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      1 /*
      2  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
      3  * Copyright (C) 2007 Nicholas Shanks <webkit (at) nickshanks.com>
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * 1.  Redistributions of source code must retain the above copyright
     10  *     notice, this list of conditions and the following disclaimer.
     11  * 2.  Redistributions in binary form must reproduce the above copyright
     12  *     notice, this list of conditions and the following disclaimer in the
     13  *     documentation and/or other materials provided with the distribution.
     14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     15  *     its contributors may be used to endorse or promote products derived
     16  *     from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include "config.h"
     31 #include "FontCache.h"
     32 
     33 #include "Font.h"
     34 #include "FontFallbackList.h"
     35 #include "FontPlatformData.h"
     36 #include "FontSelector.h"
     37 #include <wtf/HashMap.h>
     38 #include <wtf/ListHashSet.h>
     39 #include <wtf/StdLibExtras.h>
     40 #include <wtf/text/StringHash.h>
     41 
     42 using namespace WTF;
     43 
     44 namespace WebCore {
     45 
     46 FontCache* fontCache()
     47 {
     48     DEFINE_STATIC_LOCAL(FontCache, globalFontCache, ());
     49     return &globalFontCache;
     50 }
     51 
     52 FontCache::FontCache()
     53 {
     54 }
     55 
     56 struct FontPlatformDataCacheKey {
     57     WTF_MAKE_FAST_ALLOCATED;
     58 public:
     59     FontPlatformDataCacheKey(const AtomicString& family = AtomicString(), unsigned size = 0, unsigned weight = 0, bool italic = false,
     60                              bool isPrinterFont = false, FontRenderingMode renderingMode = NormalRenderingMode, FontOrientation orientation = Horizontal,
     61                              TextOrientation textOrientation = TextOrientationVerticalRight, FontWidthVariant widthVariant = RegularWidth)
     62         : m_size(size)
     63         , m_weight(weight)
     64         , m_family(family)
     65         , m_italic(italic)
     66         , m_printerFont(isPrinterFont)
     67         , m_renderingMode(renderingMode)
     68         , m_orientation(orientation)
     69         , m_textOrientation(textOrientation)
     70         , m_widthVariant(widthVariant)
     71     {
     72     }
     73 
     74     FontPlatformDataCacheKey(HashTableDeletedValueType) : m_size(hashTableDeletedSize()) { }
     75     bool isHashTableDeletedValue() const { return m_size == hashTableDeletedSize(); }
     76 
     77     bool operator==(const FontPlatformDataCacheKey& other) const
     78     {
     79         return equalIgnoringCase(m_family, other.m_family) && m_size == other.m_size &&
     80                m_weight == other.m_weight && m_italic == other.m_italic && m_printerFont == other.m_printerFont &&
     81                m_renderingMode == other.m_renderingMode && m_orientation == other.m_orientation && m_textOrientation == other.m_textOrientation && m_widthVariant == other.m_widthVariant;
     82     }
     83 
     84     unsigned m_size;
     85     unsigned m_weight;
     86     AtomicString m_family;
     87     bool m_italic;
     88     bool m_printerFont;
     89     FontRenderingMode m_renderingMode;
     90     FontOrientation m_orientation;
     91     TextOrientation m_textOrientation;
     92     FontWidthVariant m_widthVariant;
     93 
     94 private:
     95     static unsigned hashTableDeletedSize() { return 0xFFFFFFFFU; }
     96 };
     97 
     98 inline unsigned computeHash(const FontPlatformDataCacheKey& fontKey)
     99 {
    100     unsigned hashCodes[5] = {
    101         CaseFoldingHash::hash(fontKey.m_family),
    102         fontKey.m_size,
    103         fontKey.m_weight,
    104         fontKey.m_widthVariant,
    105         static_cast<unsigned>(fontKey.m_textOrientation) << 4 | 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)
    106     };
    107     return StringHasher::hashMemory<sizeof(hashCodes)>(hashCodes);
    108 }
    109 
    110 struct FontPlatformDataCacheKeyHash {
    111     static unsigned hash(const FontPlatformDataCacheKey& font)
    112     {
    113         return computeHash(font);
    114     }
    115 
    116     static bool equal(const FontPlatformDataCacheKey& a, const FontPlatformDataCacheKey& b)
    117     {
    118         return a == b;
    119     }
    120 
    121     static const bool safeToCompareToEmptyOrDeleted = true;
    122 };
    123 
    124 struct FontPlatformDataCacheKeyTraits : WTF::SimpleClassHashTraits<FontPlatformDataCacheKey> { };
    125 
    126 typedef HashMap<FontPlatformDataCacheKey, FontPlatformData*, FontPlatformDataCacheKeyHash, FontPlatformDataCacheKeyTraits> FontPlatformDataCache;
    127 
    128 static FontPlatformDataCache* gFontPlatformDataCache = 0;
    129 
    130 static const AtomicString& alternateFamilyName(const AtomicString& familyName)
    131 {
    132     // Alias Courier <-> Courier New
    133     DEFINE_STATIC_LOCAL(AtomicString, courier, ("Courier"));
    134     DEFINE_STATIC_LOCAL(AtomicString, courierNew, ("Courier New"));
    135     if (equalIgnoringCase(familyName, courier))
    136         return courierNew;
    137 #if !OS(WINDOWS)
    138     // On Windows, Courier New (truetype font) is always present and
    139     // Courier is a bitmap font. So, we don't want to map Courier New to
    140     // Courier.
