[Python-checkins] r50916 - in python/trunk: Doc/lib/libimp.tex Lib/pkgutil.py Misc/NEWS Python/import.c
phillip.eby
python-checkins at python.org
Fri Jul 28 23:12:09 CEST 2006
Author: phillip.eby
Date: Fri Jul 28 23:12:07 2006
New Revision: 50916
Modified:
python/trunk/Doc/lib/libimp.tex
python/trunk/Lib/pkgutil.py
python/trunk/Misc/NEWS
python/trunk/Python/import.c
Log:
Bug #1529871: The speed enhancement patch #921466 broke Python's compliance
with PEP 302. This was fixed by adding an ``imp.NullImporter`` type that is
used in ``sys.path_importer_cache`` to cache non-directory paths and avoid
excessive filesystem operations during imports.
Modified: python/trunk/Doc/lib/libimp.tex
==============================================================================
--- python/trunk/Doc/lib/libimp.tex (original)
+++ python/trunk/Doc/lib/libimp.tex Fri Jul 28 23:12:07 2006
@@ -232,6 +232,24 @@
source file.
\end{funcdesc}
+\begin{classdesc}{NullImporter}{path_string}
+The \class{NullImporter} type is a \pep{302} import hook that handles
+non-directory path strings by failing to find any modules. Calling this
+type with an existing directory or empty string raises
+\exception{ImportError}. Otherwise, a \class{NullImporter} instance is
+returned.
+
+Python adds instances of this type to \code{sys.path_importer_cache} for
+any path entries that are not directories and are not handled by any other
+path hooks on \code{sys.path_hooks}. Instances have only one method:
+
+\begin{methoddesc}{find_module}{fullname \optional{, path}}
+This method always returns \code{None}, indicating that the requested
+module could not be found.
+\end{methoddesc}
+
+\versionadded{2.5}
+\end{classdesc}
\subsection{Examples}
\label{examples-imp}
@@ -257,7 +275,7 @@
# there's a problem we can't handle -- let the caller handle it.
fp, pathname, description = imp.find_module(name)
-
+
try:
return imp.load_module(name, fp, pathname, description)
finally:
Modified: python/trunk/Lib/pkgutil.py
==============================================================================
--- python/trunk/Lib/pkgutil.py (original)
+++ python/trunk/Lib/pkgutil.py Fri Jul 28 23:12:07 2006
@@ -381,9 +381,7 @@
importer = None
sys.path_importer_cache.setdefault(path_item, importer)
- # The boolean values are used for caching valid and invalid
- # file paths for the built-in import machinery
- if importer in (None, True, False):
+ if importer is None:
try:
importer = ImpImporter(path_item)
except ImportError:
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Fri Jul 28 23:12:07 2006
@@ -12,6 +12,11 @@
Core and builtins
-----------------
+- Bug #1529871: The speed enhancement patch #921466 broke Python's compliance
+ with PEP 302. This was fixed by adding an ``imp.NullImporter`` type that is
+ used in ``sys.path_importer_cache`` to cache non-directory paths and avoid
+ excessive filesystem operations during imports.
+
- Bug #1521947: When checking for overflow, ``PyOS_strtol()`` used some
operations on signed longs that are formally undefined by C.
Unfortunately, at least one compiler now cares about that, so complicated
@@ -106,10 +111,14 @@
Extension Modules
-----------------
+<<<<<<< .mine
+- Bug #1471938: Fix curses module build problem on Solaris 8; patch by
+=======
- The ``__reduce__()`` method of the new ``collections.defaultdict`` had
a memory leak, affecting pickles and deep copies.
- Bug #1471938: Fix curses module build problem on Solaris 8; patch by
+>>>>>>> .r50915
Paul Eggert.
- Patch #1448199: Release interpreter lock in _winreg.ConnectRegistry.
Modified: python/trunk/Python/import.c
==============================================================================
--- python/trunk/Python/import.c (original)
+++ python/trunk/Python/import.c Fri Jul 28 23:12:07 2006
@@ -98,6 +98,8 @@
};
#endif
+static PyTypeObject NullImporterType; /* Forward reference */
+
/* Initialize things */
void
@@ -155,6 +157,8 @@
/* adding sys.path_hooks and sys.path_importer_cache, setting up
zipimport */
+ if (PyType_Ready(&NullImporterType) < 0)
+ goto error;
if (Py_VerboseFlag)
PySys_WriteStderr("# installing zipimport hook\n");
@@ -180,9 +184,11 @@
if (err) {
error:
PyErr_Print();
- Py_FatalError("initializing sys.meta_path, sys.path_hooks or "
- "path_importer_cache failed");
+ Py_FatalError("initializing sys.meta_path, sys.path_hooks, "
+ "path_importer_cache, or NullImporter failed"
+ );
}
+
zimpimport = PyImport_ImportModule("zipimport");
if (zimpimport == NULL) {
PyErr_Clear(); /* No zip import module -- okay */
@@ -1058,9 +1064,18 @@
}
PyErr_Clear();
}
- if (importer == NULL)
- importer = Py_None;
- else if (importer != Py_None) {
+ if (importer == NULL) {
+ importer = PyObject_CallFunctionObjArgs(
+ (PyObject *)&NullImporterType, p, NULL
+ );
+ if (importer == NULL) {
+ if (PyErr_ExceptionMatches(PyExc_ImportError)) {
+ PyErr_Clear();
+ return Py_None;
+ }
+ }
+ }
+ if (importer != NULL) {
int err = PyDict_SetItem(path_importer_cache, p, importer);
Py_DECREF(importer);
if (err != 0)
@@ -1248,35 +1263,7 @@
return NULL;
}
/* Note: importer is a borrowed reference */
- if (importer == Py_False) {
- /* Cached as not being a valid dir. */
- Py_XDECREF(copy);
- continue;
- }
- else if (importer == Py_True) {
- /* Cached as being a valid dir, so just
- * continue below. */
- }
- else if (importer == Py_None) {
- /* No importer was found, so it has to be a file.
