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

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

gfx/layers/YCbCrImageDataSerializer.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: 20; 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 "mozilla/layers/YCbCrImageDataSerializer.h"
 #include <string.h>                     // for memcpy
 #include "gfx2DGlue.h"                  // for ToIntSize
 #include "mozilla/gfx/2D.h"             // for DataSourceSurface, Factory
 #include "mozilla/gfx/BaseSize.h"       // for BaseSize
 #include "mozilla/gfx/Types.h"
 #include "mozilla/mozalloc.h"           // for operator delete
 #include "yuv_convert.h"                // for ConvertYCbCrToRGB32, etc
 #define MOZ_ALIGN_WORD(x) (((x) + 3) & ~3)
 namespace mozilla {
 using namespace gfx;
 namespace layers {
 // The Data is layed out as follows:
 //
 //  +-----------------+   -++ --+ --+ <-- Beginning of the buffer
 //  | YCbCrBufferInfo |     |   |   |
 //  +-----------------+   --+   |   |
 //  |      data       |         |   | YCbCrBufferInfo->[mY/mCb/mCr]Offset
 //  +-----------------+   ------+   |
 //  |      data       |             |
 //  +-----------------+   ----------+
 //  |      data       |
 //  +-----------------+
 //
 // There can be padding between the blocks above to keep word alignment.
 // Structure written at the beginning og the data blob containing the image
 // (as shown in the figure above). It contains the necessary informations to
 // read the image in the blob.
 struct YCbCrBufferInfo
 {
   uint32_t mYOffset;
   uint32_t mCbOffset;
   uint32_t mCrOffset;
   uint32_t mYStride;
   uint32_t mYWidth;
   uint32_t mYHeight;
   uint32_t mCbCrStride;
   uint32_t mCbCrWidth;
   uint32_t mCbCrHeight;
   StereoMode mStereoMode;
 };
 static YCbCrBufferInfo* GetYCbCrBufferInfo(uint8_t* aData, size_t aDataSize)
 {
   return aDataSize >= sizeof(YCbCrBufferInfo)
          ? reinterpret_cast<YCbCrBufferInfo*>(aData)
          : nullptr;
 }
 void YCbCrImageDataDeserializerBase::Validate()
 {
   mIsValid = false;
   if (!mData) {
     return;
   }
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   if (!info) {
     return;
   }
   size_t requiredSize = ComputeMinBufferSize(
                           IntSize(info->mYWidth, info->mYHeight),
                           info->mYStride,
                           IntSize(info->mCbCrWidth, info->mCbCrHeight),
                           info->mCbCrStride);
   mIsValid = requiredSize <= mDataSize;
 }
 uint8_t* YCbCrImageDataDeserializerBase::GetYData()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return reinterpret_cast<uint8_t*>(info) + info->mYOffset;
 }
 uint8_t* YCbCrImageDataDeserializerBase::GetCbData()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return reinterpret_cast<uint8_t*>(info) + info->mCbOffset;
 }
 uint8_t* YCbCrImageDataDeserializerBase::GetCrData()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return reinterpret_cast<uint8_t*>(info) + info->mCrOffset;
 }
 uint8_t* YCbCrImageDataDeserializerBase::GetData()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return (reinterpret_cast<uint8_t*>(info)) + MOZ_ALIGN_WORD(sizeof(YCbCrBufferInfo));
 }
 uint32_t YCbCrImageDataDeserializerBase::GetYStride()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return info->mYStride;
 }
 uint32_t YCbCrImageDataDeserializerBase::GetCbCrStride()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return info->mCbCrStride;
 }
 gfx::IntSize YCbCrImageDataDeserializerBase::GetYSize()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return gfx::IntSize(info->mYWidth, info->mYHeight);
 }
 gfx::IntSize YCbCrImageDataDeserializerBase::GetCbCrSize()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return gfx::IntSize(info->mCbCrWidth, info->mCbCrHeight);
 }
 StereoMode YCbCrImageDataDeserializerBase::GetStereoMode()
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   return info->mStereoMode;
 }
 // Offset in bytes
 static size_t ComputeOffset(uint32_t aHeight, uint32_t aStride)
 {
   return MOZ_ALIGN_WORD(aHeight * aStride);
 }
 // Minimum required shmem size in bytes
 size_t
 YCbCrImageDataDeserializerBase::ComputeMinBufferSize(const gfx::IntSize& aYSize,
                                                    uint32_t aYStride,
                                                    const gfx::IntSize& aCbCrSize,
                                                    uint32_t aCbCrStride)
 {
   return ComputeOffset(aYSize.height, aYStride)
          + 2 * ComputeOffset(aCbCrSize.height, aCbCrStride)
          + MOZ_ALIGN_WORD(sizeof(YCbCrBufferInfo));
 }
 // Minimum required shmem size in bytes
 size_t
 YCbCrImageDataDeserializerBase::ComputeMinBufferSize(const gfx::IntSize& aYSize,
                                                    const gfx::IntSize& aCbCrSize)
 {
   return ComputeMinBufferSize(aYSize, aYSize.width, aCbCrSize, aCbCrSize.width);
 }
 // Offset in bytes
 static size_t ComputeOffset(uint32_t aSize)
 {
   return MOZ_ALIGN_WORD(aSize);
 }
