1 files changed, 939 insertions, 0 deletions
diff --git a/image/imgFrame.cpp b/image/imgFrame.cpp
new file mode 100644
index 000000000..9c5bf9b99
--- /dev/null
+++ b/image/imgFrame.cpp
@@ -0,0 +1,939 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* 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 "imgFrame.h"
+#include "ImageRegion.h"
+#include "ShutdownTracker.h"
+
+#include "prenv.h"
+
+#include "gfx2DGlue.h"
+#include "gfxPlatform.h"
+#include "gfxPrefs.h"
+#include "gfxUtils.h"
+#include "gfxAlphaRecovery.h"
+
+#include "GeckoProfiler.h"
+#include "MainThreadUtils.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/gfx/Tools.h"
+#include "mozilla/Likely.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Telemetry.h"
+#include "nsMargin.h"
+#include "nsThreadUtils.h"
+
+
+namespace mozilla {
+
+using namespace gfx;
+
+namespace image {
+
+static void
+VolatileBufferRelease(void* vbuf)
+{
+  delete static_cast<VolatileBufferPtr<unsigned char>*>(vbuf);
+}
+
+static int32_t
+VolatileSurfaceStride(const IntSize& size, SurfaceFormat format)
+{
+  // Stride must be a multiple of four or cairo will complain.
+  return (size.width * BytesPerPixel(format) + 0x3) & ~0x3;
+}
+
+static already_AddRefed<DataSourceSurface>
+CreateLockedSurface(VolatileBuffer* vbuf,
+                    const IntSize& size,
+                    SurfaceFormat format)
+{
+  VolatileBufferPtr<unsigned char>* vbufptr =
+    new VolatileBufferPtr<unsigned char>(vbuf);
+  MOZ_ASSERT(!vbufptr->WasBufferPurged(), "Expected image data!");
+
+  const int32_t stride = VolatileSurfaceStride(size, format);
+
+  // The VolatileBufferPtr is held by this DataSourceSurface.
+  RefPtr<DataSourceSurface> surf =
+    Factory::CreateWrappingDataSourceSurface(*vbufptr, stride, size, format,
+                                             &VolatileBufferRelease,
+                                             static_cast<void*>(vbufptr));
+  if (!surf) {
+    delete vbufptr;
+    return nullptr;
+  }
+
+  return surf.forget();
+}
+
+static already_AddRefed<VolatileBuffer>
+AllocateBufferForImage(const IntSize& size, SurfaceFormat format)
+{
+  int32_t stride = VolatileSurfaceStride(size, format);
+  RefPtr<VolatileBuffer> buf = new VolatileBuffer();
+  if (buf->Init(stride * size.height,
+                size_t(1) << gfxAlphaRecovery::GoodAlignmentLog2())) {
+    return buf.forget();
+  }
+
+  return nullptr;
+}
+
+static bool
+ClearSurface(VolatileBuffer* aVBuf, const IntSize& aSize, SurfaceFormat aFormat)
+{
+  VolatileBufferPtr<unsigned char> vbufptr(aVBuf);
+  if (vbufptr.WasBufferPurged()) {
+    NS_WARNING("VolatileBuffer was purged");
+    return false;
+  }
+
+  int32_t stride = VolatileSurfaceStride(aSize, aFormat);
+  if (aFormat == SurfaceFormat::B8G8R8X8) {
+    // Skia doesn't support RGBX surfaces, so ensure the alpha value is set
+    // to opaque white. While it would be nice to only do this for Skia,
+    // imgFrame can run off main thread and past shutdown where
+    // we might not have gfxPlatform, so just memset everytime instead.
+    memset(vbufptr, 0xFF, stride * aSize.height);
+  } else if (aVBuf->OnHeap()) {
+    // We only need to memset it if the buffer was allocated on the heap.
+    // Otherwise, it's allocated via mmap and refers to a zeroed page and will
+    // be COW once it's written to.
+    memset(vbufptr, 0, stride * aSize.height);
+  }
+
+  return true;
+}
+
+// Returns true if an image of aWidth x aHeight is allowed and legal.
