/* -*- 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_imagelib_RasterImage_h_ #define mozilla_imagelib_RasterImage_h_ #include "Image.h" #include "FrameBlender.h" #include "nsCOMPtr.h" #include "imgIContainer.h" #include "nsIProperties.h" #include "nsTArray.h" #include "imgFrame.h" #include "nsThreadUtils.h" #include "DiscardTracker.h" #include "Orientation.h" #include "nsIObserver.h" #include "mozilla/MemoryReporting.h" #include "mozilla/TimeStamp.h" #include "mozilla/StaticPtr.h" #include "mozilla/WeakPtr.h" #include "mozilla/Mutex.h" #ifdef DEBUG #include "imgIContainerDebug.h" #endif class nsIInputStream; class nsIThreadPool; 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. */ class ScaleRequest; namespace mozilla { namespace layers { class LayerManager; class ImageContainer; class Image; } namespace image { class Decoder; class FrameAnimator; class RasterImage : public ImageResource , public nsIProperties , public SupportsWeakPtr #ifdef DEBUG , public imgIContainerDebug #endif { public: NS_DECL_THREADSAFE_ISUPPORTS NS_DECL_NSIPROPERTIES NS_DECL_IMGICONTAINER #ifdef DEBUG NS_DECL_IMGICONTAINERDEBUG #endif // (no public constructor - use ImageFactory) virtual ~RasterImage(); virtual nsresult StartAnimation(); virtual nsresult StopAnimation(); // Methods inherited from Image nsresult Init(const char* aMimeType, uint32_t aFlags); virtual nsIntRect FrameRect(uint32_t aWhichFrame) MOZ_OVERRIDE; // Raster-specific methods static NS_METHOD WriteToRasterImage(nsIInputStream* aIn, void* aClosure, const char* aFromRawSegment, uint32_t aToOffset, uint32_t aCount, uint32_t* aWriteCount); /* The index of the current frame that would be drawn if the image was to be * drawn now. */ uint32_t GetCurrentFrameIndex(); /* The total number of frames in this image. */ uint32_t GetNumFrames() const; virtual size_t HeapSizeOfSourceWithComputedFallback(mozilla::MallocSizeOf aMallocSizeOf) const; virtual size_t HeapSizeOfDecodedWithComputedFallback(mozilla::MallocSizeOf aMallocSizeOf) const; virtual size_t NonHeapSizeOfDecoded() const; virtual size_t OutOfProcessSizeOfDecoded() const; /* Triggers discarding. */ void Discard(bool force = false); void ForceDiscard() { Discard(/* force = */ true); } /* Callbacks for decoders */ nsresult SetFrameAsNonPremult(uint32_t aFrameNum, bool aIsNonPremult); /** Sets the size and inherent orientation of the container. This should only * be called by the decoder. This function may be called multiple times, but * will throw an error if subsequent calls do not match the first. */ nsresult SetSize(int32_t aWidth, int32_t aHeight, Orientation aOrientation); /** * Ensures that a given frame number exists with the given parameters, and * returns pointers to the data storage for that frame. * It is not possible to create sparse frame arrays; you can only append * frames to the current frame array. */ nsresult EnsureFrame(uint32_t aFramenum, int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight, gfxImageFormat aFormat, uint8_t aPaletteDepth, uint8_t** imageData, uint32_t* imageLength, uint32_t** paletteData, uint32_t* paletteLength, imgFrame** aFrame); /** * A shorthand for EnsureFrame, above, with aPaletteDepth = 0 and paletteData * and paletteLength set to null. */ nsresult EnsureFrame(uint32_t aFramenum, int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight, gfxImageFormat aFormat, uint8_t** imageData, uint32_t* imageLength, imgFrame** aFrame); /* notification that the entire image has been decoded */ nsresult DecodingComplete(); /** * Number of times to loop the image. * @note -1 means forever. */ void SetLoopCount(int32_t aLoopCount); /* Add compressed source data to the imgContainer. * * The decoder will use this data, either immediately or at draw time, to * decode the image. * * XXX This method's only caller (WriteToContainer) ignores the return * value. Should this just return void? */ nsresult AddSourceData(const char *aBuffer, uint32_t aCount); virtual nsresult OnImageDataAvailable(nsIRequest* aRequest, nsISupports* aContext, nsIInputStream* aInStr, uint64_t aSourceOffset, uint32_t aCount) MOZ_OVERRIDE; virtual nsresult OnImageDataComplete(nsIRequest* aRequest, nsISupports* aContext, nsresult aStatus, bool aLastPart) MOZ_OVERRIDE; virtual nsresult OnNewSourceData() MOZ_OVERRIDE; static already_AddRefed GetEventTarget() { return DecodePool::Singleton()->GetEventTarget(); } /** * 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 sizeHint); /* Provide