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 #include "platform/PlatformExport.h" 33 34 namespace blink { 35 class WebDiscardableMemory; 36 } 37 38 namespace WebCore { 39 40 class PLATFORM_EXPORT PurgeableBuffer { 41 WTF_MAKE_NONCOPYABLE(PurgeableBuffer); 42 public: 43 static PassOwnPtr<PurgeableBuffer> create(const char* data, size_t); 44 ~PurgeableBuffer(); 45 46 // Call lock and check the return value before accessing the data. 47 const char* data() const; size()48 size_t size() const { return m_size; } 49 isPurgeable()50 bool isPurgeable() const { return m_state != Locked; } 51 bool wasPurged() const; 52 53 bool lock(); 54 void unlock(); 55 56 private: 57 enum State { 58 Locked, 59 Unlocked, 60 Purged 61 }; 62 63 PurgeableBuffer(PassOwnPtr<blink::WebDiscardableMemory>, const char* data, size_t); 64 65 OwnPtr<blink::WebDiscardableMemory> m_memory; 66 size_t m_size; 67 State m_state; 68 }; 69 70 } 71 72 #endif 73