+static bool
+AllowedImageSize(int32_t aWidth, int32_t aHeight)
+{
+  // reject over-wide or over-tall images
+  const int32_t k64KLimit = 0x0000FFFF;
+  if (MOZ_UNLIKELY(aWidth > k64KLimit || aHeight > k64KLimit )) {
+    NS_WARNING("image too big");
+    return false;
+  }
+
+  // protect against invalid sizes
+  if (MOZ_UNLIKELY(aHeight <= 0 || aWidth <= 0)) {
+    return false;
+  }
+
+  // check to make sure we don't overflow a 32-bit
+  CheckedInt32 requiredBytes = CheckedInt32(aWidth) * CheckedInt32(aHeight) * 4;
+  if (MOZ_UNLIKELY(!requiredBytes.isValid())) {
+    NS_WARNING("width or height too large");
+    return false;
+  }
+#if defined(XP_MACOSX)
+  // CoreGraphics is limited to images < 32K in *height*, so clamp all surfaces
+  // on the Mac to that height
+  if (MOZ_UNLIKELY(aHeight > SHRT_MAX)) {
+    NS_WARNING("image too big");
+    return false;
+  }
+#endif
+  return true;
+}
+
+static bool AllowedImageAndFrameDimensions(const nsIntSize& aImageSize,
+                                           const nsIntRect& aFrameRect)
+{
+  if (!AllowedImageSize(aImageSize.width, aImageSize.height)) {
+    return false;
+  }
+  if (!AllowedImageSize(aFrameRect.width, aFrameRect.height)) {
+    return false;
+  }
+  nsIntRect imageRect(0, 0, aImageSize.width, aImageSize.height);
+  if (!imageRect.Contains(aFrameRect)) {
+    NS_WARNING("Animated image frame does not fit inside bounds of image");
+  }
+  return true;
+}
+
+imgFrame::imgFrame()
+  : mMonitor("imgFrame")
+  , mDecoded(0, 0, 0, 0)
+  , mLockCount(0)
+  , mTimeout(FrameTimeout::FromRawMilliseconds(100))
+  , mDisposalMethod(DisposalMethod::NOT_SPECIFIED)
+  , mBlendMethod(BlendMethod::OVER)
+  , mHasNoAlpha(false)
+  , mAborted(false)
+  , mFinished(false)
+  , mOptimizable(false)
+  , mPalettedImageData(nullptr)
+  , mPaletteDepth(0)
+  , mNonPremult(false)
+  , mCompositingFailed(false)
+{
+}
+
+imgFrame::~imgFrame()
+{
+#ifdef DEBUG
+  MonitorAutoLock lock(mMonitor);
+  MOZ_ASSERT(mAborted || AreAllPixelsWritten());
+  MOZ_ASSERT(mAborted || mFinished);
+#endif
+
+  free(mPalettedImageData);
+  mPalettedImageData = nullptr;
+}
+
+nsresult
+imgFrame::InitForDecoder(const nsIntSize& aImageSize,
+                         const nsIntRect& aRect,
+                         SurfaceFormat aFormat,
+                         uint8_t aPaletteDepth /* = 0 */,
+                         bool aNonPremult /* = false */)
+{
+  // Assert for properties that should be verified by decoders,
+  // warn for properties related to bad content.
+  if (!AllowedImageAndFrameDimensions(aImageSize, aRect)) {
+    NS_WARNING("Should have legal image size");
+    mAborted = true;
+    return NS_ERROR_FAILURE;
+  }
+
+  mImageSize = aImageSize;
+  mFrameRect = aRect;
+
+  // We only allow a non-trivial frame rect (i.e., a frame rect that doesn't
+  // cover the entire image) for paletted animation frames. We never draw those
+  // frames directly; we just use FrameAnimator to composite them and produce a
+  // BGRA surface that we actually draw. We enforce this here to make sure that
+  // imgFrame::Draw(), which is responsible for drawing all other kinds of
+  // frames, never has to deal with a non-trivial frame rect.
