/*
* Copyright (C) 2013 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.
* 3. Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef FontCacheKey_h
#define FontCacheKey_h
#include "wtf/HashMap.h"
#include "wtf/HashTableDeletedValueType.h"
#include "wtf/text/AtomicStringHash.h"
#include "wtf/text/StringHash.h"
namespace WebCore {
// Multiplying the floating point size by 100 gives two decimal point
// precision which should be sufficient.
static const unsigned s_fontSizePrecisionMultiplier = 100;
struct FontCacheKey {
WTF_MAKE_FAST_ALLOCATED;
public:
FontCacheKey()
: m_familyName()
, m_fontSize(0)
, m_options(0) { }
FontCacheKey(AtomicString familyName, float fontSize, unsigned options)
: m_familyName(familyName)
, m_fontSize(fontSize * s_fontSizePrecisionMultiplier)
, m_options(options) { }
FontCacheKey(WTF::HashTableDeletedValueType)
: m_fontSize(hashTableDeletedSize()) { }
unsigned hash() const
{
unsigned hashCodes[3] = {
CaseFoldingHash::hash(m_familyName),
m_fontSize,
m_options
};
return StringHasher::hashMemory<sizeof(hashCodes)>(hashCodes);
}
bool operator==(const FontCacheKey& other) const
{
return equalIgnoringCase(m_familyName, other.m_familyName)
&& m_fontSize == other.m_fontSize
&& m_options == other.m_options;
}
bool isHashTableDeletedValue() const
{
return m_fontSize == hashTableDeletedSize();
}
static unsigned precisionMultiplier()
{
return s_fontSizePrecisionMultiplier;
}
private:
static unsigned hashTableDeletedSize()
{
return 0xFFFFFFFFU;
}
AtomicString m_familyName;
unsigned m_fontSize;
unsigned m_options;
};
struct FontCacheKeyHash {
static unsigned hash(const FontCacheKey& key)
{
return key.hash();
}
static bool equal(const FontCacheKey& a, const FontCacheKey& b)
{
return a == b;
}
static const bool safeToCompareToEmptyOrDeleted = true;
};
struct FontCacheKeyTraits : WTF::SimpleClassHashTraits<FontCacheKey> { };
}
#endif // FontCacheKey_h