1 /* 2 * Copyright (C) 2008 Apple 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 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #ifndef PurgeableBuffer_h 27 #define PurgeableBuffer_h 28 29 #include <wtf/Noncopyable.h> 30 #include <wtf/Vector.h> 31 32 namespace WebCore { 33 34 class PurgeableBuffer : public Noncopyable { 35 public: 36 static PurgeableBuffer* create(const char* data, size_t); 37 static PurgeableBuffer* create(const Vector<char>& v) { return create(v.data(), v.size()); } 38 39 ~PurgeableBuffer(); 40 41 // Call makePurgeable(false) and check the return value before accessing the data. 42 const char* data() const; 43 size_t size() const { return m_size; } 44 45 enum PurgePriority { PurgeLast, PurgeMiddle, PurgeFirst, PurgeDefault = PurgeMiddle }; 46 PurgePriority purgePriority() const { return m_purgePriority; } 47 void setPurgePriority(PurgePriority); 48 49 bool isPurgeable() const { return m_state != NonVolatile; } 50 bool wasPurged() const; 51 52 bool makePurgeable(bool purgeable); 53 54 private: 55 PurgeableBuffer(char* data, size_t); 56 57 char* m_data; 58 size_t m_size; 59 PurgePriority m_purgePriority; 60 61 enum State { NonVolatile, Volatile, Purged }; 62 mutable State m_state; 63 }; 64 65 #if !OS(DARWIN) || defined(BUILDING_ON_TIGER) || PLATFORM(QT) || PLATFORM(GTK) 66 inline PurgeableBuffer* PurgeableBuffer::create(const char*, size_t) { return 0; } 67 inline PurgeableBuffer::~PurgeableBuffer() { } 68 inline const char* PurgeableBuffer::data() const { return 0; } 69 inline void PurgeableBuffer::setPurgePriority(PurgePriority) { } 70 inline bool PurgeableBuffer::wasPurged() const { return false; } 71 inline bool PurgeableBuffer::makePurgeable(bool) { return false; } 72 #endif 73 74 } 75 76 #endif 77
