Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84

1 files changed, 475 insertions, 0 deletions

diff --git a/Source/WebCore/platform/graphics/FontCache.cpp b/Source/WebCore/platform/graphics/FontCache.cpp
new file mode 100644
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+++ b/Source/WebCore/platform/graphics/FontCache.cpp
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+/*
+ * 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 "FontCache.h"
+
+#include "Font.h"
+#include "FontFallbackList.h"
+#include "FontPlatformData.h"
+#include "FontSelector.h"
+#include <wtf/HashMap.h>
+#include <wtf/ListHashSet.h>
+#include <wtf/StdLibExtras.h>
+#include <wtf/text/StringHash.h>
+
+using namespace WTF;
+
+namespace WebCore {
+
+FontCache* fontCache()
+{
+    DEFINE_STATIC_LOCAL(FontCache, globalFontCache, ());
+    return &globalFontCache;
+}
+
+FontCache::FontCache()
+{
+}
+
+struct FontPlatformDataCacheKey : FastAllocBase {
+    FontPlatformDataCacheKey(const AtomicString& family = AtomicString(), unsigned size = 0, unsigned weight = 0, bool italic = false,
+                             bool isPrinterFont = false, FontRenderingMode renderingMode = NormalRenderingMode, FontOrientation orientation = Horizontal)
+        : m_size(size)
+        , m_weight(weight)
+        , m_family(family)
+        , m_italic(italic)
+        , m_printerFont(isPrinterFont)
+        , m_renderingMode(renderingMode)
+        , m_orientation(orientation)
+    {
+    }
+
+    FontPlatformDataCacheKey(HashTableDeletedValueType) : m_size(hashTableDeletedSize()) { }
+    bool isHashTableDeletedValue() const { return m_size == hashTableDeletedSize(); }
+
+    bool operator==(const FontPlatformDataCacheKey& other) const
+    {
+        return equalIgnoringCase(m_family, other.m_family) && m_size == other.m_size && 
+               m_weight == other.m_weight && m_italic == other.m_italic && m_printerFont == other.m_printerFont &&
+               m_renderingMode == other.m_renderingMode && m_orientation == other.m_orientation;
+    }
+
+    unsigned m_size;
+    unsigned m_weight;
+    AtomicString m_family;
+    bool m_italic;
+    bool m_printerFont;
+    FontRenderingMode m_renderingMode;
+    FontOrientation m_orientation;
+
+private:
+    static unsigned hashTableDeletedSize() { return 0xFFFFFFFFU; }
+};
+
+inline unsigned computeHash(const FontPlatformDataCacheKey& fontKey)
+{
+    unsigned hashCodes[4] = {
+        CaseFoldingHash::hash(fontKey.m_family),
+        fontKey.m_size,
+        fontKey.m_weight,
+        static_cast<unsigned>(fontKey.m_orientation) << 3 | static_cast<unsigned>(fontKey.m_italic) << 2 | static_cast<unsigned>(fontKey.m_printerFont) << 1 | static_cast<unsigned>(fontKey.m_renderingMode)
+    };
+    return WTF::StringHasher::createBlobHash<sizeof(hashCodes)>(hashCodes);
+}
+
+struct FontPlatformDataCacheKeyHash {
+    static unsigned hash(const FontPlatformDataCacheKey& font)
+    {
+        return computeHash(font);
+    }
+         
+    static bool equal(const FontPlatformDataCacheKey& a, const FontPlatformDataCacheKey& b)
+    {
+        return a == b;
+    }
+
+    static const bool safeToCompareToEmptyOrDeleted = true;
+};
+
+struct FontPlatformDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformDataCacheKey> {
+    static const bool emptyValueIsZero = true;
+    static const FontPlatformDataCacheKey& emptyValue()
+    {
+        DEFINE_STATIC_LOCAL(FontPlatformDataCacheKey, key, (nullAtom));
+        return key;
+    }
+    static void constructDeletedValue(FontPlatformDataCacheKey& slot)
+    {
+        new (&slot) FontPlatformDataCacheKey(HashTableDeletedValue);
+    }
+    static bool isDeletedValue(const FontPlatformDataCacheKey& value)
+    {
+        return value.isHashTableDeletedValue();
+    }
+};
+
+typedef HashMap<FontPlatformDataCacheKey, FontPlatformData*, FontPlatformDataCacheKeyHash, FontPlatformDataCacheKeyTraits> FontPlatformDataCache;
+
+static FontPlatformDataCache* gFontPlatformDataCache = 0;
+
+static const AtomicString& alternateFamilyName(const AtomicString& familyName)
+{
+    // Alias Courier <-> Courier New
+    DEFINE_STATIC_LOCAL(AtomicString, courier, ("Courier"));
+    DEFINE_STATIC_LOCAL(AtomicString, courierNew, ("Courier New"));
+    if (equalIgnoringCase(familyName, courier))
+        return courierNew;
+#if !OS(WINDOWS)
+    // On Windows, Courier New (truetype font) is always present and
+    // Courier is a bitmap font. So, we don't want to map Courier New to
+    // Courier.
