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 31 using WTF::ThreadSpecific; 32 33 namespace JSC { 34 35 typedef HashMap<const char*, RefPtr<UString::Rep>, PtrHash<const char*> > LiteralIdentifierTable; 36 37 class IdentifierTable : public FastAllocBase { 38 public: 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(r); } 62 63 LiteralIdentifierTable& literalTable() { return m_literalTable; } 64 65 private: 66 HashSet<UString::Rep*> m_table; 67 LiteralIdentifierTable m_literalTable; 68 }; 69 70 IdentifierTable* createIdentifierTable() 71 { 72 return new IdentifierTable; 73 } 74 75 void deleteIdentifierTable(IdentifierTable* table) 76 { 77 delete table; 78 } 79 80 bool 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 90 bool 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 } 100 101 struct CStringTranslator { 102 static unsigned hash(const char* c) 103 { 104 return UString::Rep::computeHash(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(c); 115 UChar* d; 116 UString::Rep* r = UString::Rep::createUninitialized(length, 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 }; 123 124 PassRefPtr<UString::Rep> Identifier::add(JSGlobalData* globalData, const char* c) 125 { 126 ASSERT(c); 127 128 if (!c[0]) { 129 UString::Rep::empty().hash(); 130 return &UString::Rep::empty(); 131 } 132 if (!c[1]) 133 return add(globalData, globalData->smallStrings.singleCharacterStringRep(static_cast<unsigned char>(c[0]))); 134 135 IdentifierTable& identifierTable = *globalData->identifierTable; 136 LiteralIdentifierTable& literalIdentifierTable = identifierTable.literalTable(); 137 138 const LiteralIdentifierTable::iterator& iter = literalIdentifierTable.find(c); 139 if (iter != literalIdentifierTable.end()) 140 return iter->second; 141 142 pair<HashSet<UString::Rep*>::iterator, bool> addResult = identifierTable.add<const char*, CStringTranslator>(c); 143 144 // If the string is newly-translated, then we need to adopt it. 145 // The boolean in the pair tells us if that is so. 146 RefPtr<UString::Rep> addedString = addResult.second ? adoptRef(*addResult.first) : *addResult.first; 147 148 literalIdentifierTable.add(c, addedString.get()); 149 150 return addedString.release(); 151 } 152 153 PassRefPtr<UString::Rep> Identifier::add(ExecState* exec, const char* c) 154 { 155 return add(&exec->globalData(), c); 156 } 157 158 struct UCharBuffer { 159 const UChar* s; 160 unsigned int length; 161 }; 162 163 struct UCharBufferTranslator { 164 static unsigned hash(const UCharBuffer& buf) 165 { 166 return UString::Rep::computeHash(buf.s, buf.length); 167 } 168 169 static bool equal(UString::Rep* str, const UCharBuffer& buf) 170 { 171 return Identifier::equal(str, buf.s, buf.length); 172 } 173 174 static void translate(UString::Rep*& location, const UCharBuffer& buf, unsigned hash) 175 { 176 UChar* d; 177 UString::Rep* r = UString::Rep::createUninitialized(buf.length, d).releaseRef(); 178 for (unsigned i = 0; i != buf.length; i++) 179 d[i] = buf.s[i]; 180 r->setHash(hash); 181 location = r; 182 } 183 }; 184 185 PassRefPtr<UString::Rep> Identifier::add(JSGlobalData* globalData, const UChar* s, int length) 186 { 187 if (length == 1) { 188 UChar c = s[0]; 189 if (c <= 0xFF) 190 return add(globalData, globalData->smallStrings.singleCharacterStringRep(c)); 191 } 192 if (!length) { 193 UString::Rep::empty().hash(); 194 return &UString::Rep::empty(); 195 } 196 UCharBuffer buf = {s, length}; 197 pair<HashSet<UString::Rep*>::iterator, bool> addResult = globalData->identifierTable->add<UCharBuffer, UCharBufferTranslator>(buf); 198 199 // If the string is newly-translated, then we need to adopt it. 200 // The boolean in the pair tells us if that is so. 201 return addResult.second ? adoptRef(*addResult.first) : *addResult.first; 202 } 203 204 PassRefPtr<UString::Rep> Identifier::add(ExecState* exec, const UChar* s, int length) 205 { 206 return add(&exec->globalData(), s, length); 207 } 208 209 PassRefPtr<UString::Rep> Identifier::addSlowCase(JSGlobalData* globalData, UString::Rep* r) 210 { 211 ASSERT(!r->isIdentifier()); 212 if (r->size() == 1) { 213 UChar c = r->data()[0]; 214 if (c <= 0xFF) 215 r = globalData->smallStrings.singleCharacterStringRep(c); 216 if (r->isIdentifier()) { 217 #ifndef NDEBUG 218 checkSameIdentifierTable(globalData, r); 219 #endif 220 return r; 221 } 222 } 223 if (!r->size()) { 224 UString::Rep::empty().hash(); 225 return &UString::Rep::empty(); 226 } 227 return *globalData->identifierTable->add(r).first; 228 } 229 230 PassRefPtr<UString::Rep> Identifier::addSlowCase(ExecState* exec, UString::Rep* r) 231 { 232 return addSlowCase(&exec->globalData(), r); 233 } 234 235 void Identifier::remove(UString::Rep* r) 236 { 237 currentIdentifierTable()->remove(r); 238 } 239 240 #ifndef NDEBUG 241 242 void Identifier::checkSameIdentifierTable(ExecState* exec, UString::Rep*) 243 { 244 ASSERT_UNUSED(exec, exec->globalData().identifierTable == currentIdentifierTable()); 245 } 246 247 void Identifier::checkSameIdentifierTable(JSGlobalData* globalData, UString::Rep*) 248 { 249 ASSERT_UNUSED(globalData, globalData->identifierTable == currentIdentifierTable()); 250 } 251 252 #else 253 254 void Identifier::checkSameIdentifierTable(ExecState*, UString::Rep*) 255 { 256 } 257 258 void Identifier::checkSameIdentifierTable(JSGlobalData*, UString::Rep*) 259 { 260 } 261 262 #endif 263 264 ThreadSpecific<ThreadIdentifierTableData>* g_identifierTableSpecific = 0; 265 266 #if ENABLE(JSC_MULTIPLE_THREADS) 267 268 pthread_once_t createIdentifierTableSpecificOnce = PTHREAD_ONCE_INIT; 269 static void createIdentifierTableSpecificCallback() 270 { 271 ASSERT(!g_identifierTableSpecific); 272 g_identifierTableSpecific = new ThreadSpecific<ThreadIdentifierTableData>(); 273 } 274 void createIdentifierTableSpecific() 275 { 276 pthread_once(&createIdentifierTableSpecificOnce, createIdentifierTableSpecificCallback); 277 ASSERT(g_identifierTableSpecific); 278 } 279 280 #else 281 282 void createIdentifierTableSpecific() 283 { 284 ASSERT(!g_identifierTableSpecific); 285 g_identifierTableSpecific = new ThreadSpecific<ThreadIdentifierTableData>(); 286 } 287 288 #endif 289 290 } // namespace JSC 291
