src/third_party/WebKit/Source/WTF/wtf/text/AtomicString.h

/*
 * Copyright (C) 2004, 2005, 2006, 2008 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 AtomicString_h
#define AtomicString_h

#include <wtf/text/AtomicStringImpl.h>
#include <wtf/text/WTFString.h>

// Define 'NO_IMPLICIT_ATOMICSTRING' before including this header,
// to disallow (expensive) implicit String-->AtomicString conversions.
#ifdef NO_IMPLICIT_ATOMICSTRING
#define ATOMICSTRING_CONVERSION explicit
#else
#define ATOMICSTRING_CONVERSION
#endif

namespace WTF {

struct AtomicStringHash;
class MemoryObjectInfo;

class AtomicString {
public:
    WTF_EXPORT_PRIVATE static void init();

    AtomicString() { }
    AtomicString(const LChar* s) : m_string(add(s)) { }
    AtomicString(const char* s) : m_string(add(s)) { }
    AtomicString(const LChar* s, unsigned length) : m_string(add(s, length)) { }
    AtomicString(const UChar* s, unsigned length) : m_string(add(s, length)) { }
    AtomicString(const UChar* s, unsigned length, unsigned existingHash) : m_string(add(s, length, existingHash)) { }
    AtomicString(const UChar* s) : m_string(add(s)) { }
    ATOMICSTRING_CONVERSION AtomicString(StringImpl* imp) : m_string(add(imp)) { }
    AtomicString(AtomicStringImpl* imp) : m_string(imp) { }
    ATOMICSTRING_CONVERSION AtomicString(const String& s) : m_string(add(s.impl())) { }
    AtomicString(StringImpl* baseString, unsigned start, unsigned length) : m_string(add(baseString, start, length)) { }

    enum ConstructFromLiteralTag { ConstructFromLiteral };
    AtomicString(const char* characters, unsigned length, ConstructFromLiteralTag)
        : m_string(addFromLiteralData(characters, length))
    {
    }
    template<unsigned charactersCount>
    ALWAYS_INLINE AtomicString(const char (&characters)[charactersCount], ConstructFromLiteralTag)
        : m_string(addFromLiteralData(characters, charactersCount - 1))
    {
        COMPILE_ASSERT(charactersCount > 1, AtomicStringFromLiteralNotEmpty);
        COMPILE_ASSERT((charactersCount - 1 <= ((unsigned(~0) - sizeof(StringImpl)) / sizeof(LChar))), AtomicStringFromLiteralCannotOverflow);
    }

#if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
    // We have to declare the copy constructor and copy assignment operator as well, otherwise
    // they'll be implicitly deleted by adding the move constructor and move assignment operator.
    // FIXME: Instead of explicitly casting to String&& here, we should use std::move, but that requires us to
    // have a standard library that supports move semantics.
    AtomicString(const AtomicString& other) : m_string(other.m_string) { }
    AtomicString(AtomicString&& other) : m_string(static_cast<String&&>(other.m_string)) { }
    AtomicString& operator=(const AtomicString& other) { m_string = other.m_string; return *this; }
    AtomicString& operator=(AtomicString&& other) { m_string = static_cast<String&&>(other.m_string); return *this; }
#endif

    // Hash table deleted values, which are only constructed and never copied or destroyed.
    AtomicString(WTF::HashTableDeletedValueType) : m_string(WTF::HashTableDeletedValue) { }
    bool isHashTableDeletedValue() const { return m_string.isHashTableDeletedValue(); }

    WTF_EXPORT_STRING_API static AtomicStringImpl* find(const StringImpl*);

    operator const String&() const { return m_string; }
    const String& string() const { return m_string; };

    AtomicStringImpl* impl() const { return static_cast<AtomicStringImpl *>(m_string.impl()); }

    bool is8Bit() const { return m_string.is8Bit(); }
    const UChar* characters() const { return m_string.characters(); }
    const LChar* characters8() const { return m_string.characters8(); }
    const UChar* characters16() const { return m_string.characters16(); }
    unsigned length() const { return m_string.length(); }
    
