2 * Copyright (C) 2011 Apple Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
27 #include "ShareableBitmap.h"
31 static void derefSharedMemory(void* typelessSharedMemory, const void*, size_t)
33 ASSERT_ARG(typelessSharedMemory, typelessSharedMemory);
35 // Balanced by leakRef in makeCGImageCopy.
36 RefPtr<SharedMemory> memory = adoptRef(static_cast<SharedMemory*>(typelessSharedMemory));
39 RetainPtr<CGImageRef> ShareableBitmap::makeCGImageCopy()
41 RetainPtr<CGDataProviderRef> dataProvider;
42 if (isBackedBySharedMemory()) {
43 if (RefPtr<SharedMemory> copyOnWriteMemory = m_sharedMemory->createCopyOnWriteCopy(sizeInBytes())) {
44 RefPtr<SharedMemory> originalMemory = m_sharedMemory.release();
45 // Writes to originalMemory will affect copyOnWriteMemory (until copyOnWriteMemory is
46 // written to for the first time), but writes to copyOnWriteMemory will not affect
47 // originalMemory. So we wrap originalMemory in a CGImage (which will never write to
48 // it) and use copyOnWriteMemory to back this ShareableBitmap from here on out. That
49 // way, writes to this ShareableBitmap will not affect the CGImage.
50 m_sharedMemory = copyOnWriteMemory.release();
51 dataProvider.adoptCF(CGDataProviderCreateWithData(originalMemory.get(), originalMemory->data(), sizeInBytes(), derefSharedMemory));
52 // Balanced by adoptRef in derefSharedMemory.
53 originalMemory.release().leakRef();
57 // We weren't able to make a copy-on-write copy, so we'll just have to fall back to a
58 // normal copy (which is more expensive, but the best we can do).
59 RetainPtr<CFDataRef> cfData(AdoptCF, CFDataCreate(0, static_cast<UInt8*>(data()), sizeInBytes()));
60 dataProvider.adoptCF(CGDataProviderCreateWithCFData(cfData.get()));
63 return createCGImage(dataProvider.get());