root/Source/platform/fonts/FontCache.cpp

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DEFINITIONS

This source file includes following definitions.
  1. fontCache
  2. getFontPlatformData
  3. fontVerticalDataCacheInstance
  4. getVerticalData
  5. getFontData
  6. fontDataFromFontPlatformData
  7. isPlatformFontAvailable
  8. getNonRetainedLastResortFallbackFont
  9. releaseFontData
  10. purgePlatformFontDataCache
  11. purgeFontVerticalDataCache
  12. purge
  13. addClient
  14. removeClient
  15. generation
  16. invalidate

/*
 * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
 *
 * 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.
 */

#include "config.h"
#include "platform/fonts/FontCache.h"

#include "FontFamilyNames.h"

#include "RuntimeEnabledFeatures.h"
#include "platform/fonts/AlternateFontFamily.h"
#include "platform/fonts/FontCacheClient.h"
#include "platform/fonts/FontCacheKey.h"
#include "platform/fonts/FontDataCache.h"
#include "platform/fonts/FontDescription.h"
#include "platform/fonts/FontFallbackList.h"
#include "platform/fonts/FontPlatformData.h"
#include "platform/fonts/FontSmoothingMode.h"
#include "platform/fonts/TextRenderingMode.h"
#include "platform/fonts/opentype/OpenTypeVerticalData.h"
#include "wtf/HashMap.h"
#include "wtf/ListHashSet.h"
#include "wtf/StdLibExtras.h"
#include "wtf/text/AtomicStringHash.h"
#include "wtf/text/StringHash.h"

using namespace WTF;

namespace WebCore {

#if !OS(WIN)
FontCache::FontCache()
    : m_purgePreventCount(0)
{
}
#endif // !OS(WIN)

typedef HashMap<FontCacheKey, OwnPtr<FontPlatformData>, FontCacheKeyHash, FontCacheKeyTraits> FontPlatformDataCache;

static FontPlatformDataCache* gFontPlatformDataCache = 0;

#if OS(WIN)
bool FontCache::s_useDirectWrite = false;
IDWriteFactory* FontCache::s_directWriteFactory = 0;
bool FontCache::s_useSubpixelPositioning = false;
#endif // OS(WIN)

FontCache* FontCache::fontCache()
{
    DEFINE_STATIC_LOCAL(FontCache, globalFontCache, ());
    return &globalFontCache;
}

FontPlatformData* FontCache::getFontPlatformData(const FontDescription& fontDescription,
    const AtomicString& passedFamilyName, bool checkingAlternateName)
{
#if OS(WIN) && ENABLE(OPENTYPE_VERTICAL)
    // Leading "@" in the font name enables Windows vertical flow flag for the font.
    // Because we do vertical flow by ourselves, we don't want to use the Windows feature.
    // IE disregards "@" regardless of the orientatoin, so we follow the behavior.
    const AtomicString& familyName = (passedFamilyName.isEmpty() || passedFamilyName[0] != '@') ?
        passedFamilyName : AtomicString(passedFamilyName.impl()->substring(1));
#else
    const AtomicString& familyName = passedFamilyName;
#endif

    if (!gFontPlatformDataCache) {
        gFontPlatformDataCache = new FontPlatformDataCache;
        platformInit();
    }

    FontCacheKey key = fontDescription.cacheKey(familyName);
    FontPlatformData* result = 0;
    bool foundResult;
    FontPlatformDataCache::iterator it = gFontPlatformDataCache->find(key);
    if (it == gFontPlatformDataCache->end()) {
        result = createFontPlatformData(fontDescription, familyName, fontDescription.effectiveFontSize());
        gFontPlatformDataCache->set(key, adoptPtr(result));
        foundResult = result;
    } else {
        result = it->value.get();
        foundResult = true;
    }

    if (!foundResult && !checkingAlternateName) {
        // We were unable to find a font. We have a small set of fonts that we alias to other names,
        // e.g., Arial/Helvetica, Courier/Courier New, etc. Try looking up the font under the aliased name.
        const AtomicString& alternateName = alternateFamilyName(familyName);
        if (!alternateName.isEmpty())
            result = getFontPlatformData(fontDescription, alternateName, true);
        if (result)
            gFontPlatformDataCache->set(key, adoptPtr(new FontPlatformData(*result))); // Cache the result under the old name.
    }

    return result;
}

#if ENABLE(OPENTYPE_VERTICAL)
typedef HashMap<FontCache::FontFileKey, RefPtr<OpenTypeVerticalData>, WTF::IntHash<FontCache::FontFileKey>, WTF::UnsignedWithZeroKeyHashTraits<FontCache::FontFileKey> > FontVerticalDataCache;

FontVerticalDataCache& fontVerticalDataCacheInstance()
{
    DEFINE_STATIC_LOCAL(FontVerticalDataCache, fontVerticalDataCache, ());
    return fontVerticalDataCache;
}

PassRefPtr<OpenTypeVerticalData> FontCache::getVerticalData(const FontFileKey& key, const FontPlatformData& platformData)
{
    FontVerticalDataCache& fontVerticalDataCache = fontVerticalDataCacheInstance();
    FontVerticalDataCache::iterator result = fontVerticalDataCache.find(key);
    if (result != fontVerticalDataCache.end())
        return result.get()->value;

    RefPtr<OpenTypeVerticalData> verticalData = OpenTypeVerticalData::create(platformData);
    if (!verticalData->isOpenType())
        verticalData.clear();
    fontVerticalDataCache.set(key, verticalData);
    return verticalData;
}
#endif

static FontDataCache* gFontDataCache = 0;