    UChar operator[](unsigned int i) const { return m_string[i]; }
    
    bool contains(UChar c) const { return m_string.contains(c); }
    bool contains(const LChar* s, bool caseSensitive = true) const
        { return m_string.contains(s, caseSensitive); }
    bool contains(const String& s, bool caseSensitive = true) const
        { return m_string.contains(s, caseSensitive); }

    size_t find(UChar c, size_t start = 0) const { return m_string.find(c, start); }
    size_t find(const LChar* s, size_t start = 0, bool caseSentitive = true) const
        { return m_string.find(s, start, caseSentitive); }
    size_t find(const String& s, size_t start = 0, bool caseSentitive = true) const
        { return m_string.find(s, start, caseSentitive); }
    
    bool startsWith(const String& s, bool caseSensitive = true) const
        { return m_string.startsWith(s, caseSensitive); }
    bool startsWith(UChar character) const
        { return m_string.startsWith(character); }
    template<unsigned matchLength>
    bool startsWith(const char (&prefix)[matchLength], bool caseSensitive = true) const
        { return m_string.startsWith<matchLength>(prefix, caseSensitive); }

    bool endsWith(const String& s, bool caseSensitive = true) const
        { return m_string.endsWith(s, caseSensitive); }
    bool endsWith(UChar character) const
        { return m_string.endsWith(character); }
    template<unsigned matchLength>
    bool endsWith(const char (&prefix)[matchLength], bool caseSensitive = true) const
        { return m_string.endsWith<matchLength>(prefix, caseSensitive); }
    
    WTF_EXPORT_STRING_API AtomicString lower() const;
    AtomicString upper() const { return AtomicString(impl()->upper()); }
    
    int toInt(bool* ok = 0) const { return m_string.toInt(ok); }
    double toDouble(bool* ok = 0) const { return m_string.toDouble(ok); }
    float toFloat(bool* ok = 0) const { return m_string.toFloat(ok); }
    bool percentage(int& p) const { return m_string.percentage(p); }

    bool isNull() const { return m_string.isNull(); }
    bool isEmpty() const { return m_string.isEmpty(); }

    static void remove(StringImpl*);
    
#if USE(CF)
    AtomicString(CFStringRef s) :  m_string(add(s)) { }
#endif    
#ifdef __OBJC__
    AtomicString(NSString* s) : m_string(add((CFStringRef)s)) { }
    operator NSString*() const { return m_string; }
#endif
#if PLATFORM(QT)
    AtomicString(const QString& s) : m_string(add(String(s).impl())) { }
    operator QString() const { return m_string; }
#endif
#if PLATFORM(BLACKBERRY)
    AtomicString(const BlackBerry::Platform::String& s) : m_string(add(String(s).impl())) { }
    operator BlackBerry::Platform::String() const { return m_string; }
#endif

    // AtomicString::fromUTF8 will return a null string if
    // the input data contains invalid UTF-8 sequences.
    static AtomicString fromUTF8(const char*, size_t);
    static AtomicString fromUTF8(const char*);

#ifndef NDEBUG
    void show() const;
#endif

private:
    // The explicit constructors with AtomicString::ConstructFromLiteral must be used for literals.
    AtomicString(ASCIILiteral);

    String m_string;
    
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const LChar*);
    ALWAYS_INLINE static PassRefPtr<StringImpl> add(const char* s) { return add(reinterpret_cast<const LChar*>(s)); };
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const LChar*, unsigned length);
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const UChar*, unsigned length);
    ALWAYS_INLINE static PassRefPtr<StringImpl> add(const char* s, unsigned length) { return add(reinterpret_cast<const LChar*>(s), length); };
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const UChar*, unsigned length, unsigned existingHash);
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(const UChar*);
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> add(StringImpl*, unsigned offset, unsigned length);
    ALWAYS_INLINE static PassRefPtr<StringImpl> add(StringImpl* r)
    {
        if (!r || r->isAtomic())
            return r;
        return addSlowCase(r);
    }
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> addFromLiteralData(const char* characters, unsigned length);
    WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> addSlowCase(StringImpl*);
#if USE(CF)
    static PassRefPtr<StringImpl> add(CFStringRef);
#endif