    141     if (equalIgnoringCase(familyName, courierNew))
    142         return courier;
    143 #endif
    144 
    145     // Alias Times and Times New Roman.
    146     DEFINE_STATIC_LOCAL(AtomicString, times, ("Times"));
    147     DEFINE_STATIC_LOCAL(AtomicString, timesNewRoman, ("Times New Roman"));
    148     if (equalIgnoringCase(familyName, times))
    149         return timesNewRoman;
    150     if (equalIgnoringCase(familyName, timesNewRoman))
    151         return times;
    152 
    153     // Alias Arial and Helvetica
    154     DEFINE_STATIC_LOCAL(AtomicString, arial, ("Arial"));
    155     DEFINE_STATIC_LOCAL(AtomicString, helvetica, ("Helvetica"));
    156     if (equalIgnoringCase(familyName, arial))
    157         return helvetica;
    158     if (equalIgnoringCase(familyName, helvetica))
    159         return arial;
    160 
    161 #if OS(WINDOWS)
    162     // On Windows, bitmap fonts are blocked altogether so that we have to
    163     // alias MS Sans Serif (bitmap font) -> Microsoft Sans Serif (truetype font)
    164     DEFINE_STATIC_LOCAL(AtomicString, msSans, ("MS Sans Serif"));
    165     DEFINE_STATIC_LOCAL(AtomicString, microsoftSans, ("Microsoft Sans Serif"));
    166     if (equalIgnoringCase(familyName, msSans))
    167         return microsoftSans;
    168 
    169     // Alias MS Serif (bitmap) -> Times New Roman (truetype font). There's no
    170     // 'Microsoft Sans Serif-equivalent' for Serif.
    171     static AtomicString msSerif("MS Serif");
    172     if (equalIgnoringCase(familyName, msSerif))
    173         return timesNewRoman;
    174 #endif
    175 
    176     return emptyAtom;
    177 }
    178 
    179 FontPlatformData* FontCache::getCachedFontPlatformData(const FontDescription& fontDescription,
    180                                                        const AtomicString& familyName,
    181                                                        bool checkingAlternateName)
    182 {
    183     if (!gFontPlatformDataCache) {
    184         gFontPlatformDataCache = new FontPlatformDataCache;
    185         platformInit();
    186     }
    187 
    188     FontPlatformDataCacheKey key(familyName, fontDescription.computedPixelSize(), fontDescription.weight(), fontDescription.italic(),
    189                                  fontDescription.usePrinterFont(), fontDescription.renderingMode(), fontDescription.orientation(),
    190                                  fontDescription.textOrientation(), fontDescription.widthVariant());
    191     FontPlatformData* result = 0;
    192     bool foundResult;
    193     FontPlatformDataCache::iterator it = gFontPlatformDataCache->find(key);
    194     if (it == gFontPlatformDataCache->end()) {
    195         result = createFontPlatformData(fontDescription, familyName);
    196         gFontPlatformDataCache->set(key, result);
    197         foundResult = result;
    198     } else {
    199         result = it->second;
    200         foundResult = true;
    201     }
    202 
    203     if (!foundResult && !checkingAlternateName) {
    204         // We were unable to find a font.  We have a small set of fonts that we alias to other names,
    205         // e.g., Arial/Helvetica, Courier/Courier New, etc.  Try looking up the font under the aliased name.
    206         const AtomicString& alternateName = alternateFamilyName(familyName);
    207         if (!alternateName.isEmpty())
    208             result = getCachedFontPlatformData(fontDescription, alternateName, true);
    209         if (result)
    210             gFontPlatformDataCache->set(key, new FontPlatformData(*result)); // Cache the result under the old name.
