[Python-checkins] cpython: Cleanup import.c

Fri May 20 05:36:56 EDT 2016

https://hg.python.org/cpython/rev/779563dd701c
changeset: 101442:779563dd701c
user: Victor Stinner <victor.stinner at gmail.com>
date: Fri May 20 11:36:13 2016 +0200
summary:
 Cleanup import.c
* Replace PyUnicode_RPartition() with PyUnicode_FindChar() and
 PyUnicode_Substring() to avoid the creation of a temporary tuple.
* Use PyUnicode_FromFormat() to build a string and avoid the single_dot ('.')
 singleton
Thanks Serhiy Storchaka for your review.
files:
 Python/import.c | 67 +++++++++++++++---------------------
 1 files changed, 28 insertions(+), 39 deletions(-)

diff --git a/Python/import.c b/Python/import.c
--- a/Python/import.c
+++ b/Python/import.c
@@ -1349,7 +1349,6 @@
 _Py_IDENTIFIER(_find_and_load);
 _Py_IDENTIFIER(_handle_fromlist);
 _Py_IDENTIFIER(_lock_unlock_module);
- _Py_static_string(single_dot, ".");
 PyObject *abs_name = NULL;
 PyObject *builtins_import = NULL;
 PyObject *final_mod = NULL;
@@ -1471,19 +1470,25 @@
 }
 
 if (_PyDict_GetItemId(globals, &PyId___path__) == NULL) {
- PyObject *partition = NULL;
- PyObject *borrowed_dot = _PyUnicode_FromId(&single_dot);
- if (borrowed_dot == NULL) {
+ Py_ssize_t dot;
+
+ if (PyUnicode_READY(package) < 0) {
 goto error;
 }
- partition = PyUnicode_RPartition(package, borrowed_dot);
- Py_DECREF(package);
- if (partition == NULL) {
+
+ dot = PyUnicode_FindChar(package, '.',
+ 0, PyUnicode_GET_LENGTH(package), -1);
+ if (dot == -2) {
 goto error;
 }
- package = PyTuple_GET_ITEM(partition, 0);
- Py_INCREF(package);
- Py_DECREF(partition);
+
+ if (dot >= 0) {
+ PyObject *substr = PyUnicode_Substring(package, 0, dot);
+ if (substr == NULL) {
+ goto error;
+ }
+ Py_SETREF(package, substr);
+ }
 }
 }
 
@@ -1531,17 +1536,8 @@
 goto error;
 
 if (PyUnicode_GET_LENGTH(name) > 0) {
- PyObject *borrowed_dot, *seq = NULL;
-
- borrowed_dot = _PyUnicode_FromId(&single_dot);
- seq = PyTuple_Pack(2, base, name);
+ abs_name = PyUnicode_FromFormat("%U.%U", base, name);
 Py_DECREF(base);
- if (borrowed_dot == NULL || seq == NULL) {
- goto error;
- }
-
- abs_name = PyUnicode_Join(borrowed_dot, seq);
- Py_DECREF(seq);
 if (abs_name == NULL) {
 goto error;
 }
@@ -1639,43 +1635,36 @@
 if (has_from < 0)
 goto error;
 if (!has_from) {
- if (level == 0 || PyUnicode_GET_LENGTH(name) > 0) {
- PyObject *front = NULL;
- PyObject *partition = NULL;
- PyObject *borrowed_dot = _PyUnicode_FromId(&single_dot);
+ Py_ssize_t len = PyUnicode_GET_LENGTH(name);
+ if (level == 0 || len > 0) {
+ Py_ssize_t dot;
 
- if (borrowed_dot == NULL) {
+ dot = PyUnicode_FindChar(name, '.', 0, len, 1);
+ if (dot == -2) {
 goto error;
 }
 
- partition = PyUnicode_Partition(name, borrowed_dot);
- if (partition == NULL) {
- goto error;
- }
-
- if (PyUnicode_GET_LENGTH(PyTuple_GET_ITEM(partition, 1)) == 0) {
+ if (dot == -1) {
 /* No dot in module name, simple exit */
- Py_DECREF(partition);
 final_mod = mod;
 Py_INCREF(mod);
 goto error;
 }
 
- front = PyTuple_GET_ITEM(partition, 0);
- Py_INCREF(front);
- Py_DECREF(partition);
+ if (level == 0) {
+ PyObject *front = PyUnicode_Substring(name, 0, dot);
+ if (front == NULL) {
+ goto error;
+ }
 
- if (level == 0) {
 final_mod = PyObject_CallFunctionObjArgs(builtins_import, front, NULL);
 Py_DECREF(front);
 }
 else {
- Py_ssize_t cut_off = PyUnicode_GET_LENGTH(name) -
- PyUnicode_GET_LENGTH(front);
+ Py_ssize_t cut_off = len - dot;
 Py_ssize_t abs_name_len = PyUnicode_GET_LENGTH(abs_name);
 PyObject *to_return = PyUnicode_Substring(abs_name, 0,
 abs_name_len - cut_off);
- Py_DECREF(front);
 if (to_return == NULL) {
 goto error;
 }
-- 
Repository URL: https://hg.python.org/cpython
