The Tor Browser: image/src/imgStatusTracker.h@6474c204b198 (annotated)

image/src/imgStatusTracker.h@6474c204b198 (annotated)

image/src/imgStatusTracker.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- 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 imgStatusTracker_h__
 #define imgStatusTracker_h__
 class imgDecoderObserver;
 class imgIContainer;
 class imgStatusNotifyRunnable;
 class imgRequestNotifyRunnable;
 class imgStatusTrackerObserver;
 class nsIRunnable;
 #include "mozilla/RefPtr.h"
 #include "mozilla/WeakPtr.h"
 #include "nsCOMPtr.h"
 #include "nsTObserverArray.h"
 #include "nsThreadUtils.h"
 #include "nsRect.h"
 #include "imgRequestProxy.h"
 namespace mozilla {
 namespace image {
 class Image;
 struct ImageStatusDiff
 {
   ImageStatusDiff()
     : invalidRect()
     , diffState(0)
     , diffImageStatus(0)
     , unblockedOnload(false)
     , unsetDecodeStarted(false)
     , foundError(false)
     , foundIsMultipart(false)
     , foundLastPart(false)
     , gotDecoded(false)
   { }
   static ImageStatusDiff NoChange() { return ImageStatusDiff(); }
   bool IsNoChange() const { return *this == NoChange(); }
   bool operator!=(const ImageStatusDiff& aOther) const { return !(*this == aOther); }
   bool operator==(const ImageStatusDiff& aOther) const {
     return aOther.invalidRect == invalidRect
         && aOther.diffState == diffState
         && aOther.diffImageStatus == diffImageStatus
         && aOther.unblockedOnload == unblockedOnload
         && aOther.unsetDecodeStarted == unsetDecodeStarted
         && aOther.foundError == foundError
         && aOther.foundIsMultipart == foundIsMultipart
         && aOther.foundLastPart == foundLastPart
         && aOther.gotDecoded == gotDecoded;
   }
   void Combine(const ImageStatusDiff& aOther) {
     invalidRect = invalidRect.Union(aOther.invalidRect);
     diffState |= aOther.diffState;
     diffImageStatus |= aOther.diffImageStatus;
     unblockedOnload = unblockedOnload || aOther.unblockedOnload;
     unsetDecodeStarted = unsetDecodeStarted || aOther.unsetDecodeStarted;
     foundError = foundError || aOther.foundError;
     foundIsMultipart = foundIsMultipart || aOther.foundIsMultipart;
     foundLastPart = foundLastPart || aOther.foundLastPart;
     gotDecoded = gotDecoded || aOther.gotDecoded;
   }
   nsIntRect invalidRect;
   uint32_t  diffState;
   uint32_t  diffImageStatus;
   bool      unblockedOnload    : 1;
   bool      unsetDecodeStarted : 1;
   bool      foundError         : 1;
   bool      foundIsMultipart   : 1;
   bool      foundLastPart      : 1;
   bool      gotDecoded         : 1;
 };
 enum {
   stateRequestStarted    = 1u << 0,
   stateHasSize           = 1u << 1,
   stateDecodeStarted     = 1u << 2,
   stateDecodeStopped     = 1u << 3,
   stateFrameStopped      = 1u << 4,
   stateRequestStopped    = 1u << 5,
   stateBlockingOnload    = 1u << 6,
   stateImageIsAnimated   = 1u << 7
 };
 } // namespace image
 } // namespace mozilla
 /*
  * The image status tracker is a class that encapsulates all the loading and
  * decoding status about an Image, and makes it possible to send notifications
  * to imgRequestProxys, both synchronously (i.e., the status now) and
  * asynchronously (the status later).
  *
  * When a new proxy needs to be notified of the current state of an image, call
  * the Notify() method on this class with the relevant proxy as its argument,
  * and the notifications will be replayed to the proxy asynchronously.
  */
 class imgStatusTracker : public mozilla::SupportsWeakPtr<imgStatusTracker>
 {
 public:
   MOZ_DECLARE_REFCOUNTED_TYPENAME(imgStatusTracker)
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(imgStatusTracker)
   // aImage is the image that this status tracker will pass to the
   // imgRequestProxys in SyncNotify() and EmulateRequestFinished(), and must be
   // alive as long as this instance is, because we hold a weak reference to it.
   imgStatusTracker(mozilla::image::Image* aImage);
   virtual ~imgStatusTracker();
   // Image-setter, for imgStatusTrackers created by imgRequest::Init, which
   // are created before their Image is created.  This method should only
   // be called once, and only on an imgStatusTracker that was initialized
   // without an image.
   void SetImage(mozilla::image::Image* aImage);
   // Image resetter, for when mImage is about to go out of scope. mImage is a
   // weak reference, and thus must be set to null when it's object is deleted.
   void ResetImage();
   // Inform this status tracker that it is associated with a multipart image.
   void SetIsMultipart() { mIsMultipart = true; }
   // Schedule an asynchronous "replaying" of all the notifications that would
   // have to happen to put us in the current state.
