1 /* 2 * Copyright (C) 2008, 2010 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 "PurgePriority.h" 30 #include <wtf/PassOwnPtr.h> 31 #include <wtf/Vector.h> 32 33 namespace WebCore { 34 35 class PurgeableBuffer { 36 WTF_MAKE_NONCOPYABLE(PurgeableBuffer); 37 public: 38 static PassOwnPtr<PurgeableBuffer> create(const char* data, size_t); 39 40 ~PurgeableBuffer(); 41 42 // Call makePurgeable(false) and check the return value before accessing the data. 43 const char* data() const; 44 size_t size() const { return m_size; } 45 46 PurgePriority purgePriority() const { return m_purgePriority; } 47 void setPurgePriority(PurgePriority priority) { m_purgePriority = priority; } 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 !ENABLE(PURGEABLE_MEMORY) 66 inline PassOwnPtr<PurgeableBuffer> PurgeableBuffer::create(const char*, size_t) { return PassOwnPtr<PurgeableBuffer>(); } 67 inline PurgeableBuffer::~PurgeableBuffer() { } 68 inline const char* PurgeableBuffer::data() const { return 0; } 69 inline bool PurgeableBuffer::wasPurged() const { return false; } 70 inline bool PurgeableBuffer::makePurgeable(bool) { return false; } 71 #endif 72 73 } 74 75 #endif 76