+  if (aPaletteDepth == 0 &&
+      !mFrameRect.IsEqualEdges(IntRect(IntPoint(), mImageSize))) {
+    MOZ_ASSERT_UNREACHABLE("Creating a non-paletted imgFrame with a "
+                           "non-trivial frame rect");
+    return NS_ERROR_FAILURE;
+  }
+
+  mFormat = aFormat;
+  mPaletteDepth = aPaletteDepth;
+  mNonPremult = aNonPremult;
+
+  if (aPaletteDepth != 0) {
+    // We're creating for a paletted image.
+    if (aPaletteDepth > 8) {
+      NS_WARNING("Should have legal palette depth");
+      NS_ERROR("This Depth is not supported");
+      mAborted = true;
+      return NS_ERROR_FAILURE;
+    }
+
+    // Use the fallible allocator here. Paletted images always use 1 byte per
+    // pixel, so calculating the amount of memory we need is straightforward.
+    size_t dataSize = PaletteDataLength() + mFrameRect.Area();
+    mPalettedImageData = static_cast<uint8_t*>(calloc(dataSize, sizeof(uint8_t)));
+    if (!mPalettedImageData) {
+      NS_WARNING("Call to calloc for paletted image data should succeed");
+    }
+    NS_ENSURE_TRUE(mPalettedImageData, NS_ERROR_OUT_OF_MEMORY);
+  } else {
+    MOZ_ASSERT(!mImageSurface, "Called imgFrame::InitForDecoder() twice?");
+
+    mVBuf = AllocateBufferForImage(mFrameRect.Size(), mFormat);
+    if (!mVBuf) {
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    mImageSurface = CreateLockedSurface(mVBuf, mFrameRect.Size(), mFormat);
+
+    if (!mImageSurface) {
+      NS_WARNING("Failed to create ImageSurface");
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    if (!ClearSurface(mVBuf, mFrameRect.Size(), mFormat)) {
+      NS_WARNING("Could not clear allocated buffer");
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult
+imgFrame::InitWithDrawable(gfxDrawable* aDrawable,
+                           const nsIntSize& aSize,
+                           const SurfaceFormat aFormat,
+                           SamplingFilter aSamplingFilter,
+                           uint32_t aImageFlags,
+                           gfx::BackendType aBackend)
+{
+  // Assert for properties that should be verified by decoders,
+  // warn for properties related to bad content.
+  if (!AllowedImageSize(aSize.width, aSize.height)) {
+    NS_WARNING("Should have legal image size");
+    mAborted = true;
+    return NS_ERROR_FAILURE;
+  }
+
+  mImageSize = aSize;
+  mFrameRect = IntRect(IntPoint(0, 0), aSize);
+
+  mFormat = aFormat;
+  mPaletteDepth = 0;
+
+  RefPtr<DrawTarget> target;
+
+  bool canUseDataSurface =
+    gfxPlatform::GetPlatform()->CanRenderContentToDataSurface();
+
+  if (canUseDataSurface) {
+    // It's safe to use data surfaces for content on this platform, so we can
+    // get away with using volatile buffers.
+    MOZ_ASSERT(!mImageSurface, "Called imgFrame::InitWithDrawable() twice?");
+
+    mVBuf = AllocateBufferForImage(mFrameRect.Size(), mFormat);
+    if (!mVBuf) {
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    int32_t stride = VolatileSurfaceStride(mFrameRect.Size(), mFormat);
+    VolatileBufferPtr<uint8_t> ptr(mVBuf);
+    if (!ptr) {
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    mImageSurface = CreateLockedSurface(mVBuf, mFrameRect.Size(), mFormat);
+
+    if (!mImageSurface) {
+      NS_WARNING("Failed to create ImageSurface");
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    if (!ClearSurface(mVBuf, mFrameRect.Size(), mFormat)) {
+      NS_WARNING("Could not clear allocated buffer");
+      mAborted = true;
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    target = gfxPlatform::CreateDrawTargetForData(
+                            ptr,
+                            mFrameRect.Size(),
+                            stride,
+                            mFormat);
+  } else {
+    // We can't use data surfaces for content, so we'll create an offscreen
+    // surface instead.  This means if someone later calls RawAccessRef(), we
+    // may have to do an expensive readback, but we warned callers about that in
+    // the documentation for this method.
