runtime/Identifier.h

   1 /*
   2  *  Copyright (C) 2003, 2006, 2007, 2008, 2009, 2012 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 #ifndef Identifier_h
  22 #define Identifier_h
  23
  24 #include "VM.h"
  25 #include <wtf/ThreadSpecific.h>
  26 #include <wtf/WTFThreadData.h>
  27 #include <wtf/text/CString.h>
  28 #include <wtf/text/WTFString.h>
  29
  30 namespace JSC {
  31
  32     class ExecState;
  33
  34     class Identifier {
  35         friend class Structure;
  36     public:
  37         Identifier() { }
  38         enum EmptyIdentifierFlag { EmptyIdentifier };
  39         Identifier(EmptyIdentifierFlag) : m_string(StringImpl::empty()) { ASSERT(m_string.impl()->isAtomic()); }
  40
  41         // Only to be used with string literals.
  42         template<unsigned charactersCount>
  43         Identifier(ExecState* exec, const char (&characters)[charactersCount]) : m_string(add(exec, characters)) { ASSERT(m_string.impl()->isAtomic()); }
  44         template<unsigned charactersCount>
  45         Identifier(VM* vm, const char (&characters)[charactersCount]) : m_string(add(vm, characters)) { ASSERT(m_string.impl()->isAtomic()); }
  46
  47         Identifier(ExecState* exec, StringImpl* rep) : m_string(add(exec, rep)) { ASSERT(m_string.impl()->isAtomic()); }
  48         Identifier(ExecState* exec, const String& s) : m_string(add(exec, s.impl())) { ASSERT(m_string.impl()->isAtomic()); }
  49
  50         Identifier(VM* vm, const LChar* s, int length) : m_string(add(vm, s, length)) { ASSERT(m_string.impl()->isAtomic()); }
  51         Identifier(VM* vm, const UChar* s, int length) : m_string(add(vm, s, length)) { ASSERT(m_string.impl()->isAtomic()); }
  52         Identifier(VM* vm, StringImpl* rep) : m_string(add(vm, rep)) { ASSERT(m_string.impl()->isAtomic()); }
  53         Identifier(VM* vm, const String& s) : m_string(add(vm, s.impl())) { ASSERT(m_string.impl()->isAtomic()); }
  54
  55         const String& string() const { return m_string; }
  56         StringImpl* impl() const { return m_string.impl(); }
  57
  58         int length() const { return m_string.length(); }
  59
  60         CString ascii() const { return m_string.ascii(); }
  61         CString utf8() const { return m_string.utf8(); }
  62
  63         static Identifier from(const PrivateName& name)
  64         {
  65             Identifier result;
  66             result.m_string = name.uid();
  67             return result;
  68         }
  69
  70         static Identifier createLCharFromUChar(VM* vm, const UChar* s, int length) { return Identifier(vm, add8(vm, s, length)); }
  71
  72         JS_EXPORT_PRIVATE static Identifier from(ExecState* exec, unsigned y);
  73         JS_EXPORT_PRIVATE static Identifier from(ExecState* exec, int y);
  74         static Identifier from(ExecState* exec, double y);
  75         static Identifier from(VM*, unsigned y);
  76         static Identifier from(VM*, int y);
  77         static Identifier from(VM*, double y);
  78
  79         bool isNull() const { return m_string.isNull(); }
  80         bool isEmpty() const { return m_string.isEmpty(); }
  81
  82         friend bool operator==(const Identifier&, const Identifier&);
  83         friend bool operator!=(const Identifier&, const Identifier&);
  84
  85         friend bool operator==(const Identifier&, const LChar*);
  86         friend bool operator==(const Identifier&, const char*);
  87         friend bool operator!=(const Identifier&, const LChar*);
  88         friend bool operator!=(const Identifier&, const char*);
  89
  90         static bool equal(const StringImpl*, const LChar*);
  91         static inline bool equal(const StringImpl*a, const char*b) { return Identifier::equal(a, reinterpret_cast<const LChar*>(b)); };
  92         static bool equal(const StringImpl*, const LChar*, unsigned length);
  93         static bool equal(const StringImpl*, const UChar*, unsigned length);
  94         static bool equal(const StringImpl* a, const StringImpl* b) { return ::equal(a, b); }
  95
  96         // Only to be used with string literals.