   // We will also take note of any notifications that happen between the time
   // Notify() is called and when we call SyncNotify on |proxy|, and replay them
   // as well.
   // Should be called on the main thread only, since imgRequestProxy and GetURI
   // are not threadsafe.
   void Notify(imgRequestProxy* proxy);
   // Schedule an asynchronous "replaying" of all the notifications that would
   // have to happen to put us in the state we are in right now.
   // Unlike Notify(), does *not* take into account future notifications.
   // This is only useful if you do not have an imgRequest, e.g., if you are a
   // static request returned from imgIRequest::GetStaticRequest().
   // Should be called on the main thread only, since imgRequestProxy and GetURI
   // are not threadsafe.
   void NotifyCurrentState(imgRequestProxy* proxy);
   // "Replay" all of the notifications that would have to happen to put us in
   // the state we're currently in.
   // Only use this if you're already servicing an asynchronous call (e.g.
   // OnStartRequest).
   // Should be called on the main thread only, since imgRequestProxy and GetURI
   // are not threadsafe.
   void SyncNotify(imgRequestProxy* proxy);
   // Send some notifications that would be necessary to make |proxy| believe
   // the request is finished downloading and decoding.  We only send
   // OnStopRequest and UnblockOnload, and only if necessary.
   void EmulateRequestFinished(imgRequestProxy* proxy, nsresult aStatus);
   // We manage a set of consumers that are using an image and thus concerned
   // with its status. Weak pointers.
   void AddConsumer(imgRequestProxy* aConsumer);
   bool RemoveConsumer(imgRequestProxy* aConsumer, nsresult aStatus);
   size_t ConsumerCount() const {
     MOZ_ASSERT(NS_IsMainThread(), "Use mConsumers on main thread only");
     return mConsumers.Length();
   }
   // This is intentionally non-general because its sole purpose is to support an
   // some obscure network priority logic in imgRequest. That stuff could probably
   // be improved, but it's too scary to mess with at the moment.
   bool FirstConsumerIs(imgRequestProxy* aConsumer);
   void AdoptConsumers(imgStatusTracker* aTracker) {
     MOZ_ASSERT(NS_IsMainThread(), "Use mConsumers on main thread only");
     MOZ_ASSERT(aTracker);
     mConsumers = aTracker->mConsumers;
   }
   // Returns whether we are in the process of loading; that is, whether we have
   // not received OnStopRequest.
   bool IsLoading() const;
   // Get the current image status (as in imgIRequest).
   uint32_t GetImageStatus() const;
   // Following are all the notification methods. You must call the Record
   // variant on this status tracker, then call the Send variant for each proxy
   // you want to notify.
   // Call when the request is being cancelled.
   void RecordCancel();
   // Shorthand for recording all the load notifications: StartRequest,
   // StartContainer, StopRequest.
   void RecordLoaded();
   // Shorthand for recording all the decode notifications: StartDecode,
   // StartFrame, DataAvailable, StopFrame, StopDecode.
   void RecordDecoded();
   /* non-virtual imgDecoderObserver methods */
   // Functions with prefix Send- are main thread only, since they contain calls
   // to imgRequestProxy functions, which are expected on the main thread.
   void RecordStartDecode();
   void SendStartDecode(imgRequestProxy* aProxy);
   void RecordStartContainer(imgIContainer* aContainer);
   void SendStartContainer(imgRequestProxy* aProxy);
   void RecordStartFrame();
   // No SendStartFrame since it's not observed below us.
   void RecordFrameChanged(const nsIntRect* aDirtyRect);
   void SendFrameChanged(imgRequestProxy* aProxy, const nsIntRect* aDirtyRect);
   void RecordStopFrame();
   void SendStopFrame(imgRequestProxy* aProxy);
   void RecordStopDecode(nsresult statusg);
   void SendStopDecode(imgRequestProxy* aProxy, nsresult aStatus);
   void RecordDiscard();
   void SendDiscard(imgRequestProxy* aProxy);
   void RecordUnlockedDraw();
   void SendUnlockedDraw(imgRequestProxy* aProxy);
   void RecordImageIsAnimated();
   void SendImageIsAnimated(imgRequestProxy *aProxy);
   /* non-virtual sort-of-nsIRequestObserver methods */
   // Functions with prefix Send- are main thread only, since they contain calls
   // to imgRequestProxy functions, which are expected on the main thread.
