/* -*- 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/. */ /** @file * This file declares the RasterImage class, which * handles static and animated rasterized images. * * @author Stuart Parmenter * @author Chris Saari * @author Arron Mogge * @author Andrew Smith */ #ifndef mozilla_image_RasterImage_h #define mozilla_image_RasterImage_h #include "Image.h" #include "nsCOMPtr.h" #include "imgIContainer.h" #include "nsIProperties.h" #include "nsTArray.h" #include "imgFrame.h" #include "LookupResult.h" #include "nsThreadUtils.h" #include "DecodePool.h" #include "DecoderFactory.h" #include "Orientation.h" #include "nsIObserver.h" #include "mozilla/Attributes.h" #include "mozilla/Maybe.h" #include "mozilla/MemoryReporting.h" #include "mozilla/Pair.h" #include "mozilla/TimeStamp.h" #include "mozilla/WeakPtr.h" #include "mozilla/UniquePtr.h" #ifdef DEBUG #include "imgIContainerDebug.h" #endif class nsIInputStream; class nsIRequest; #define NS_RASTERIMAGE_CID \ { /* 376ff2c1-9bf6-418a-b143-3340c00112f7 */ \ 0x376ff2c1, \ 0x9bf6, \ 0x418a, \ {0xb1, 0x43, 0x33, 0x40, 0xc0, 0x01, 0x12, 0xf7} \ } /** * Handles static and animated image containers. * * * @par A Quick Walk Through * The decoder initializes this class and calls AppendFrame() to add a frame. * Once RasterImage detects more than one frame, it starts the animation * with StartAnimation(). Note that the invalidation events for RasterImage are * generated automatically using nsRefreshDriver. * * @par * StartAnimation() initializes the animation helper object and sets the time * the first frame was displayed to the current clock time. * * @par * When the refresh driver corresponding to the imgIContainer that this image is * a part of notifies the RasterImage that it's time to invalidate, * RequestRefresh() is called with a given TimeStamp to advance to. As long as * the timeout of the given frame (the frame's "delay") plus the time that frame * was first displayed is less than or equal to the TimeStamp given, * RequestRefresh() calls AdvanceFrame(). * * @par * AdvanceFrame() is responsible for advancing a single frame of the animation. * It can return true, meaning that the frame advanced, or false, meaning that * the frame failed to advance (usually because the next frame hasn't been * decoded yet). It is also responsible for performing the final animation stop * procedure if the final frame of a non-looping animation is reached. * * @par * Each frame can have a different method of removing itself. These are * listed as imgIContainer::cDispose... constants. Notify() calls * DoComposite() to handle any special frame destruction. * * @par * The basic path through DoComposite() is: * 1) Calculate Area that needs updating, which is at least the area of * aNextFrame. * 2) Dispose of previous frame. * 3) Draw new image onto compositingFrame. * See comments in DoComposite() for more information and optimizations. * * @par * The rest of the RasterImage specific functions are used by DoComposite to * destroy the old frame and build the new one. * * @note *
  • "Mask", "Alpha", and "Alpha Level" are interchangeable phrases in * respects to RasterImage. * * @par *
  • GIFs never have more than a 1 bit alpha. *
  • APNGs may have a full alpha channel. * * @par *
  • Background color specified in GIF is ignored by web browsers. * * @par *
  • If Frame 3 wants to dispose by restoring previous, what it wants is to * restore the composition up to and including Frame 2, as well as Frame 2s * disposal. So, in the middle of DoComposite when composing Frame 3, right * after destroying Frame 2's area, we copy compositingFrame to * prevCompositingFrame. When DoComposite gets called to do Frame 4, we * copy prevCompositingFrame back, and then draw Frame 4 on top. * * @par * The mAnim structure has members only needed for animated images, so * it's not allocated until the second frame is added. */ namespace mozilla { namespace layers { class ImageContainer; class Image; } // namespace layers namespace image { class Decoder; class FrameAnimator; class ImageMetadata; class SourceBuffer; class RasterImage final : public ImageResource , public nsIProperties , public SupportsWeakPtr #ifdef DEBUG , public imgIContainerDebug #endif { // (no public constructor - use ImageFactory) virtual ~RasterImage(); public: MOZ_DECLARE_WEAKREFERENCE_TYPENAME(RasterImage) NS_DECL_THREADSAFE_ISUPPORTS NS_DECL_NSIPROPERTIES NS_DECL_IMGICONTAINER #ifdef DEBUG NS_DECL_IMGICONTAINERDEBUG #endif virtual nsresult StartAnimation() override; virtual nsresult