+    if (equalIgnoringCase(familyName, courierNew))
+        return courier;
+#endif
+
+    // Alias Times and Times New Roman.
+    DEFINE_STATIC_LOCAL(AtomicString, times, ("Times"));
+    DEFINE_STATIC_LOCAL(AtomicString, timesNewRoman, ("Times New Roman"));
+    if (equalIgnoringCase(familyName, times))
+        return timesNewRoman;
+    if (equalIgnoringCase(familyName, timesNewRoman))
+        return times;
+    
+    // Alias Arial and Helvetica
+    DEFINE_STATIC_LOCAL(AtomicString, arial, ("Arial"));
+    DEFINE_STATIC_LOCAL(AtomicString, helvetica, ("Helvetica"));
+    if (equalIgnoringCase(familyName, arial))
+        return helvetica;
+    if (equalIgnoringCase(familyName, helvetica))
+        return arial;
+
+#if OS(WINDOWS)
+    // On Windows, bitmap fonts are blocked altogether so that we have to 
+    // alias MS Sans Serif (bitmap font) -> Microsoft Sans Serif (truetype font)
+    DEFINE_STATIC_LOCAL(AtomicString, msSans, ("MS Sans Serif"));
+    DEFINE_STATIC_LOCAL(AtomicString, microsoftSans, ("Microsoft Sans Serif"));
+    if (equalIgnoringCase(familyName, msSans))
+        return microsoftSans;
+
+    // Alias MS Serif (bitmap) -> Times New Roman (truetype font). There's no 
+    // 'Microsoft Sans Serif-equivalent' for Serif. 
+    static AtomicString msSerif("MS Serif");
+    if (equalIgnoringCase(familyName, msSerif))
+        return timesNewRoman;
+#endif
+
+    return emptyAtom;
+}
+
+FontPlatformData* FontCache::getCachedFontPlatformData(const FontDescription& fontDescription, 
+                                                       const AtomicString& familyName,
+                                                       bool checkingAlternateName)
+{
+    if (!gFontPlatformDataCache) {
+        gFontPlatformDataCache = new FontPlatformDataCache;
+        platformInit();
+    }
+
+    FontPlatformDataCacheKey key(familyName, fontDescription.computedPixelSize(), fontDescription.weight(), fontDescription.italic(),
+                                 fontDescription.usePrinterFont(), fontDescription.renderingMode(), fontDescription.orientation());
+    FontPlatformData* result = 0;
+    bool foundResult;
+    FontPlatformDataCache::iterator it = gFontPlatformDataCache->find(key);
+    if (it == gFontPlatformDataCache->end()) {
+        result = createFontPlatformData(fontDescription, familyName);
+        gFontPlatformDataCache->set(key, result);
+        foundResult = result;
+    } else {
+        result = it->second;
+        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 = getCachedFontPlatformData(fontDescription, alternateName, true);
+        if (result)
+            gFontPlatformDataCache->set(key, new FontPlatformData(*result)); // Cache the result under the old name.
