Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

1 files changed, 258 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/Identifier.h b/Source/JavaScriptCore/runtime/Identifier.h
new file mode 100644
index 000000000..2cc88b256
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/Identifier.h
@@ -0,0 +1,258 @@
+/*
+ *  Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef Identifier_h
+#define Identifier_h
+
+#include "JSGlobalData.h"
+#include "ThreadSpecific.h"
+#include "UString.h"
+#include <wtf/WTFThreadData.h>
+#include <wtf/text/CString.h>
+
+namespace JSC {
+
+    class ExecState;
+
+    class Identifier {
+        friend class Structure;
+    public:
+        Identifier() { }
+
+        Identifier(ExecState* exec, const char* s) : m_string(add(exec, s)) { } // Only to be used with string literals.
+        Identifier(ExecState* exec, StringImpl* rep) : m_string(add(exec, rep)) { } 
+        Identifier(ExecState* exec, const UString& s) : m_string(add(exec, s.impl())) { }
+
+        Identifier(JSGlobalData* globalData, const char* s) : m_string(add(globalData, s)) { } // Only to be used with string literals.
+        Identifier(JSGlobalData* globalData, const LChar* s, int length) : m_string(add(globalData, s, length)) { }
+        Identifier(JSGlobalData* globalData, const UChar* s, int length) : m_string(add(globalData, s, length)) { }
+        Identifier(JSGlobalData* globalData, StringImpl* rep) : m_string(add(globalData, rep)) { } 
+        Identifier(JSGlobalData* globalData, const UString& s) : m_string(add(globalData, s.impl())) { }
+
+        const UString& ustring() const { return m_string; }
+        StringImpl* impl() const { return m_string.impl(); }
+        
+        const UChar* characters() const { return m_string.characters(); }
+        int length() const { return m_string.length(); }
+        
+        CString ascii() const { return m_string.ascii(); }
+
+        static Identifier createLCharFromUChar(JSGlobalData* globalData, const UChar* s, int length) { return Identifier(globalData, add8(globalData, s, length)); }
+
+        static Identifier from(ExecState* exec, unsigned y);
+        static Identifier from(ExecState* exec, int y);
+        static Identifier from(ExecState* exec, double y);
+        static Identifier from(JSGlobalData*, unsigned y);
+        static Identifier from(JSGlobalData*, int y);
+        static Identifier from(JSGlobalData*, double y);
+
+        static uint32_t toUInt32(const UString&, bool& ok);
+        uint32_t toUInt32(bool& ok) const { return toUInt32(m_string, ok); }
+        unsigned toArrayIndex(bool& ok) const;
+
+        bool isNull() const { return m_string.isNull(); }
+        bool isEmpty() const { return m_string.isEmpty(); }
+        
+        friend bool operator==(const Identifier&, const Identifier&);
+        friend bool operator!=(const Identifier&, const Identifier&);
+
+        friend bool operator==(const Identifier&, const LChar*);
+        friend bool operator==(const Identifier&, const char*);
+        friend bool operator!=(const Identifier&, const LChar*);
+        friend bool operator!=(const Identifier&, const char*);
+    
+        static bool equal(const StringImpl*, const LChar*);
+        static inline bool equal(const StringImpl*a, const char*b) { return Identifier::equal(a, reinterpret_cast<const LChar*>(b)); };
+        static bool equal(const StringImpl*, const LChar*, unsigned length);
+        static bool equal(const StringImpl*, const UChar*, unsigned length);
+        static bool equal(const StringImpl* a, const StringImpl* b) { return ::equal(a, b); }
+
+        static PassRefPtr<StringImpl> add(ExecState*, const char*); // Only to be used with string literals.
+        static PassRefPtr<StringImpl> add(JSGlobalData*, const char*); // Only to be used with string literals.