StopAnimation() override; // Methods inherited from Image virtual void OnSurfaceDiscarded() override; /* The total number of frames in this image. */ uint32_t GetNumFrames() const { return mFrameCount; } virtual size_t SizeOfSourceWithComputedFallback(MallocSizeOf aMallocSizeOf) const override; virtual void CollectSizeOfSurfaces(nsTArray& aCounters, MallocSizeOf aMallocSizeOf) const override; /* Triggers discarding. */ void Discard(); ////////////////////////////////////////////////////////////////////////////// // Decoder callbacks. ////////////////////////////////////////////////////////////////////////////// void OnAddedFrame(uint32_t aNewFrameCount, const nsIntRect& aNewRefreshArea); /** * Sends the provided progress notifications to ProgressTracker. * * Main-thread only. * * @param aProgress The progress notifications to send. * @param aInvalidRect An invalidation rect to send. * @param aFlags The surface flags used by the decoder that generated * these notifications, or DefaultSurfaceFlags() if the * notifications don't come from a decoder. */ void NotifyProgress(Progress aProgress, const nsIntRect& aInvalidRect = nsIntRect(), SurfaceFlags aSurfaceFlags = DefaultSurfaceFlags()); /** * Records telemetry and does final teardown of the provided decoder. * * Main-thread only. */ void FinalizeDecoder(Decoder* aDecoder); // Helper method for FinalizeDecoder. void ReportDecoderError(Decoder* aDecoder); ////////////////////////////////////////////////////////////////////////////// // Network callbacks. ////////////////////////////////////////////////////////////////////////////// virtual nsresult OnImageDataAvailable(nsIRequest* aRequest, nsISupports* aContext, nsIInputStream* aInStr, uint64_t aSourceOffset, uint32_t aCount) override; virtual nsresult OnImageDataComplete(nsIRequest* aRequest, nsISupports* aContext, nsresult aStatus, bool aLastPart) override; void NotifyForLoadEvent(Progress aProgress); /** * A hint of the number of bytes of source data that the image contains. If * called early on, this can help reduce copying and reallocations by * appropriately preallocating the source data buffer. * * We take this approach rather than having the source data management code do * something more complicated (like chunklisting) because HTTP is by far the * dominant source of images, and the Content-Length header is quite reliable. * Thus, pre-allocation simplifies code and reduces the total number of * allocations. */ nsresult SetSourceSizeHint(uint32_t aSizeHint); /* Provide a hint for the requested dimension of the resulting image. */ void SetRequestedSampleSize(int requestedSampleSize) { mRequestedSampleSize = requestedSampleSize; } nsCString GetURIString() { nsCString spec; if (GetURI()) { GetURI()->GetSpec(spec); } return spec; } private: nsresult Init(const char* aMimeType, uint32_t aFlags); DrawResult DrawInternal(DrawableFrameRef&& aFrameRef, gfxContext* aContext, const nsIntSize& aSize, const ImageRegion& aRegion, GraphicsFilter aFilter, uint32_t aFlags); already_AddRefed CopyFrame(uint32_t aWhichFrame, uint32_t aFlags); Pair> GetFrameInternal(const gfx::IntSize& aSize, uint32_t aWhichFrame, uint32_t aFlags); LookupResult LookupFrameInternal(uint32_t aFrameNum, const gfx::IntSize& aSize, uint32_t aFlags); DrawableFrameRef LookupFrame(uint32_t aFrameNum, const nsIntSize& aSize, uint32_t aFlags); uint32_t GetCurrentFrameIndex() const; uint32_t GetRequestedFrameIndex(uint32_t aWhichFrame) const; nsIntRect GetFirstFrameRect(); Pair> GetCurrentImage(layers::ImageContainer* aContainer, uint32_t aFlags); void UpdateImageContainer(); // We would like to just check if we have a zero lock count, but we can't do // that for animated images because in EnsureAnimExists we lock the image and // never unlock so that animated images always have their lock count >= 1. In // that case we use our animation consumers count as a proxy for lock count. bool IsUnlocked() { return (mLockCount == 0 || (mAnim && mAnimationConsumers == 0)); } ////////////////////////////////////////////////////////////////////////////// // Decoding. ////////////////////////////////////////////////////////////////////////////// /** * Creates and runs a decoder, either synchronously or asynchronously * according to @aFlags. Decodes at the provided target size @aSize, using * decode flags @aFlags. * * It's an error to call Decode() before this image's intrinsic size is * available. A metadata decode must successfully complete first. */ NS_IMETHOD Decode(const gfx::IntSize& aSize, uint32_t aFlags); /** * Creates