Changeset 81071 in webkit for trunk/Source/JavaScriptCore/runtime/SmallStrings.cpp

Timestamp:

Mar 14, 2011, 3:31:29 PM (14 years ago)

Author:

[email protected]

Message:

2011-03-14 Geoffrey Garen <​[email protected]>

Reviewed by Oliver Hunt.

Removed more cases of DeprecatedPtr (exception, SmallStrings)
​https://bugs.webkit.org/show_bug.cgi?id=56332

• runtime/Identifier.cpp: (JSC::Identifier::add): (JSC::Identifier::addSlowCase): Use a variable instead of a hard-coded constant, to make this code less brittle.

• runtime/JSGlobalData.h: Use HeapRoot instead of DeprecatedPtr because this reference is owned and managed directly by the heap.

• runtime/JSString.cpp: (JSC::JSString::substringFromRope):
• runtime/JSString.h: (JSC::jsSingleCharacterString): (JSC::jsSingleCharacterSubstring): (JSC::jsString): (JSC::jsStringWithFinalizer): (JSC::jsSubstring): (JSC::jsOwnedString): Use a variable instead of a hard-coded constant, to make this code less brittle.

• runtime/SmallStrings.cpp: (JSC::SmallStringsStorage::rep): (JSC::SmallStringsStorage::SmallStringsStorage): (JSC::SmallStrings::SmallStrings): (JSC::SmallStrings::markChildren): (JSC::SmallStrings::clear): (JSC::SmallStrings::count): Use a variable instead of a hard-coded constant, to make this code less brittle.

• runtime/SmallStrings.h: (JSC::SmallStrings::singleCharacterString): Use HeapRoot instead of DeprecatedPtr because these references are owned and managed directly by the heap.

Stop using FixedArray because we only want a very limited set
of classes to be able to use HeapRoot. (Replaced with manual ASSERTs.)

• runtime/WriteBarrier.h: (JSC::operator==): (JSC::WriteBarrier::WriteBarrier): (JSC::HeapRoot::HeapRoot): (JSC::HeapRoot::operator=): Added HeapRoot, which is allowed to set without write barrier because we assume all HeapRoots are scanned during all GC passes.

File:

• trunk/Source/JavaScriptCore/runtime/SmallStrings.cpp (modified) (8 diffs)

trunk/Source/JavaScriptCore/runtime/SmallStrings.cpp

@@ -34 +34 @@
 namespace JSC {
 
-static const unsigned numCharactersToStore = 0x100;
-
 static inline bool isMarked(JSCell* string)
 {
@@ -46 +44 @@
     SmallStringsStorage();
 
-    StringImpl* rep(unsigned char character) { return m_reps[character].get(); }
+    StringImpl* rep(unsigned char character)
+    {
+        return m_reps[character].get();
+    }
 
 private:
-    RefPtr<StringImpl> m_reps[numCharactersToStore];
+    static const unsigned singleCharacterStringCount = maxSingleCharacterString + 1;
+
+    RefPtr<StringImpl> m_reps[singleCharacterStringCount];
 };
 
@@ -55 +58 @@
 {
     UChar* characterBuffer = 0;
-    RefPtr<StringImpl> baseString = StringImpl::createUninitialized(numCharactersToStore, characterBuffer);
-    for (unsigned i = 0; i < numCharactersToStore; ++i) {
+    RefPtr<StringImpl> baseString = StringImpl::createUninitialized(singleCharacterStringCount, characterBuffer);
+    for (unsigned i = 0; i < singleCharacterStringCount; ++i) {
         characterBuffer[i] = i;
         m_reps[i] = StringImpl::create(baseString, i, 1);
@@ -64 +67 @@
 SmallStrings::SmallStrings()
 {
-    COMPILE_ASSERT(numCharactersToStore == sizeof(m_singleCharacterStrings) / sizeof(m_singleCharacterStrings[0]), IsNumCharactersConstInSyncWithClassUsage);
+    COMPILE_ASSERT(singleCharacterStringCount == sizeof(m_singleCharacterStrings) / sizeof(m_singleCharacterStrings[0]), IsNumCharactersConstInSyncWithClassUsage);
     clear();
 }
@@ -85 +88 @@
 
     bool isAnyStringMarked = isMarked(m_emptyString.get());
-    for (unsigned i = 0; i < numCharactersToStore && !isAnyStringMarked; ++i)
+    for (unsigned i = 0; i < singleCharacterStringCount && !isAnyStringMarked; ++i)
         isAnyStringMarked = isMarked(m_singleCharacterStrings[i].get());
     
@@ -95 +98 @@
     if (m_emptyString)
         markStack.append(&m_emptyString);
-    for (unsigned i = 0; i < numCharactersToStore; ++i) {
+    for (unsigned i = 0; i < singleCharacterStringCount; ++i) {
         if (m_singleCharacterStrings[i])
             markStack.append(&m_singleCharacterStrings[i]);
@@ -104 +107 @@
 {
     m_emptyString = 0;
-    for (unsigned i = 0; i < numCharactersToStore; ++i)
+    for (unsigned i = 0; i < singleCharacterStringCount; ++i)
         m_singleCharacterStrings[i] = 0;
 }
@@ -113 +116 @@
     if (m_emptyString)
         ++count;
-    for (unsigned i = 0; i < numCharactersToStore; ++i) {
+    for (unsigned i = 0; i < singleCharacterStringCount; ++i) {
         if (m_singleCharacterStrings[i])
             ++count;