[SCM] WebKit Debian packaging branch, webkit-1.2, updated. upstream/1.1.90-6072-g9a69373

[oliver at apple.com]

The following commit has been merged in the webkit-1.2 branch:
commit d493fb50ee7f2d5460a68700ffeb53f8bb34f057
Author: oliver at apple.com <oliver at apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Date:   Tue Nov 24 21:41:53 2009 +0000

    JSON.stringify performance on undefined is very poor
    https://bugs.webkit.org/show_bug.cgi?id=31839
    
    Reviewed by Alexey Proskuryakov.
    
    Switch from a UString to a Vector<UChar> when building
    the JSON string, allowing us to safely remove the substr-copy
    we otherwise did when unwinding an undefined property.
    
    Also turns out to be a ~5% speedup on stringification.
    
    git-svn-id: http://svn.webkit.org/repository/webkit/trunk@51352 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/JavaScriptCore/ChangeLog b/JavaScriptCore/ChangeLog
index c7d520b..195ecde 100644
--- a/JavaScriptCore/ChangeLog
+++ b/JavaScriptCore/ChangeLog
@@ -1,3 +1,21 @@
+2009-11-24  Oliver Hunt  <oliver at apple.com>
+
+        Reviewed by Alexey Proskuryakov.
+
+        JSON.stringify performance on undefined is very poor
+        https://bugs.webkit.org/show_bug.cgi?id=31839
+
+        Switch from a UString to a Vector<UChar> when building
+        the JSON string, allowing us to safely remove the substr-copy
+        we otherwise did when unwinding an undefined property.
+
+        Also turns out to be a ~5% speedup on stringification.
+
+        * runtime/JSONObject.cpp:
+        (JSC::Stringifier::StringBuilder::append):
+        (JSC::Stringifier::stringify):
+        (JSC::Stringifier::Holder::appendNextProperty):
+
 2009-11-24  Mark Rowe  <mrowe at apple.com>
 
         Fix production builds where the source tree may be read-only.
diff --git a/JavaScriptCore/runtime/JSONObject.cpp b/JavaScriptCore/runtime/JSONObject.cpp
index 297d457..f011ebe 100644
--- a/JavaScriptCore/runtime/JSONObject.cpp
+++ b/JavaScriptCore/runtime/JSONObject.cpp
@@ -70,7 +70,23 @@ public:
     void markAggregate(MarkStack&);
 
 private:
-    typedef UString StringBuilder;
+    class StringBuilder : public Vector<UChar> {
+    public:
+        using Vector<UChar>::append;
+
+        inline void append(const char* str)
+        {
+            size_t len = strlen(str);
+            reserveCapacity(size() + len);
+            for (size_t i = 0; i < len; i++)
+                Vector<UChar>::append(str[i]);
+        }
+
+        inline void append(const UString& str)
+        {
+            append(str.data(), str.size());
+        }
+    };
 
     class Holder {
     public:
@@ -269,7 +285,9 @@ JSValue Stringifier::stringify(JSValue value)
     if (m_exec->hadException())
         return jsNull();
 
-    return jsString(m_exec, result);
+    result.shrinkToFit();
+    size_t length = result.size();
+    return jsString(m_exec, UString(result.releaseBuffer(), length, false));
 }
 
 void Stringifier::appendQuotedString(StringBuilder& builder, const UString& value)
@@ -586,7 +604,7 @@ bool Stringifier::Holder::appendNextProperty(Stringifier& stringifier, StringBui
             // This only occurs when get an undefined value for an object property.
             // In this case we don't want the separator and property name that we
             // already appended, so roll back.
-            builder = builder.substr(0, rollBackPoint);
+            builder.resize(rollBackPoint);
             break;
     }
 

-- 
WebKit Debian packaging