1/*
2 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#include "config.h"
22#include "Identifier.h"
23
24#include "CallFrame.h"
25#include <new> // for placement new
26#include <string.h> // for strlen
27#include <wtf/Assertions.h>
28#include <wtf/FastMalloc.h>
29#include <wtf/HashSet.h>
30
31using WTF::ThreadSpecific;
32
33namespace JSC {
34
35typedef HashMap<const char*, RefPtr<UString::Rep>, PtrHash<const char*> > LiteralIdentifierTable;
36
37class IdentifierTable : public FastAllocBase {
38public:
39 ~IdentifierTable()
40 {
41 HashSet<UString::Rep*>::iterator end = m_table.end();
42 for (HashSet<UString::Rep*>::iterator iter = m_table.begin(); iter != end; ++iter)
43 (*iter)->setIsIdentifier(false);
44 }
45
46 std::pair<HashSet<UString::Rep*>::iterator, bool> add(UString::Rep* value)
47 {
48 std::pair<HashSet<UString::Rep*>::iterator, bool> result = m_table.add(value);
49 (*result.first)->setIsIdentifier(true);
50 return result;
51 }
52
53 template<typename U, typename V>
54 std::pair<HashSet<UString::Rep*>::iterator, bool> add(U value)
55 {
56 std::pair<HashSet<UString::Rep*>::iterator, bool> result = m_table.add<U, V>(value);
57 (*result.first)->setIsIdentifier(true);
58 return result;
59 }
60
61 void remove(UString::Rep* r) { m_table.remove(value: r); }
62
63 LiteralIdentifierTable& literalTable() { return m_literalTable; }
64
65private:
66 HashSet<UString::Rep*> m_table;
67 LiteralIdentifierTable m_literalTable;
68};
69
70IdentifierTable* createIdentifierTable()
71{
72 return new IdentifierTable;
73}
74
75void deleteIdentifierTable(IdentifierTable* table)
76{
77 delete table;
78}
79
80bool Identifier::equal(const UString::Rep* r, const char* s)
81{
82 int length = r->size();
83 const UChar* d = r->data();
84 for (int i = 0; i != length; ++i)
85 if (d[i] != (unsigned char)s[i])
86 return false;
87 return s[length] == 0;
88}
89
90bool Identifier::equal(const UString::Rep* r, const UChar* s, int length)
91{
92 if (r->size() != length)
93 return false;
94 const UChar* d = r->data();
95 for (int i = 0; i != length; ++i)
96 if (d[i] != s[i])
97 return false;
98 return true;
99}
100
101struct CStringTranslator {
102 static unsigned hash(const char* c)
103 {
104 return UString::Rep::computeHash(s: c);
105 }
106
107 static bool equal(UString::Rep* r, const char* s)
108 {
109 return Identifier::equal(r, s);
110 }
111
112 static void translate(UString::Rep*& location, const char* c, unsigned hash)
113 {
114 size_t length = strlen(s: c);
115 UChar* d;
116 UString::Rep* r = UString::Rep::createUninitialized(length, output&: d).releaseRef();
117 for (size_t i = 0; i != length; i++)
118 d[i] = static_cast<unsigned char>(c[i]); // use unsigned char to zero-extend instead of sign-extend
119 r->setHash(hash);
120 location = r;
121 }
122};
123
124PassRefPtr<UString::Rep> Identifier::add(JSGlobalData* globalData, const char* c)
125{
126 if (!c) {
127 UString::Rep::null().hash();
128 return &UString::Rep::null();
129 }
130 if (!c[0]) {
131 UString::Rep::empty().hash();
132 return &UString::Rep::empty();
133 }
134 if (!c[1])
135 return add(globalData, r: globalData->smallStrings.singleCharacterStringRep(character: static_cast<unsigned char>(c[0])));
136
137 IdentifierTable& identifierTable = *globalData->identifierTable;
138 LiteralIdentifierTable& literalIdentifierTable = identifierTable.literalTable();
139
140 const LiteralIdentifierTable::iterator& iter = literalIdentifierTable.find(key: c);
141 if (iter != literalIdentifierTable.end())
142 return iter->second;
143
144 pair<HashSet<UString::Rep*>::iterator, bool> addResult = identifierTable.add<const char*, CStringTranslator>(value: c);
145
146 // If the string is newly-translated, then we need to adopt it.
147 // The boolean in the pair tells us if that is so.