a hint for the requested resolution of the resulting image. */ void SetRequestedResolution(const nsIntSize requestedResolution) { mRequestedResolution = requestedResolution; } nsIntSize GetRequestedResolution() { return mRequestedResolution; } nsCString GetURIString() { nsCString spec; if (GetURI()) { GetURI()->GetSpec(spec); } return spec; } // Called from module startup. Sets up RasterImage to be used. static void Initialize(); enum ScaleStatus { SCALE_INVALID, SCALE_PENDING, SCALE_DONE }; // Call this with a new ScaleRequest to mark this RasterImage's scale result // as waiting for the results of this request. You call to ScalingDone before // request is destroyed! void ScalingStart(ScaleRequest* request); // Call this with a finished ScaleRequest to set this RasterImage's scale // result. Give it a ScaleStatus of SCALE_DONE if everything succeeded, and // SCALE_INVALID otherwise. void ScalingDone(ScaleRequest* request, ScaleStatus status); // Decoder shutdown enum eShutdownIntent { eShutdownIntent_Done = 0, eShutdownIntent_NotNeeded = 1, eShutdownIntent_Error = 2, eShutdownIntent_AllCount = 3 }; private: already_AddRefed CurrentStatusTracker() { nsRefPtr statusTracker; statusTracker = mDecodeRequest ? mDecodeRequest->mStatusTracker : mStatusTracker; MOZ_ASSERT(statusTracker); return statusTracker.forget(); } nsresult OnImageDataCompleteCore(nsIRequest* aRequest, nsISupports*, nsresult aStatus); /** * Each RasterImage has a pointer to one or zero heap-allocated * DecodeRequests. */ struct DecodeRequest { DecodeRequest(RasterImage* aImage) : mImage(aImage) , mBytesToDecode(0) , mRequestStatus(REQUEST_INACTIVE) , mChunkCount(0) , mAllocatedNewFrame(false) { MOZ_ASSERT(aImage, "aImage cannot be null"); MOZ_ASSERT(aImage->mStatusTracker, "aImage should have an imgStatusTracker"); mStatusTracker = aImage->mStatusTracker->CloneForRecording(); } NS_INLINE_DECL_THREADSAFE_REFCOUNTING(DecodeRequest) // The status tracker that is associated with a given decode request, to // ensure their lifetimes are linked. nsRefPtr mStatusTracker; RasterImage* mImage; uint32_t mBytesToDecode; enum DecodeRequestStatus { REQUEST_INACTIVE, REQUEST_PENDING, REQUEST_ACTIVE, REQUEST_WORK_DONE, REQUEST_STOPPED } mRequestStatus; /* Keeps track of how much time we've burned decoding this particular decode * request. */ TimeDuration mDecodeTime; /* The number of chunks it took to decode this image. */ int32_t mChunkCount; /* True if a new frame has been allocated, but DecodeSomeData hasn't yet * been called to flush data to it */ bool mAllocatedNewFrame; }; /* * DecodePool is a singleton class we use when decoding large images. * * When we wish to decode an image larger than * image.mem.max_bytes_for_sync_decode, we call DecodePool::RequestDecode() * for the image. This adds the image to a queue of pending requests and posts * the DecodePool singleton to the event queue, if it's not already pending * there. * * When the DecodePool is run from the event queue, it decodes the image (and * all others it's managing) in chunks, periodically yielding control back to * the event loop. */ class DecodePool : public nsIObserver { public: NS_DECL_THREADSAFE_ISUPPORTS NS_DECL_NSIOBSERVER static DecodePool* Singleton(); /** * Ask the DecodePool to asynchronously decode this image. */ void RequestDecode(RasterImage* aImg); /** * Decode aImg for a short amount of time, and post the remainder to the * queue. */ void DecodeABitOf(RasterImage* aImg); /** * Ask the DecodePool to stop decoding this image. Internally, we also * call this function when we finish decoding an image. * * Since the DecodePool keeps raw pointers to RasterImages, make sure you * call this before a RasterImage is destroyed! */ static void StopDecoding(RasterImage* aImg); /** * Synchronously decode the beginning of the image until we run out of * bytes or we get the image's size. Note that this done on a best-effort * basis; if the size is burried too deep in the image, we'll give up. * * @return NS_ERROR if an error is encountered, and NS_OK otherwise. (Note * that we return NS_OK even when the size was not found.) */ nsresult DecodeUntilSizeAvailable(RasterImage* aImg); /** * Returns an event target interface to the thread pool; primarily for * OnDataAvailable delivery off main thread. * * @return An nsIEventTarget interface to mThreadPool. */ already_AddRefed GetEventTarget(); virtual ~DecodePool(); private: /* statics */ static StaticRefPtr sSingleton; private: /* methods */ DecodePool(); enum DecodeType { DECODE_TYPE_UNTIL_TIME, DECODE_TYPE_UNTIL_SIZE, DECODE_TYPE_UNTIL_DONE_BYTES }; /* Decode some chunks of the given image. If aDecodeType is UNTIL_SIZE, * decode until we have the image's size, then stop. If bytesToDecode is * non-0, at most bytesToDecode bytes will be decoded. if aDecodeType is * UNTIL_DONE_BYTES, decode until all bytesToDecode bytes are decoded. */ nsresult DecodeSomeOfImage(RasterImage* aImg, DecodeType aDecodeType = DECODE_TYPE_UNTIL_TIME, uint32_t bytesToDecode = 0); /* A decode job dispatched to a thread pool by DecodePool. */ class DecodeJob : public nsRunnable { public: DecodeJob(DecodeRequest* aRequest, RasterImage* aImg) : mRequest(aRequest) , mImage(aImg) {} NS_IMETHOD Run(); private: nsRefPtr mRequest; nsRefPtr mImage; }; private: /* members */ // mThreadPoolMutex protects mThreadPool. For all RasterImages R, // R::mDecodingMutex must be acquired before mThreadPoolMutex if both are // acquired; the other order may cause deadlock. mozilla::Mutex mThreadPoolMutex; nsCOMPtr mThreadPool; }; class DecodeDoneWorker : public nsRunnable { public: /** * Called by the DecodePool with an image when it's done some significant * portion of decoding that needs to be notified about. * * Ensures the decode state accumulated by the decoding process gets * applied to the image. */ static void NotifyFinishedSomeDecoding(RasterImage* image, DecodeRequest* request); NS_IMETHOD Run(); private: /* methods */ DecodeDoneWorker(RasterImage* image, DecodeRequest* request); private: /* members */ nsRefPtr mImage; nsRefPtr mRequest; }; class FrameNeededWorker : public nsRunnable { public: /** * Called by the DecodeJob with an image when it's been told by the * decoder that it needs a new frame to be allocated on the main thread. * * Dispatches an event to do so, which will further dispatch a * DecodeRequest event to continue decoding. */ static void GetNewFrame(RasterImage* image); NS_IMETHOD Run(); private: /* methods */ FrameNeededWorker(RasterImage* image); private: /* members */ nsRefPtr mImage; }; nsresult FinishedSomeDecoding(eShutdownIntent intent = eShutdownIntent_Done, DecodeRequest* request = nullptr); void DrawWithPreDownscaleIfNeeded(imgFrame *aFrame, gfxContext *aContext, GraphicsFilter aFilter, const gfxMatrix &aUserSpaceToImageSpace, const gfxRect &aFill, const nsIntRect &aSubimage, uint32_t aFlags); nsresult CopyFrame(uint32_t aWhichFrame, uint32_t aFlags, gfxImageSurface **_retval); /** * Deletes and nulls out the frame in mFrames[framenum]. * * Does not change the size of mFrames. * * @param framenum The index of the frame to be deleted. * Must lie in [0, mFrames.Length() ) */ void DeleteImgFrame(uint32_t framenum); imgFrame* GetImgFrameNoDecode(uint32_t framenum); imgFrame* GetImgFrame(uint32_t framenum); imgFrame* GetDrawableImgFrame(uint32_t framenum); imgFrame* GetCurrentImgFrame(); uint32_t GetCurrentImgFrameIndex() const; size_t SizeOfDecodedWithComputedFallbackIfHeap(gfxMemoryLocation aLocation, mozilla::MallocSizeOf aMallocSizeOf) const; void EnsureAnimExists(); nsresult InternalAddFrameHelper(uint32_t framenum, imgFrame *frame, uint8_t **imageData, uint32_t *imageLength, uint32_t **paletteData, uint32_t *paletteLength, imgFrame** aRetFrame); nsresult InternalAddFrame(uint32_t framenum, int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight, gfxImageFormat aFormat, uint8_t aPaletteDepth, uint8_t **imageData, uint32_t *imageLength, uint32_t **paletteData, uint32_t *paletteLength, imgFrame** aRetFrame); nsresult DoImageDataComplete(); bool ApplyDecodeFlags(uint32_t aNewFlags); already_AddRefed GetCurrentImage(); void UpdateImageContainer(); void SetInUpdateImageContainer(bool aInUpdate) { mInUpdateImageContainer = aInUpdate; } bool IsInUpdateImageContainer() { return mInUpdateImageContainer; } enum RequestDecodeType { ASYNCHRONOUS, SYNCHRONOUS_NOTIFY, SYNCHRONOUS_NOTIFY_AND_SOME_DECODE }; NS_IMETHOD RequestDecodeCore(RequestDecodeType aDecodeType); // 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)); } private: // data nsIntSize mSize; Orientation mOrientation; // Whether our frames were decoded using any special flags. // Some flags (e.g. unpremultiplied data) may not be compatible // with the browser's needs for displaying the image to the user. // As such, we may need to redecode if we're being asked for // a frame with different flags. 