Changeset 2740 in webkit for trunk/JavaScriptCore/kjs/ustring.cpp

Timestamp:

Nov 18, 2002, 3:43:22 PM (23 years ago)

Author:

darin

Message:

• another string constant discovered that can be optimized

• kjs/object.h: Add a property name constant for "proto".
• kjs/object.cpp: Define it. (ObjectImp::get): Use it. (ObjectImp::hasProperty): Use it.

• prepare to turn PropertyMap into a hash table

• kjs/object.cpp: (ObjectImp::mark): Use the new PropertyMap::mark(). (ObjectImp::put): Use the new overload of PropertyMap::get(). (ObjectImp::deleteProperty): Use the new overload of PropertyMap::get(). (ObjectImp::propList): Use PropertyMap::addEnumerablesToReferenceList().

• kjs/property_map.h: Remove PropertyMapNode and make all node-related methods private. Add mark(), a new overload of get() that returns attributes, a clear() that takes no attributes, and addEnumerablesToReferenceList().
• kjs/property_map.cpp: (PropertyMap::get): Added new overload. (PropertyMap::clear): Added new overload. (PropertyMap::mark): Added. (PropertyMap::addEnumerablesToReferenceList): Added.

• kjs/ustring.h: Added a hash function.
• kjs/ustring.cpp: (KJS::hash): Added.

File:

• trunk/JavaScriptCore/kjs/ustring.cpp (modified) (1 diff)

trunk/JavaScriptCore/kjs/ustring.cpp

@@ -665 +665 @@
   return (l1 < l2) ? 1 : -1;
 }
+
+// Algorithm concept from Algorithms in C++, Sedgewick, Program 14.1.
+int KJS::hash(const UString &s, int hashTableSize)
+{
+    int h = 0;
+    int length = s.size();
+    int prefix = length < 8 ? length : 8;
+    for (int i = 0; i != prefix; i++)
+        h = (127 * h + s[i].unicode()) % hashTableSize;
+    int suffix = length < 16 ? 8 : length - 8;
+    for (int i = suffix; i != length; i++)
+        h = (127 * h + s[i].unicode()) % hashTableSize;
+    return h;
+}