Changeset 50705 in webkit for trunk/JavaScriptCore

Timestamp:

Nov 9, 2009, 7:14:26 PM (16 years ago)

Author:

[email protected]

Message:

Added a tiny cache for Date parsing.

Reviewed by Sam "Home Wrecker" Weinig.

SunSpider says 1.2% faster.

• runtime/DateConversion.cpp:

(JSC::parseDate): Try to reuse the last parsed Date, if present.

• runtime/JSGlobalData.cpp:

(JSC::JSGlobalData::resetDateCache):

• runtime/JSGlobalData.h: Added storage for last parsed Date. Refactored

this code to make resetting the date cache easier.

• runtime/JSGlobalObject.h:

(JSC::DynamicGlobalObjectScope::DynamicGlobalObjectScope): Updated for
refactoring.

• wtf/DateMath.cpp:

(JSC::parseDateFromNullTerminatedCharacters):

• wtf/DateMath.h: Changed ExecState to be first parameter, as is the JSC custom.

Location:

trunk/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/DateConversion.cpp (modified) (2 diffs)
• runtime/JSGlobalData.cpp (modified) (1 diff)
• runtime/JSGlobalData.h (modified) (1 diff)
• runtime/JSGlobalObject.h (modified) (1 diff)
• wtf/DateMath.cpp (modified) (1 diff)
• wtf/DateMath.h (modified) (1 diff)

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+2009-11-09  Geoffrey Garen  <[email protected]>
+
+        Reviewed by Sam "Home Wrecker" Weinig.
+
+        Added a tiny cache for Date parsing.
+        
+        SunSpider says 1.2% faster.
+
+        * runtime/DateConversion.cpp:
+        (JSC::parseDate): Try to reuse the last parsed Date, if present.
+
+        * runtime/JSGlobalData.cpp:
+        (JSC::JSGlobalData::resetDateCache):
+        * runtime/JSGlobalData.h: Added storage for last parsed Date. Refactored
+        this code to make resetting the date cache easier.
+
+        * runtime/JSGlobalObject.h:
+        (JSC::DynamicGlobalObjectScope::DynamicGlobalObjectScope): Updated for
+        refactoring.
+
+        * wtf/DateMath.cpp:
+        (JSC::parseDateFromNullTerminatedCharacters):
+        * wtf/DateMath.h: Changed ExecState to be first parameter, as is the JSC custom.
+
 2009-11-09  Oliver Hunt  <[email protected]>
 

trunk/JavaScriptCore/runtime/DateConversion.cpp

@@ -44 +44 @@
 #include "DateConversion.h"
 
+#include "CallFrame.h"
 #include "UString.h"
 #include <wtf/DateMath.h>
@@ -54 +55 @@
 double parseDate(ExecState* exec, const UString &date)
 {
-    return parseDateFromNullTerminatedCharacters(date.UTF8String().c_str(), exec);
+    if (date == exec->globalData().cachedDateString)
+        return exec->globalData().cachedDateStringValue;
+    double value = parseDateFromNullTerminatedCharacters(exec, date.UTF8String().c_str());
+    exec->globalData().cachedDateString = date;
+    exec->globalData().cachedDateStringValue = value;
+    return value;
 }
 

trunk/JavaScriptCore/runtime/JSGlobalData.cpp

@@ -253 +253 @@
 }
 
+void JSGlobalData::resetDateCache()
+{
+    cachedUTCOffset = NaN;
+    cachedDateString = UString();
+}
+
 void JSGlobalData::startSampling()
 {

trunk/JavaScriptCore/runtime/JSGlobalData.h

@@ -156 +156 @@
         double cachedUTCOffset;
 
+        UString cachedDateString;
+        double cachedDateStringValue;
+
 #ifndef NDEBUG
         bool mainThreadOnly;
 #endif
+
+        void resetDateCache();
 
         void startSampling();

trunk/JavaScriptCore/runtime/JSGlobalObject.h

@@ -446 +446 @@
                 m_dynamicGlobalObjectSlot = dynamicGlobalObject;
 
-                // Reset the UTC cache between JS invocations to force the VM
+                // Reset the date cache between JS invocations to force the VM
                 // to observe time zone changes.
-                callFrame->globalData().cachedUTCOffset = NaN;
+                callFrame->globalData().resetDateCache();
             }
         }

trunk/JavaScriptCore/wtf/DateMath.cpp

@@ -874 +874 @@
 }
 
-double parseDateFromNullTerminatedCharacters(const char* dateString, ExecState* exec)
+double parseDateFromNullTerminatedCharacters(ExecState* exec, const char* dateString)
 {
     ASSERT(exec);

trunk/JavaScriptCore/wtf/DateMath.h

@@ -86 +86 @@
 double gregorianDateTimeToMS(ExecState*, const GregorianDateTime&, double, bool inputIsUTC);
 double getUTCOffset(ExecState*);
-double parseDateFromNullTerminatedCharacters(const char* dateString, ExecState*);
+double parseDateFromNullTerminatedCharacters(ExecState*, const char* dateString);
 
 // Intentionally overridding the default tm of the system.