0 indicates default flags. // // Valid flag bits are imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA // and imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION. uint32_t mFrameDecodeFlags; //! All the frames of the image FrameBlender mFrameBlender; // The last frame we decoded for multipart images. imgFrame* mMultipartDecodedFrame; nsCOMPtr mProperties; // IMPORTANT: if you use mAnim in a method, call EnsureImageIsDecoded() first to ensure // that the frames actually exist (they may have been discarded to save memory, or // we maybe decoding on draw). FrameAnimator* mAnim; // Discard members uint32_t mLockCount; DiscardTracker::Node mDiscardTrackerNode; // Source data members nsCString mSourceDataMimeType; friend class DiscardTracker; // How many times we've decoded this image. // This is currently only used for statistics int32_t mDecodeCount; // If the image contains multiple resolutions, a hint as to which one should be used nsIntSize mRequestedResolution; // Cached value for GetImageContainer. nsRefPtr mImageContainer; #ifdef DEBUG uint32_t mFramesNotified; #endif // Below are the pieces of data that can be accessed on more than one thread // at once, and hence need to be locked by mDecodingMutex. // BEGIN LOCKED MEMBER VARIABLES mozilla::Mutex mDecodingMutex; FallibleTArray mSourceData; // Decoder and friends nsRefPtr mDecoder; nsRefPtr mDecodeRequest; uint32_t mBytesDecoded; bool mInDecoder; // END LOCKED MEMBER VARIABLES // Boolean flags (clustered together to conserve space): bool mHasSize:1; // Has SetSize() been called? bool mDecodeOnDraw:1; // Decoding on draw? bool mMultipart:1; // Multipart? bool mDiscardable:1; // Is container discardable? bool mHasSourceData:1; // Do we have source data? // Do we have the frames in decoded form? bool mDecoded:1; bool mHasBeenDecoded:1; // Whether the animation can stop, due to running out // of frames, or no more owning request bool mAnimationFinished:1; // Whether we're calling Decoder::Finish() from ShutdownDecoder. bool mFinishing:1; bool mInUpdateImageContainer:1; // Whether, once we are done doing a size decode, we should immediately kick // off a full decode. bool mWantFullDecode:1; // Set when a decode worker detects an error off-main-thread. Once the error // is handled on the main thread, mError is set, but mPendingError is used to // stop decode work immediately. bool mPendingError:1; // Decoding nsresult WantDecodedFrames(); nsresult SyncDecode(); nsresult InitDecoder(bool aDoSizeDecode, bool aIsSynchronous = false); nsresult WriteToDecoder(const char *aBuffer, uint32_t aCount); nsresult DecodeSomeData(uint32_t aMaxBytes); bool IsDecodeFinished(); TimeStamp mDrawStartTime; inline bool CanQualityScale(const gfxSize& scale); inline bool CanScale(GraphicsFilter aFilter, gfxSize aScale, uint32_t aFlags); struct ScaleResult { ScaleResult() : status(SCALE_INVALID) {} gfxSize scale; nsAutoPtr frame; ScaleStatus status; }; ScaleResult mScaleResult; // We hold on to a bare pointer to a ScaleRequest while it's outstanding so // we can mark it as stopped if necessary. The ScaleWorker/DrawWorker duo // will inform us when to let go of this pointer. ScaleRequest* mScaleRequest; // Initializes imgStatusTracker and resets it on RasterImage destruction. nsAutoPtr mStatusTrackerInit; nsresult ShutdownDecoder(eShutdownIntent aIntent); // 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: HandleErrorWorker(RasterImage* aImage); nsRefPtr mImage; }; // Helpers bool CanDiscard(); bool CanForciblyDiscard(); bool DiscardingActive(); bool StoringSourceData() const; protected: RasterImage(imgStatusTracker* aStatusTracker = nullptr, ImageURL* aURI = nullptr); bool ShouldAnimate(); friend class ImageFactory; }; inline NS_IMETHODIMP RasterImage::GetAnimationMode(uint16_t *aAnimationMode) { return GetAnimationModeInternal(aAnimationMode); } // Asynchronous Decode Requestor // // We use this class when someone calls requestDecode() from within a decode // notification. Since requestDecode() involves modifying the decoder's state // (for example, possibly shutting down a header-only decode and starting a // full decode), we don't want to do this from inside a decoder. class imgDecodeRequestor : public nsRunnable { public: imgDecodeRequestor(RasterImage &aContainer) { mContainer = aContainer.asWeakPtr(); } NS_IMETHOD Run() { if (mContainer) mContainer->StartDecoding(); return NS_OK; } private: WeakPtr mContainer; }; } // namespace image } // namespace mozilla #endif /* mozilla_imagelib_RasterImage_h_ */