    211     }
    212 
    213     return result;
    214 }
    215 
    216 struct FontDataCacheKeyHash {
    217     static unsigned hash(const FontPlatformData& platformData)
    218     {
    219         return platformData.hash();
    220     }
    221 
    222     static bool equal(const FontPlatformData& a, const FontPlatformData& b)
    223     {
    224         return a == b;
    225     }
    226 
    227     static const bool safeToCompareToEmptyOrDeleted = true;
    228 };
    229 
    230 struct FontDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformData> {
    231     static const bool emptyValueIsZero = true;
    232     static const bool needsDestruction = true;
    233     static const FontPlatformData& emptyValue()
    234     {
    235         DEFINE_STATIC_LOCAL(FontPlatformData, key, (0.f, false, false));
    236         return key;
    237     }
    238     static void constructDeletedValue(FontPlatformData& slot)
    239     {
    240         new (&slot) FontPlatformData(HashTableDeletedValue);
    241     }
    242     static bool isDeletedValue(const FontPlatformData& value)
    243     {
    244         return value.isHashTableDeletedValue();
    245     }
    246 };
    247 
    248 typedef HashMap<FontPlatformData, pair<SimpleFontData*, unsigned>, FontDataCacheKeyHash, FontDataCacheKeyTraits> FontDataCache;
    249 
    250 static FontDataCache* gFontDataCache = 0;
    251 
    252 const int cMaxInactiveFontData = 120;  // Pretty Low Threshold
    253 const int cTargetInactiveFontData = 100;
    254 static ListHashSet<const SimpleFontData*>* gInactiveFontData = 0;
    255 
    256 SimpleFontData* FontCache::getCachedFontData(const FontDescription& fontDescription, const AtomicString& family, bool checkingAlternateName)
    257 {
    258     FontPlatformData* platformData = getCachedFontPlatformData(fontDescription, family, checkingAlternateName);
    259     if (!platformData)
    260         return 0;
    261 
    262     return getCachedFontData(platformData);
    263 }
    264 
    265 SimpleFontData* FontCache::getCachedFontData(const FontPlatformData* platformData)
    266 {
    267     if (!platformData)
    268         return 0;
    269 
    270     if (!gFontDataCache) {
    271         gFontDataCache = new FontDataCache;
    272         gInactiveFontData = new ListHashSet<const SimpleFontData*>;
    273     }
    274 
    275     FontDataCache::iterator result = gFontDataCache->find(*platformData);
    276     if (result == gFontDataCache->end()) {
    277         pair<SimpleFontData*, unsigned> newValue(new SimpleFontData(*platformData), 1);
    278         gFontDataCache->set(*platformData, newValue);
    279         return newValue.first;
    280     }
    281     if (!result.get()->second.second++) {
    282         ASSERT(gInactiveFontData->contains(result.get()->second.first));
    283         gInactiveFontData->remove(result.get()->second.first);
    284     }
    285 
    286     return result.get()->second.first;
    287 }
    288 
    289 void FontCache::releaseFontData(const SimpleFontData* fontData)
    290 {
    291     ASSERT(gFontDataCache);
    292     ASSERT(!fontData->isCustomFont());
    293 
    294     FontDataCache::iterator it = gFontDataCache->find(fontData->platformData());
    295     ASSERT(it != gFontDataCache->end());
    296 
    297     if (!--it->second.second) {
    298         gInactiveFontData->add(fontData);
    299         if (gInactiveFontData->size() > cMaxInactiveFontData)
    300             purgeInactiveFontData(gInactiveFontData->size() - cTargetInactiveFontData);
    301     }
    302 }
    303 
    304 void FontCache::purgeInactiveFontData(int count)
    305 {
    306     if (!gInactiveFontData)
    307         return;
    308 
    309     static bool isPurging;  // Guard against reentry when e.g. a deleted FontData releases its small caps FontData.
