WebCore/dom/QualifiedName.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/dom/QualifiedName.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2005, 2006, 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 QualifiedName_h
+#define QualifiedName_h
+
+#include "AtomicString.h"
+#include <wtf/HashTraits.h>
+
+namespace WebCore {
+
+struct QualifiedNameComponents {
+    StringImpl* m_prefix;
+    StringImpl* m_localName;
+    StringImpl* m_namespace;
+};
+
+class QualifiedName : public FastAllocBase {
+public:
+    class QualifiedNameImpl : public RefCounted<QualifiedNameImpl> {
+    public:
+        static PassRefPtr<QualifiedNameImpl> create(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI)
+        {
+            return adoptRef(new QualifiedNameImpl(prefix, localName, namespaceURI));
+        }
+
+        const AtomicString m_prefix;
+        const AtomicString m_localName;
+        const AtomicString m_namespace;
+        mutable AtomicString m_localNameUpper;
+
+    private:
+        QualifiedNameImpl(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI)
+            : m_prefix(prefix)
+            , m_localName(localName)
+            , m_namespace(namespaceURI)
+        {
+            ASSERT(!namespaceURI.isEmpty() || namespaceURI.isNull());
+        }        
+    };
+
+    QualifiedName(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI);
+    QualifiedName(const AtomicString& prefix, const char* localName, const AtomicString& namespaceURI);
+    QualifiedName(WTF::HashTableDeletedValueType) : m_impl(hashTableDeletedValue()) { }
+    bool isHashTableDeletedValue() const { return m_impl == hashTableDeletedValue(); }
+    ~QualifiedName() { deref(); }
+#ifdef QNAME_DEFAULT_CONSTRUCTOR
+    QualifiedName() : m_impl(0) { }
+#endif
+
+    QualifiedName(const QualifiedName& other) : m_impl(other.m_impl) { ref(); }
+    const QualifiedName& operator=(const QualifiedName& other) { other.ref(); deref(); m_impl = other.m_impl; return *this; }
+
+    bool operator==(const QualifiedName& other) const { return m_impl == other.m_impl; }
+    bool operator!=(const QualifiedName& other) const { return !(*this == other); }
+
+    bool matches(const QualifiedName& other) const { return m_impl == other.m_impl || (localName() == other.localName() && namespaceURI() == other.namespaceURI()); }
+
+    bool hasPrefix() const { return m_impl->m_prefix != nullAtom; }
+    void setPrefix(const AtomicString& prefix) { *this = QualifiedName(prefix, localName(), namespaceURI()); }
+
+    const AtomicString& prefix() const { return m_impl->m_prefix; }
+    const AtomicString& localName() const { return m_impl->m_localName; }
+    const AtomicString& namespaceURI() const { return m_impl->m_namespace; }
+
+    // Uppercased localName, cached for efficiency
+    const AtomicString& localNameUpper() const;
+
+    String toString() const;
+
+    QualifiedNameImpl* impl() const { return m_impl; }
+    
+    // Init routine for globals
+    static void init();
+    
+private:
+    void init(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI);
+    void ref() const { m_impl->ref(); }
+    void deref();
+
+    static QualifiedNameImpl* hashTableDeletedValue() { return RefPtr<QualifiedNameImpl>::hashTableDeletedValue(); }
+    
+    QualifiedNameImpl* m_impl;
+};
+
+#ifndef WEBCORE_QUALIFIEDNAME_HIDE_GLOBALS
+extern const QualifiedName anyName;
+inline const QualifiedName& anyQName() { return anyName; }
+#endif
+
+inline bool operator==(const AtomicString& a, const QualifiedName& q) { return a == q.localName(); }
+inline bool operator!=(const AtomicString& a, const QualifiedName& q) { return a != q.localName(); }
+inline bool operator==(const QualifiedName& q, const AtomicString& a) { return a == q.localName(); }
+inline bool operator!=(const QualifiedName& q, const AtomicString& a) { return a != q.localName(); }
+
+inline unsigned hashComponents(const QualifiedNameComponents& buf)
+{
+    ASSERT(sizeof(QualifiedNameComponents) % (sizeof(uint16_t) * 2) == 0);
+    
+    unsigned l = sizeof(QualifiedNameComponents) / (sizeof(uint16_t) * 2);
+    const uint16_t* s = reinterpret_cast<const uint16_t*>(&buf);
+    uint32_t hash = WTF::stringHashingStartValue;
+    
+    // Main loop
+    for (; l > 0; l--) {
+        hash += s[0];
+        uint32_t tmp = (s[1] << 11) ^ hash;
+        hash = (hash << 16) ^ tmp;
+        s += 2;
+        hash += hash >> 11;
+    }
+    
+    // Force "avalanching" of final 127 bits
+    hash ^= hash << 3;
+    hash += hash >> 5;
+    hash ^= hash << 2;
+    hash += hash >> 15;
+    hash ^= hash << 10;
+    
+    // this avoids ever returning a hash code of 0, since that is used to
+    // signal "hash not computed yet", using a value that is likely to be
+    // effectively the same as 0 when the low bits are masked
+    if (hash == 0)
+        hash = 0x80000000;
+    
+    return hash;
+}
+    
+struct QualifiedNameHash {
+    static unsigned hash(const QualifiedName& name) { return hash(name.impl()); }
+    
+    static unsigned hash(const QualifiedName::QualifiedNameImpl* name) 
+    {    
+        QualifiedNameComponents c = { name->m_prefix.impl(), name->m_localName.impl(), name->m_namespace.impl() };
+        return hashComponents(c);
+    }
+    
+    static bool equal(const QualifiedName& a, const QualifiedName& b) { return a == b; }
+    static bool equal(const QualifiedName::QualifiedNameImpl* a, const QualifiedName::QualifiedNameImpl* b) { return a == b; }
+    
+    static const bool safeToCompareToEmptyOrDeleted = false;
+};
+    
+}
+
+namespace WTF {
+    
+    template<typename T> struct DefaultHash;
+
+    template<> struct DefaultHash<WebCore::QualifiedName> {
+        typedef WebCore::QualifiedNameHash Hash;
+    };
+    
+    template<> struct HashTraits<WebCore::QualifiedName> : GenericHashTraits<WebCore::QualifiedName> {
+        static const bool emptyValueIsZero = false;
+        static WebCore::QualifiedName emptyValue() { return WebCore::QualifiedName(WebCore::nullAtom, WebCore::nullAtom, WebCore::nullAtom); }
+        static void constructDeletedValue(WebCore::QualifiedName& slot) { new (&slot) WebCore::QualifiedName(WTF::HashTableDeletedValue); }
+        static bool isDeletedValue(const WebCore::QualifiedName& slot) { return slot.isHashTableDeletedValue(); }
+    };
+}
+
+#endif