1 /*

     2  * Copyright (C) 2005, 2006, 2009 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 QualifiedName_h

    22 #define QualifiedName_h

    23 

    24 #include "AtomicString.h"

    25 #include <wtf/HashTraits.h>

    26 

    27 namespace WebCore {

    28 

    29 struct QualifiedNameComponents {

    30     StringImpl* m_prefix;

    31     StringImpl* m_localName;

    32     StringImpl* m_namespace;

    33 };

    34 

    35 class QualifiedName : public FastAllocBase {

    36 public:

    37     class QualifiedNameImpl : public RefCounted<QualifiedNameImpl> {

    38     public:

    39         static PassRefPtr<QualifiedNameImpl> create(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI)

    40         {

    41             return adoptRef(new QualifiedNameImpl(prefix, localName, namespaceURI));

    42         }

    43 

    44         const AtomicString m_prefix;

    45         const AtomicString m_localName;

    46         const AtomicString m_namespace;

    47         mutable AtomicString m_localNameUpper;

    48 

    49     private:

    50         QualifiedNameImpl(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI)

    51             : m_prefix(prefix)

    52             , m_localName(localName)

    53             , m_namespace(namespaceURI)

    54         {

    55             ASSERT(!namespaceURI.isEmpty() || namespaceURI.isNull());

    56         }        

    57     };

    58 

    59     QualifiedName(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI);

    60     QualifiedName(const AtomicString& prefix, const char* localName, const AtomicString& namespaceURI);

    61     QualifiedName(WTF::HashTableDeletedValueType) : m_impl(hashTableDeletedValue()) { }

    62     bool isHashTableDeletedValue() const { return m_impl == hashTableDeletedValue(); }

    63     ~QualifiedName() { deref(); }

    64 #ifdef QNAME_DEFAULT_CONSTRUCTOR

    65     QualifiedName() : m_impl(0) { }

    66 #endif

    67 

    68     QualifiedName(const QualifiedName& other) : m_impl(other.m_impl) { ref(); }

    69     const QualifiedName& operator=(const QualifiedName& other) { other.ref(); deref(); m_impl = other.m_impl; return *this; }

    70 

    71     bool operator==(const QualifiedName& other) const { return m_impl == other.m_impl; }

    72     bool operator!=(const QualifiedName& other) const { return !(*this == other); }

    73 

    74     bool matches(const QualifiedName& other) const { return m_impl == other.m_impl || (localName() == other.localName() && namespaceURI() == other.namespaceURI()); }

    75 

    76     bool hasPrefix() const { return m_impl->m_prefix != nullAtom; }

    77     void setPrefix(const AtomicString& prefix) { *this = QualifiedName(prefix, localName(), namespaceURI()); }

    78 

    79     const AtomicString& prefix() const { return m_impl->m_prefix; }

    80     const AtomicString& localName() const { return m_impl->m_localName; }

    81     const AtomicString& namespaceURI() const { return m_impl->m_namespace; }

    82 

    83     // Uppercased localName, cached for efficiency

    84     const AtomicString& localNameUpper() const;

    85 

    86     String toString() const;

    87 

    88     QualifiedNameImpl* impl() const { return m_impl; }

    89     

    90     // Init routine for globals

    91     static void init();

    92     

    93 private:

    94     void init(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI);

    95     void ref() const { m_impl->ref(); }

    96     void deref();

    97 

    98     static QualifiedNameImpl* hashTableDeletedValue() { return RefPtr<QualifiedNameImpl>::hashTableDeletedValue(); }

    99     

   100     QualifiedNameImpl* m_impl;

   101 };

   102 

   103 #ifndef WEBCORE_QUALIFIEDNAME_HIDE_GLOBALS

   104 extern const QualifiedName anyName;

   105 inline const QualifiedName& anyQName() { return anyName; }

   106 #endif

   107 

   108 inline bool operator==(const AtomicString& a, const QualifiedName& q) { return a == q.localName(); }

   109 inline bool operator!=(const AtomicString& a, const QualifiedName& q) { return a != q.localName(); }

   110 inline bool operator==(const QualifiedName& q, const AtomicString& a) { return a == q.localName(); }

   111 inline bool operator!=(const QualifiedName& q, const AtomicString& a) { return a != q.localName(); }

   112 

   113 inline unsigned hashComponents(const QualifiedNameComponents& buf)

   114 {

   115     ASSERT(sizeof(QualifiedNameComponents) % (sizeof(uint16_t) * 2) == 0);

   116     

   117     unsigned l = sizeof(QualifiedNameComponents) / (sizeof(uint16_t) * 2);

   118     const uint16_t* s = reinterpret_cast<const uint16_t*>(&buf);

   119     uint32_t hash = WTF::stringHashingStartValue;

   120     

   121     // Main loop

   122     for (; l > 0; l--) {

   123         hash += s[0];

   124         uint32_t tmp = (s[1] << 11) ^ hash;

   125         hash = (hash << 16) ^ tmp;

   126         s += 2;

   127         hash += hash >> 11;

   128     }

   129     

   130     // Force "avalanching" of final 127 bits

   131     hash ^= hash << 3;

   132     hash += hash >> 5;

   133     hash ^= hash << 2;

   134     hash += hash >> 15;

   135     hash ^= hash << 10;

   136     

   137     // this avoids ever returning a hash code of 0, since that is used to

   138     // signal "hash not computed yet", using a value that is likely to be

   139     // effectively the same as 0 when the low bits are masked

   140     if (hash == 0)

   141         hash = 0x80000000;

   142     

   143     return hash;

   144 }

   145     

   146 struct QualifiedNameHash {

   147     static unsigned hash(const QualifiedName& name) { return hash(name.impl()); }

   148     

   149     static unsigned hash(const QualifiedName::QualifiedNameImpl* name) 

   150     {    

   151         QualifiedNameComponents c = { name->m_prefix.impl(), name->m_localName.impl(), name->m_namespace.impl() };

   152         return hashComponents(c);

   153     }

   154     

   155     static bool equal(const QualifiedName& a, const QualifiedName& b) { return a == b; }

   156     static bool equal(const QualifiedName::QualifiedNameImpl* a, const QualifiedName::QualifiedNameImpl* b) { return a == b; }

   157     

   158     static const bool safeToCompareToEmptyOrDeleted = false;

   159 };

   160     

   161 }

   162 

   163 namespace WTF {

   164     

   165     template<typename T> struct DefaultHash;

   166 

   167     template<> struct DefaultHash<WebCore::QualifiedName> {

   168         typedef WebCore::QualifiedNameHash Hash;

   169     };

   170     

   171     template<> struct HashTraits<WebCore::QualifiedName> : GenericHashTraits<WebCore::QualifiedName> {

   172         static const bool emptyValueIsZero = false;

   173         static WebCore::QualifiedName emptyValue() { return WebCore::QualifiedName(WebCore::nullAtom, WebCore::nullAtom, WebCore::nullAtom); }

   174         static void constructDeletedValue(WebCore::QualifiedName& slot) { new (&slot) WebCore::QualifiedName(WTF::HashTableDeletedValue); }

   175         static bool isDeletedValue(const WebCore::QualifiedName& slot) { return slot.isHashTableDeletedValue(); }

   176     };

   177 }

   178 

   179 #endif