   void RecordStartRequest();
   void SendStartRequest(imgRequestProxy* aProxy);
   void RecordStopRequest(bool aLastPart, nsresult aStatus);
   void SendStopRequest(imgRequestProxy* aProxy, bool aLastPart, nsresult aStatus);
   // All main thread only because they call functions (like SendStartRequest)
   // which are expected to be called on the main thread.
   void OnStartRequest();
   // OnDataAvailable will dispatch a call to itself onto the main thread if not
   // called there.
   void OnDataAvailable();
   void OnStopRequest(bool aLastPart, nsresult aStatus);
   void OnDiscard();
   void FrameChanged(const nsIntRect* aDirtyRect);
   void OnUnlockedDraw();
   // This is called only by VectorImage, and only to ensure tests work
   // properly. Do not use it.
   void OnStopFrame();
   /* non-virtual imgIOnloadBlocker methods */
   // NB: If UnblockOnload is sent, and then we are asked to replay the
   // notifications, we will not send a BlockOnload/UnblockOnload pair.  This
   // is different from all the other notifications.
   void RecordBlockOnload();
   void SendBlockOnload(imgRequestProxy* aProxy);
   void RecordUnblockOnload();
   void SendUnblockOnload(imgRequestProxy* aProxy);
   // Main thread only because mConsumers is not threadsafe.
   void MaybeUnblockOnload();
   void RecordError();
   bool IsMultipart() const { return mIsMultipart; }
   // Weak pointer getters - no AddRefs.
   inline already_AddRefed<mozilla::image::Image> GetImage() const {
     nsRefPtr<mozilla::image::Image> image = mImage;
     return image.forget();
   }
   inline bool HasImage() { return mImage; }
   inline imgDecoderObserver* GetDecoderObserver() { return mTrackerObserver.get(); }
   already_AddRefed<imgStatusTracker> CloneForRecording();
   // Compute the difference between this status tracker and aOther.
   mozilla::image::ImageStatusDiff Difference(imgStatusTracker* aOther) const;
   // Captures all of the decode notifications (i.e., not OnStartRequest /
   // OnStopRequest) so far as an ImageStatusDiff.
   mozilla::image::ImageStatusDiff DecodeStateAsDifference() const;
   // Update our state to incorporate the changes in aDiff.
   void ApplyDifference(const mozilla::image::ImageStatusDiff& aDiff);
   // Notify for the changes captured in an ImageStatusDiff. Because this may
   // result in recursive notifications, no decoding locks may be held.
   // Called on the main thread only.
   void SyncNotifyDifference(const mozilla::image::ImageStatusDiff& aDiff);
   nsIntRect GetInvalidRect() const { return mInvalidRect; }
 private:
   typedef nsTObserverArray<mozilla::WeakPtr<imgRequestProxy>> ProxyArray;
   friend class imgStatusNotifyRunnable;
   friend class imgRequestNotifyRunnable;
   friend class imgStatusTrackerObserver;
   friend class imgStatusTrackerInit;
   imgStatusTracker(const imgStatusTracker& aOther);
   // Main thread only because it deals with the observer service.
   void FireFailureNotification();
   // Main thread only, since imgRequestProxy calls are expected on the main
   // thread, and mConsumers is not threadsafe.
   static void SyncNotifyState(ProxyArray& proxies,
                               bool hasImage, uint32_t state,
                               nsIntRect& dirtyRect, bool hadLastPart);
   nsCOMPtr<nsIRunnable> mRequestRunnable;
   // The invalid area of the most recent frame we know about. (All previous
   // frames are assumed to be fully valid.)
   nsIntRect mInvalidRect;
   // This weak ref should be set null when the image goes out of scope.
   mozilla::image::Image* mImage;
   // List of proxies attached to the image. Each proxy represents a consumer
   // using the image. Array and/or individual elements should only be accessed
   // on the main thread.
   ProxyArray mConsumers;
   mozilla::RefPtr<imgDecoderObserver> mTrackerObserver;
   uint32_t mState;
   uint32_t mImageStatus;
   bool mIsMultipart    : 1;
   bool mHadLastPart    : 1;
   bool mHasBeenDecoded : 1;
 };
 class imgStatusTrackerInit
 {
 public:
   imgStatusTrackerInit(mozilla::image::Image* aImage,
                        imgStatusTracker* aTracker);
   ~imgStatusTrackerInit();
 private:
   imgStatusTracker* mTracker;
 };
 #endif

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image/src/imgStatusTracker.h@6474c204b198 (annotated)

image/src/imgStatusTracker.h