[Python-checkins] cpython: Issue #12797: Added custom opener parameter to builtin open() and FileIO.open().
ross.lagerwall
python-checkins at python.org
Mon Oct 31 19:34:23 CET 2011
http://hg.python.org/cpython/rev/0d64d9ac2b78
changeset: 73261:0d64d9ac2b78
parent: 73257:e3e5b6f03f79
user: Ross Lagerwall <rosslagerwall at 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
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