/*
* Copyright (C) 2008 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef AtomicStringHash_h
#define AtomicStringHash_h
#include "wtf/text/AtomicString.h"
#include "wtf/HashTraits.h"
namespace WTF {
struct AtomicStringHash {
static unsigned hash(const AtomicString& key)
{
return key.impl()->existingHash();
}
static bool equal(const AtomicString& a, const AtomicString& b)
{
return a == b;
}
static const bool safeToCompareToEmptyOrDeleted = false;
};
// AtomicStringHash is the default hash for AtomicString
template<> struct HashTraits<WTF::AtomicString> : GenericHashTraits<WTF::AtomicString> {
// Unlike other types, we can return a const reference for AtomicString's empty value (nullAtom).
typedef const WTF::AtomicString& PeekOutType;
static const WTF::AtomicString& emptyValue() { return nullAtom; }
static PeekOutType peek(const WTF::AtomicString& value) { return value; }
static const bool emptyValueIsZero = true;
static void constructDeletedValue(WTF::AtomicString& slot) { new (NotNull, &slot) WTF::AtomicString(HashTableDeletedValue); }
static bool isDeletedValue(const WTF::AtomicString& slot) { return slot.isHashTableDeletedValue(); }
};
}
using WTF::AtomicStringHash;
#endif