Moving GraphicsContext and dependencies from core to platform.

Source/core/platform/graphics/FontDataCache.h

-/*
- * 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:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * 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.
- *     * 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
- * OWNER 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 FontDataCache_h
-#define FontDataCache_h
-
-#include "core/platform/graphics/FontCache.h"
-#include "core/platform/graphics/FontPlatformData.h"
-#include "wtf/HashMap.h"
-#include "wtf/ListHashSet.h"
-
-namespace WebCore {
-
-class SimpleFontData;
-
-struct FontDataCacheKeyHash {
-    static unsigned hash(const FontPlatformData& platformData)
-    {
-        return platformData.hash();
-    }
-
-    static bool equal(const FontPlatformData& a, const FontPlatformData& b)
-    {
-        return a == b;
-    }
-
-    static const bool safeToCompareToEmptyOrDeleted = true;
-};
-
-struct FontDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformData> {
-    static const bool emptyValueIsZero = true;
-    static const bool needsDestruction = true;
-    static const FontPlatformData& emptyValue()
-    {
-        DEFINE_STATIC_LOCAL(FontPlatformData, key, (0.f, false, false));
-        return key;
-    }
-    static void constructDeletedValue(FontPlatformData& slot)
-    {
-        new (NotNull, &slot) FontPlatformData(WTF::HashTableDeletedValue);
-    }
-    static bool isDeletedValue(const FontPlatformData& value)
-    {
-        return value.isHashTableDeletedValue();
-    }
-};
-
-class FontDataCache {
-public:
-    PassRefPtr<SimpleFontData> get(const FontPlatformData*, ShouldRetain = Retain);
-    bool contains(const FontPlatformData*) const;
-    void release(const SimpleFontData*);
-
-    // This is used by FontVerticalDataCache to mark all items with vertical data
-    // that are currently in cache as "in cache", which is later used to sweep the FontVerticalDataCache.
-    void markAllVerticalData();
-
-    // Purges items in FontDataCache according to provided severity.
-    // Returns true if any removal of cache items actually occurred.
-    bool purge(PurgeSeverity);
-
-private:
-    bool purgeLeastRecentlyUsed(int count);
-
-    typedef HashMap<FontPlatformData, pair<RefPtr<SimpleFontData>, unsigned>, FontDataCacheKeyHash, FontDataCacheKeyTraits> Cache;
-    Cache m_cache;
-    ListHashSet<RefPtr<SimpleFontData> > m_inactiveFontData;
-};
-
-}
-
-#endif