The Tor Browser: gfx/layers/CopyableCanvasLayer.cpp@97036ab72558 (annotated)

gfx/layers/CopyableCanvasLayer.cpp@97036ab72558 (annotated)

gfx/layers/CopyableCanvasLayer.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "BasicLayersImpl.h"            // for FillWithMask, etc
 #include "CopyableCanvasLayer.h"
 #include "GLContext.h"                  // for GLContext
 #include "GLScreenBuffer.h"             // for GLScreenBuffer
 #include "SharedSurface.h"              // for SharedSurface
 #include "SharedSurfaceGL.h"            // for SharedSurface_GL, etc
 #include "SurfaceTypes.h"               // for APITypeT, APITypeT::OpenGL, etc
 #include "gfxMatrix.h"                  // for gfxMatrix
 #include "gfxPattern.h"                 // for gfxPattern, etc
 #include "gfxPlatform.h"                // for gfxPlatform, gfxImageFormat
 #include "gfxRect.h"                    // for gfxRect
 #include "gfxUtils.h"                   // for gfxUtils
 #include "gfx2DGlue.h"                  // for thebes --> moz2d transition
 #include "mozilla/gfx/BaseSize.h"       // for BaseSize
 #include "nsDebug.h"                    // for NS_ASSERTION, NS_WARNING, etc
 #include "nsISupportsImpl.h"            // for gfxContext::AddRef, etc
 #include "nsRect.h"                     // for nsIntRect
 #include "nsSize.h"                     // for nsIntSize
 #include "LayerUtils.h"
 using namespace mozilla::gfx;
 using namespace mozilla::gl;
 namespace mozilla {
 namespace layers {
 CopyableCanvasLayer::CopyableCanvasLayer(LayerManager* aLayerManager, void *aImplData) :
   CanvasLayer(aLayerManager, aImplData)
   , mStream(nullptr)
 {
   MOZ_COUNT_CTOR(CopyableCanvasLayer);
 }
 CopyableCanvasLayer::~CopyableCanvasLayer()
 {
   MOZ_COUNT_DTOR(CopyableCanvasLayer);
 }
 void
 CopyableCanvasLayer::Initialize(const Data& aData)
 {
   NS_ASSERTION(mSurface == nullptr, "BasicCanvasLayer::Initialize called twice!");
   if (aData.mGLContext) {
     mGLContext = aData.mGLContext;
     mStream = aData.mStream;
     mIsGLAlphaPremult = aData.mIsGLAlphaPremult;
     mNeedsYFlip = true;
     MOZ_ASSERT(mGLContext->IsOffscreen(), "canvas gl context isn't offscreen");
     // [Basic Layers, non-OMTC] WebGL layer init.
     // `GLScreenBuffer::Morph`ing is only needed in BasicShadowableCanvasLayer.
   } else if (aData.mDrawTarget) {
     mDrawTarget = aData.mDrawTarget;
     mSurface = mDrawTarget->Snapshot();
     mNeedsYFlip = false;
   } else {
     NS_ERROR("CanvasLayer created without mSurface, mDrawTarget or mGLContext?");
   }
   mBounds.SetRect(0, 0, aData.mSize.width, aData.mSize.height);
 }
 bool
 CopyableCanvasLayer::IsDataValid(const Data& aData)
 {
   return mGLContext == aData.mGLContext && mStream == aData.mStream;
 }
 void
 CopyableCanvasLayer::UpdateTarget(DrawTarget* aDestTarget)
 {
   if (!IsDirty())
     return;
   Painted();
   if (mDrawTarget) {
     mDrawTarget->Flush();
     mSurface = mDrawTarget->Snapshot();
   }
   if (!mGLContext && aDestTarget) {
     NS_ASSERTION(mSurface, "Must have surface to draw!");
     if (mSurface) {
       aDestTarget->CopySurface(mSurface,
                                IntRect(0, 0, mBounds.width, mBounds.height),
                                IntPoint(0, 0));
     }
     return;
   }
   if (mGLContext) {
     RefPtr<DataSourceSurface> readSurf;
     RefPtr<SourceSurface> resultSurf;
