image/imgFrame.h
author Timothy Nikkel <tnikkel@gmail.com>
Fri, 01 Apr 2016 12:44:17 -0500
changeset 291288 5005b1604f269e2204260bdff4b26a92564e42f6
parent 290221 c75b2b195f28a5ed556a7dfc12e9b45bc56c971a
permissions -rw-r--r--
Bug 1222596. If RasterImage::LookupFrame does (some) sync decoding and encouters an error we don't want to return the surface with an error. r=seth If the sync decoding the LookupFrame does encounters an error it will set mError on the RasterImage, which LookupFrame callers check before calling LookupFrame. But they've called LookupFrame before the error was encountered, so we check if the frame has had Abort called on it to determine if we should return it at all. We only does this if one of the sync decode flags was passed in because IsAborted needs to get the imgFrame's monitor, so we don't want to block consumers that haven't asked for decoding.

/* -*- 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/. */

#ifndef mozilla_image_imgFrame_h
#define mozilla_image_imgFrame_h

#include "mozilla/MemoryReporting.h"
#include "mozilla/Monitor.h"
#include "mozilla/Move.h"
#include "mozilla/VolatileBuffer.h"
#include "gfxDrawable.h"
#include "imgIContainer.h"
#include "MainThreadUtils.h"

namespace mozilla {
namespace image {

class ImageRegion;
class DrawableFrameRef;
class RawAccessFrameRef;

enum class BlendMethod : int8_t {
  // All color components of the frame, including alpha, overwrite the current
  // contents of the frame's output buffer region.
  SOURCE,

  // The frame should be composited onto the output buffer based on its alpha,
  // using a simple OVER operation.
  OVER
};

enum class DisposalMethod : int8_t {
  CLEAR_ALL = -1,  // Clear the whole image, revealing what's underneath.
  NOT_SPECIFIED,   // Leave the frame and let the new frame draw on top.
  KEEP,            // Leave the frame and let the new frame draw on top.
  CLEAR,           // Clear the frame's area, revealing what's underneath.
  RESTORE_PREVIOUS // Restore the previous (composited) frame.
};

enum class Opacity : uint8_t {
  FULLY_OPAQUE,
  SOME_TRANSPARENCY
};

/**
 * AnimationData contains all of the information necessary for using an imgFrame
 * as part of an animation.
 *
 * It includes pointers to the raw image data of the underlying imgFrame, but
 * does not own that data. A RawAccessFrameRef for the underlying imgFrame must
 * outlive the AnimationData for it to remain valid.
 */
struct AnimationData
{
  AnimationData(uint8_t* aRawData, uint32_t aPaletteDataLength,
                int32_t aRawTimeout, const nsIntRect& aRect,
                BlendMethod aBlendMethod, DisposalMethod aDisposalMethod,
                bool aHasAlpha)
    : mRawData(aRawData)
    , mPaletteDataLength(aPaletteDataLength)
    , mRawTimeout(aRawTimeout)
    , mRect(aRect)
    , mBlendMethod(aBlendMethod)
    , mDisposalMethod(aDisposalMethod)
    , mHasAlpha(aHasAlpha)
  { }

  uint8_t* mRawData;
  uint32_t mPaletteDataLength;
  int32_t mRawTimeout;
  nsIntRect mRect;
  BlendMethod mBlendMethod;
  DisposalMethod mDisposalMethod;
  bool mHasAlpha;
};

/**
 * ScalingData contains all of the information necessary for performing
 * high-quality (CPU-based) scaling an imgFrame.
 *
 * It includes pointers to the raw image data of the underlying imgFrame, but
 * does not own that data. A RawAccessFrameRef for the underlying imgFrame must
 * outlive the ScalingData for it to remain valid.
 */
struct ScalingData
{
  ScalingData(uint8_t* aRawData,
              gfx::IntSize aSize,
              uint32_t aBytesPerRow,
              gfx::SurfaceFormat aFormat)
    : mRawData(aRawData)
    , mSize(aSize)
    , mBytesPerRow(aBytesPerRow)
    , mFormat(aFormat)
  { }

  uint8_t* mRawData;
  gfx::IntSize mSize;
  uint32_t mBytesPerRow;
  gfx::SurfaceFormat mFormat;
};

class imgFrame
{
  typedef gfx::Color Color;
  typedef gfx::DataSourceSurface DataSourceSurface;
  typedef gfx::DrawTarget DrawTarget;
  typedef gfx::Filter Filter;
  typedef gfx::IntSize IntSize;
  typedef gfx::SourceSurface SourceSurface;
  typedef gfx::SurfaceFormat SurfaceFormat;

public:
  MOZ_DECLARE_REFCOUNTED_TYPENAME(imgFrame)
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(imgFrame)

  imgFrame();

