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 "nsIPrincipal.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 "IProgressObserver.h"
  23
  24 #define NS_IMGREQUESTPROXY_CID                       \
  25   { /* 20557898-1dd2-11b2-8f65-9c462ee2bc95 */       \
  26     0x20557898, 0x1dd2, 0x11b2, {                    \
  27       0x8f, 0x65, 0x9c, 0x46, 0x2e, 0xe2, 0xbc, 0x95 \
  28     }                                                \
  29   }
  30
  31 class imgCacheValidator;
  32 class imgINotificationObserver;
  33 class imgRequest;
  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, nsIURI* aURI,
  70                 imgINotificationObserver* aObserver);
  71
  72   nsresult ChangeOwner(imgRequest* aNewOwner);  // this will change mOwner.
  73                                                 // Do not call this if the
  74                                                 // previous owner has already
  75                                                 // sent notifications out!
  76
  77   // Add the request to the load group, if any. This should only be called once
  78   // during initialization.
  79   void AddToLoadGroup();
  80
  81   inline bool HasObserver() const { return mListener != nullptr; }
  82
  83   // Asynchronously notify this proxy's listener of the current state of the
  84   // image, and, if we have an imgRequest mOwner, any status changes that
  85   // happen between the time this function is called and the time the
  86   // notification is scheduled.
  87   void NotifyListener();
  88
  89   // Synchronously notify this proxy's listener of the current state of the
  90   // image. Only use this function if you are currently servicing an
  91   // asynchronously-called function.
  92   void SyncNotifyListener();
  93
  94   // imgINotificationObserver methods:
  95   virtual void Notify(int32_t aType,
  96                       const mozilla::gfx::IntRect* aRect = nullptr) override;
  97   virtual void OnLoadComplete(bool aLastPart) override;
  98
  99   // Other, internal-only methods:
 100   virtual void SetHasImage() override;
 101
 102   // Whether we want notifications from ProgressTracker to be deferred until
 103   // an event it has scheduled has been fired and/or validation is complete.
 104   virtual bool NotificationsDeferred() const override {
 105     return IsValidating() || mPendingNotify;
 106   }
 107   virtual void MarkPendingNotify() override { mPendingNotify = true; }
 108   virtual void ClearPendingNotify() override { mPendingNotify = false; }
 109   bool IsValidating() const { return mValidating; }
 110   void MarkValidating();
 111   void ClearValidating();
 112
 113   // Flags this image load as not cancelable temporarily. This is needed so that
 114   // stylesheets can be shared across documents properly, see bug 1800979.
 115   void SetCancelable(bool);
 116
 117   // Removes all animation consumers that were created with
 118   // IncrementAnimationConsumers. This is necessary since we need
 119   // to do it before the proxy itself is destroyed. See
 120   // imgRequest::RemoveProxy
 121   void ClearAnimationConsumers();
 122
 123   nsresult SyncClone(imgINotificationObserver* aObserver,
 124                      Document* aLoadingDocument, imgRequestProxy** aClone);
 125   nsresult Clone(imgINotificationObserver* aObserver,
 126                  Document* aLoadingDocument, imgRequestProxy** aClone);
 127   already_AddRefed<imgRequestProxy> GetStaticRequest(
 128       Document* aLoadingDocument);
 129
 130   imgRequest* GetOwner() const;
 131
 132   // PreloaderBase
 133   // We are using the default image loader prioritization for preloads.
