 @@ def mkstemp(suffix="", prefix=template, dir=None, text=False): mode. Else (the default) the file is opened in binary mode. On some operating systems, this makes no difference. + suffix, prefix and dir must all contain the same type if specified. + If they are bytes, the returned name will be bytes; str otherwise. + A value of None will cause an appropriate default to be used. + 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 @@ -267,18 +332,17 @@ def mkstemp(suffix="", prefix=template, dir=None, text=False): Caller is responsible for deleting the file when done with it. """ - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) if text: flags = _text_openflags else: flags = _bin_openflags - return _mkstemp_inner(dir, prefix, suffix, flags) + return _mkstemp_inner(dir, prefix, suffix, flags, output_type) -def mkdtemp(suffix="", prefix=template, dir=None): +def mkdtemp(suffix=None, prefix=None, dir=None): """User-callable function to create and return a unique temporary directory. The return value is the pathname of the directory. @@ -291,17 +355,17 @@ def mkdtemp(suffix="", prefix=template, dir=None): Caller is responsible for deleting the directory when done with it. """ - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) names = _get_candidate_names() + if output_type is bytes: + names = map(_os.fsencode, 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 except PermissionError: @@ -312,6 +376,7 @@ def mkdtemp(suffix="", prefix=template, dir=None): continue else: raise + return file raise FileExistsError(_errno.EEXIST, "No usable temporary directory name found") @@ -323,8 +388,8 @@ def mktemp(suffix="", prefix=template, dir=None): 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 + THIS FUNCTION IS UNSAFE AND SHOULD NOT BE USED. The file name may + refer 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. """ @@ -454,7 +519,7 @@ class _TemporaryFileWrapper: def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, - newline=None, suffix="", prefix=template, + newline=None, suffix=None, prefix=None, dir=None, delete=True): """Create and return a temporary file. Arguments: @@ -471,8 +536,7 @@ def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, when it is closed unless the 'delete' argument is set to False. """ - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) flags = _bin_openflags @@ -481,7 +545,7 @@ def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None, if _os.name == 'nt' and delete: flags |= _os.O_TEMPORARY - (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) + (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type) try: file = _io.open(fd, mode, buffering=buffering, newline=newline, encoding=encoding) @@ -497,8 +561,13 @@ if _os.name != 'posix' or _os.sys.platform == 'cygwin': TemporaryFile = NamedTemporaryFile else: + # Is the O_TMPFILE flag available and does it work? + # The flag is set to False if os.open(dir, os.O_TMPFILE) raises an + # IsADirectoryError exception + _O_TMPFILE_WORKS = hasattr(_os, 'O_TMPFILE') + def TemporaryFile(mode='w+b', buffering=-1, encoding=None, - newline=None, suffix="", prefix=template, + newline=None, suffix=None, prefix=None, dir=None): """Create and return a temporary file. Arguments: @@ -512,13 +581,33 @@ else: Returns an object with a file-like interface. The file has no name, and will cease to exist when it is closed. """ + global _O_TMPFILE_WORKS - if dir is None: - dir = gettempdir() + prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir) flags = _bin_openflags - - (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) + if _O_TMPFILE_WORKS: + try: + flags2 = (flags | _os.O_TMPFILE) & ~_os.O_CREAT + fd = _os.open(dir, flags2, 0o600) + except IsADirectoryError: + # Linux kernel older than 3.11 ignores O_TMPFILE flag. + # Set flag to False to not try again. + _O_TMPFILE_WORKS = False + except OSError: + # The filesystem of the directory does not support O_TMPFILE. + # For example, OSError(95, 'Operation not supported'). + pass + else: + try: + return _io.open(fd, mode, buffering=buffering, + newline=newline, encoding=encoding) + except: + _os.close(fd) + raise + # Fallback to _mkstemp_inner(). + + (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type) try: _os.unlink(name) return _io.open(fd, mode, buffering=buffering, @@ -536,7 +625,7 @@ class SpooledTemporaryFile: def __init__(self, max_size=0, mode='w+b', buffering=-1, encoding=None, newline=None, - suffix="", prefix=template, dir=None): + suffix=None, prefix=None, dir=None): if 'b' in mode: self._file = _io.BytesIO() else: @@ -687,7 +776,7 @@ class TemporaryDirectory(object): in it are removed. """ - def __init__(self, suffix="", prefix=template, dir=None): + def __init__(self, suffix=None, prefix=None, dir=None): self.name = mkdtemp(suffix, prefix, dir) self._finalizer = _weakref.finalize( self, self._cleanup, self.name, |