+    MOZ_ASSERT(!mOptSurface, "Called imgFrame::InitWithDrawable() twice?");
+
+    if (gfxPlatform::GetPlatform()->SupportsAzureContentForType(aBackend)) {
+      target = gfxPlatform::GetPlatform()->
+        CreateDrawTargetForBackend(aBackend, mFrameRect.Size(), mFormat);
+    } else {
+      target = gfxPlatform::GetPlatform()->
+        CreateOffscreenContentDrawTarget(mFrameRect.Size(), mFormat);
+    }
+  }
+
+  if (!target || !target->IsValid()) {
+    mAborted = true;
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // Draw using the drawable the caller provided.
+  RefPtr<gfxContext> ctx = gfxContext::CreateOrNull(target);
+  MOZ_ASSERT(ctx);  // Already checked the draw target above.
+  gfxUtils::DrawPixelSnapped(ctx, aDrawable, mFrameRect.Size(),
+                             ImageRegion::Create(ThebesRect(mFrameRect)),
+                             mFormat, aSamplingFilter, aImageFlags);
+
+  if (canUseDataSurface && !mImageSurface) {
+    NS_WARNING("Failed to create VolatileDataSourceSurface");
+    mAborted = true;
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (!canUseDataSurface) {
+    // We used an offscreen surface, which is an "optimized" surface from
+    // imgFrame's perspective.
+    mOptSurface = target->Snapshot();
+  }
+
+  // If we reach this point, we should regard ourselves as complete.
+  mDecoded = GetRect();
+  mFinished = true;
+
+#ifdef DEBUG
+  MonitorAutoLock lock(mMonitor);
+  MOZ_ASSERT(AreAllPixelsWritten());
+#endif
+
+  return NS_OK;
+}
+
+bool
+imgFrame::CanOptimizeOpaqueImage()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!ShutdownTracker::ShutdownHasStarted());
+  mMonitor.AssertCurrentThreadOwns();
+
+  // If we're using a surface format with alpha but the image has no alpha,
+  // change the format. This doesn't change the underlying data at all, but
+  // allows DrawTargets to avoid blending when drawing known opaque images.
+  // This optimization is free and safe, so we always do it when we can except
+  // if we have a Skia backend. Skia doesn't support RGBX so ensure we don't
+  // optimize to a RGBX surface.
+  return mHasNoAlpha && mFormat == SurfaceFormat::B8G8R8A8 && mImageSurface &&
+         (gfxPlatform::GetPlatform()->GetDefaultContentBackend() != BackendType::SKIA);
+}
+
+nsresult
+imgFrame::Optimize(DrawTarget* aTarget)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mMonitor.AssertCurrentThreadOwns();
+  
+  if (mLockCount > 0 || !mOptimizable) {
+    // Don't optimize right now.
+    return NS_OK;
+  }
+
+  // Check whether image optimization is disabled -- not thread safe!
+  static bool gDisableOptimize = false;
+  static bool hasCheckedOptimize = false;
+  if (!hasCheckedOptimize) {
+    if (PR_GetEnv("MOZ_DISABLE_IMAGE_OPTIMIZE")) {
+      gDisableOptimize = true;
+    }
+    hasCheckedOptimize = true;
+  }
+
+  // Don't optimize during shutdown because gfxPlatform may not be available.
+  if (ShutdownTracker::ShutdownHasStarted()) {
+    return NS_OK;
+  }
+
+  // This optimization is basically free, so we perform it even if optimization is disabled.
+  if (CanOptimizeOpaqueImage()) {
+    mFormat = SurfaceFormat::B8G8R8X8;
+    mImageSurface = CreateLockedSurface(mVBuf, mFrameRect.Size(), mFormat);
+  }
+
+  if (gDisableOptimize) {
+    return NS_OK;
+  }
+
+  if (mPalettedImageData || mOptSurface) {
+    return NS_OK;
+  }
+
+  // XXX(seth): It's currently unclear if there's any reason why we can't
+  // optimize non-premult surfaces. We should look into removing this.
