Changeset 111433 in webkit

Timestamp:

Mar 20, 2012 1:22:57 PM (12 years ago)

Author:

benjamin@webkit.org

Message:

Cache the type string of JavaScript object
​https://bugs.webkit.org/show_bug.cgi?id=81446

Patch by Benjamin Poulain <​bpoulain@apple.com> on 2012-03-20
Reviewed by Geoffrey Garen.

Instead of creating the JSString every time, we create
lazily the strings in JSGlobalData.

This avoid the construction of the StringImpl and of the JSString,
which gives some performance improvements.

• runtime/CommonIdentifiers.h:
• runtime/JSValue.cpp:

(JSC::JSValue::toStringSlowCase):

• runtime/Operations.cpp:

(JSC::jsTypeStringForValue):

• runtime/SmallStrings.cpp:

(JSC::SmallStrings::SmallStrings):
(JSC::SmallStrings::finalizeSmallStrings):
(JSC::SmallStrings::initialize):
(JSC):

• runtime/SmallStrings.h:

(SmallStrings):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/CommonIdentifiers.h (modified) (1 diff)
• runtime/JSValue.cpp (modified) (1 diff)
• runtime/Operations.cpp (modified) (1 diff)
• runtime/SmallStrings.cpp (modified) (3 diffs)
• runtime/SmallStrings.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2012-03-20  Benjamin Poulain  <bpoulain@apple.com>
+
+        Cache the type string of JavaScript object
+        https://bugs.webkit.org/show_bug.cgi?id=81446
+
+        Reviewed by Geoffrey Garen.
+
+        Instead of creating the JSString every time, we create
+        lazily the strings in JSGlobalData.
+
+        This avoid the construction of the StringImpl and of the JSString,
+        which gives some performance improvements.
+
+        * runtime/CommonIdentifiers.h:
+        * runtime/JSValue.cpp:
+        (JSC::JSValue::toStringSlowCase):
+        * runtime/Operations.cpp:
+        (JSC::jsTypeStringForValue):
+        * runtime/SmallStrings.cpp:
+        (JSC::SmallStrings::SmallStrings):
+        (JSC::SmallStrings::finalizeSmallStrings):
+        (JSC::SmallStrings::initialize):
+        (JSC):
+        * runtime/SmallStrings.h:
+        (SmallStrings):
+
 2012-03-20  Oliver Hunt  <oliver@apple.com>
 

trunk/Source/JavaScriptCore/runtime/CommonIdentifiers.h

@@ -73 +73 @@
     macro(valueOf) \
     macro(writable) \
-    macro(displayName) \
-    macro(undefined)
+    macro(displayName)
 
 #define JSC_COMMON_IDENTIFIERS_EACH_KEYWORD(macro) \

trunk/Source/JavaScriptCore/runtime/JSValue.cpp

@@ -261 +261 @@
 JSString* JSValue::toStringSlowCase(ExecState* exec) const
 {
+    JSGlobalData& globalData = exec->globalData();
     ASSERT(!isString());
     if (isInt32())
-        return jsString(&exec->globalData(), exec->globalData().numericStrings.add(asInt32()));
+        return jsString(&globalData, globalData.numericStrings.add(asInt32()));
     if (isDouble())
-        return jsString(&exec->globalData(), exec->globalData().numericStrings.add(asDouble()));
+        return jsString(&globalData, globalData.numericStrings.add(asDouble()));
     if (isTrue())
-        return jsNontrivialString(exec, exec->propertyNames().trueKeyword.ustring());
+        return globalData.smallStrings.trueString(&globalData);
     if (isFalse())
-        return jsNontrivialString(exec, exec->propertyNames().falseKeyword.ustring());
+        return globalData.smallStrings.falseString(&globalData);
     if (isNull())
-        return jsNontrivialString(exec, exec->propertyNames().nullKeyword.ustring());
+        return globalData.smallStrings.nullString(&globalData);
     if (isUndefined())
-        return jsNontrivialString(exec, exec->propertyNames().undefined.ustring());
+        return globalData.smallStrings.undefinedString(&globalData);
 