 134   virtual void PrioritizeAsPreload() override {}
 135
 136  protected:
 137   friend class mozilla::image::ProgressTracker;
 138   friend class imgStatusNotifyRunnable;
 139
 140   class imgCancelRunnable;
 141   friend class imgCancelRunnable;
 142
 143   class imgCancelRunnable : public mozilla::Runnable {
 144    public:
 145     imgCancelRunnable(imgRequestProxy* owner, nsresult status)
 146         : Runnable("imgCancelRunnable"), mOwner(owner), mStatus(status) {}
 147
 148     NS_IMETHOD Run() override {
 149       mOwner->DoCancel(mStatus);
 150       return NS_OK;
 151     }
 152
 153    private:
 154     RefPtr<imgRequestProxy> mOwner;
 155     nsresult mStatus;
 156   };
 157
 158   /* Remove from and forget the load group. */
 159   void RemoveFromLoadGroup();
 160
 161   /* Remove from the load group and re-add as a background request. */
 162   void MoveToBackgroundInLoadGroup();
 163
 164   /* Finish up canceling ourselves */
 165   void DoCancel(nsresult status);
 166
 167   /* Do the proper refcount management to null out mListener */
 168   void NullOutListener();
 169
 170   // Return the ProgressTracker associated with mOwner and/or mImage. It may
 171   // live either on mOwner or mImage, depending on whether
 172   //   (a) we have an mOwner at all
 173   //   (b) whether mOwner has instantiated its image yet
 174   already_AddRefed<ProgressTracker> GetProgressTracker() const;
 175
 176   nsITimedChannel* TimedChannel();
 177
 178   already_AddRefed<Image> GetImage() const;
 179   bool HasImage() const;
 180   imgCacheValidator* GetValidator() const;
 181
 182   nsresult PerformClone(imgINotificationObserver* aObserver,
 183                         Document* aLoadingDocument, bool aSyncNotify,
 184                         imgRequestProxy** aClone);
 185
 186   virtual imgRequestProxy* NewClonedProxy();
 187
 188  public:
 189   NS_FORWARD_SAFE_NSITIMEDCHANNEL(TimedChannel())
 190
 191  protected:
 192   mozilla::UniquePtr<ProxyBehaviour> mBehaviour;
 193
 194  private:
 195   friend class imgCacheValidator;
 196
 197   void AddToOwner();
 198   void RemoveFromOwner(nsresult aStatus);
 199
 200   nsresult DispatchWithTargetIfAvailable(already_AddRefed<nsIRunnable> aEvent);
 201
 202   // The URI of our request.
 203   nsCOMPtr<nsIURI> mURI;
 204
 205   // mListener is only promised to be a weak ref (see imgILoader.idl),
 206   // but we actually keep a strong ref to it until we've seen our
 207   // first OnStopRequest.
 208   imgINotificationObserver* MOZ_UNSAFE_REF(
 209       "Observers must call Cancel() or "
 210       "CancelAndForgetObserver() before "
 211       "they are destroyed") mListener;
 212
 213   nsCOMPtr<nsILoadGroup> mLoadGroup;
 214
 215   nsLoadFlags mLoadFlags;
 216   uint32_t mLockCount;
 217   uint32_t mAnimationConsumers;
 218   bool mCancelable : 1;
 219   bool mCanceled : 1;
 220   bool mIsInLoadGroup : 1;
 221   bool mForceDispatchLoadGroup : 1;
 222   bool mListenerIsStrongRef : 1;
 223   bool mDecodeRequested : 1;
 224
 225   // Whether we want to defer our notifications by the non-virtual Observer
 226   // interfaces as image loads proceed.
 227   bool mPendingNotify : 1;
 228   bool mValidating : 1;
 229   bool mHadListener : 1;
 230 };
 231
 232 NS_DEFINE_STATIC_IID_ACCESSOR(imgRequestProxy, NS_IMGREQUESTPROXY_CID)
 233
 234 // Used for static image proxies for which no requests are available, so
 235 // certain behaviours must be overridden to compensate.
 236 class imgRequestProxyStatic : public imgRequestProxy {
 237  public:
 238   imgRequestProxyStatic(Image* aImage, nsIPrincipal* aImagePrincipal,
 239                         nsIPrincipal* aTriggeringPrincipal,
 240                         bool hadCrossOriginRedirects);
 241
 242   NS_IMETHOD GetImagePrincipal(nsIPrincipal** aPrincipal) override;
 243   NS_IMETHOD GetTriggeringPrincipal(nsIPrincipal** aPrincipal) override;
 244
 245   NS_IMETHOD GetHadCrossOriginRedirects(
 246       bool* aHadCrossOriginRedirects) override;
 247
 248  protected:
 249   imgRequestProxy* NewClonedProxy() override;
 250
 251   // Our principal. We have to cache it, rather than accessing the underlying
 252   // request on-demand, because static proxies don't have an underlying request.
 253   const nsCOMPtr<nsIPrincipal> mImagePrincipal;
 254   const nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 255   const bool mHadCrossOriginRedirects;
 256 };
 257
 258 #endif  // mozilla_image_imgRequestProxy_h