and runs a metadata decoder, either synchronously or * asynchronously according to @aFlags. */ NS_IMETHOD DecodeMetadata(uint32_t aFlags); /** * Sets the size, inherent orientation, animation metadata, and other * information about the image gathered during decoding. * * This function may be called multiple times, but will throw an error if * subsequent calls do not match the first. * * @param aMetadata The metadata to set on this image. * @param aFromMetadataDecode True if this metadata came from a metadata * decode; false if it came from a full decode. * @return |true| unless a catastrophic failure was discovered. If |false| is * returned, it indicates that the image is corrupt in a way that requires all * surfaces to be discarded to recover. */ bool SetMetadata(const ImageMetadata& aMetadata, bool aFromMetadataDecode); /** * In catastrophic circumstances like a GPU driver crash, the contents of our * frames may become invalid. If the information we gathered during the * metadata decode proves to be wrong due to image corruption, the frames we * have may violate this class's invariants. Either way, we need to * immediately discard the invalid frames and redecode so that callers don't * perceive that we've entered an invalid state. * * RecoverFromInvalidFrames discards all existing frames and redecodes using * the provided @aSize and @aFlags. */ void RecoverFromInvalidFrames(const nsIntSize& aSize, uint32_t aFlags); private: // data nsIntSize mSize; Orientation mOrientation; /// If this has a value, we're waiting for SetSize() to send the load event. Maybe mLoadProgress; nsCOMPtr mProperties; /// If this image is animated, a FrameAnimator which manages its animation. UniquePtr mAnim; // Image locking. uint32_t mLockCount; // The type of decoder this image needs. Computed from the MIME type in Init(). DecoderType mDecoderType; // How many times we've decoded this image. // This is currently only used for statistics int32_t mDecodeCount; // A hint for image decoder that directly scale the image to smaller buffer int mRequestedSampleSize; // A weak pointer to our ImageContainer, which stays alive only as long as // the layer system needs it. WeakPtr mImageContainer; // If mImageContainer is non-null, this contains the DrawResult we obtained // the last time we updated it. DrawResult mLastImageContainerDrawResult; #ifdef DEBUG uint32_t mFramesNotified; #endif // The source data for this image. nsRefPtr mSourceBuffer; // The number of frames this image has. uint32_t mFrameCount; // Boolean flags (clustered together to conserve space): bool mHasSize:1; // Has SetSize() been called? bool mTransient:1; // Is the image short-lived? bool mSyncLoad:1; // Are we loading synchronously? bool mDiscardable:1; // Is container discardable? bool mHasSourceData:1; // Do we have source data? bool mHasBeenDecoded:1; // Decoded at least once? // Whether we're waiting to start animation. If we get a StartAnimation() call // but we don't yet have more than one frame, mPendingAnimation is set so that // we know to start animation later if/when we have more frames. bool mPendingAnimation:1; // Whether the animation can stop, due to running out // of frames, or no more owning request bool mAnimationFinished:1; // Whether, once we are done doing a metadata decode, we should immediately // kick off a full decode. bool mWantFullDecode:1; TimeStamp mDrawStartTime; ////////////////////////////////////////////////////////////////////////////// // Scaling. ////////////////////////////////////////////////////////////////////////////// // Determines whether we can downscale during decode with the given // parameters. bool CanDownscaleDuringDecode(const nsIntSize& aSize, uint32_t aFlags); // Error handling. void DoError(); class HandleErrorWorker : public nsRunnable { public: /** * Called from decoder threads when DoError() is called, since errors can't * be handled safely off-main-thread. Dispatches an event which reinvokes * DoError on the main thread if there isn't one already pending. */ static void DispatchIfNeeded(RasterImage* aImage); NS_IMETHOD Run(); private: explicit HandleErrorWorker(RasterImage* aImage); nsRefPtr mImage; }; // Helpers bool CanDiscard(); protected: explicit RasterImage(ImageURL* aURI = nullptr); bool ShouldAnimate() override; friend class ImageFactory; }; inline NS_IMETHODIMP RasterImage::GetAnimationMode(uint16_t* aAnimationMode) { return GetAnimationModeInternal(aAnimationMode); } } // namespace image } // namespace mozilla #endif /* mozilla_image_RasterImage_h */