changeset:   104742:deb3e5857d8c
parent:      104740:849826a900d2
parent:      104741:8c2615decd2e
user:        INADA Naoki <songofacandy@gmail.com>
date:        Thu Oct 27 19:30:10 2016 +0900
files:       Misc/NEWS Objects/dictobject.c
description:
Issue #28509: dict.update() no longer allocate unnecessary large memory


diff -r 849826a900d2 -r deb3e5857d8c Misc/NEWS
--- a/Misc/NEWS	Tue Oct 25 21:49:19 2016 -0500
+++ b/Misc/NEWS	Thu Oct 27 19:30:10 2016 +0900
@@ -10,6 +10,8 @@
 Core and Builtins
 -----------------
 
+- Issue #28509: dict.update() no longer allocate unnecessary large memory.
+
 - Issue #28426: Fixed potential crash in PyUnicode_AsDecodedObject() in debug
   build.
 
diff -r 849826a900d2 -r deb3e5857d8c Objects/dictobject.c
--- a/Objects/dictobject.c	Tue Oct 25 21:49:19 2016 -0500
+++ b/Objects/dictobject.c	Thu Oct 27 19:30:10 2016 +0900
@@ -2407,9 +2407,11 @@
          * incrementally resizing as we insert new items.  Expect
          * that there will be no (or few) overlapping keys.
          */
-        if (mp->ma_keys->dk_usable * 3 < other->ma_used * 2)
-            if (dictresize(mp, (mp->ma_used + other->ma_used)*2) != 0)
+        if (USABLE_FRACTION(mp->ma_keys->dk_size) < other->ma_used) {
+            if (dictresize(mp, ESTIMATE_SIZE(mp->ma_used + other->ma_used))) {
                return -1;
+            }
+        }
         ep0 = DK_ENTRIES(other->ma_keys);
         for (i = 0, n = other->ma_keys->dk_nentries; i < n; i++) {
             PyObject *key, *value;