     SharedSurface_GL* sharedSurf = nullptr;
     if (mStream) {
       sharedSurf = SharedSurface_GL::Cast(mStream->SwapConsumer());
     } else {
       sharedSurf = mGLContext->RequestFrame();
     }
     if (!sharedSurf) {
       NS_WARNING("Null frame received.");
       return;
     }
     IntSize readSize(sharedSurf->Size());
     SurfaceFormat format = (GetContentFlags() & CONTENT_OPAQUE)
                             ? SurfaceFormat::B8G8R8X8
                             : SurfaceFormat::B8G8R8A8;
     if (aDestTarget) {
       resultSurf = aDestTarget->Snapshot();
       if (!resultSurf) {
         resultSurf = GetTempSurface(readSize, format);
       }
     } else {
       resultSurf = GetTempSurface(readSize, format);
     }
     MOZ_ASSERT(resultSurf);
     MOZ_ASSERT(sharedSurf->APIType() == APITypeT::OpenGL);
     SharedSurface_GL* surfGL = SharedSurface_GL::Cast(sharedSurf);
     if (surfGL->Type() == SharedSurfaceType::Basic) {
       // sharedSurf_Basic->mData must outlive readSurf. Alas, readSurf may not
       // leave the scope it was declared in.
       SharedSurface_Basic* sharedSurf_Basic = SharedSurface_Basic::Cast(surfGL);
       readSurf = sharedSurf_Basic->GetData();
     } else {
       if (resultSurf->GetSize() != readSize ||
           !(readSurf = resultSurf->GetDataSurface()) ||
           readSurf->GetFormat() != format)
       {
         readSurf = GetTempSurface(readSize, format);
       }
       // Readback handles Flush/MarkDirty.
       mGLContext->Screen()->Readback(surfGL, readSurf);
     }
     MOZ_ASSERT(readSurf);
     bool needsPremult = surfGL->HasAlpha() && !mIsGLAlphaPremult;
     if (needsPremult) {
       PremultiplySurface(readSurf);
     }
     if (readSurf != resultSurf) {
       RefPtr<DataSourceSurface> resultDataSurface =
         resultSurf->GetDataSurface();
       RefPtr<DrawTarget> dt =
         Factory::CreateDrawTargetForData(BackendType::CAIRO,
                                          resultDataSurface->GetData(),
                                          resultDataSurface->GetSize(),
                                          resultDataSurface->Stride(),
                                          resultDataSurface->GetFormat());
       IntSize readSize = readSurf->GetSize();
       dt->CopySurface(readSurf,
                       IntRect(0, 0, readSize.width, readSize.height),
                       IntPoint(0, 0));
     }
     // If !aDestSurface then we will end up painting using mSurface, so
     // stick our surface into mSurface, so that the Paint() path is the same.
     if (!aDestTarget) {
       mSurface = resultSurf;
     }
   }
 }
 DataSourceSurface*
 CopyableCanvasLayer::GetTempSurface(const IntSize& aSize,
                                     const SurfaceFormat aFormat)
 {
   if (!mCachedTempSurface ||
       aSize.width != mCachedSize.width ||
       aSize.height != mCachedSize.height ||
       aFormat != mCachedFormat)
   {
     mCachedTempSurface = Factory::CreateDataSourceSurface(aSize, aFormat);
     mCachedSize = aSize;
     mCachedFormat = aFormat;
   }
   return mCachedTempSurface;
 }
 void
 CopyableCanvasLayer::DiscardTempSurface()
 {
   mCachedTempSurface = nullptr;
 }
 }
 }

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gfx/layers/CopyableCanvasLayer.cpp@97036ab72558 (annotated)

gfx/layers/CopyableCanvasLayer.cpp