source: webkit/trunk/JavaScriptCore/kjs/JSVariableObject.cpp@ 31119

Last change on this file since 31119 was 31114, checked in by [email protected], 17 years ago

Add fast multi-level scope lookup

Reviewed by Geoff, Darin and Weinig

Add logic and AST nodes to provide rapid variable resolution across
static scope boundaries. This also adds logic that allows us to skip
any static scopes that do not contain the variable to be resolved.

This results in a ~2.5% speedup in SunSpider, and gives a 25-30% speedup
in some simple and ad hoc closure and global variable access tests.

  • Property svn:eol-style set to native
File size: 3.9 KB
Line 
1/*
2 * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "config.h"
30#include "JSVariableObject.h"
31
32#include "PropertyNameArray.h"
33#include "property_map.h"
34
35namespace KJS {
36
37UString::Rep* IdentifierRepHashTraits::nullRepPtr = &UString::Rep::null; // Didn't want to make a whole source file for just this.
38
39void JSVariableObject::saveLocalStorage(SavedProperties& p) const
40{
41 ASSERT(d->symbolTable);
42 ASSERT(static_cast<size_t>(d->symbolTable->size()) == d->localStorage.size());
43
44 unsigned count = d->symbolTable->size();
45
46 p.properties.clear();
47 p.count = count;
48
49 if (!count)
50 return;
51
52 p.properties.set(new SavedProperty[count]);
53
54 SymbolTable::const_iterator end = d->symbolTable->end();
55 for (SymbolTable::const_iterator it = d->symbolTable->begin(); it != end; ++it) {
56 size_t i = it->second;
57 const LocalStorageEntry& entry = d->localStorage[i];
58 p.properties[i].init(it->first.get(), entry.value, entry.attributes);
59 }
60}
61
62void JSVariableObject::restoreLocalStorage(const SavedProperties& p)
63{
64 unsigned count = p.count;
65 d->symbolTable->clear();
66 d->localStorage.resize(count);
67 SavedProperty* property = p.properties.get();
68 for (size_t i = 0; i < count; ++i, ++property) {
69 ASSERT(!d->symbolTable->contains(property->name()));
70 LocalStorageEntry& entry = d->localStorage[i];
71 d->symbolTable->set(property->name(), i);
72 entry.value = property->value();
73 entry.attributes = property->attributes();
74 }
75}
76
77bool JSVariableObject::deleteProperty(ExecState* exec, const Identifier& propertyName)
78{
79 if (symbolTable().contains(propertyName.ustring().rep()))
80 return false;
81
82 return JSObject::deleteProperty(exec, propertyName);
83}
84
85void JSVariableObject::getPropertyNames(ExecState* exec, PropertyNameArray& propertyNames)
86{
87 SymbolTable::const_iterator::Keys end = symbolTable().end().keys();
88 for (SymbolTable::const_iterator::Keys it = symbolTable().begin().keys(); it != end; ++it)
89 propertyNames.add(Identifier(it->get()));
90
91 JSObject::getPropertyNames(exec, propertyNames);
92}
93
94void JSVariableObject::mark()
95{
96 JSObject::mark();
97
98 size_t size = d->localStorage.size();
99 for (size_t i = 0; i < size; ++i) {
100 JSValue* value = d->localStorage[i].value;
101 if (!value->marked())
102 value->mark();
103 }
104}
105
106bool JSVariableObject::isVariableObject() const
107{
108 return true;
109}
110
111} // namespace KJS
Note: See TracBrowser for help on using the repository browser.