+  if (mNonPremult) {
+    return NS_OK;
+  }
+
+  mOptSurface = gfxPlatform::GetPlatform()
+    ->ScreenReferenceDrawTarget()->OptimizeSourceSurface(mImageSurface);
+  if (mOptSurface == mImageSurface) {
+    mOptSurface = nullptr;
+  }
+
+  if (mOptSurface) {
+    // There's no reason to keep our volatile buffer around at all if we have an
+    // optimized surface. Release our reference to it. This will leave
+    // |mVBufPtr| and |mImageSurface| as the only things keeping it alive, so
+    // it'll get freed below.
+    mVBuf = nullptr;
+  }
+
+  // Release all strong references to our volatile buffer's memory. This will
+  // allow the operating system to free the memory if it needs to.
+  mVBufPtr = nullptr;
+  mImageSurface = nullptr;
+  mOptimizable = false;
+
+  return NS_OK;
+}
+
+DrawableFrameRef
+imgFrame::DrawableRef()
+{
+  return DrawableFrameRef(this);
+}
+
+RawAccessFrameRef
+imgFrame::RawAccessRef()
+{
+  return RawAccessFrameRef(this);
+}
+
+void
+imgFrame::SetRawAccessOnly()
+{
+  AssertImageDataLocked();
+
+  // Lock our data and throw away the key.
+  LockImageData();
+}
+
+
+imgFrame::SurfaceWithFormat
+imgFrame::SurfaceForDrawing(bool               aDoPartialDecode,
+                            bool               aDoTile,
+                            ImageRegion&       aRegion,
+                            SourceSurface*     aSurface)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mMonitor.AssertCurrentThreadOwns();
+
+  if (!aDoPartialDecode) {
+    return SurfaceWithFormat(new gfxSurfaceDrawable(aSurface, mImageSize),
+                             mFormat);
+  }
+
+  gfxRect available = gfxRect(mDecoded.x, mDecoded.y, mDecoded.width,
+                              mDecoded.height);
+
+  if (aDoTile) {
+    // Create a temporary surface.
+    // Give this surface an alpha channel because there are
+    // transparent pixels in the padding or undecoded area
+    RefPtr<DrawTarget> target =
+      gfxPlatform::GetPlatform()->
+        CreateOffscreenContentDrawTarget(mImageSize, SurfaceFormat::B8G8R8A8);
+    if (!target) {
+      return SurfaceWithFormat();
+    }
+
+    SurfacePattern pattern(aSurface,
+                           aRegion.GetExtendMode(),
+                           Matrix::Translation(mDecoded.x, mDecoded.y));
+    target->FillRect(ToRect(aRegion.Intersect(available).Rect()), pattern);
+
+    RefPtr<SourceSurface> newsurf = target->Snapshot();
+    return SurfaceWithFormat(new gfxSurfaceDrawable(newsurf, mImageSize),
+                             target->GetFormat());
+  }
+
+  // Not tiling, and we have a surface, so we can account for
+  // a partial decode just by twiddling parameters.
+  aRegion = aRegion.Intersect(available);
+  IntSize availableSize(mDecoded.width, mDecoded.height);
+
+  return SurfaceWithFormat(new gfxSurfaceDrawable(aSurface, availableSize),
+                           mFormat);
+}
+
+bool imgFrame::Draw(gfxContext* aContext, const ImageRegion& aRegion,
+                    SamplingFilter aSamplingFilter, uint32_t aImageFlags)
+{
+  PROFILER_LABEL("imgFrame", "Draw",
+    js::ProfileEntry::Category::GRAPHICS);
+
+  MOZ_ASSERT(NS_IsMainThread());
+  NS_ASSERTION(!aRegion.Rect().IsEmpty(), "Drawing empty region!");
+  NS_ASSERTION(!aRegion.IsRestricted() ||
+               !aRegion.Rect().Intersect(aRegion.Restriction()).IsEmpty(),
+               "We must be allowed to sample *some* source pixels!");
+  MOZ_ASSERT(mFrameRect.IsEqualEdges(IntRect(IntPoint(), mImageSize)),
+             "Directly drawing an image with a non-trivial frame rect!");
+
+  if (mPalettedImageData) {
+    MOZ_ASSERT_UNREACHABLE("Directly drawing a paletted image!");
+    return false;
+  }
+
+  MonitorAutoLock lock(mMonitor);
+
+  // Possibly convert this image into a GPU texture, this may also cause our
+  // mImageSurface to be released and the OS to release the underlying memory.