    310     if (isPurging)
    311         return;
    312 
    313     isPurging = true;
    314 
    315     Vector<const SimpleFontData*, 20> fontDataToDelete;
    316     ListHashSet<const SimpleFontData*>::iterator end = gInactiveFontData->end();
    317     ListHashSet<const SimpleFontData*>::iterator it = gInactiveFontData->begin();
    318     for (int i = 0; i < count && it != end; ++it, ++i) {
    319         const SimpleFontData* fontData = *it.get();
    320         gFontDataCache->remove(fontData->platformData());
    321         fontDataToDelete.append(fontData);
    322     }
    323 
    324     if (it == end) {
    325         // Removed everything
    326         gInactiveFontData->clear();
    327     } else {
    328         for (int i = 0; i < count; ++i)
    329             gInactiveFontData->remove(gInactiveFontData->begin());
    330     }
    331 
    332     size_t fontDataToDeleteCount = fontDataToDelete.size();
    333     for (size_t i = 0; i < fontDataToDeleteCount; ++i)
    334         delete fontDataToDelete[i];
    335 
    336     if (gFontPlatformDataCache) {
    337         Vector<FontPlatformDataCacheKey> keysToRemove;
    338         keysToRemove.reserveInitialCapacity(gFontPlatformDataCache->size());
    339         FontPlatformDataCache::iterator platformDataEnd = gFontPlatformDataCache->end();
    340         for (FontPlatformDataCache::iterator platformData = gFontPlatformDataCache->begin(); platformData != platformDataEnd; ++platformData) {
    341             if (platformData->second && !gFontDataCache->contains(*platformData->second))
    342                 keysToRemove.append(platformData->first);
    343         }
    344 
    345         size_t keysToRemoveCount = keysToRemove.size();
    346         for (size_t i = 0; i < keysToRemoveCount; ++i)
    347             delete gFontPlatformDataCache->take(keysToRemove[i]);
    348     }
    349 
    350     isPurging = false;
    351 }
    352 
    353 size_t FontCache::fontDataCount()
    354 {
    355     if (gFontDataCache)
    356         return gFontDataCache->size();
    357     return 0;
    358 }
    359 
    360 size_t FontCache::inactiveFontDataCount()
    361 {
    362     if (gInactiveFontData)
    363         return gInactiveFontData->size();
    364     return 0;
    365 }
    366 
    367 const FontData* FontCache::getFontData(const Font& font, int& familyIndex, FontSelector* fontSelector)
    368 {
    369     SimpleFontData* result = 0;
    370 
    371     int startIndex = familyIndex;
    372     const FontFamily* startFamily = &font.fontDescription().family();
    373     for (int i = 0; startFamily && i < startIndex; i++)
    374         startFamily = startFamily->next();
    375     const FontFamily* currFamily = startFamily;
    376     while (currFamily && !result) {
    377         familyIndex++;
    378         if (currFamily->family().length()) {
    379             if (fontSelector) {
    380                 FontData* data = fontSelector->getFontData(font.fontDescription(), currFamily->family());
    381                 if (data)
    382                     return data;
    383             }
    384             result = getCachedFontData(font.fontDescription(), currFamily->family());
    385         }
    386         currFamily = currFamily->next();
    387     }
    388 
    389     if (!currFamily)
    390         familyIndex = cAllFamiliesScanned;
    391 
    392     if (!result)
    393         // We didn't find a font. Try to find a similar font using our own specific knowledge about our platform.
    394         // For example on OS X, we know to map any families containing the words Arabic, Pashto, or Urdu to the
    395         // Geeza Pro font.
    396         result = getSimilarFontPlatformData(font);
    397 
    398     if (!result && startIndex == 0) {
    399         // If it's the primary font that we couldn't find, we try the following. In all other cases, we will
    400         // just use per-character system fallback.
    401 
    402         if (fontSelector) {
    403             // Try the user's preferred standard font.
    404             if (FontData* data = fontSelector->getFontData(font.fontDescription(), "-webkit-standard"))
    405                 return data;
    406         }
    407 
    408         // Still no result.  Hand back our last resort fallback font.
    409         result = getLastResortFallbackFont(font.fontDescription());
    410     }
    411     return result;
    412 }
    413 
    414 static HashSet<FontSelector*>* gClients;
    415 
    416 void FontCache::addClient(FontSelector* client)
    417 {
    418     if (!gClients)
    419         gClients = new HashSet<FontSelector*>;
    420 
    421     ASSERT(!gClients->contains(client));
    422     gClients->add(client);
    423 }
    424 
    425 void FontCache::removeClient(FontSelector* client)
    426 {
    427     ASSERT(gClients);
    428     ASSERT(gClients->contains(client));
    429 
    430     gClients->remove(client);
    431 }
    432 
    433 static unsigned gGeneration = 0;
    434 
    435 unsigned FontCache::generation()
    436 {
    437     return gGeneration;
    438 }
    439 
    440 void FontCache::invalidate()
    441 {
    442     if (!gClients) {
    443         ASSERT(!gFontPlatformDataCache);
    444         return;
    445     }
    446 
    447     if (gFontPlatformDataCache) {
    448         deleteAllValues(*gFontPlatformDataCache);
    449         delete gFontPlatformDataCache;
    450         gFontPlatformDataCache = new FontPlatformDataCache;
    451     }
    452 
    453     gGeneration++;
    454 
    455     Vector<RefPtr<FontSelector> > clients;
    456     size_t numClients = gClients->size();
    457     clients.reserveInitialCapacity(numClients);
    458     HashSet<FontSelector*>::iterator end = gClients->end();
    459     for (HashSet<FontSelector*>::iterator it = gClients->begin(); it != end; ++it)
    460         clients.append(*it);
    461 
    462     ASSERT(numClients == clients.size());
    463     for (size_t i = 0; i < numClients; ++i)
    464         clients[i]->fontCacheInvalidated();
    465 
    466     purgeInactiveFontData();
    467 }
    468 
    469 } // namespace WebCore
    470