  /**
   * Initialize this imgFrame with an empty surface and prepare it for being
   * written to by a decoder.
   *
   * This is appropriate for use with decoded images, but it should not be used
   * when drawing content into an imgFrame, as it may use a different graphics
   * backend than normal content drawing.
   */
  nsresult InitForDecoder(const nsIntSize& aImageSize,
                          const nsIntRect& aRect,
                          SurfaceFormat aFormat,
                          uint8_t aPaletteDepth = 0,
                          bool aNonPremult = false);

  nsresult InitForDecoder(const nsIntSize& aSize,
                          SurfaceFormat aFormat,
                          uint8_t aPaletteDepth = 0)
  {
    return InitForDecoder(aSize, nsIntRect(0, 0, aSize.width, aSize.height),
                          aFormat, aPaletteDepth);
  }


  /**
   * Initialize this imgFrame with a new surface and draw the provided
   * gfxDrawable into it.
   *
   * This is appropriate to use when drawing content into an imgFrame, as it
   * uses the same graphics backend as normal content drawing. The downside is
   * that the underlying surface may not be stored in a volatile buffer on all
   * platforms, and raw access to the surface (using RawAccessRef()) may be much
   * more expensive than in the InitForDecoder() case.
   */
  nsresult InitWithDrawable(gfxDrawable* aDrawable,
                            const nsIntSize& aSize,
                            const SurfaceFormat aFormat,
                            Filter aFilter,
                            uint32_t aImageFlags);

  DrawableFrameRef DrawableRef();
  RawAccessFrameRef RawAccessRef();

  /**
   * Make this imgFrame permanently available for raw access.
   *
   * This is irrevocable, and should be avoided whenever possible, since it
   * prevents this imgFrame from being optimized and makes it impossible for its
   * volatile buffer to be freed.
   *
   * It is an error to call this without already holding a RawAccessFrameRef to
   * this imgFrame.
   */
  void SetRawAccessOnly();

  bool Draw(gfxContext* aContext, const ImageRegion& aRegion,
            Filter aFilter, uint32_t aImageFlags);

  nsresult ImageUpdated(const nsIntRect& aUpdateRect);

  /**
   * Mark this imgFrame as completely decoded, and set final options.
   *
   * You must always call either Finish() or Abort() before releasing the last
   * RawAccessFrameRef pointing to an imgFrame.
   *
   * @param aFrameOpacity    Whether this imgFrame is opaque.
   * @param aDisposalMethod  For animation frames, how this imgFrame is cleared
   *                         from the compositing frame before the next frame is
   *                         displayed.
   * @param aRawTimeout      For animation frames, the timeout in milliseconds
   *                         before the next frame is displayed. This timeout is
   *                         not necessarily the timeout that will actually be
   *                         used; see FrameAnimator::GetTimeoutForFrame.
   * @param aBlendMethod     For animation frames, a blending method to be used
   *                         when compositing this frame.
   */
  void Finish(Opacity aFrameOpacity = Opacity::SOME_TRANSPARENCY,
              DisposalMethod aDisposalMethod = DisposalMethod::KEEP,
              int32_t aRawTimeout = 0,
              BlendMethod aBlendMethod = BlendMethod::OVER);

  /**
   * Mark this imgFrame as aborted. This informs the imgFrame that if it isn't
   * completely decoded now, it never will be.
   *
   * You must always call either Finish() or Abort() before releasing the last
   * RawAccessFrameRef pointing to an imgFrame.
   */
  void Abort();

  /**
   * Returns true if this imgFrame has been aborted.
   */
  bool IsAborted() const;

  /**
   * Returns true if this imgFrame is completely decoded.
   */
  bool IsFinished() const;

  /**
   * Blocks until this imgFrame is either completely decoded, or is marked as
   * aborted.
   *
   * Note that calling this on the main thread _blocks the main thread_. Be very
   * careful in your use of this method to avoid excessive main thread jank or
   * deadlock.
   */
  void WaitUntilFinished() const;

  /**
   * Returns the number of bytes per pixel this imgFrame requires.  This is a
   * worst-case value that does not take into account the effects of format
   * changes caused by Optimize(), since an imgFrame is not optimized throughout
   * its lifetime.
   */
  uint32_t GetBytesPerPixel() const { return GetIsPaletted() ? 1 : 4; }