PassRefPtr<SimpleFontData> FontCache::getFontData(const FontDescription& fontDescription, const AtomicString& family, bool checkingAlternateName, ShouldRetain shouldRetain)
{
    if (FontPlatformData* platformData = getFontPlatformData(fontDescription, adjustFamilyNameToAvoidUnsupportedFonts(family), checkingAlternateName))
        return fontDataFromFontPlatformData(platformData, shouldRetain);

    return nullptr;
}

PassRefPtr<SimpleFontData> FontCache::fontDataFromFontPlatformData(const FontPlatformData* platformData, ShouldRetain shouldRetain)
{
    if (!gFontDataCache)
        gFontDataCache = new FontDataCache;

#if !ASSERT_DISABLED
    if (shouldRetain == DoNotRetain)
        ASSERT(m_purgePreventCount);
#endif

    return gFontDataCache->get(platformData, shouldRetain);
}

bool FontCache::isPlatformFontAvailable(const FontDescription& fontDescription, const AtomicString& family)
{
    bool checkingAlternateName = true;
    return getFontPlatformData(fontDescription, family, checkingAlternateName);
}

SimpleFontData* FontCache::getNonRetainedLastResortFallbackFont(const FontDescription& fontDescription)
{
    return getLastResortFallbackFont(fontDescription, DoNotRetain).leakRef();
}

void FontCache::releaseFontData(const SimpleFontData* fontData)
{
    ASSERT(gFontDataCache);

    gFontDataCache->release(fontData);
}

static inline void purgePlatformFontDataCache()
{
    if (!gFontPlatformDataCache)
        return;

    Vector<FontCacheKey> keysToRemove;
    keysToRemove.reserveInitialCapacity(gFontPlatformDataCache->size());
    FontPlatformDataCache::iterator platformDataEnd = gFontPlatformDataCache->end();
    for (FontPlatformDataCache::iterator platformData = gFontPlatformDataCache->begin(); platformData != platformDataEnd; ++platformData) {
        if (platformData->value && !gFontDataCache->contains(platformData->value.get()))
            keysToRemove.append(platformData->key);
    }

    size_t keysToRemoveCount = keysToRemove.size();
    for (size_t i = 0; i < keysToRemoveCount; ++i)
        gFontPlatformDataCache->remove(keysToRemove[i]);
}

static inline void purgeFontVerticalDataCache()
{
#if ENABLE(OPENTYPE_VERTICAL)
    FontVerticalDataCache& fontVerticalDataCache = fontVerticalDataCacheInstance();
    if (!fontVerticalDataCache.isEmpty()) {
        // Mark & sweep unused verticalData
        FontVerticalDataCache::iterator verticalDataEnd = fontVerticalDataCache.end();
        for (FontVerticalDataCache::iterator verticalData = fontVerticalDataCache.begin(); verticalData != verticalDataEnd; ++verticalData) {
            if (verticalData->value)
                verticalData->value->setInFontCache(false);
        }

        gFontDataCache->markAllVerticalData();

        Vector<FontCache::FontFileKey> keysToRemove;
        keysToRemove.reserveInitialCapacity(fontVerticalDataCache.size());
        for (FontVerticalDataCache::iterator verticalData = fontVerticalDataCache.begin(); verticalData != verticalDataEnd; ++verticalData) {
            if (!verticalData->value || !verticalData->value->inFontCache())
                keysToRemove.append(verticalData->key);
        }
        for (size_t i = 0, count = keysToRemove.size(); i < count; ++i)
            fontVerticalDataCache.take(keysToRemove[i]);
    }
#endif
}

void FontCache::purge(PurgeSeverity PurgeSeverity)
{
    // We should never be forcing the purge while the FontCachePurgePreventer is in scope.
    ASSERT(!m_purgePreventCount || PurgeSeverity == PurgeIfNeeded);
    if (m_purgePreventCount)
        return;

    if (!gFontDataCache || !gFontDataCache->purge(PurgeSeverity))
        return;

    purgePlatformFontDataCache();
    purgeFontVerticalDataCache();
}

static HashSet<FontCacheClient*>* gClients;

void FontCache::addClient(FontCacheClient* client)
{
    if (!gClients)
        gClients = new HashSet<FontCacheClient*>;

    ASSERT(!gClients->contains(client));
    gClients->add(client);
}

void FontCache::removeClient(FontCacheClient* client)
{
    ASSERT(gClients);
    ASSERT(gClients->contains(client));

    gClients->remove(client);
}

static unsigned short gGeneration = 0;

unsigned short FontCache::generation()
{
    return gGeneration;
}

void FontCache::invalidate()
{
    if (!gClients) {
        ASSERT(!gFontPlatformDataCache);
        return;
    }

    if (gFontPlatformDataCache) {
        delete gFontPlatformDataCache;
        gFontPlatformDataCache = new FontPlatformDataCache;
    }

    gGeneration++;

    Vector<RefPtr<FontCacheClient> > clients;
    size_t numClients = gClients->size();
    clients.reserveInitialCapacity(numClients);
    HashSet<FontCacheClient*>::iterator end = gClients->end();
    for (HashSet<FontCacheClient*>::iterator it = gClients->begin(); it != end; ++it)
        clients.append(*it);

    ASSERT(numClients == clients.size());
    for (size_t i = 0; i < numClients; ++i)
        clients[i]->fontCacheInvalidated();

    purge(ForcePurge);
}

} // namespace WebCore

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