     ASSERT(isCell());

trunk/Source/JavaScriptCore/runtime/Operations.cpp

@@ -59 +59 @@
 JSValue jsTypeStringForValue(CallFrame* callFrame, JSValue v)
 {
+    JSGlobalData& globalData = callFrame->globalData();
     if (v.isUndefined())
-        return jsNontrivialString(callFrame, "undefined");
+        return globalData.smallStrings.undefinedString(&globalData);
     if (v.isBoolean())
-        return jsNontrivialString(callFrame, "boolean");
+        return globalData.smallStrings.booleanString(&globalData);
     if (v.isNumber())
-        return jsNontrivialString(callFrame, "number");
+        return globalData.smallStrings.numberString(&globalData);
     if (v.isString())
-        return jsNontrivialString(callFrame, "string");
+        return globalData.smallStrings.stringString(&globalData);
     if (v.isObject()) {
         // Return "undefined" for objects that should be treated
         // as null when doing comparisons.
         if (asObject(v)->structure()->typeInfo().masqueradesAsUndefined())
-            return jsNontrivialString(callFrame, "undefined");
+            return globalData.smallStrings.undefinedString(&globalData);
         CallData callData;
         JSObject* object = asObject(v);
         if (object->methodTable()->getCallData(object, callData) != CallTypeNone)
-            return jsNontrivialString(callFrame, "function");
+            return globalData.smallStrings.functionString(&globalData);
     }
-    return jsNontrivialString(callFrame, "object");
+    return globalData.smallStrings.objectString(&globalData);
 }
 

trunk/Source/JavaScriptCore/runtime/SmallStrings.cpp

@@ -69 +69 @@
 
 SmallStrings::SmallStrings()
+    : m_emptyString(0)
+#define JSC_COMMON_STRINGS_ATTRIBUTE_INITIALIZE(name) , m_##name(0)
+    JSC_COMMON_STRINGS_EACH_NAME(JSC_COMMON_STRINGS_ATTRIBUTE_INITIALIZE)
+#undef JSC_COMMON_STRINGS_ATTRIBUTE_INITIALIZE
 {
     COMPILE_ASSERT(singleCharacterStringCount == sizeof(m_singleCharacterStrings) / sizeof(m_singleCharacterStrings[0]), IsNumCharactersConstInSyncWithClassUsage);
 
-    m_emptyString = 0;
     for (unsigned i = 0; i < singleCharacterStringCount; ++i)
         m_singleCharacterStrings[i] = 0;
@@ -86 +89 @@
     for (unsigned i = 0; i < singleCharacterStringCount; ++i)
         finalize(m_singleCharacterStrings[i]);
+#define JSC_COMMON_STRINGS_ATTRIBUTE_FINALIZE(name) finalize(m_##name);
+    JSC_COMMON_STRINGS_EACH_NAME(JSC_COMMON_STRINGS_ATTRIBUTE_FINALIZE)
+#undef JSC_COMMON_STRINGS_ATTRIBUTE_FINALIZE
 }
 
@@ -109 +115 @@
 }
 
+void SmallStrings::initialize(JSGlobalData* globalData, JSString*& string, const char* value) const
+{
+    string = JSString::create(*globalData, StringImpl::create(value));
+}
+
 } // namespace JSC

trunk/Source/JavaScriptCore/runtime/SmallStrings.h

@@ -30 +30 @@
 #include <wtf/FixedArray.h>
 #include <wtf/OwnPtr.h>
+
+#define JSC_COMMON_STRINGS_EACH_NAME(macro) \
+    macro(boolean) \
+    macro(false) \
+    macro(function) \
+    macro(number) \
+    macro(null) \
+    macro(object) \
+    macro(undefined) \
+    macro(string) \
+    macro(true)
 
 namespace JSC {
@@ -67 +78 @@
         JSString** singleCharacterStrings() { return &m_singleCharacterStrings[0]; }
 
+#define JSC_COMMON_STRINGS_ACCESSOR_DEFINITION(name) \
+        JSString* name##String(JSGlobalData* globalData) const \
+        { \
+            if (!m_##name) \
+                initialize(globalData, m_##name, #name); \
+            return m_##name; \
+        }
+        JSC_COMMON_STRINGS_EACH_NAME(JSC_COMMON_STRINGS_ACCESSOR_DEFINITION)
+#undef JSC_COMMON_STRINGS_ACCESSOR_DEFINITION
+
     private:
         static const unsigned singleCharacterStringCount = maxSingleCharacterString + 1;
@@ -73 +94 @@
         JS_EXPORT_PRIVATE void createSingleCharacterString(JSGlobalData*, unsigned char);
 
+        void initialize(JSGlobalData* globalData, JSString*& string, const char* value) const;
+
         JSString* m_emptyString;
+#define JSC_COMMON_STRINGS_ATTRIBUTE_DECLARATION(name) mutable JSString* m_##name;
+        JSC_COMMON_STRINGS_EACH_NAME(JSC_COMMON_STRINGS_ATTRIBUTE_DECLARATION)
+#undef JSC_COMMON_STRINGS_ATTRIBUTE_DECLARATION
         JSString* m_singleCharacterStrings[singleCharacterStringCount];
         OwnPtr<SmallStringsStorage> m_storage;