  IntSize GetImageSize() const { return mImageSize; }
  nsIntRect GetRect() const;
  IntSize GetSize() const { return mSize; }
  bool NeedsPadding() const { return mOffset != nsIntPoint(0, 0); }
  void GetImageData(uint8_t** aData, uint32_t* length) const;
  uint8_t* GetImageData() const;

  bool GetIsPaletted() const;
  void GetPaletteData(uint32_t** aPalette, uint32_t* length) const;
  uint32_t* GetPaletteData() const;
  uint8_t GetPaletteDepth() const { return mPaletteDepth; }

  /**
   * Get the SurfaceFormat for this imgFrame.
   *
   * This should only be used for assertions.
   */
  SurfaceFormat GetFormat() const;

  AnimationData GetAnimationData() const;
  ScalingData GetScalingData() const;

  bool GetCompositingFailed() const;
  void SetCompositingFailed(bool val);

  void SetOptimizable();

  Color SinglePixelColor() const;
  bool IsSinglePixel() const;

  already_AddRefed<SourceSurface> GetSurface();
  already_AddRefed<DrawTarget> GetDrawTarget();

  void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf, size_t& aHeapSizeOut,
                              size_t& aNonHeapSizeOut) const;

private: // methods

  ~imgFrame();

  nsresult LockImageData();
  nsresult UnlockImageData();
  nsresult Optimize();

  void AssertImageDataLocked() const;

  bool AreAllPixelsWritten() const;
  nsresult ImageUpdatedInternal(const nsIntRect& aUpdateRect);
  void GetImageDataInternal(uint8_t** aData, uint32_t* length) const;
  uint32_t GetImageBytesPerRow() const;
  uint32_t GetImageDataLength() const;
  int32_t GetStride() const;
  already_AddRefed<SourceSurface> GetSurfaceInternal();

  uint32_t PaletteDataLength() const
  {
    return mPaletteDepth ? (size_t(1) << mPaletteDepth) * sizeof(uint32_t)
                         : 0;
  }

  struct SurfaceWithFormat {
    RefPtr<gfxDrawable> mDrawable;
    SurfaceFormat mFormat;
    SurfaceWithFormat() { }
    SurfaceWithFormat(gfxDrawable* aDrawable, SurfaceFormat aFormat)
      : mDrawable(aDrawable), mFormat(aFormat)
    { }
    bool IsValid() { return !!mDrawable; }
  };

  SurfaceWithFormat SurfaceForDrawing(bool               aDoPadding,
                                      bool               aDoPartialDecode,
                                      bool               aDoTile,
                                      gfxContext*        aContext,
                                      const nsIntMargin& aPadding,
                                      gfxRect&           aImageRect,
                                      ImageRegion&       aRegion,
                                      SourceSurface*     aSurface);

private: // data
  friend class DrawableFrameRef;
  friend class RawAccessFrameRef;
  friend class UnlockImageDataRunnable;

  //////////////////////////////////////////////////////////////////////////////
  // Thread-safe mutable data, protected by mMonitor.
  //////////////////////////////////////////////////////////////////////////////

  mutable Monitor mMonitor;

  RefPtr<DataSourceSurface> mImageSurface;
  RefPtr<SourceSurface> mOptSurface;

  RefPtr<VolatileBuffer> mVBuf;
  VolatileBufferPtr<uint8_t> mVBufPtr;

  nsIntRect mDecoded;

  //! Number of RawAccessFrameRefs currently alive for this imgFrame.
  int32_t mLockCount;

  //! Raw timeout for this frame. (See FrameAnimator::GetTimeoutForFrame.)
  int32_t mTimeout; // -1 means display forever.

  DisposalMethod mDisposalMethod;
  BlendMethod    mBlendMethod;
  SurfaceFormat  mFormat;

  bool mHasNoAlpha;
  bool mAborted;
  bool mFinished;
  bool mOptimizable;


  //////////////////////////////////////////////////////////////////////////////
  // Effectively const data, only mutated in the Init methods.
  //////////////////////////////////////////////////////////////////////////////

  IntSize      mImageSize;
  IntSize      mSize;
  nsIntPoint   mOffset;

  // The palette and image data for images that are paletted, since Cairo
  // doesn't support these images.
  // The paletted data comes first, then the image data itself.
  // Total length is PaletteDataLength() + GetImageDataLength().
  uint8_t*     mPalettedImageData;
  uint8_t      mPaletteDepth;

  bool mNonPremult;