+    }
+
+    return result;
+}
+
+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 (&slot) FontPlatformData(HashTableDeletedValue);
+    }
+    static bool isDeletedValue(const FontPlatformData& value)
+    {
+        return value.isHashTableDeletedValue();
+    }
+};
+
+typedef HashMap<FontPlatformData, pair<SimpleFontData*, unsigned>, FontDataCacheKeyHash, FontDataCacheKeyTraits> FontDataCache;
+
+static FontDataCache* gFontDataCache = 0;
+
+const int cMaxInactiveFontData = 120;  // Pretty Low Threshold
+const float cTargetInactiveFontData = 100;
+static ListHashSet<const SimpleFontData*>* gInactiveFontData = 0;
+
+SimpleFontData* FontCache::getCachedFontData(const FontDescription& fontDescription, const AtomicString& family, bool checkingAlternateName)
+{
+    FontPlatformData* platformData = getCachedFontPlatformData(fontDescription, family, checkingAlternateName);
+    if (!platformData)
+        return 0;
+
+    return getCachedFontData(platformData);
+}
+
+SimpleFontData* FontCache::getCachedFontData(const FontPlatformData* platformData)
+{
+    if (!platformData)
+        return 0;
+
+    if (!gFontDataCache) {
+        gFontDataCache = new FontDataCache;
+        gInactiveFontData = new ListHashSet<const SimpleFontData*>;
+    }
+    
+    FontDataCache::iterator result = gFontDataCache->find(*platformData);
+    if (result == gFontDataCache->end()) {
+        pair<SimpleFontData*, unsigned> newValue(new SimpleFontData(*platformData), 1);
+        gFontDataCache->set(*platformData, newValue);
+        return newValue.first;
+    }
+    if (!result.get()->second.second++) {
+        ASSERT(gInactiveFontData->contains(result.get()->second.first));
+        gInactiveFontData->remove(result.get()->second.first);
+    }
+
+    return result.get()->second.first;
+}
+
+void FontCache::releaseFontData(const SimpleFontData* fontData)
+{
+    ASSERT(gFontDataCache);
+    ASSERT(!fontData->isCustomFont());
+
+    FontDataCache::iterator it = gFontDataCache->find(fontData->platformData());
+    ASSERT(it != gFontDataCache->end());
+
+    if (!--it->second.second) {
+        gInactiveFontData->add(fontData);
+        if (gInactiveFontData->size() > cMaxInactiveFontData)
+            purgeInactiveFontData(gInactiveFontData->size() - cTargetInactiveFontData);
+    }
+}
+
+void FontCache::purgeInactiveFontData(int count)
+{
+    if (!gInactiveFontData)
+        return;
+
+    static bool isPurging;  // Guard against reentry when e.g. a deleted FontData releases its small caps FontData.
+    if (isPurging)
+        return;
+
+    isPurging = true;
+
+    Vector<const SimpleFontData*, 20> fontDataToDelete;
+    ListHashSet<const SimpleFontData*>::iterator end = gInactiveFontData->end();
+    ListHashSet<const SimpleFontData*>::iterator it = gInactiveFontData->begin();
+    for (int i = 0; i < count && it != end; ++it, ++i) {
+        const SimpleFontData* fontData = *it.get();
+        gFontDataCache->remove(fontData->platformData());
+        fontDataToDelete.append(fontData);
+    }
+
+    if (it == end) {
+        // Removed everything
+        gInactiveFontData->clear();
+    } else {
+        for (int i = 0; i < count; ++i)
+            gInactiveFontData->remove(gInactiveFontData->begin());
+    }
+
+    size_t fontDataToDeleteCount = fontDataToDelete.size();
+    for (size_t i = 0; i < fontDataToDeleteCount; ++i)
+        delete fontDataToDelete[i];
+
+    if (gFontPlatformDataCache) {
+        Vector<FontPlatformDataCacheKey> keysToRemove;
+        keysToRemove.reserveInitialCapacity(gFontPlatformDataCache->size());
+        FontPlatformDataCache::iterator platformDataEnd = gFontPlatformDataCache->end();
+        for (FontPlatformDataCache::iterator platformData = gFontPlatformDataCache->begin(); platformData != platformDataEnd; ++platformData) {
