[Python-checkins] cpython (3.5): Issue #24483: C implementation of functools.lru_cache() now calculates key's
serhiy.storchaka
python-checkins at python.org
Fri Oct 2 05:51:07 EDT 2015
https://hg.python.org/cpython/rev/3f4c319a822f
changeset: 98475:3f4c319a822f
branch: 3.5
parent: 98473:a2d30dfa46a7
user: Serhiy Storchaka <storchaka at gmail.com>
date: Fri Oct 02 12:47:11 2015 +0300
summary:
Issue #24483: C implementation of functools.lru_cache() now calculates key's
hash only once.
files:
Include/dictobject.h | 4 ++
Misc/NEWS | 3 ++
Modules/_functoolsmodule.c | 26 ++++++++++++++----
Objects/dictobject.c | 37 ++++++++++++++++++++++++++
4 files changed, 64 insertions(+), 6 deletions(-)
diff --git a/Include/dictobject.h b/Include/dictobject.h
--- a/Include/dictobject.h
+++ b/Include/dictobject.h
@@ -72,6 +72,10 @@
PyObject *item, Py_hash_t hash);
#endif
PyAPI_FUNC(int) PyDict_DelItem(PyObject *mp, PyObject *key);
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(int) _PyDict_DelItem_KnownHash(PyObject *mp, PyObject *key,
+ Py_hash_t hash);
+#endif
PyAPI_FUNC(void) PyDict_Clear(PyObject *mp);
PyAPI_FUNC(int) PyDict_Next(
PyObject *mp, Py_ssize_t *pos, PyObject **key, PyObject **value);
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -32,6 +32,9 @@
Library
-------
+- Issue #24483: C implementation of functools.lru_cache() now calculates key's
+ hash only once.
+
- Issue #22958: Constructor and update method of weakref.WeakValueDictionary
now accept the self and the dict keyword arguments.
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
--- a/Modules/_functoolsmodule.c
+++ b/Modules/_functoolsmodule.c
@@ -601,6 +601,7 @@
typedef struct lru_list_elem {
PyObject_HEAD
struct lru_list_elem *prev, *next; /* borrowed links */
+ Py_hash_t hash;
PyObject *key, *result;
} lru_list_elem;
@@ -762,10 +763,14 @@
infinite_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds)
{
PyObject *result;
+ Py_hash_t hash;
PyObject *key = lru_cache_make_key(args, kwds, self->typed);
if (!key)
return NULL;
- result = PyDict_GetItemWithError(self->cache, key);
+ hash = PyObject_Hash(key);
+ if (hash == -1)
+ return NULL;
+ result = _PyDict_GetItem_KnownHash(self->cache, key, hash);
if (result) {
Py_INCREF(result);
self->hits++;
@@ -781,7 +786,7 @@
Py_DECREF(key);
return NULL;
}
- if (PyDict_SetItem(self->cache, key, result) < 0) {
+ if (_PyDict_SetItem_KnownHash(self->cache, key, result, hash) < 0) {
Py_DECREF(result);
Py_DECREF(key);
return NULL;
@@ -813,11 +818,15 @@
{
lru_list_elem *link;
PyObject *key, *result;
+ Py_hash_t hash;
key = lru_cache_make_key(args, kwds, self->typed);
if (!key)
return NULL;
- link = (lru_list_elem *)PyDict_GetItemWithError(self->cache, key);
+ hash = PyObject_Hash(key);
+ if (hash == -1)
+ return NULL;
+ link = (lru_list_elem *)_PyDict_GetItem_KnownHash(self->cache, key, hash);
if (link) {
lru_cache_extricate_link(link);
lru_cache_append_link(self, link);
@@ -845,7 +854,8 @@
/* Remove it from the cache.
The cache dict holds one reference to the link,
and the linked list holds yet one reference to it. */
- if (PyDict_DelItem(self->cache, link->key) < 0) {
+ if (_PyDict_DelItem_KnownHash(self->cache, link->key,
+ link->hash) < 0) {
lru_cache_append_link(self, link);
Py_DECREF(key);
Py_DECREF(result);
@@ -859,9 +869,11 @@
oldkey = link->key;
oldresult = link->result;
+ link->hash = hash;
link->key = key;
link->result = result;
- if (PyDict_SetItem(self->cache, key, (PyObject *)link) < 0) {
+ if (_PyDict_SetItem_KnownHash(self->cache, key, (PyObject *)link,
+ hash) < 0) {
Py_DECREF(link);
Py_DECREF(oldkey);
Py_DECREF(oldresult);
@@ -881,10 +893,12 @@
return NULL;
}
+ link->hash = hash;
link->key = key;
link->result = result;
_PyObject_GC_TRACK(link);
- if (PyDict_SetItem(self->cache, key, (PyObject *)link) < 0) {
+ if (_PyDict_SetItem_KnownHash(self->cache, key, (PyObject *)link,
+ hash) < 0) {
Py_DECREF(link);
return NULL;
}
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1242,6 +1242,7 @@
}
assert(key);
assert(value);
+ assert(hash != -1);
mp = (PyDictObject *)op;
/* insertdict() handles any resizing that might be necessary */
@@ -1290,6 +1291,42 @@
return 0;
}
+int
+_PyDict_DelItem_KnownHash(PyObject *op, PyObject *key, Py_hash_t hash)
+{
+ PyDictObject *mp;
+ PyDictKeyEntry *ep;
+ PyObject *old_key, *old_value;
+ PyObject **value_addr;
+
+ if (!PyDict_Check(op)) {
+ PyErr_BadInternalCall();
+ return -1;
+ }
+ assert(key);
+ assert(hash != -1);
+ mp = (PyDictObject *)op;
+ ep = (mp->ma_keys->dk_lookup)(mp, key, hash, &value_addr);
+ if (ep == NULL)
+ return -1;
+ if (*value_addr == NULL) {
+ _PyErr_SetKeyError(key);
+ return -1;
+ }
+ old_value = *value_addr;
+ *value_addr = NULL;
+ mp->ma_used--;
+ if (!_PyDict_HasSplitTable(mp)) {
+ ENSURE_ALLOWS_DELETIONS(mp);
+ old_key = ep->me_key;
+ Py_INCREF(dummy);
+ ep->me_key = dummy;
+ Py_DECREF(old_key);
+ }
+ Py_DECREF(old_value);
+ return 0;
+}
+
void
PyDict_Clear(PyObject *op)
{
--
Repository URL: https://hg.python.org/cpython
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