[Python-checkins] cpython: Issue #28580: Optimize iterating split table values.

Fri Nov 4 03:59:23 EDT 2016

https://hg.python.org/cpython/rev/3904194d06e6
changeset: 104904:3904194d06e6
user: INADA Naoki <songofacandy at gmail.com>
date: Fri Nov 04 16:59:10 2016 +0900
summary:
 Issue #28580: Optimize iterating split table values.
Patch by Xiang Zhang.
files:
 Misc/NEWS | 3 +
 Objects/dictobject.c | 62 ++++++++++++-------------------
 2 files changed, 28 insertions(+), 37 deletions(-)

diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #28580: Optimize iterating split table values.
+ Patch by Xiang Zhang.
+
 - Issue #28583: PyDict_SetDefault didn't combine split table when needed.
 Patch by Xiang Zhang.
 
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1700,7 +1700,7 @@
 _PyDict_Next(PyObject *op, Py_ssize_t *ppos, PyObject **pkey,
 PyObject **pvalue, Py_hash_t *phash)
 {
- Py_ssize_t i, n;
+ Py_ssize_t i;
 PyDictObject *mp;
 PyDictKeyEntry *entry_ptr;
 PyObject *value;
@@ -1709,21 +1709,18 @@
 return 0;
 mp = (PyDictObject *)op;
 i = *ppos;
- n = mp->ma_keys->dk_nentries;
- if ((size_t)i >= (size_t)n)
- return 0;
 if (mp->ma_values) {
- PyObject **value_ptr = &mp->ma_values[i];
- while (i < n && *value_ptr == NULL) {
- value_ptr++;
- i++;
- }
- if (i >= n)
+ if (i < 0 || i >= mp->ma_used)
 return 0;
+ /* values of split table is always dense */
 entry_ptr = &DK_ENTRIES(mp->ma_keys)[i];
- value = *value_ptr;
+ value = mp->ma_values[i];
+ assert(value != NULL);
 }
 else {
+ Py_ssize_t n = mp->ma_keys->dk_nentries;
+ if (i < 0 || i >= n)
+ return 0;
 entry_ptr = &DK_ENTRIES(mp->ma_keys)[i];
 while (i < n && entry_ptr->me_value == NULL) {
 entry_ptr++;
@@ -3380,7 +3377,7 @@
 dictiter_iternextkey(dictiterobject *di)
 {
 PyObject *key;
- Py_ssize_t i, n;
+ Py_ssize_t i;
 PyDictKeysObject *k;
 PyDictObject *d = di->di_dict;
 
@@ -3397,18 +3394,15 @@
 
 i = di->di_pos;
 k = d->ma_keys;
- n = k->dk_nentries;
+ assert(i >= 0);
 if (d->ma_values) {
- PyObject **value_ptr = &d->ma_values[i];
- while (i < n && *value_ptr == NULL) {
- value_ptr++;
- i++;
- }
- if (i >= n)
+ if (i >= d->ma_used)
 goto fail;
 key = DK_ENTRIES(k)[i].me_key;
+ assert(d->ma_values[i] != NULL);
 }
 else {
+ Py_ssize_t n = k->dk_nentries;
 PyDictKeyEntry *entry_ptr = &DK_ENTRIES(k)[i];
 while (i < n && entry_ptr->me_value == NULL) {
 entry_ptr++;
@@ -3466,7 +3460,7 @@
 dictiter_iternextvalue(dictiterobject *di)
 {
 PyObject *value;
- Py_ssize_t i, n;
+ Py_ssize_t i;
 PyDictObject *d = di->di_dict;
 
 if (d == NULL)
@@ -3481,18 +3475,15 @@
 }
 
 i = di->di_pos;
- n = d->ma_keys->dk_nentries;
+ assert(i >= 0);
 if (d->ma_values) {
- PyObject **value_ptr = &d->ma_values[i];
- while (i < n && *value_ptr == NULL) {
- value_ptr++;
- i++;
- }
- if (i >= n)
+ if (i >= d->ma_used)
 goto fail;
- value = *value_ptr;
+ value = d->ma_values[i];
+ assert(value != NULL);
 }
 else {
+ Py_ssize_t n = d->ma_keys->dk_nentries;
 PyDictKeyEntry *entry_ptr = &DK_ENTRIES(d->ma_keys)[i];
 while (i < n && entry_ptr->me_value == NULL) {
 entry_ptr++;
@@ -3550,7 +3541,7 @@
 dictiter_iternextitem(dictiterobject *di)
 {
 PyObject *key, *value, *result = di->di_result;
- Py_ssize_t i, n;
+ Py_ssize_t i;
 PyDictObject *d = di->di_dict;
 
 if (d == NULL)
@@ -3565,19 +3556,16 @@
 }
 
 i = di->di_pos;
- n = d->ma_keys->dk_nentries;
+ assert(i >= 0);
 if (d->ma_values) {
- PyObject **value_ptr = &d->ma_values[i];
- while (i < n && *value_ptr == NULL) {
- value_ptr++;
- i++;
- }
- if (i >= n)
+ if (i >= d->ma_used)
 goto fail;
 key = DK_ENTRIES(d->ma_keys)[i].me_key;
- value = *value_ptr;
+ value = d->ma_values[i];
+ assert(value != NULL);
 }
 else {
+ Py_ssize_t n = d->ma_keys->dk_nentries;
 PyDictKeyEntry *entry_ptr = &DK_ENTRIES(d->ma_keys)[i];
 while (i < n && entry_ptr->me_value == NULL) {
 entry_ptr++;
-- 
Repository URL: https://hg.python.org/cpython
