[Python-checkins] cpython (merge 3.3 -> default): merge
raymond.hettinger
python-checkins at python.org
Fri May 17 12:25:19 CEST 2013
http://hg.python.org/cpython/rev/ffd353a4fdc7
changeset: 83813:ffd353a4fdc7
parent: 83811:1babfb6261fa
parent: 83812:cd2457463eeb
user: Raymond Hettinger <python at rcn.com>
date: Fri May 17 03:24:54 2013 -0700
summary:
merge
files:
Objects/dictobject.c | 18 +++++++++++-------
1 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -305,14 +305,18 @@
* #define USABLE_FRACTION(n) (((n) >> 1) + ((n) >> 2) - ((n) >> 3))
*/
-/* GROWTH_RATE. Growth rate upon hitting maximum load. Currently set to *2.
- * Raising this to *4 doubles memory consumption depending on the size of
+/* GROWTH_RATE. Growth rate upon hitting maximum load.
+ * Currently set to used*2 + capacity/2.
+ * This means that dicts double in size when growing without deletions,
+ * but have more head room when the number of deletions is on a par with the
+ * number of insertions.
+ * Raising this to used*4 doubles memory consumption depending on the size of
* the dictionary, but results in half the number of resizes, less effort to
- * resize and better sparseness for some (but not all dict sizes).
- * Setting to *4 eliminates every other resize step.
- * GROWTH_RATE was set to *4 up to version 3.2.
+ * resize.
+ * GROWTH_RATE was set to used*4 up to version 3.2.
+ * GROWTH_RATE was set to used*2 in version 3.3.0
*/
-#define GROWTH_RATE(x) ((x) * 2)
+#define GROWTH_RATE(d) (((d)->ma_used*2)+((d)->ma_keys->dk_size>>1))
#define ENSURE_ALLOWS_DELETIONS(d) \
if ((d)->ma_keys->dk_lookup == lookdict_unicode_nodummy) { \
@@ -790,7 +794,7 @@
static int
insertion_resize(PyDictObject *mp)
{
- return dictresize(mp, GROWTH_RATE(mp->ma_used));
+ return dictresize(mp, GROWTH_RATE(mp));
}
/*
--
Repository URL: http://hg.python.org/cpython
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