+
+    private:
+        UString m_string;
+
+        template <typename CharType>
+        ALWAYS_INLINE static uint32_t toUInt32FromCharacters(const CharType* characters, unsigned length, bool& ok);
+
+        static bool equal(const Identifier& a, const Identifier& b) { return a.m_string.impl() == b.m_string.impl(); }
+        static bool equal(const Identifier& a, const LChar* b) { return equal(a.m_string.impl(), b); }
+
+        template <typename T> static PassRefPtr<StringImpl> add(JSGlobalData*, const T*, int length);
+        static PassRefPtr<StringImpl> add8(JSGlobalData*, const UChar*, int length);
+        template <typename T> ALWAYS_INLINE static bool canUseSingleCharacterString(T);
+
+        static PassRefPtr<StringImpl> add(ExecState* exec, StringImpl* r)
+        {
+#ifndef NDEBUG
+            checkCurrentIdentifierTable(exec);
+#endif
+            if (r->isIdentifier())
+                return r;
+            return addSlowCase(exec, r);
+        }
+        static PassRefPtr<StringImpl> add(JSGlobalData* globalData, StringImpl* r)
+        {
+#ifndef NDEBUG
+            checkCurrentIdentifierTable(globalData);
+#endif
+            if (r->isIdentifier())
+                return r;
+            return addSlowCase(globalData, r);
+        }
+
+        static PassRefPtr<StringImpl> addSlowCase(ExecState*, StringImpl* r);
+        static PassRefPtr<StringImpl> addSlowCase(JSGlobalData*, StringImpl* r);
+
+        static void checkCurrentIdentifierTable(ExecState*);
+        static void checkCurrentIdentifierTable(JSGlobalData*);
+    };
+
+    template <> ALWAYS_INLINE bool Identifier::canUseSingleCharacterString(LChar)
+    {
+        ASSERT(maxSingleCharacterString == 0xff);
+        return true;
+    }
+
+    template <> ALWAYS_INLINE bool Identifier::canUseSingleCharacterString(UChar c)
+    {
+        return (c <= maxSingleCharacterString);
+    }
+
+    template <typename T>
+    struct CharBuffer {
+        const T* s;
+        unsigned int length;
+    };
+    
+    template <typename T>
+    struct IdentifierCharBufferTranslator {
+        static unsigned hash(const CharBuffer<T>& buf)
+        {
+            return StringHasher::computeHash<T>(buf.s, buf.length);
+        }
+        
+        static bool equal(StringImpl* str, const CharBuffer<T>& buf)
+        {
+            return Identifier::equal(str, buf.s, buf.length);
+        }
+
+        static void translate(StringImpl*& location, const CharBuffer<T>& buf, unsigned hash)
+        {
+            T* d;
+            StringImpl* r = StringImpl::createUninitialized(buf.length, d).leakRef();
+            for (unsigned i = 0; i != buf.length; i++)
+                d[i] = buf.s[i];
+            r->setHash(hash);
+            location = r; 
+        }
+    };
+
+    template <typename T>
+    PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const T* s, int length)
+    {
+        if (length == 1) {
+            T c = s[0];
+            if (canUseSingleCharacterString(c))
+                return add(globalData, globalData->smallStrings.singleCharacterStringRep(c));
+        }
+        
+        if (!length)
+            return StringImpl::empty();
+        CharBuffer<T> buf = {s, length}; 
+        pair<HashSet<StringImpl*>::iterator, bool> addResult = globalData->identifierTable->add<CharBuffer<T>, IdentifierCharBufferTranslator<T> >(buf);
+        
+        // If the string is newly-translated, then we need to adopt it.
+        // The boolean in the pair tells us if that is so.
+        return addResult.second ? adoptRef(*addResult.first) : *addResult.first;
+    }
+
+    inline bool operator==(const Identifier& a, const Identifier& b)
+    {
+        return Identifier::equal(a, b);
+    }
+
+    inline bool operator!=(const Identifier& a, const Identifier& b)
+    {
+        return !Identifier::equal(a, b);
+    }
+
+    inline bool operator==(const Identifier& a, const LChar* b)
+    {
+        return Identifier::equal(a, b);
+    }
+
+    inline bool operator==(const Identifier& a, const char* b)
+    {
+        return Identifier::equal(a, reinterpret_cast<const LChar*>(b));
+    }
+    
+    inline bool operator!=(const Identifier& a, const LChar* b)
+    {
+        return !Identifier::equal(a, b);
+    }
+
+    inline bool operator!=(const Identifier& a, const char* b)
+    {
+        return !Identifier::equal(a, reinterpret_cast<const LChar*>(b));
+    }
+    
+    inline bool Identifier::equal(const StringImpl* r, const LChar* s)
+    {
+        return WTF::equal(r, s);
+    }
+
+    inline bool Identifier::equal(const StringImpl* r, const LChar* s, unsigned length)
+    {
+        return WTF::equal(r, s, length);
+    }
+
+    inline bool Identifier::equal(const StringImpl* r, const UChar* s, unsigned length)
+    {
+        return WTF::equal(r, s, length);
+    }
+    
+    IdentifierTable* createIdentifierTable();
+    void deleteIdentifierTable(IdentifierTable*);
+
+    struct IdentifierRepHash : PtrHash<RefPtr<StringImpl> > {
+        static unsigned hash(const RefPtr<StringImpl>& key) { return key->existingHash(); }
+        static unsigned hash(StringImpl* key) { return key->existingHash(); }
+    };
+
+    struct IdentifierMapIndexHashTraits : HashTraits<int> {
+        static int emptyValue() { return std::numeric_limits<int>::max(); }
+        static const bool emptyValueIsZero = false;
+    };
+
+    typedef HashMap<RefPtr<StringImpl>, int, IdentifierRepHash, HashTraits<RefPtr<StringImpl> >, IdentifierMapIndexHashTraits> IdentifierMap;
+
+    template<typename U, typename V>
+    std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(U value)
+    {
+        std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add<U, V>(value);
+        (*result.first)->setIsIdentifier(true);
+        return result;
+    }
+
+} // namespace JSC
+
+#endif // Identifier_h