1 /* 2 * Copyright (C) 2013 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef FontDataCache_h 32 #define FontDataCache_h 33 34 #include "platform/fonts/FontCache.h" 35 #include "platform/fonts/FontPlatformData.h" 36 #include "wtf/HashMap.h" 37 #include "wtf/ListHashSet.h" 38 39 namespace WebCore { 40 41 class SimpleFontData; 42 43 struct FontDataCacheKeyHash { 44 static unsigned hash(const FontPlatformData& platformData) 45 { 46 return platformData.hash(); 47 } 48 49 static bool equal(const FontPlatformData& a, const FontPlatformData& b) 50 { 51 return a == b; 52 } 53 54 static const bool safeToCompareToEmptyOrDeleted = true; 55 }; 56 57 struct FontDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformData> { 58 static const bool emptyValueIsZero = true; 59 static const bool needsDestruction = true; 60 static const FontPlatformData& emptyValue() 61 { 62 DEFINE_STATIC_LOCAL(FontPlatformData, key, (0.f, false, false)); 63 return key; 64 } 65 static void constructDeletedValue(FontPlatformData& slot) 66 { 67 new (NotNull, &slot) FontPlatformData(WTF::HashTableDeletedValue); 68 } 69 static bool isDeletedValue(const FontPlatformData& value) 70 { 71 return value.isHashTableDeletedValue(); 72 } 73 }; 74 75 class FontDataCache { 76 public: 77 PassRefPtr<SimpleFontData> get(const FontPlatformData*, ShouldRetain = Retain); 78 bool contains(const FontPlatformData*) const; 79 void release(const SimpleFontData*); 80 81 // This is used by FontVerticalDataCache to mark all items with vertical data 82 // that are currently in cache as "in cache", which is later used to sweep the FontVerticalDataCache. 83 void markAllVerticalData(); 84 85 // Purges items in FontDataCache according to provided severity. 86 // Returns true if any removal of cache items actually occurred. 87 bool purge(PurgeSeverity); 88 89 private: 90 bool purgeLeastRecentlyUsed(int count); 91 92 typedef HashMap<FontPlatformData, pair<RefPtr<SimpleFontData>, unsigned>, FontDataCacheKeyHash, FontDataCacheKeyTraits> Cache; 93 Cache m_cache; 94 ListHashSet<RefPtr<SimpleFontData> > m_inactiveFontData; 95 }; 96 97 } 98 99 #endif 100