+  Optimize(aContext->GetDrawTarget());
+
+  bool doPartialDecode = !AreAllPixelsWritten();
+
+  RefPtr<SourceSurface> surf = GetSourceSurfaceInternal();
+  if (!surf) {
+    return false;
+  }
+
+  gfxRect imageRect(0, 0, mImageSize.width, mImageSize.height);
+  bool doTile = !imageRect.Contains(aRegion.Rect()) &&
+                !(aImageFlags & imgIContainer::FLAG_CLAMP);
+
+  ImageRegion region(aRegion);
+  SurfaceWithFormat surfaceResult =
+    SurfaceForDrawing(doPartialDecode, doTile, region, surf);
+
+  if (surfaceResult.IsValid()) {
+    gfxUtils::DrawPixelSnapped(aContext, surfaceResult.mDrawable,
+                               imageRect.Size(), region, surfaceResult.mFormat,
+                               aSamplingFilter, aImageFlags);
+  }
+  return true;
+}
+
+nsresult
+imgFrame::ImageUpdated(const nsIntRect& aUpdateRect)
+{
+  MonitorAutoLock lock(mMonitor);
+  return ImageUpdatedInternal(aUpdateRect);
+}
+
+nsresult
+imgFrame::ImageUpdatedInternal(const nsIntRect& aUpdateRect)
+{
+  mMonitor.AssertCurrentThreadOwns();
+
+  mDecoded.UnionRect(mDecoded, aUpdateRect);
+
+  // Clamp to the frame rect to ensure that decoder bugs don't result in a
+  // decoded rect that extends outside the bounds of the frame rect.
+  mDecoded.IntersectRect(mDecoded, mFrameRect);
+
+  return NS_OK;
+}
+
+void
+imgFrame::Finish(Opacity aFrameOpacity /* = Opacity::SOME_TRANSPARENCY */,
+                 DisposalMethod aDisposalMethod /* = DisposalMethod::KEEP */,
+                 FrameTimeout aTimeout
+                   /* = FrameTimeout::FromRawMilliseconds(0) */,
+                 BlendMethod aBlendMethod /* = BlendMethod::OVER */,
+                 const Maybe<IntRect>& aBlendRect /* = Nothing() */)
+{
+  MonitorAutoLock lock(mMonitor);
+  MOZ_ASSERT(mLockCount > 0, "Image data should be locked");
+
+  if (aFrameOpacity == Opacity::FULLY_OPAQUE) {
+    mHasNoAlpha = true;
+    Telemetry::Accumulate(Telemetry::IMAGE_DECODE_OPAQUE_BGRA,
+                          mFormat == SurfaceFormat::B8G8R8A8);
+  }
+
+  mDisposalMethod = aDisposalMethod;
+  mTimeout = aTimeout;
+  mBlendMethod = aBlendMethod;
+  mBlendRect = aBlendRect;
+  ImageUpdatedInternal(GetRect());
+  mFinished = true;
+
+  // The image is now complete, wake up anyone who's waiting.