- * Check if the directory is valid.
- * Note that the empty string is a valid path, but
- * not stat'able, hence the check for len. */
-#ifdef HAVE_STAT
- if (len && stat(buf, &statbuf) != 0) {
- /* Directory does not exist. */
- PyDict_SetItem(path_importer_cache,
- v, Py_False);
- Py_XDECREF(copy);
- continue;
- } else {
- PyDict_SetItem(path_importer_cache,
- v, Py_True);
- }
-#endif
- }
- else {
- /* A real import hook importer was found. */
+ if (importer != Py_None) {
PyObject *loader;
loader = PyObject_CallMethod(importer,
"find_module",
@@ -2935,11 +2922,120 @@
return err;
}
+typedef struct {
+ PyObject_HEAD
+} NullImporter;
+
+static int
+NullImporter_init(NullImporter *self, PyObject *args, PyObject *kwds)
+{
+ char *path;
+
+ if (!_PyArg_NoKeywords("NullImporter()", kwds))
+ return -1;
+
+ if (!PyArg_ParseTuple(args, "s:NullImporter",
+ &path))
+ return -1;
+
+ if (strlen(path) == 0) {
+ PyErr_SetString(PyExc_ImportError, "empty pathname");
+ return -1;
+ } else {
+#ifndef RISCOS
+ struct stat statbuf;
+ int rv;
+
+ rv = stat(path, &statbuf);
+ if (rv == 0) {
+ /* it exists */
+ if (S_ISDIR(statbuf.st_mode)) {
+ /* it's a directory */
+ PyErr_SetString(PyExc_ImportError,
+ "existing directory");
+ return -1;
+ }
+ }
+#else
+ if (object_exists(path)) {
+ /* it exists */
+ if (isdir(path)) {
+ /* it's a directory */
+ PyErr_SetString(PyExc_ImportError,
+ "existing directory");
+ return -1;
+ }
+ }
+#endif
+ }
+ return 0;
+}
+
+static PyObject *
+NullImporter_find_module(NullImporter *self, PyObject *args)
+{
+ Py_RETURN_NONE;
+}
+
+static PyMethodDef NullImporter_methods[] = {
+ {"find_module", (PyCFunction)NullImporter_find_module, METH_VARARGS,
+ "Always return None"
+ },
+ {NULL} /* Sentinel */
+};
+
+
+static PyTypeObject NullImporterType = {
+ PyObject_HEAD_INIT(NULL)
+ 0, /*ob_size*/
+ "imp.NullImporter", /*tp_name*/
+ sizeof(NullImporter), /*tp_basicsize*/
+ 0, /*tp_itemsize*/
+ 0, /*tp_dealloc*/
+ 0, /*tp_print*/
+ 0, /*tp_getattr*/
+ 0, /*tp_setattr*/
+ 0, /*tp_compare*/
+ 0, /*tp_repr*/
+ 0, /*tp_as_number*/
+ 0, /*tp_as_sequence*/
+ 0, /*tp_as_mapping*/
+ 0, /*tp_hash */
+ 0, /*tp_call*/
+ 0, /*tp_str*/
+ 0, /*tp_getattro*/
+ 0, /*tp_setattro*/
+ 0, /*tp_as_buffer*/
+ Py_TPFLAGS_DEFAULT, /*tp_flags*/
+ "Null importer object", /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ 0, /* tp_iter */
+ 0, /* tp_iternext */
+ NullImporter_methods, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ (initproc)NullImporter_init, /* tp_init */
+ 0, /* tp_alloc */
+ PyType_GenericNew /* tp_new */
+};
+
+
PyMODINIT_FUNC
initimp(void)
{
PyObject *m, *d;
+ if (PyType_Ready(&NullImporterType) < 0)
+ goto failure;
+
m = Py_InitModule4("imp", imp_methods, doc_imp,
NULL, PYTHON_API_VERSION);
if (m == NULL)
@@ -2957,6 +3053,8 @@
if (setint(d, "PY_CODERESOURCE", PY_CODERESOURCE) < 0) goto failure;
if (setint(d, "IMP_HOOK", IMP_HOOK) < 0) goto failure;
+ Py_INCREF(&NullImporterType);
+ PyModule_AddObject(m, "NullImporter", (PyObject *)&NullImporterType);
failure:
;
}
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