http://hg.python.org/cpython/rev/0d64d9ac2b78 changeset: 73261:0d64d9ac2b78 parent: 73257:e3e5b6f03f79 user: Ross Lagerwall <rosslagerwall@gmail.com> date: Mon Oct 31 20:34:46 2011 +0200 summary: Issue #12797: Added custom opener parameter to builtin open() and FileIO.open(). files: Doc/library/functions.rst | 11 +++++- Doc/library/io.rst | 11 +++++- Lib/_pyio.py | 10 ++++- Lib/test/test_io.py | 9 ++++ Misc/NEWS | 3 + Modules/_io/_iomodule.c | 18 ++++++--- Modules/_io/fileio.c | 49 ++++++++++++++++++++------ 7 files changed, 89 insertions(+), 22 deletions(-) diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -776,7 +776,7 @@ :meth:`__index__` method that returns an integer. -.. function:: open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True) +.. function:: open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None) Open *file* and return a corresponding stream. If the file cannot be opened, an :exc:`OSError` is raised. @@ -883,6 +883,15 @@ closed. If a filename is given *closefd* has no effect and must be ``True`` (the default). + A custom opener can be used by passing a callable as *opener*. The underlying + file descriptor for the file object is then obtained by calling *opener* with + (*file*, *flags*). *opener* must return an open file descriptor (passing + :mod:`os.open` as *opener* results in functionality similar to passing + ``None``). + + .. versionchanged:: 3.3 + The *opener* parameter was added. + The type of file object returned by the :func:`open` function depends on the mode. When :func:`open` is used to open a file in a text mode (``'w'``, ``'r'``, ``'wt'``, ``'rt'``, etc.), it returns a subclass of diff --git a/Doc/library/io.rst b/Doc/library/io.rst --- a/Doc/library/io.rst +++ b/Doc/library/io.rst @@ -458,7 +458,7 @@ Raw File I/O ^^^^^^^^^^^^ -.. class:: FileIO(name, mode='r', closefd=True) +.. class:: FileIO(name, mode='r', closefd=True, opener=None) :class:`FileIO` represents an OS-level file containing bytes data. It implements the :class:`RawIOBase` interface (and therefore the @@ -479,6 +479,15 @@ The :meth:`read` (when called with a positive argument), :meth:`readinto` and :meth:`write` methods on this class will only make one system call. + A custom opener can be used by passing a callable as *opener*. The underlying + file descriptor for the file object is then obtained by calling *opener* with + (*name*, *flags*). *opener* must return an open file descriptor (passing + :mod:`os.open` as *opener* results in functionality similar to passing + ``None``). + + .. versionchanged:: 3.3 + The *opener* parameter was added. + In addition to the attributes and methods from :class:`IOBase` and :class:`RawIOBase`, :class:`FileIO` provides the following data attributes and methods: diff --git a/Lib/_pyio.py b/Lib/_pyio.py --- a/Lib/_pyio.py +++ b/Lib/_pyio.py @@ -27,7 +27,7 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None, - newline=None, closefd=True): + newline=None, closefd=True, opener=None): r"""Open file and return a stream. Raise IOError upon failure. @@ -122,6 +122,12 @@ be kept open when the file is closed. This does not work when a file name is given and must be True in that case. + A custom opener can be used by passing a callable as *opener*. The + underlying file descriptor for the file object is then obtained by calling + *opener* with (*file*, *flags*). *opener* must return an open file + descriptor (passing os.open as *opener* results in functionality similar to + passing None). + open() returns a file object whose type depends on the mode, and through which the standard file operations such as reading and writing are performed. When open() is used to open a file in a text mode ('w', @@ -176,7 +182,7 @@ (writing and "w" or "") + (appending and "a" or "") + (updating and "+" or ""), - closefd) + closefd, opener=opener) line_buffering = False if buffering == 1 or buffering < 0 and raw.isatty(): buffering = -1 diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py --- a/Lib/test/test_io.py +++ b/Lib/test/test_io.py @@ -621,6 +621,15 @@ for obj in test: self.assertTrue(hasattr(obj, "__dict__")) + def test_opener(self): + with self.open(support.TESTFN, "w") as f: + f.write("egg\n") + fd = os.open(support.TESTFN, os.O_RDONLY) + def opener(path, flags): + return fd + with self.open("non-existent", "r", opener=opener) as f: + self.assertEqual(f.read(), "egg\n") + class CIOTest(IOTest): def test_IOBase_finalize(self): diff --git a/Misc/NEWS b/Misc/NEWS --- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,9 @@ Core and Builtins ----------------- +- Issue #12797: Added custom opener parameter to builtin open() and + FileIO.open(). + - Issue #10519: Avoid unnecessary recursive function calls in setobject.c. diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c --- a/Modules/_io/_iomodule.c +++ b/Modules/_io/_iomodule.c @@ -95,7 +95,7 @@ */ PyDoc_STRVAR(open_doc, "open(file, mode='r', buffering=-1, encoding=None,\n" -" errors=None, newline=None, closefd=True) -> file object\n" +" errors=None, newline=None, closefd=True, opener=None) -> file object\n" "\n" "Open file and return a stream. Raise IOError upon failure.