+  mMonitor.NotifyAll();
+}
+
+uint32_t
+imgFrame::GetImageBytesPerRow() const
+{
+  mMonitor.AssertCurrentThreadOwns();
+
+  if (mVBuf) {
+    return mFrameRect.width * BytesPerPixel(mFormat);
+  }
+
+  if (mPaletteDepth) {
+    return mFrameRect.width;
+  }
+
+  return 0;
+}
+
+uint32_t
+imgFrame::GetImageDataLength() const
+{
+  return GetImageBytesPerRow() * mFrameRect.height;
+}
+
+void
+imgFrame::GetImageData(uint8_t** aData, uint32_t* aLength) const
+{
+  MonitorAutoLock lock(mMonitor);
+  GetImageDataInternal(aData, aLength);
+}
+
+void
+imgFrame::GetImageDataInternal(uint8_t** aData, uint32_t* aLength) const
+{
+  mMonitor.AssertCurrentThreadOwns();
+  MOZ_ASSERT(mLockCount > 0, "Image data should be locked");
+
+  if (mImageSurface) {
+    *aData = mVBufPtr;
+    MOZ_ASSERT(*aData,
+      "mImageSurface is non-null, but mVBufPtr is null in GetImageData");
+  } else if (mPalettedImageData) {
+    *aData = mPalettedImageData + PaletteDataLength();
+    MOZ_ASSERT(*aData,
+      "mPalettedImageData is non-null, but result is null in GetImageData");
+  } else {
+    MOZ_ASSERT(false,
+      "Have neither mImageSurface nor mPalettedImageData in GetImageData");
+    *aData = nullptr;
+  }
+
+  *aLength = GetImageDataLength();
+}
+
+uint8_t*
+imgFrame::GetImageData() const
+{
+  uint8_t* data;
+  uint32_t length;
+  GetImageData(&data, &length);
+  return data;
+}
+
+bool
+imgFrame::GetIsPaletted() const
+{
+  return mPalettedImageData != nullptr;
+}
+
+void
+imgFrame::GetPaletteData(uint32_t** aPalette, uint32_t* length) const
+{
+  AssertImageDataLocked();
+
+  if (!mPalettedImageData) {
+    *aPalette = nullptr;
+    *length = 0;
+  } else {
+    *aPalette = (uint32_t*) mPalettedImageData;
+    *length = PaletteDataLength();
+  }
+}
+
+uint32_t*
+imgFrame::GetPaletteData() const
+{
+  uint32_t* data;
+  uint32_t length;
+  GetPaletteData(&data, &length);
+  return data;
+}
+
+nsresult
+imgFrame::LockImageData()
+{
+  MonitorAutoLock lock(mMonitor);
+
+  MOZ_ASSERT(mLockCount >= 0, "Unbalanced locks and unlocks");
+  if (mLockCount < 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mLockCount++;
+
+  // If we are not the first lock, there's nothing to do.
+  if (mLockCount != 1) {
+    return NS_OK;
+  }
+
+  // If we're the first lock, but have an image surface, we're OK.
+  if (mImageSurface) {
+    mVBufPtr = mVBuf;
+    return NS_OK;
+  }
+
+  // Paletted images don't have surfaces, so there's nothing to do.
