Changeset 89184 in webkit for trunk/Source/JavaScriptCore/ChangeLog

Timestamp:

Jun 17, 2011, 9:25:57 PM (14 years ago)

Author:

[email protected]

Message:

2011-06-17 Oliver Hunt <​[email protected]>

Reviewed by Gavin Barraclough.

JSONP is unnecessarily slow
​https://bugs.webkit.org/show_bug.cgi?id=62920

JSONP has unfortunately become a fairly common idiom online, yet
it triggers very poor performance in JSC as we end up doing codegen
for a large number of property accesses that will

• only be run once, so the vast amount of logic we dump to handle caching of accesses is unnecessary.
• We are doing codegen that is directly proportional to just creating the object in the first place.

This patch extends the use of the literal parser to JSONP-like structures
in global code, handling a number of different forms I have seen online.
In an extreme case this improves performance of JSONP by more than 2x
due to removal of code generation and execution time, and a few optimisations
that I made to the parser itself.

• API/JSValueRef.cpp: (JSValueMakeFromJSONString):
• interpreter/Interpreter.cpp: (JSC::Interpreter::callEval): (JSC::Interpreter::execute):
• parser/Lexer.cpp: (JSC::Lexer::isKeyword):
• parser/Lexer.h:
• runtime/JSGlobalObjectFunctions.cpp: (JSC::globalFuncEval):
• runtime/JSONObject.cpp: (JSC::JSONProtoFuncParse):
• runtime/LiteralParser.cpp: (JSC::LiteralParser::tryJSONPParse): (JSC::LiteralParser::makeIdentifier): (JSC::LiteralParser::Lexer::lex): (JSC::LiteralParser::Lexer::next): (JSC::isSafeStringCharacter): (JSC::LiteralParser::Lexer::lexString): (JSC::LiteralParser::Lexer::lexNumber): (JSC::LiteralParser::parse):
• runtime/LiteralParser.h: (JSC::LiteralParser::LiteralParser): (JSC::LiteralParser::tryLiteralParse): (JSC::LiteralParser::Lexer::Lexer):

File:

• trunk/Source/JavaScriptCore/ChangeLog (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-06-17  Oliver Hunt  <[email protected]>
+
+        Reviewed by Gavin Barraclough.
+
+        JSONP is unnecessarily slow
+        https://bugs.webkit.org/show_bug.cgi?id=62920
+
+        JSONP has unfortunately become a fairly common idiom online, yet
+        it triggers very poor performance in JSC as we end up doing codegen
+        for a large number of property accesses that will
+           * only be run once, so the vast amount of logic we dump to handle
+             caching of accesses is unnecessary.
+           * We are doing codegen that is directly proportional to just
+             creating the object in the first place.
+
+        This patch extends the use of the literal parser to JSONP-like structures
+        in global code, handling a number of different forms I have seen online.
+        In an extreme case this improves performance of JSONP by more than 2x
+        due to removal of code generation and execution time, and a few optimisations
+        that I made to the parser itself.
+
+        * API/JSValueRef.cpp:
+        (JSValueMakeFromJSONString):
+        * interpreter/Interpreter.cpp:
+        (JSC::Interpreter::callEval):
+        (JSC::Interpreter::execute):
+        * parser/Lexer.cpp:
+        (JSC::Lexer::isKeyword):
+        * parser/Lexer.h:
+        * runtime/JSGlobalObjectFunctions.cpp:
+        (JSC::globalFuncEval):
+        * runtime/JSONObject.cpp:
+        (JSC::JSONProtoFuncParse):
+        * runtime/LiteralParser.cpp:
+        (JSC::LiteralParser::tryJSONPParse):
+        (JSC::LiteralParser::makeIdentifier):
+        (JSC::LiteralParser::Lexer::lex):
+        (JSC::LiteralParser::Lexer::next):
+        (JSC::isSafeStringCharacter):
+        (JSC::LiteralParser::Lexer::lexString):
+        (JSC::LiteralParser::Lexer::lexNumber):
+        (JSC::LiteralParser::parse):
+        * runtime/LiteralParser.h:
+        (JSC::LiteralParser::LiteralParser):
+        (JSC::LiteralParser::tryLiteralParse):
+        (JSC::LiteralParser::Lexer::Lexer):
+
 2011-06-17  Geoffrey Garen  <[email protected]>