[Python-checkins] r77802 - in python/branches/release26-maint: Lib/io.py Lib/test/test_fileio.py Lib/test/test_io.py Lib/test/test_memoryio.py Misc/NEWS Modules/_bytesio.c Modules/_fileio.c
antoine.pitrou
python-checkins at python.org
Wed Jan 27 22:48:46 CET 2010
Author: antoine.pitrou
Date: Wed Jan 27 22:48:46 2010
New Revision: 77802
Log:
Issue #6939: Fix file I/O objects in the `io` module to keep the original
file position when calling `truncate()`. It would previously change the
file position to the given argument, which goes against the tradition of
`ftruncate()` and other truncation APIs. Patch by Pascal Chambon.
Modified:
python/branches/release26-maint/Lib/io.py
python/branches/release26-maint/Lib/test/test_fileio.py
python/branches/release26-maint/Lib/test/test_io.py
python/branches/release26-maint/Lib/test/test_memoryio.py
python/branches/release26-maint/Misc/NEWS
python/branches/release26-maint/Modules/_bytesio.c
python/branches/release26-maint/Modules/_fileio.c
Modified: python/branches/release26-maint/Lib/io.py
==============================================================================
--- python/branches/release26-maint/Lib/io.py (original)
+++ python/branches/release26-maint/Lib/io.py Wed Jan 27 22:48:46 2010
@@ -880,7 +880,7 @@
elif pos < 0:
raise ValueError("negative truncate position %r" % (pos,))
del self._buffer[pos:]
- return self.seek(pos)
+ return pos
def readable(self):
return True
@@ -1215,8 +1215,7 @@
if pos is None:
pos = self.tell()
# Use seek to flush the read buffer.
- self.seek(pos)
- return BufferedWriter.truncate(self)
+ return BufferedWriter.truncate(self, pos)
def read(self, n=None):
if n is None:
@@ -1667,8 +1666,7 @@
self.flush()
if pos is None:
pos = self.tell()
- self.seek(pos)
- return self.buffer.truncate()
+ return self.buffer.truncate(pos)
def seek(self, cookie, whence=0):
if self.closed:
Modified: python/branches/release26-maint/Lib/test/test_fileio.py
==============================================================================
--- python/branches/release26-maint/Lib/test/test_fileio.py (original)
+++ python/branches/release26-maint/Lib/test/test_fileio.py Wed Jan 27 22:48:46 2010
@@ -197,6 +197,17 @@
f.close()
self.fail("no error for invalid mode: %s" % bad_mode)
+ def testTruncate(self):
+ f = _fileio._FileIO(TESTFN, 'w')
+ f.write(bytes(bytearray(range(10))))
+ self.assertEqual(f.tell(), 10)
+ f.truncate(5)
+ self.assertEqual(f.tell(), 10)
+ self.assertEqual(f.seek(0, os.SEEK_END), 5)
+ f.truncate(15)
+ self.assertEqual(f.tell(), 5)
+ self.assertEqual(f.seek(0, os.SEEK_END), 15)
+
def testTruncateOnWindows(self):
def bug801631():
# SF bug <http://www.python.org/sf/801631>
Modified: python/branches/release26-maint/Lib/test/test_io.py
==============================================================================
--- python/branches/release26-maint/Lib/test/test_io.py (original)
+++ python/branches/release26-maint/Lib/test/test_io.py Wed Jan 27 22:48:46 2010
@@ -87,6 +87,12 @@
test_support.unlink(test_support.TESTFN)
def write_ops(self, f):
+
+ self.assertEqual(f.write(b"blah."), 5)
+ f.truncate(0)
+ self.assertEqual(f.tell(), 5)
+ f.seek(0)
+
self.assertEqual(f.write(b"blah."), 5)
self.assertEqual(f.seek(0), 0)
self.assertEqual(f.write(b"Hello."), 6)
@@ -98,8 +104,9 @@
self.assertEqual(f.write(b"h"), 1)
self.assertEqual(f.seek(-1, 2), 13)
self.assertEqual(f.tell(), 13)
+
self.assertEqual(f.truncate(12), 12)
- self.assertEqual(f.tell(), 12)
+ self.assertEqual(f.tell(), 13)
self.assertRaises(TypeError, f.seek, 0.0)
def read_ops(self, f, buffered=False):
@@ -144,7 +151,7 @@
self.assertEqual(f.tell(), self.LARGE + 2)
self.assertEqual(f.seek(0, 2), self.LARGE + 2)
self.assertEqual(f.truncate(self.LARGE + 1), self.LARGE + 1)
- self.assertEqual(f.tell(), self.LARGE + 1)
+ self.assertEqual(f.tell(), self.LARGE + 2)
self.assertEqual(f.seek(0, 2), self.LARGE + 1)
self.assertEqual(f.seek(-1, 2), self.LARGE)
self.assertEqual(f.read(2), b"x")
Modified: python/branches/release26-maint/Lib/test/test_memoryio.py
==============================================================================
--- python/branches/release26-maint/Lib/test/test_memoryio.py (original)
+++ python/branches/release26-maint/Lib/test/test_memoryio.py Wed Jan 27 22:48:46 2010
@@ -32,7 +32,7 @@
self.assertEqual(f.seek(0), 0)
self.assertEqual(f.write(t("h")), 1)
self.assertEqual(f.truncate(12), 12)
- self.assertEqual(f.tell(), 12)
+ self.assertEqual(f.tell(), 1)
def test_write(self):
buf = self.buftype("hello world\n")
@@ -83,7 +83,8 @@
# truncate() accepts long objects
self.assertEqual(memio.truncate(4L), 4)
self.assertEqual(memio.getvalue(), buf[:4])
- self.assertEqual(memio.tell(), 4)
+ self.assertEqual(memio.tell(), 6)
+ memio.seek(0, 2)
memio.write(buf)
self.assertEqual(memio.getvalue(), buf[:4] + buf)
pos = memio.tell()
Modified: python/branches/release26-maint/Misc/NEWS
==============================================================================
--- python/branches/release26-maint/Misc/NEWS (original)
+++ python/branches/release26-maint/Misc/NEWS Wed Jan 27 22:48:46 2010
@@ -53,6 +53,11 @@
Library
-------
+- Issue #6939: Fix file I/O objects in the `io` module to keep the original
+ file position when calling `truncate()`. It would previously change the
+ file position to the given argument, which goes against the tradition of
+ ftruncate() and other truncation APIs. Patch by Pascal Chambon.
