/*
* Copyright (C) 2008 Google 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR
* 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 LinkHash_h
#define LinkHash_h
#include "platform/PlatformExport.h"
#include "wtf/Forward.h"
#include "wtf/text/StringHash.h"
namespace WebCore {
class KURL;
typedef uint64_t LinkHash;
// Use the low 32-bits of the 64-bit LinkHash as the key for HashSets.
struct LinkHashHash {
static unsigned hash(LinkHash key) { return static_cast<unsigned>(key); }
static bool equal(LinkHash a, LinkHash b) { return a == b; }
static const bool safeToCompareToEmptyOrDeleted = true;
// See AlreadyHashed::avoidDeletedValue.
static unsigned avoidDeletedValue(LinkHash hash64)
{
ASSERT(hash64);
unsigned hash = static_cast<unsigned>(hash64);
unsigned newHash = hash | (!(hash + 1) << 31);
ASSERT(newHash);
ASSERT(newHash != 0xFFFFFFFF);
return newHash;
}
};
// Resolves the potentially relative URL "attributeURL" relative to the given
// base URL, and returns the hash of the string that will be used for visited
// link coloring. It will return the special value of 0 if attributeURL does not
// look like a relative URL.
PLATFORM_EXPORT LinkHash visitedLinkHash(const KURL& base, const AtomicString& attributeURL);
} // namespace WebCore
#endif // LinkHash_h