+            if (platformData->second && !gFontDataCache->contains(*platformData->second))
+                keysToRemove.append(platformData->first);
+        }
+        
+        size_t keysToRemoveCount = keysToRemove.size();
+        for (size_t i = 0; i < keysToRemoveCount; ++i)
+            delete gFontPlatformDataCache->take(keysToRemove[i]);
+    }
+
+    isPurging = false;
+}
+
+size_t FontCache::fontDataCount()
+{
+    if (gFontDataCache)
+        return gFontDataCache->size();
+    return 0;
+}
+
+size_t FontCache::inactiveFontDataCount()
+{
+    if (gInactiveFontData)
+        return gInactiveFontData->size();
+    return 0;
+}
+
+const FontData* FontCache::getFontData(const Font& font, int& familyIndex, FontSelector* fontSelector)
+{
+    SimpleFontData* result = 0;
+
+    int startIndex = familyIndex;
+    const FontFamily* startFamily = &font.fontDescription().family();
+    for (int i = 0; startFamily && i < startIndex; i++)
+        startFamily = startFamily->next();
+    const FontFamily* currFamily = startFamily;
+    while (currFamily && !result) {
+        familyIndex++;
+        if (currFamily->family().length()) {
+            if (fontSelector) {
+                FontData* data = fontSelector->getFontData(font.fontDescription(), currFamily->family());
+                if (data)
+                    return data;
+            }
+            result = getCachedFontData(font.fontDescription(), currFamily->family());
+        }
+        currFamily = currFamily->next();
+    }
+
+    if (!currFamily)
+        familyIndex = cAllFamiliesScanned;
+
+    if (!result)
+        // We didn't find a font. Try to find a similar font using our own specific knowledge about our platform.
+        // For example on OS X, we know to map any families containing the words Arabic, Pashto, or Urdu to the
+        // Geeza Pro font.
+        result = getSimilarFontPlatformData(font);
+
+    if (!result && startIndex == 0) {
+        // If it's the primary font that we couldn't find, we try the following. In all other cases, we will
+        // just use per-character system fallback.
+
+        if (fontSelector) {
+            // Try the user's preferred standard font.
+            if (FontData* data = fontSelector->getFontData(font.fontDescription(), "-webkit-standard"))
+                return data;
+        }
+
+        // Still no result.  Hand back our last resort fallback font.
+        result = getLastResortFallbackFont(font.fontDescription());
+    }
+    return result;
+}
+
+static HashSet<FontSelector*>* gClients;
+
+void FontCache::addClient(FontSelector* client)
+{
+    if (!gClients)
+        gClients = new HashSet<FontSelector*>;
+
+    ASSERT(!gClients->contains(client));
+    gClients->add(client);
+}
+
+void FontCache::removeClient(FontSelector* client)
+{
+    ASSERT(gClients);
+    ASSERT(gClients->contains(client));
+
+    gClients->remove(client);
+}
+
+static unsigned gGeneration = 0;
+
+unsigned FontCache::generation()
+{
+    return gGeneration;
+}
+
+void FontCache::invalidate()
+{
+    if (!gClients) {
+        ASSERT(!gFontPlatformDataCache);
+        return;
+    }
+
+    if (gFontPlatformDataCache) {
+        deleteAllValues(*gFontPlatformDataCache);
+        delete gFontPlatformDataCache;
+        gFontPlatformDataCache = new FontPlatformDataCache;
+    }
+
+    gGeneration++;
+
+    Vector<RefPtr<FontSelector> > clients;
+    size_t numClients = gClients->size();
+    clients.reserveInitialCapacity(numClients);
+    HashSet<FontSelector*>::iterator end = gClients->end();
+    for (HashSet<FontSelector*>::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();
+
+    purgeInactiveFontData();
+}
+
+} // namespace WebCore