image/imgRequestProxy.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_image_imgRequestProxy_h
   8 #define mozilla_image_imgRequestProxy_h
   9
  10 #include "imgIRequest.h"
  11
  12 #include "nsILoadGroup.h"
  13 #include "nsISupportsPriority.h"
  14 #include "nsITimedChannel.h"
  15 #include "nsCOMPtr.h"
  16 #include "nsThreadUtils.h"
  17 #include "mozilla/PreloaderBase.h"
  18 #include "mozilla/TimeStamp.h"
  19 #include "mozilla/UniquePtr.h"
  20 #include "mozilla/gfx/Rect.h"
  21
  22 #include "imgRequest.h"
  23 #include "IProgressObserver.h"
  24
  25 #define NS_IMGREQUESTPROXY_CID                       \
  26   { /* 20557898-1dd2-11b2-8f65-9c462ee2bc95 */       \
  27     0x20557898, 0x1dd2, 0x11b2, {                    \
  28       0x8f, 0x65, 0x9c, 0x46, 0x2e, 0xe2, 0xbc, 0x95 \
  29     }                                                \
  30   }
  31
  32 class imgCacheValidator;
  33 class imgINotificationObserver;
  34 class imgStatusNotifyRunnable;
  35 class ProxyBehaviour;
  36
  37 namespace mozilla {
  38 namespace image {
  39 class Image;
  40 class ProgressTracker;
  41 }  // namespace image
  42 }  // namespace mozilla
  43
  44 class imgRequestProxy : public mozilla::PreloaderBase,
  45                         public imgIRequest,
  46                         public mozilla::image::IProgressObserver,
  47                         public nsISupportsPriority,
  48                         public nsITimedChannel {
  49  protected:
  50   virtual ~imgRequestProxy();
  51
  52  public:
  53   typedef mozilla::dom::Document Document;
  54   typedef mozilla::image::Image Image;
  55   typedef mozilla::image::ProgressTracker ProgressTracker;
  56
  57   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMGREQUESTPROXY_CID)
  58   MOZ_DECLARE_REFCOUNTED_TYPENAME(imgRequestProxy)
  59   NS_DECL_ISUPPORTS
  60   NS_DECL_IMGIREQUEST
  61   NS_DECL_NSIREQUEST
  62   NS_DECL_NSISUPPORTSPRIORITY
  63   // nsITimedChannel declared below
  64
  65   imgRequestProxy();
  66
  67   // Callers to Init or ChangeOwner are required to call NotifyListener after
  68   // (although not immediately after) doing so.
  69   nsresult Init(imgRequest* aOwner, nsILoadGroup* aLoadGroup,
  70                 Document* aLoadingDocument, nsIURI* aURI,
  71                 imgINotificationObserver* aObserver);
  72
  73   nsresult ChangeOwner(imgRequest* aNewOwner);  // this will change mOwner.
  74                                                 // Do not call this if the
  75                                                 // previous owner has already
  76                                                 // sent notifications out!
  77
  78   // Add the request to the load group, if any. This should only be called once
  79   // during initialization.
  80   void AddToLoadGroup();
  81
  82   inline bool HasObserver() const { return mListener != nullptr; }
  83
  84   // Asynchronously notify this proxy's listener of the current state of the
  85   // image, and, if we have an imgRequest mOwner, any status changes that
  86   // happen between the time this function is called and the time the
  87   // notification is scheduled.
  88   void NotifyListener();
  89
  90   // Synchronously notify this proxy's listener of the current state of the
  91   // image. Only use this function if you are currently servicing an
  92   // asynchronously-called function.
  93   void SyncNotifyListener();
  94
  95   // imgINotificationObserver methods:
  96   virtual void Notify(int32_t aType,
  97                       const mozilla::gfx::IntRect* aRect = nullptr) override;
  98   virtual void OnLoadComplete(bool aLastPart) override;
  99
 100   // Other, internal-only methods:
 101   virtual void SetHasImage() override;
 102
 103   // Whether we want notifications from ProgressTracker to be deferred until
 104   // an event it has scheduled has been fired and/or validation is complete.
 105   virtual bool NotificationsDeferred() const override {
 106     return IsValidating() || mPendingNotify;
 107   }
 108   virtual void MarkPendingNotify() override { mPendingNotify = true; }
 109   virtual void ClearPendingNotify() override { mPendingNotify = false; }
 110   bool IsValidating() const { return mValidating; }
 111   void MarkValidating();
 112   void ClearValidating();
 113
 114   already_AddRefed<nsIEventTarget> GetEventTarget() const override;
 115
 116   // Removes all animation consumers that were created with
 117   // IncrementAnimationConsumers. This is necessary since we need
 118   // to do it before the proxy itself is destroyed. See
 119   // imgRequest::RemoveProxy
 120   void ClearAnimationConsumers();
 121
 122   nsresult SyncClone(imgINotificationObserver* aObserver,
 123                      Document* aLoadingDocument, imgRequestProxy** aClone);
 124   nsresult Clone(imgINotificationObserver* aObserver,
 125                  Document* aLoadingDocument, imgRequestProxy** aClone);
 126   already_AddRefed<imgRequestProxy> GetStaticRequest(Document* aLoadingDocument);
 127
 128   imgRequest* GetOwner() const;
 129
 130   // PreloaderBase
 131   // We are using the default image loader prioritization for preloads.