148 RefPtr<UString::Rep> addedString = addResult.second ? adoptRef(p: *addResult.first) : *addResult.first;
149
150 literalIdentifierTable.add(key: c, mapped: addedString.get());
151
152 return addedString.release();
153}
154
155PassRefPtr<UString::Rep> Identifier::add(ExecState* exec, const char* c)
156{
157 return add(globalData: &exec->globalData(), c);
158}
159
160struct UCharBuffer {
161 const UChar* s;
162 unsigned int length;
163};
164
165struct UCharBufferTranslator {
166 static unsigned hash(const UCharBuffer& buf)
167 {
168 return UString::Rep::computeHash(s: buf.s, length: buf.length);
169 }
170
171 static bool equal(UString::Rep* str, const UCharBuffer& buf)
172 {
173 return Identifier::equal(r: str, s: buf.s, length: buf.length);
174 }
175
176 static void translate(UString::Rep*& location, const UCharBuffer& buf, unsigned hash)
177 {
178 UChar* d;
179 UString::Rep* r = UString::Rep::createUninitialized(length: buf.length, output&: d).releaseRef();
180 for (unsigned i = 0; i != buf.length; i++)
181 d[i] = buf.s[i];
182 r->setHash(hash);
183 location = r;
184 }
185};
186
187PassRefPtr<UString::Rep> Identifier::add(JSGlobalData* globalData, const UChar* s, int length)
188{
189 if (length == 1) {
190 UChar c = s[0];
191 if (c <= 0xFF)
192 return add(globalData, r: globalData->smallStrings.singleCharacterStringRep(character: c));
193 }
194 if (!length) {
195 UString::Rep::empty().hash();
196 return &UString::Rep::empty();
197 }
198 UCharBuffer buf = {.s: s, .length: static_cast<unsigned>(length)};
199 pair<HashSet<UString::Rep*>::iterator, bool> addResult = globalData->identifierTable->add<UCharBuffer, UCharBufferTranslator>(value: buf);
200
201 // If the string is newly-translated, then we need to adopt it.
202 // The boolean in the pair tells us if that is so.
203 return addResult.second ? adoptRef(p: *addResult.first) : *addResult.first;
204}
205
206PassRefPtr<UString::Rep> Identifier::add(ExecState* exec, const UChar* s, int length)
207{
208 return add(globalData: &exec->globalData(), s, length);
209}
210
211PassRefPtr<UString::Rep> Identifier::addSlowCase(JSGlobalData* globalData, UString::Rep* r)
212{
213 ASSERT(!r->isIdentifier());
214 if (r->size() == 1) {
215 UChar c = r->data()[0];
216 if (c <= 0xFF)
217 r = globalData->smallStrings.singleCharacterStringRep(character: c);
218 if (r->isIdentifier()) {
219#ifndef NDEBUG
220 checkSameIdentifierTable(globalData, r);
221#endif
222 return r;
223 }
224 }
225 if (!r->size()) {
226 UString::Rep::empty().hash();
227 return &UString::Rep::empty();
228 }
229 return *globalData->identifierTable->add(value: r).first;
230}
231
232PassRefPtr<UString::Rep> Identifier::addSlowCase(ExecState* exec, UString::Rep* r)
233{
234 return addSlowCase(globalData: &exec->globalData(), r);
235}
236
237void Identifier::remove(UString::Rep* r)
238{
239 currentIdentifierTable()->remove(r);
240}
241
242#ifndef NDEBUG
243
244void Identifier::checkSameIdentifierTable(ExecState* exec, UString::Rep*)
245{
246 ASSERT_UNUSED(exec, exec->globalData().identifierTable == currentIdentifierTable());
247}
248
249void Identifier::checkSameIdentifierTable(JSGlobalData* globalData, UString::Rep*)
250{
251 ASSERT_UNUSED(globalData, globalData->identifierTable == currentIdentifierTable());
252}
253
254#else
255
256void Identifier::checkSameIdentifierTable(ExecState*, UString::Rep*)
257{
258}
259
260void Identifier::checkSameIdentifierTable(JSGlobalData*, UString::Rep*)
261{
262}
263
264#endif
265
266ThreadSpecific<ThreadIdentifierTableData>* g_identifierTableSpecific = 0;
267
268#if ENABLE(JSC_MULTIPLE_THREADS)
269
270pthread_once_t createIdentifierTableSpecificOnce = PTHREAD_ONCE_INIT;
271static void createIdentifierTableSpecificCallback()
272{
273 ASSERT(!g_identifierTableSpecific);
274 g_identifierTableSpecific = new ThreadSpecific<ThreadIdentifierTableData>();
275}
276void createIdentifierTableSpecific()
277{
278 pthread_once(&createIdentifierTableSpecificOnce, createIdentifierTableSpecificCallback);
279 ASSERT(g_identifierTableSpecific);
280}
281
282#else
283
284void createIdentifierTableSpecific()
285{
286 ASSERT(!g_identifierTableSpecific);
287 g_identifierTableSpecific = new ThreadSpecific<ThreadIdentifierTableData>();
288}
289
290#endif
291
292} // namespace JSC
293

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/runtime/Identifier.cpp