Moving GraphicsContext and dependencies from core to platform.

Source/core/platform/graphics/DiscardablePixelRef.cpp

-/*
- * Copyright (C) 2013 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "config.h"
-#include "core/platform/graphics/DiscardablePixelRef.h"
-
-#include "public/platform/Platform.h"
-#include "wtf/StdLibExtras.h"
-
-namespace WebCore {
-
-namespace {
-
-// URI label for a discardable SkPixelRef.
-const char labelDiscardable[] = "discardable";
-
-} // namespace
-
-
-bool DiscardablePixelRefAllocator::allocPixelRef(SkBitmap* dst, SkColorTable* ctable)
-{
-    // It should not be possible to have a non-null color table in Blink.
-    ASSERT(!ctable);
-
-    Sk64 size = dst->getSize64();
-    if (size.isNeg() || !size.is32())
-        return false;
-
-    SkAutoTUnref<DiscardablePixelRef> pixelRef(new DiscardablePixelRef(adoptPtr(new SkMutex())));
-    if (pixelRef->allocAndLockDiscardableMemory(size.get32())) {
-        pixelRef->setURI(labelDiscardable);
-        dst->setPixelRef(pixelRef.get());
-        // This method is only called when a DiscardablePixelRef is created to back a SkBitmap.
-        // It is necessary to lock this SkBitmap to have a valid pointer to pixels. Otherwise,
-        // this SkBitmap could be assigned to another SkBitmap and locking/unlocking the other
-        // SkBitmap will make this one losing its pixels.
-        dst->lockPixels();
-        return true;
-    }
-
-    // Fallback to heap allocator if discardable memory is not available.
-    return dst->allocPixels();
-}
-
-DiscardablePixelRef::DiscardablePixelRef(PassOwnPtr<SkMutex> mutex)
-    : SkPixelRef(mutex.get())
-    , m_lockedMemory(0)
-    , m_mutex(mutex)
-{
-}
-
-DiscardablePixelRef::~DiscardablePixelRef()
-{
-}
-
-bool DiscardablePixelRef::allocAndLockDiscardableMemory(size_t bytes)
-{
-    m_discardable = adoptPtr(blink::Platform::current()->allocateAndLockDiscardableMemory(bytes));
-    if (m_discardable) {
-        m_lockedMemory = m_discardable->data();
-        return true;
-    }
-    return false;
-}
-
-void* DiscardablePixelRef::onLockPixels(SkColorTable** ctable)
-{
-    if (!m_lockedMemory && m_discardable->lock())
-        m_lockedMemory = m_discardable->data();
-
-    *ctable = 0;
-    return m_lockedMemory;
-}
-
-void DiscardablePixelRef::onUnlockPixels()
-{
-    if (m_lockedMemory)
-        m_discardable->unlock();
-    m_lockedMemory = 0;
-}
-
-bool DiscardablePixelRef::isDiscardable(SkPixelRef* pixelRef)
-{
-    // FIXME: DEFINE_STATIC_LOCAL is not thread safe.
-    // ImageDecodingStore provides the synchronization for this.
-    DEFINE_STATIC_LOCAL(const SkString, discardable, (labelDiscardable));
-    return pixelRef && pixelRef->getURI() && discardable.equals(pixelRef->getURI());
-}
-
-} // namespace WebCore