 132   virtual void PrioritizeAsPreload() override {}
 133
 134  protected:
 135   friend class mozilla::image::ProgressTracker;
 136   friend class imgStatusNotifyRunnable;
 137
 138   class imgCancelRunnable;
 139   friend class imgCancelRunnable;
 140
 141   class imgCancelRunnable : public mozilla::Runnable {
 142    public:
 143     imgCancelRunnable(imgRequestProxy* owner, nsresult status)
 144         : Runnable("imgCancelRunnable"), mOwner(owner), mStatus(status) {}
 145
 146     NS_IMETHOD Run() override {
 147       mOwner->DoCancel(mStatus);
 148       return NS_OK;
 149     }
 150
 151    private:
 152     RefPtr<imgRequestProxy> mOwner;
 153     nsresult mStatus;
 154   };
 155
 156   /* Remove from and forget the load group. */
 157   void RemoveFromLoadGroup();
 158
 159   /* Remove from the load group and re-add as a background request. */
 160   void MoveToBackgroundInLoadGroup();
 161
 162   /* Finish up canceling ourselves */
 163   void DoCancel(nsresult status);
 164
 165   /* Do the proper refcount management to null out mListener */
 166   void NullOutListener();
 167
 168   // Return the ProgressTracker associated with mOwner and/or mImage. It may
 169   // live either on mOwner or mImage, depending on whether
 170   //   (a) we have an mOwner at all
 171   //   (b) whether mOwner has instantiated its image yet
 172   already_AddRefed<ProgressTracker> GetProgressTracker() const;
 173
 174   nsITimedChannel* TimedChannel() {
 175     if (!GetOwner()) {
 176       return nullptr;
 177     }
 178     return GetOwner()->GetTimedChannel();
 179   }
 180
 181   already_AddRefed<Image> GetImage() const;
 182   bool HasImage() const;
 183   imgCacheValidator* GetValidator() const;
 184
 185   nsresult PerformClone(imgINotificationObserver* aObserver,
 186                         Document* aLoadingDocument, bool aSyncNotify,
 187                         imgRequestProxy** aClone);
 188
 189   virtual imgRequestProxy* NewClonedProxy();
 190
 191  public:
 192   NS_FORWARD_SAFE_NSITIMEDCHANNEL(TimedChannel())
 193
 194  protected:
 195   mozilla::UniquePtr<ProxyBehaviour> mBehaviour;
 196
 197  private:
 198   friend class imgCacheValidator;
 199
 200   void AddToOwner(Document* aLoadingDocument);
 201   void RemoveFromOwner(nsresult aStatus);
 202
 203   nsresult DispatchWithTargetIfAvailable(already_AddRefed<nsIRunnable> aEvent);
 204
 205   // The URI of our request.
 206   nsCOMPtr<nsIURI> mURI;
 207
 208   // mListener is only promised to be a weak ref (see imgILoader.idl),
 209   // but we actually keep a strong ref to it until we've seen our
 210   // first OnStopRequest.
 211   imgINotificationObserver* MOZ_UNSAFE_REF(
 212       "Observers must call Cancel() or "
 213       "CancelAndForgetObserver() before "
 214       "they are destroyed") mListener;
 215
 216   nsCOMPtr<nsILoadGroup> mLoadGroup;
 217   nsCOMPtr<nsIEventTarget> mEventTarget;
 218
 219   nsLoadFlags mLoadFlags;
 220   uint32_t mLockCount;
 221   uint32_t mAnimationConsumers;
 222   bool mCanceled : 1;
 223   bool mIsInLoadGroup : 1;
 224   bool mForceDispatchLoadGroup : 1;
 225   bool mListenerIsStrongRef : 1;
 226   bool mDecodeRequested : 1;
 227
 228   // Whether we want to defer our notifications by the non-virtual Observer
 229   // interfaces as image loads proceed.
 230   bool mPendingNotify : 1;
 231   bool mValidating : 1;
 232   bool mHadListener : 1;
 233   bool mHadDispatch : 1;
 234 };
 235
 236 NS_DEFINE_STATIC_IID_ACCESSOR(imgRequestProxy, NS_IMGREQUESTPROXY_CID)
 237
 238 // Used for static image proxies for which no requests are available, so
 239 // certain behaviours must be overridden to compensate.
 240 class imgRequestProxyStatic : public imgRequestProxy {
 241  public:
 242   imgRequestProxyStatic(Image* aImage, nsIPrincipal* aPrincipal,
 243                         bool hadCrossOriginRedirects);
 244
 245   NS_IMETHOD GetImagePrincipal(nsIPrincipal** aPrincipal) override;
 246
 247   NS_IMETHOD GetHadCrossOriginRedirects(
 248       bool* aHadCrossOriginRedirects) override;
 249
 250  protected:
 251   imgRequestProxy* NewClonedProxy() override;
 252
 253   // Our principal. We have to cache it, rather than accessing the underlying
 254   // request on-demand, because static proxies don't have an underlying request.
 255   nsCOMPtr<nsIPrincipal> mPrincipal;
 256   const bool mHadCrossOriginRedirects;
 257 };
 258
 259 #endif  // mozilla_image_imgRequestProxy_h