  97         JS_EXPORT_PRIVATE static PassRef<StringImpl> add(VM*, const char*);
  98         JS_EXPORT_PRIVATE static PassRef<StringImpl> add(ExecState*, const char*);
  99
 100     private:
 101         String m_string;
 102
 103         template <typename CharType>
 104         ALWAYS_INLINE static uint32_t toUInt32FromCharacters(const CharType* characters, unsigned length, bool& ok);
 105
 106         static bool equal(const Identifier& a, const Identifier& b) { return a.m_string.impl() == b.m_string.impl(); }
 107         static bool equal(const Identifier& a, const LChar* b) { return equal(a.m_string.impl(), b); }
 108
 109         template <typename T> static PassRef<StringImpl> add(VM*, const T*, int length);
 110         static PassRef<StringImpl> add8(VM*, const UChar*, int length);
 111         template <typename T> ALWAYS_INLINE static bool canUseSingleCharacterString(T);
 112
 113         static PassRef<StringImpl> add(ExecState*, StringImpl*);
 114         static PassRef<StringImpl> add(VM*, StringImpl*);
 115
 116         JS_EXPORT_PRIVATE static void checkCurrentAtomicStringTable(ExecState*);
 117         JS_EXPORT_PRIVATE static void checkCurrentAtomicStringTable(VM*);
 118     };
 119
 120     template <> ALWAYS_INLINE bool Identifier::canUseSingleCharacterString(LChar)
 121     {
 122         ASSERT(maxSingleCharacterString == 0xff);
 123         return true;
 124     }
 125
 126     template <> ALWAYS_INLINE bool Identifier::canUseSingleCharacterString(UChar c)
 127     {
 128         return (c <= maxSingleCharacterString);
 129     }
 130
 131     template <typename T>
 132     PassRef<StringImpl> Identifier::add(VM* vm, const T* s, int length)
 133     {
 134         if (length == 1) {
 135             T c = s[0];
 136             if (canUseSingleCharacterString(c))
 137                 return *vm->smallStrings.singleCharacterStringRep(c);
 138         }
 139         if (!length)
 140             return *StringImpl::empty();
 141
 142         return *AtomicString::add(s, length);
 143     }
 144
 145     inline bool operator==(const Identifier& a, const Identifier& b)
 146     {
 147         return Identifier::equal(a, b);
 148     }
 149
 150     inline bool operator!=(const Identifier& a, const Identifier& b)
 151     {
 152         return !Identifier::equal(a, b);
 153     }
 154
 155     inline bool operator==(const Identifier& a, const LChar* b)
 156     {
 157         return Identifier::equal(a, b);
 158     }
 159
 160     inline bool operator==(const Identifier& a, const char* b)
 161     {
 162         return Identifier::equal(a, reinterpret_cast<const LChar*>(b));
 163     }
 164
 165     inline bool operator!=(const Identifier& a, const LChar* b)
 166     {
 167         return !Identifier::equal(a, b);
 168     }
 169
 170     inline bool operator!=(const Identifier& a, const char* b)
 171     {
 172         return !Identifier::equal(a, reinterpret_cast<const LChar*>(b));
 173     }
 174
 175     inline bool Identifier::equal(const StringImpl* r, const LChar* s)
 176     {
 177         return WTF::equal(r, s);
 178     }
 179
 180     inline bool Identifier::equal(const StringImpl* r, const LChar* s, unsigned length)
 181     {
 182         return WTF::equal(r, s, length);
 183     }
 184
 185     inline bool Identifier::equal(const StringImpl* r, const UChar* s, unsigned length)
 186     {
 187         return WTF::equal(r, s, length);
 188     }
 189
 190     struct IdentifierRepHash : PtrHash<RefPtr<StringImpl>> {
 191         static unsigned hash(const RefPtr<StringImpl>& key) { return key->existingHash(); }
 192         static unsigned hash(StringImpl* key) { return key->existingHash(); }
 193     };
 194
 195     struct IdentifierMapIndexHashTraits : HashTraits<int> {
 196         static int emptyValue() { return std::numeric_limits<int>::max(); }
 197         static const bool emptyValueIsZero = false;
 198     };
 199
 200     typedef HashMap<RefPtr<StringImpl>, int, IdentifierRepHash, HashTraits<RefPtr<StringImpl>>, IdentifierMapIndexHashTraits> IdentifierMap;
 201     typedef HashMap<StringImpl*, int, IdentifierRepHash, HashTraits<StringImpl*>, IdentifierMapIndexHashTraits> BorrowedIdentifierMap;
 202
 203 } // namespace JSC
 204
 205 namespace WTF {
 206
 207 template <> struct VectorTraits<JSC::Identifier> : SimpleClassVectorTraits { };
 208
 209 } // namespace WTF
 210
 211 #endif // Identifier_h