  //////////////////////////////////////////////////////////////////////////////
  // Main-thread-only mutable data.
  //////////////////////////////////////////////////////////////////////////////

  // Note that the data stored in gfx::Color is *non-alpha-premultiplied*.
  Color        mSinglePixelColor;

  bool mSinglePixel;
  bool mCompositingFailed;
};

/**
 * A reference to an imgFrame that holds the imgFrame's surface in memory,
 * allowing drawing. If you have a DrawableFrameRef |ref| and |if (ref)| returns
 * true, then calls to Draw() and GetSurface() are guaranteed to succeed.
 */
class DrawableFrameRef final
{
public:
  DrawableFrameRef() { }

  explicit DrawableFrameRef(imgFrame* aFrame)
    : mFrame(aFrame)
    , mRef(aFrame->mVBuf)
  {
    if (mRef.WasBufferPurged()) {
      mFrame = nullptr;
      mRef = nullptr;
    }
  }

  DrawableFrameRef(DrawableFrameRef&& aOther)
    : mFrame(aOther.mFrame.forget())
    , mRef(Move(aOther.mRef))
  { }

  DrawableFrameRef& operator=(DrawableFrameRef&& aOther)
  {
    MOZ_ASSERT(this != &aOther, "Self-moves are prohibited");
    mFrame = aOther.mFrame.forget();
    mRef = Move(aOther.mRef);
    return *this;
  }

  explicit operator bool() const { return bool(mFrame); }

  imgFrame* operator->()
  {
    MOZ_ASSERT(mFrame);
    return mFrame;
  }

  const imgFrame* operator->() const
  {
    MOZ_ASSERT(mFrame);
    return mFrame;
  }

  imgFrame* get() { return mFrame; }
  const imgFrame* get() const { return mFrame; }

  void reset()
  {
    mFrame = nullptr;
    mRef = nullptr;
  }

private:
  DrawableFrameRef(const DrawableFrameRef& aOther) = delete;

  RefPtr<imgFrame> mFrame;
  VolatileBufferPtr<uint8_t> mRef;
};

/**
 * A reference to an imgFrame that holds the imgFrame's surface in memory in a
 * format appropriate for access as raw data. If you have a RawAccessFrameRef
 * |ref| and |if (ref)| is true, then calls to GetImageData(), GetPaletteData(),
 * and GetDrawTarget() are guaranteed to succeed. This guarantee is stronger
 * than DrawableFrameRef, so everything that a valid DrawableFrameRef guarantees
 * is also guaranteed by a valid RawAccessFrameRef.
 *
 * This may be considerably more expensive than is necessary just for drawing,
 * so only use this when you need to read or write the raw underlying image data
 * that the imgFrame holds.
 *
 * Once all an imgFrame's RawAccessFrameRefs go out of scope, new
 * RawAccessFrameRefs cannot be created.
 */
class RawAccessFrameRef final
{
public:
  RawAccessFrameRef() { }

  explicit RawAccessFrameRef(imgFrame* aFrame)
    : mFrame(aFrame)
  {
    MOZ_ASSERT(mFrame, "Need a frame");

    if (NS_FAILED(mFrame->LockImageData())) {
      mFrame->UnlockImageData();
      mFrame = nullptr;
    }
  }

  RawAccessFrameRef(RawAccessFrameRef&& aOther)
    : mFrame(aOther.mFrame.forget())
  { }

  ~RawAccessFrameRef()
  {
    if (mFrame) {
      mFrame->UnlockImageData();
    }
  }

  RawAccessFrameRef& operator=(RawAccessFrameRef&& aOther)
  {
    MOZ_ASSERT(this != &aOther, "Self-moves are prohibited");

    if (mFrame) {
      mFrame->UnlockImageData();
    }

    mFrame = aOther.mFrame.forget();

    return *this;
  }

  explicit operator bool() const { return bool(mFrame); }

  imgFrame* operator->()
  {
    MOZ_ASSERT(mFrame);
    return mFrame.get();
  }

  const imgFrame* operator->() const
  {
    MOZ_ASSERT(mFrame);
    return mFrame;
  }

  imgFrame* get() { return mFrame; }
  const imgFrame* get() const { return mFrame; }

  void reset()
  {
    if (mFrame) {
      mFrame->UnlockImageData();
    }
    mFrame = nullptr;
  }

private:
  RawAccessFrameRef(const RawAccessFrameRef& aOther) = delete;

  RefPtr<imgFrame> mFrame;
};

} // namespace image
} // namespace mozilla

#endif // mozilla_image_imgFrame_h