+
- Issue #7792: Registering non-classes to ABCs raised an obscure error.
- Issue #7773: Fix an UnboundLocalError in platform.linux_distribution() when
Modified: python/branches/release26-maint/Modules/_bytesio.c
==============================================================================
--- python/branches/release26-maint/Modules/_bytesio.c (original)
+++ python/branches/release26-maint/Modules/_bytesio.c Wed Jan 27 22:48:46 2010
@@ -445,7 +445,6 @@
if (resize_buffer(self, size) < 0)
return NULL;
}
- self->pos = size;
return PyInt_FromSsize_t(size);
}
Modified: python/branches/release26-maint/Modules/_fileio.c
==============================================================================
--- python/branches/release26-maint/Modules/_fileio.c (original)
+++ python/branches/release26-maint/Modules/_fileio.c Wed Jan 27 22:48:46 2010
@@ -646,8 +646,10 @@
static PyObject *
fileio_truncate(PyFileIOObject *self, PyObject *args)
{
- PyObject *posobj = NULL;
+ PyObject *posobj = NULL; /* the new size wanted by the user */
+#ifndef MS_WINDOWS
Py_off_t pos;
+#endif
int ret;
int fd;
@@ -662,56 +664,86 @@
if (posobj == Py_None || posobj == NULL) {
/* Get the current position. */
- posobj = portable_lseek(fd, NULL, 1);
- if (posobj == NULL)
+ posobj = portable_lseek(fd, NULL, 1);
+ if (posobj == NULL)
return NULL;
- }
- else {
- /* Move to the position to be truncated. */
- posobj = portable_lseek(fd, posobj, 0);
- }
-
-#if defined(HAVE_LARGEFILE_SUPPORT)
- pos = PyLong_AsLongLong(posobj);
-#else
- pos = PyLong_AsLong(posobj);
-#endif
- if (PyErr_Occurred())
- return NULL;
+ }
+ else {
+ Py_INCREF(posobj);
+ }
#ifdef MS_WINDOWS
/* MS _chsize doesn't work if newsize doesn't fit in 32 bits,
so don't even try using it. */
{
+ PyObject *oldposobj, *tempposobj;
HANDLE hFile;
+
+ /* we save the file pointer position */
+ oldposobj = portable_lseek(fd, NULL, 1);
+ if (oldposobj == NULL) {
+ Py_DECREF(posobj);
+ return NULL;
+ }
+
+ /* we then move to the truncation position */
+ tempposobj = portable_lseek(fd, posobj, 0);
+ if (tempposobj == NULL) {
+ Py_DECREF(oldposobj);
+ Py_DECREF(posobj);
+ return NULL;
+ }
+ Py_DECREF(tempposobj);
/* Truncate. Note that this may grow the file! */
Py_BEGIN_ALLOW_THREADS
errno = 0;
hFile = (HANDLE)_get_osfhandle(fd);
- ret = hFile == (HANDLE)-1;
+ ret = hFile == (HANDLE)-1; /* testing for INVALID_HANDLE value */
if (ret == 0) {
ret = SetEndOfFile(hFile) == 0;
if (ret)
errno = EACCES;
}
Py_END_ALLOW_THREADS
+
+ /* we restore the file pointer position in any case */
+ tempposobj = portable_lseek(fd, oldposobj, 0);
+ Py_DECREF(oldposobj);
+ if (tempposobj == NULL) {
+ Py_DECREF(posobj);
+ return NULL;
+ }
+ Py_DECREF(tempposobj);
}
#else
+
+#if defined(HAVE_LARGEFILE_SUPPORT)
+ pos = PyLong_AsLongLong(posobj);
+#else
+ pos = PyLong_AsLong(posobj);
+#endif
+ if (PyErr_Occurred()){
+ Py_DECREF(posobj);
+ return NULL;
+ }
+
Py_BEGIN_ALLOW_THREADS
errno = 0;
ret = ftruncate(fd, pos);
Py_END_ALLOW_THREADS
+
#endif /* !MS_WINDOWS */
if (ret != 0) {
+ Py_DECREF(posobj);
PyErr_SetFromErrno(PyExc_IOError);
return NULL;
}
return posobj;
}
-#endif
+#endif /* HAVE_FTRUNCATE */
static char *
mode_string(PyFileIOObject *self)
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