1 /* 2 * Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved. 3 * Copyright (C) 2013 Google Inc. All Rights Reserved. 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #ifndef PurgeableBuffer_h 28 #define PurgeableBuffer_h 29 30 #include "wtf/OwnPtr.h" 31 #include "wtf/PassOwnPtr.h" 32 33 namespace WebKit { 34 class WebDiscardableMemory; 35 } 36 37 namespace WebCore { 38 39 class PurgeableBuffer { 40 WTF_MAKE_NONCOPYABLE(PurgeableBuffer); 41 public: 42 static PassOwnPtr<PurgeableBuffer> create(const char* data, size_t); 43 ~PurgeableBuffer(); 44 45 // Call lock and check the return value before accessing the data. 46 const char* data() const; 47 size_t size() const { return m_size; } 48 49 bool isPurgeable() const { return m_state != Locked; } 50 bool wasPurged() const; 51 52 bool lock(); 53 void unlock(); 54 55 private: 56 enum State { 57 Locked, 58 Unlocked, 59 Purged 60 }; 61 62 PurgeableBuffer(PassOwnPtr<WebKit::WebDiscardableMemory>, const char* data, size_t); 63 64 OwnPtr<WebKit::WebDiscardableMemory> m_memory; 65 size_t m_size; 66 State m_state; 67 }; 68 69 } 70 71 #endif 72