+  if (mPalettedImageData) {
+    return NS_OK;
+  }
+
+  MOZ_ASSERT_UNREACHABLE("It's illegal to re-lock an optimized imgFrame");
+  return NS_ERROR_FAILURE;
+}
+
+void
+imgFrame::AssertImageDataLocked() const
+{
+#ifdef DEBUG
+  MonitorAutoLock lock(mMonitor);
+  MOZ_ASSERT(mLockCount > 0, "Image data should be locked");
+#endif
+}
+
+nsresult
+imgFrame::UnlockImageData()
+{
+  MonitorAutoLock lock(mMonitor);
+
+  MOZ_ASSERT(mLockCount > 0, "Unlocking an unlocked image!");
+  if (mLockCount <= 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  MOZ_ASSERT(mLockCount > 1 || mFinished || mAborted,
+             "Should have Finish()'d or aborted before unlocking");
+
+  mLockCount--;
+
+  return NS_OK;
+}
+
+void
+imgFrame::SetOptimizable()
+{
+  AssertImageDataLocked();
+  MonitorAutoLock lock(mMonitor);
+  mOptimizable = true;
+}
+
+already_AddRefed<SourceSurface>
+imgFrame::GetSourceSurface()
+{
+  MonitorAutoLock lock(mMonitor);
+  return GetSourceSurfaceInternal();
+}
+
+already_AddRefed<SourceSurface>
+imgFrame::GetSourceSurfaceInternal()
+{
+  mMonitor.AssertCurrentThreadOwns();
+
+  if (mOptSurface) {
+    if (mOptSurface->IsValid()) {
+      RefPtr<SourceSurface> surf(mOptSurface);
+      return surf.forget();
+    } else {
+      mOptSurface = nullptr;
+    }
+  }
+
+  if (mImageSurface) {
+    RefPtr<SourceSurface> surf(mImageSurface);
+    return surf.forget();
+  }
+
+  if (!mVBuf) {
+    return nullptr;
+  }
+
+  VolatileBufferPtr<char> buf(mVBuf);
+  if (buf.WasBufferPurged()) {
+    return nullptr;
+  }
+
+  return CreateLockedSurface(mVBuf, mFrameRect.Size(), mFormat);
+}
+
+AnimationData
+imgFrame::GetAnimationData() const
+{
+  MonitorAutoLock lock(mMonitor);
+  MOZ_ASSERT(mLockCount > 0, "Image data should be locked");
+
+  uint8_t* data;
+  if (mPalettedImageData) {
+    data = mPalettedImageData;
+  } else {
+    uint32_t length;
+    GetImageDataInternal(&data, &length);
+  }
+
+  bool hasAlpha = mFormat == SurfaceFormat::B8G8R8A8;
+
+  return AnimationData(data, PaletteDataLength(), mTimeout, GetRect(),
+                       mBlendMethod, mBlendRect, mDisposalMethod, hasAlpha);
+}
+
+void
+imgFrame::Abort()
+{
+  MonitorAutoLock lock(mMonitor);
+
+  mAborted = true;
+
+  // Wake up anyone who's waiting.
+  mMonitor.NotifyAll();
+}
+
+bool
+imgFrame::IsAborted() const
+{
+  MonitorAutoLock lock(mMonitor);
+  return mAborted;
+}
+
+bool
+imgFrame::IsFinished() const
+{
+  MonitorAutoLock lock(mMonitor);
+  return mFinished;
+}
+
+void
+imgFrame::WaitUntilFinished() const
+{
+  MonitorAutoLock lock(mMonitor);
+
+  while (true) {
+    // Return if we're aborted or complete.
+    if (mAborted || mFinished) {
+      return;
+    }
+
+    // Not complete yet, so we'll have to wait.
+    mMonitor.Wait();
+  }
+}
+
+bool
+imgFrame::AreAllPixelsWritten() const
+{
+  mMonitor.AssertCurrentThreadOwns();
+  return mDecoded.IsEqualInterior(mFrameRect);
+}
+
+bool imgFrame::GetCompositingFailed() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mCompositingFailed;
+}
+
+void
+imgFrame::SetCompositingFailed(bool val)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mCompositingFailed = val;
+}
+
+void
+imgFrame::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
+                                 size_t& aHeapSizeOut,
+                                 size_t& aNonHeapSizeOut) const
+{
+  MonitorAutoLock lock(mMonitor);
+
+  if (mPalettedImageData) {
+    aHeapSizeOut += aMallocSizeOf(mPalettedImageData);
+  }
+  if (mImageSurface) {
+    aHeapSizeOut += aMallocSizeOf(mImageSurface);
+  }
+  if (mOptSurface) {
+    aHeapSizeOut += aMallocSizeOf(mOptSurface);
+  }
+
+  if (mVBuf) {
+    aHeapSizeOut += aMallocSizeOf(mVBuf);
+    aHeapSizeOut += mVBuf->HeapSizeOfExcludingThis(aMallocSizeOf);
+    aNonHeapSizeOut += mVBuf->NonHeapSizeOfExcludingThis();
+  }
+}
+
+} // namespace image
+} // namespace mozilla