\n" "\n" @@ -190,6 +190,12 @@ "when the file is closed. This does not work when a file name is given\n" "and must be True in that case.\n" "\n" +"A custom opener can be used by passing a callable as *opener*. The\n" +"underlying file descriptor for the file object is then obtained by\n" +"calling *opener* with (*file*, *flags*). *opener* must return an open\n" +"file descriptor (passing os.open as *opener* results in functionality\n" +"similar to passing None).\n" +"\n" "open() returns a file object whose type depends on the mode, and\n" "through which the standard file operations such as reading and writing\n" "are performed. When open() is used to open a file in a text mode ('w',\n" @@ -210,8 +216,8 @@ { char *kwlist[] = {"file", "mode", "buffering", "encoding", "errors", "newline", - "closefd", NULL}; - PyObject *file; + "closefd", "opener", NULL}; + PyObject *file, *opener = Py_None; char *mode = "r"; int buffering = -1, closefd = 1; char *encoding = NULL, *errors = NULL, *newline = NULL; @@ -228,10 +234,10 @@ _Py_IDENTIFIER(isatty); _Py_IDENTIFIER(fileno); - if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|sizzzi:open", kwlist, + if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|sizzziO:open", kwlist, &file, &mode, &buffering, &encoding, &errors, &newline, - &closefd)) { + &closefd, &opener)) { return NULL; } @@ -331,7 +337,7 @@ /* Create the Raw file stream */ raw = PyObject_CallFunction((PyObject *)&PyFileIO_Type, - "Osi", file, rawmode, closefd); + "OsiO", file, rawmode, closefd, opener); if (raw == NULL) return NULL; diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c --- a/Modules/_io/fileio.c +++ b/Modules/_io/fileio.c @@ -212,9 +212,9 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds) { fileio *self = (fileio *) oself; - static char *kwlist[] = {"file", "mode", "closefd", NULL}; + static char *kwlist[] = {"file", "mode", "closefd", "opener", NULL}; const char *name = NULL; - PyObject *nameobj, *stringobj = NULL; + PyObject *nameobj, *stringobj = NULL, *opener = Py_None; char *mode = "r"; char *s; #ifdef MS_WINDOWS @@ -233,8 +233,9 @@ return -1; } - if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|si:fileio", - kwlist, &nameobj, &mode, &closefd)) + if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|siO:fileio", + kwlist, &nameobj, &mode, &closefd, + &opener)) return -1; if (PyFloat_Check(nameobj)) { @@ -363,15 +364,35 @@ goto error; } - Py_BEGIN_ALLOW_THREADS errno = 0; + if (opener == Py_None) { + Py_BEGIN_ALLOW_THREADS #ifdef MS_WINDOWS - if (widename != NULL) - self->fd = _wopen(widename, flags, 0666); - else + if (widename != NULL) + self->fd = _wopen(widename, flags, 0666); + else #endif - self->fd = open(name, flags, 0666); - Py_END_ALLOW_THREADS + self->fd = open(name, flags, 0666); + Py_END_ALLOW_THREADS + } else { + PyObject *fdobj = PyObject_CallFunction( + opener, "Oi", nameobj, flags); + if (fdobj == NULL) + goto error; + if (!PyLong_Check(fdobj)) { + Py_DECREF(fdobj); + PyErr_SetString(PyExc_TypeError, + "expected integer from opener"); + goto error; + } + + self->fd = PyLong_AsLong(fdobj); + Py_DECREF(fdobj); + if (self->fd == -1) { + goto error; + } + } + if (self->fd < 0) { #ifdef MS_WINDOWS if (widename != NULL) @@ -1017,13 +1038,17 @@ PyDoc_STRVAR(fileio_doc, -"file(name: str[, mode: str]) -> file IO object\n" +"file(name: str[, mode: str][, opener: None]) -> file IO object\n" "\n" "Open a file. The mode can be 'r', 'w' or 'a' for reading (default),\n" "writing or appending. The file will be created if it doesn't exist\n" "when opened for writing or appending; it will be truncated when\n" "opened for writing. Add a '+' to the mode to allow simultaneous\n" -"reading and writing."); +"reading and writing. A custom opener can be used by passing a\n" +"callable as *opener*. The underlying file descriptor for the file\n" +"object is then obtained by calling opener with (*name*, *flags*).\n" +"*opener* must return an open file descriptor (passing os.open as\n" +"*opener* results in functionality similar to passing None)."); PyDoc_STRVAR(read_doc, "read(size: int) -> bytes. read at most size bytes, returned as bytes.\n" -- Repository URL: http://hg.python.org/cpython