 // Minimum required shmem size in bytes
 size_t
 YCbCrImageDataDeserializerBase::ComputeMinBufferSize(uint32_t aSize)
 {
   return ComputeOffset(aSize) + MOZ_ALIGN_WORD(sizeof(YCbCrBufferInfo));
 }
 void
 YCbCrImageDataSerializer::InitializeBufferInfo(uint32_t aYOffset,
                                                uint32_t aCbOffset,
                                                uint32_t aCrOffset,
                                                uint32_t aYStride,
                                                uint32_t aCbCrStride,
                                                const gfx::IntSize& aYSize,
                                                const gfx::IntSize& aCbCrSize,
                                                StereoMode aStereoMode)
 {
   YCbCrBufferInfo* info = GetYCbCrBufferInfo(mData, mDataSize);
   MOZ_ASSERT(info); // OK to assert here, this method is client-side-only
   uint32_t info_size = MOZ_ALIGN_WORD(sizeof(YCbCrBufferInfo));
   info->mYOffset = info_size + aYOffset;
   info->mCbOffset = info_size + aCbOffset;
   info->mCrOffset = info_size + aCrOffset;
   info->mYStride = aYStride;
   info->mYWidth = aYSize.width;
   info->mYHeight = aYSize.height;
   info->mCbCrStride = aCbCrStride;
   info->mCbCrWidth = aCbCrSize.width;
   info->mCbCrHeight = aCbCrSize.height;
   info->mStereoMode = aStereoMode;
   Validate();
 }
 void
 YCbCrImageDataSerializer::InitializeBufferInfo(uint32_t aYStride,
                                                uint32_t aCbCrStride,
                                                const gfx::IntSize& aYSize,
                                                const gfx::IntSize& aCbCrSize,
                                                StereoMode aStereoMode)
 {
   uint32_t yOffset = 0;
   uint32_t cbOffset = yOffset + MOZ_ALIGN_WORD(aYStride * aYSize.height);
   uint32_t crOffset = cbOffset + MOZ_ALIGN_WORD(aCbCrStride * aCbCrSize.height);
   return InitializeBufferInfo(yOffset, cbOffset, crOffset,
       aYStride, aCbCrStride, aYSize, aCbCrSize, aStereoMode);
 }
 void
 YCbCrImageDataSerializer::InitializeBufferInfo(const gfx::IntSize& aYSize,
                                                const gfx::IntSize& aCbCrSize,
                                                StereoMode aStereoMode)
 {
   return InitializeBufferInfo(aYSize.width, aCbCrSize.width, aYSize, aCbCrSize, aStereoMode);
 }
 static void CopyLineWithSkip(const uint8_t* src, uint8_t* dst, uint32_t len, uint32_t skip) {
   for (uint32_t i = 0; i < len; ++i) {
     *dst = *src;
     src += 1 + skip;
     ++dst;
   }
 }
 bool
 YCbCrImageDataSerializer::CopyData(const uint8_t* aYData,
                                    const uint8_t* aCbData, const uint8_t* aCrData,
                                    gfx::IntSize aYSize, uint32_t aYStride,
                                    gfx::IntSize aCbCrSize, uint32_t aCbCrStride,
                                    uint32_t aYSkip, uint32_t aCbCrSkip)
 {
   if (!IsValid() || GetYSize() != aYSize || GetCbCrSize() != aCbCrSize) {
     return false;
   }
   for (int i = 0; i < aYSize.height; ++i) {
     if (aYSkip == 0) {
       // fast path
       memcpy(GetYData() + i * GetYStride(),
              aYData + i * aYStride,
              aYSize.width);
     } else {
       // slower path
       CopyLineWithSkip(aYData + i * aYStride,
                        GetYData() + i * GetYStride(),
                        aYSize.width, aYSkip);
     }
   }
   for (int i = 0; i < aCbCrSize.height; ++i) {
     if (aCbCrSkip == 0) {
       // fast path
       memcpy(GetCbData() + i * GetCbCrStride(),
              aCbData + i * aCbCrStride,
              aCbCrSize.width);
       memcpy(GetCrData() + i * GetCbCrStride(),
              aCrData + i * aCbCrStride,
              aCbCrSize.width);
     } else {
       // slower path
       CopyLineWithSkip(aCbData + i * aCbCrStride,
                        GetCbData() + i * GetCbCrStride(),
                        aCbCrSize.width, aCbCrSkip);
       CopyLineWithSkip(aCrData + i * aCbCrStride,
                        GetCrData() + i * GetCbCrStride(),
                        aCbCrSize.width, aCbCrSkip);
     }
   }
   return true;
 }
 TemporaryRef<DataSourceSurface>
 YCbCrImageDataDeserializer::ToDataSourceSurface()
 {
   RefPtr<DataSourceSurface> result =
     Factory::CreateDataSourceSurface(GetYSize(), gfx::SurfaceFormat::B8G8R8X8);
   DataSourceSurface::MappedSurface map;
   result->Map(DataSourceSurface::MapType::WRITE, &map);
   gfx::ConvertYCbCrToRGB32(GetYData(), GetCbData(), GetCrData(),
                            map.mData,
 , 0, //pic x and y
                            GetYSize().width, GetYSize().height,
                            GetYStride(), GetCbCrStride(),
                            map.mStride,
                            gfx::YV12);
   result->Unmap();
   return result.forget();
 }
 } // namespace
 } // namespace

The Tor Browser / annotate

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

gfx/layers/YCbCrImageDataSerializer.cpp