Changeset 154861 in webkit for trunk/Source/JavaScriptCore/runtime/JSGlobalObject.h

Timestamp:

Aug 29, 2013, 5:55:34 PM (12 years ago)

Author:

[email protected]

Message:

Implement ES6 Map object
​https://bugs.webkit.org/show_bug.cgi?id=120333

Reviewed by Geoffrey Garen.

Source/JavaScriptCore:

Implement support for the ES6 Map type and related classes.

• JavaScriptCore.xcodeproj/project.pbxproj:
• heap/CopyToken.h: Add a new token to track copying the backing store
• runtime/CommonIdentifiers.h: Add new identifiers
• runtime/JSGlobalObject.cpp:
• runtime/JSGlobalObject.h:

Add new structures and prototypes

• runtime/JSMap.cpp: Added.
• runtime/JSMap.h: Added.

New JSMap class to represent a Map instance

• runtime/MapConstructor.cpp: Added.
• runtime/MapConstructor.h: Added.

The Map constructor

• runtime/MapData.cpp: Added.
• runtime/MapData.h: Added.

The most interesting data structure. The roughly corresponds
to the ES6 notion of MapData. It provides the core JSValue->JSValue
map implementation. We implement it using 2 hashtables and a flat
table. Due to the different semantics of string comparisons vs.
all others we need have one map keyed by String and the other by
generic JSValue. The actual table is represented more or less
exactly as described in the ES6 draft - a single contiguous list of
key/value pairs. The entire map could be achieved with just this
table, however we need the HashMaps in order to maintain O(1) lookup.

Deleted values are simply cleared as the draft says, however the
implementation compacts the storage on copy as long as the are no
active iterators.

• runtime/MapPrototype.cpp: Added.
• runtime/MapPrototype.h: Added.

Implement Map prototype functions

• runtime/VM.cpp:

Add new structures.

LayoutTests:

Tests

• fast/js/basic-map-expected.txt: Added.
• fast/js/basic-map.html: Added.
• fast/js/script-tests/basic-map.js: Added.

File:

• trunk/Source/JavaScriptCore/runtime/JSGlobalObject.h (modified) (4 diffs)

trunk/Source/JavaScriptCore/runtime/JSGlobalObject.h

@@ -64 +64 @@
 class JSStack;
 class LLIntOffsetsExtractor;
+class MapPrototype;
 class NativeErrorConstructor;
 class ProgramCodeBlock;
@@ -151 +152 @@
     WriteBarrier<JSPromisePrototype> m_promisePrototype;
     WriteBarrier<JSPromiseResolverPrototype> m_promiseResolverPrototype;
+    WriteBarrier<MapPrototype> m_mapPrototype;
 
     WriteBarrier<Structure> m_withScopeStructure;
@@ -192 +194 @@
 #endif // ENABLE(PROMISES)
 
+    WriteBarrier<Structure> m_mapDataStructure;
+    WriteBarrier<Structure> m_mapStructure;
+    
     WriteBarrier<JSArrayBufferPrototype> m_arrayBufferPrototype;
     WriteBarrier<Structure> m_arrayBufferStructure;
@@ -382 +387 @@
     Structure* privateNameStructure() const { return m_privateNameStructure.get(); }
     Structure* internalFunctionStructure() const { return m_internalFunctionStructure.get(); }
+    Structure* mapStructure() const { return m_mapStructure.get(); }
+    Structure* mapDataStructure() const { return m_mapDataStructure.get(); }
     Structure* regExpMatchesArrayStructure() const { return m_regExpMatchesArrayStructure.get(); }
     Structure* regExpStructure() const { return m_regExpStructure.get(); }