Changeset 36267 in webkit for trunk/JavaScriptCore/VM/CodeBlock.h

Timestamp:

Sep 8, 2008, 5:17:33 AM (17 years ago)

Author:

[email protected]

Message:

JavaScriptCore:

2008-09-08 Maciej Stachowiak <​[email protected]>

Reviewed by Anders Carlsson.

• Cache the code generated for eval to speed up SunSpider and web sites ​https://bugs.webkit.org/show_bug.cgi?id=20718

1.052x on SunSpider
2.29x on date-format-tofte

Lots of real sites seem to get many hits on this cache as well,
including GMail, Google Spreadsheets, Slate and Digg (the last of
these gets over 100 hits on initial page load).

• VM/CodeBlock.h: (JSC::EvalCodeCache::get):
• VM/Machine.cpp: (JSC::Machine::callEval): (JSC::Machine::privateExecute): (JSC::Machine::cti_op_call_eval):
• VM/Machine.h:

LayoutTests:

2008-09-08 Maciej Stachowiak <​[email protected]>

Reviewed by Anders Carlsson.

• Test for potential bug found while fixing "Cache the code generated for eval to speed up SunSpider and web sites" ​https://bugs.webkit.org/show_bug.cgi?id=20718

• fast/js/eval-cache-crash-expected.txt: Added.
• fast/js/eval-cache-crash.html: Added.
• fast/js/resources/eval-cache-crash.js: Added.

File:

• trunk/JavaScriptCore/VM/CodeBlock.h (modified) (3 diffs)

trunk/JavaScriptCore/VM/CodeBlock.h

@@ -34 +34 @@
 #include "JSGlobalObject.h"
 #include "nodes.h"
+#include "Parser.h"
 #include "SourceRange.h"
 #include "ustring.h"
@@ -128 +129 @@
         }
 #endif
+    };
+
+    class EvalCodeCache {
+    public:
+        PassRefPtr<EvalNode> get(ExecState* exec, const UString& evalSource, ScopeChainNode* scopeChain, JSValue*& exceptionValue)
+        {
+            RefPtr<EvalNode> evalNode;
+
+            if (evalSource.size() < maxCacheableSourceLength && (*scopeChain->begin())->isVariableObject())
+                evalNode = cacheMap.get(evalSource.rep());
+
+            if (!evalNode) {
+                int sourceId;
+                int errLine;
+                UString errMsg;
+                
+                evalNode = exec->parser()->parse<EvalNode>(exec, UString(), 1, UStringSourceProvider::create(evalSource), &sourceId, &errLine, &errMsg);
+                if (evalNode) {
+                    if (evalSource.size() < maxCacheableSourceLength && (*scopeChain->begin())->isVariableObject() && cacheMap.size() < maxCacheEntries)
+                        cacheMap.set(evalSource.rep(), evalNode);
+                } else {
+                    exceptionValue = Error::create(exec, SyntaxError, errMsg, errLine, sourceId, NULL);
+                    return 0;
+                }
+            }
+
+            return evalNode.release();
+        }
+
+    private:
+        static const int maxCacheableSourceLength = 256;
+        static const int maxCacheEntries = 64;
+
+        HashMap<RefPtr<UString::Rep>, RefPtr<EvalNode> > cacheMap;
     };
 
@@ -208 +243 @@
 #endif
 
+        EvalCodeCache evalCodeCache;
+
     private:
 #if !defined(NDEBUG) || ENABLE(SAMPLING_TOOL)
         void dump(ExecState*, const Vector<Instruction>::const_iterator& begin, Vector<Instruction>::const_iterator&) const;
 #endif
+
     };