    WTF_EXPORT_STRING_API static AtomicString fromUTF8Internal(const char*, const char*);
};

inline bool operator==(const AtomicString& a, const AtomicString& b) { return a.impl() == b.impl(); }
bool operator==(const AtomicString&, const LChar*);
inline bool operator==(const AtomicString& a, const char* b) { return WTF::equal(a.impl(), reinterpret_cast<const LChar*>(b)); }
inline bool operator==(const AtomicString& a, const Vector<UChar>& b) { return a.impl() && equal(a.impl(), b.data(), b.size()); }    
inline bool operator==(const AtomicString& a, const String& b) { return equal(a.impl(), b.impl()); }
inline bool operator==(const LChar* a, const AtomicString& b) { return b == a; }
inline bool operator==(const String& a, const AtomicString& b) { return equal(a.impl(), b.impl()); }
inline bool operator==(const Vector<UChar>& a, const AtomicString& b) { return b == a; }

inline bool operator!=(const AtomicString& a, const AtomicString& b) { return a.impl() != b.impl(); }
inline bool operator!=(const AtomicString& a, const LChar* b) { return !(a == b); }
inline bool operator!=(const AtomicString& a, const char* b) { return !(a == b); }
inline bool operator!=(const AtomicString& a, const String& b) { return !equal(a.impl(), b.impl()); }
inline bool operator!=(const AtomicString& a, const Vector<UChar>& b) { return !(a == b); }
inline bool operator!=(const LChar* a, const AtomicString& b) { return !(b == a); }
inline bool operator!=(const String& a, const AtomicString& b) { return !equal(a.impl(), b.impl()); }
inline bool operator!=(const Vector<UChar>& a, const AtomicString& b) { return !(a == b); }

inline bool equalIgnoringCase(const AtomicString& a, const AtomicString& b) { return equalIgnoringCase(a.impl(), b.impl()); }
inline bool equalIgnoringCase(const AtomicString& a, const LChar* b) { return equalIgnoringCase(a.impl(), b); }
inline bool equalIgnoringCase(const AtomicString& a, const char* b) { return equalIgnoringCase(a.impl(), reinterpret_cast<const LChar*>(b)); }
inline bool equalIgnoringCase(const AtomicString& a, const String& b) { return equalIgnoringCase(a.impl(), b.impl()); }
inline bool equalIgnoringCase(const LChar* a, const AtomicString& b) { return equalIgnoringCase(a, b.impl()); }
inline bool equalIgnoringCase(const char* a, const AtomicString& b) { return equalIgnoringCase(reinterpret_cast<const LChar*>(a), b.impl()); }
inline bool equalIgnoringCase(const String& a, const AtomicString& b) { return equalIgnoringCase(a.impl(), b.impl()); }

// Define external global variables for the commonly used atomic strings.
// These are only usable from the main thread.
#ifndef ATOMICSTRING_HIDE_GLOBALS
extern const WTF_EXPORTDATA AtomicString nullAtom;
extern const WTF_EXPORTDATA AtomicString emptyAtom;
extern const WTF_EXPORTDATA AtomicString textAtom;
extern const WTF_EXPORTDATA AtomicString commentAtom;
extern const WTF_EXPORTDATA AtomicString starAtom;
extern const WTF_EXPORTDATA AtomicString xmlAtom;
extern const WTF_EXPORTDATA AtomicString xmlnsAtom;
extern const WTF_EXPORTDATA AtomicString xlinkAtom;

inline AtomicString AtomicString::fromUTF8(const char* characters, size_t length)
{
    if (!characters)
        return nullAtom;
    if (!length)
        return emptyAtom;
    return fromUTF8Internal(characters, characters + length);
}

inline AtomicString AtomicString::fromUTF8(const char* characters)
{
    if (!characters)
        return nullAtom;
    if (!*characters)
        return emptyAtom;
    return fromUTF8Internal(characters, 0);
}
#endif

// AtomicStringHash is the default hash for AtomicString
template<typename T> struct DefaultHash;
template<> struct DefaultHash<AtomicString> {
    typedef AtomicStringHash Hash;
};

} // namespace WTF

#ifndef ATOMICSTRING_HIDE_GLOBALS
using WTF::AtomicString;
using WTF::nullAtom;
using WTF::emptyAtom;
using WTF::textAtom;
using WTF::commentAtom;
using WTF::starAtom;
using WTF::xmlAtom;
using WTF::xmlnsAtom;
using WTF::xlinkAtom;
#endif

#include <wtf/text/StringConcatenate.h>
#endif // AtomicString_h