Changeset 53221 in webkit for trunk/JavaScriptCore/runtime/UStringImpl.h

Timestamp:

Jan 13, 2010, 5:20:52 PM (15 years ago)

Author:

[email protected]

Message:

Rubber stamped by Sam Weinig & Darin Adler.

Three quick fixes to UStringImpl.

• The destroy() method can be switched back to a normal destructor; since we've switched the way we protect static strings to be using an odd ref-count the destroy() won't abort.
• The cost() calculation logic was wrong. If you have multiple JSStrings wrapping substrings of a base string, they would each report the full cost of the base string to the heap. Instead we should only be reporting once for the base string.
• Remove the overloaded new operator calling fastMalloc, replace this with a 'using' to pick up the implementation from the parent class.

• JavaScriptCore.exp:
• runtime/UStringImpl.cpp:

(JSC::UStringImpl::~UStringImpl):

• runtime/UStringImpl.h:

(JSC::UStringImpl::cost):
(JSC::UStringImpl::deref):

File:

• trunk/JavaScriptCore/runtime/UStringImpl.h (modified) (4 diffs)

trunk/JavaScriptCore/runtime/UStringImpl.h

@@ -129 +129 @@
     size_t cost()
     {
-        UStringImpl* base = bufferOwnerString();
+        // For substrings, return the cost of the base string.
+        if (bufferOwnership() == BufferSubstring)
+            return m_dataBuffer.asPtr<UStringImpl*>()->cost();
+
         if (m_dataBuffer & s_reportedCostBit)
             return 0;
         m_dataBuffer |= s_reportedCostBit;
-        return base->m_length;
+        return m_length;
     }
     unsigned hash() const { if (!m_hash) m_hash = computeHash(data(), m_length); return m_hash; }
@@ -142 +145 @@
 
     UStringImpl* ref() { m_refCount += s_refCountIncrement; return this; }
-    ALWAYS_INLINE void deref() { if (!(m_refCount -= s_refCountIncrement)) destroy(); }
+    ALWAYS_INLINE void deref() { if (!(m_refCount -= s_refCountIncrement)) delete this; }
 
     static WTF::PossiblyNull<UChar*> allocChars(size_t length)
@@ -244 +247 @@
     }
 
-    void* operator new(size_t size) { return fastMalloc(size); }
+    using Noncopyable::operator new;
     void* operator new(size_t, void* inPlace) { return inPlace; }
+
+    ~UStringImpl();
 
     // This number must be at least 2 to avoid sharing empty, null as well as 1 character strings from SmallStrings.
@@ -257 +262 @@
     static const int s_staticRefCountInitialValue = 1;
 
-    void destroy();
     UStringImpl* bufferOwnerString() { return (bufferOwnership() == BufferSubstring) ? m_dataBuffer.asPtr<UStringImpl*>() :  this; }
     const UStringImpl* bufferOwnerString() const { return (bufferOwnership() == BufferSubstring) ? m_dataBuffer.asPtr<UStringImpl*>() :  this; }