DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (5b81998bb7ab)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231
/* -*- 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 imgRequestProxy_h__
#define imgRequestProxy_h__

#include "imgIRequest.h"
#include "imgIDecoderObserver.h"
#include "nsISecurityInfoProvider.h"

#include "nsIRequestObserver.h"
#include "nsIChannel.h"
#include "nsILoadGroup.h"
#include "nsISupportsPriority.h"
#include "nsITimedChannel.h"
#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "nsThreadUtils.h"

#include "imgRequest.h"

#define NS_IMGREQUESTPROXY_CID \
{ /* 20557898-1dd2-11b2-8f65-9c462ee2bc95 */         \
     0x20557898,                                     \
     0x1dd2,                                         \
     0x11b2,                                         \
    {0x8f, 0x65, 0x9c, 0x46, 0x2e, 0xe2, 0xbc, 0x95} \
}

class imgRequestNotifyRunnable;
class imgStatusNotifyRunnable;

namespace mozilla {
namespace image {
class Image;
} // namespace image
} // namespace mozilla

class imgRequestProxy : public imgIRequest, 
                        public nsISupportsPriority, 
                        public nsISecurityInfoProvider,
                        public nsITimedChannel
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_IMGIREQUEST
  NS_DECL_NSIREQUEST
  NS_DECL_NSISUPPORTSPRIORITY
  NS_DECL_NSISECURITYINFOPROVIDER
  // nsITimedChannel declared below

  imgRequestProxy();
  virtual ~imgRequestProxy();

  // Callers to Init or ChangeOwner are required to call NotifyListener after
  // (although not immediately after) doing so.
  nsresult Init(imgRequest *request, nsILoadGroup *aLoadGroup,
                mozilla::image::Image* aImage,
                nsIURI* aURI, imgIDecoderObserver *aObserver);

  nsresult ChangeOwner(imgRequest *aNewOwner); // this will change mOwner.  Do not call this if the previous
                                               // owner has already sent notifications out!

  void AddToLoadGroup();
  void RemoveFromLoadGroup(bool releaseLoadGroup);

  inline bool HasObserver() const {
    return mListener != nullptr;
  }

  void SetPrincipal(nsIPrincipal *aPrincipal);

  // Asynchronously notify this proxy's listener of the current state of the
  // image, and, if we have an imgRequest mOwner, any status changes that
  // happen between the time this function is called and the time the
  // notification is scheduled.
  void NotifyListener();

  // Synchronously notify this proxy's listener of the current state of the
  // image. Only use this function if you are currently servicing an
  // asynchronously-called function.
  void SyncNotifyListener();

  // Whether we want notifications from imgStatusTracker to be deferred until
  // an event it has scheduled has been fired.
  bool NotificationsDeferred() const
  {
    return mDeferNotifications;
  }
  void SetNotificationsDeferred(bool aDeferNotifications)
  {
    mDeferNotifications = aDeferNotifications;
  }

  // Setter for our |mImage| pointer, for imgRequest to use, once it
  // instantiates an Image.
  void SetImage(mozilla::image::Image* aImage);

  // Removes all animation consumers that were created with
  // IncrementAnimationConsumers. This is necessary since we need
  // to do it before the proxy itself is destroyed. See
  // imgRequest::RemoveProxy
  void ClearAnimationConsumers();

protected:
  friend class imgStatusTracker;
  friend class imgStatusNotifyRunnable;
  friend class imgRequestNotifyRunnable;

  class imgCancelRunnable;
  friend class imgCancelRunnable;

  class imgCancelRunnable : public nsRunnable
  {
    public:
      imgCancelRunnable(imgRequestProxy* owner, nsresult status)
        : mOwner(owner), mStatus(status)
      {}

      NS_IMETHOD Run() {
        mOwner->DoCancel(mStatus);
        return NS_OK;
      }

    private:
      nsRefPtr<imgRequestProxy> mOwner;
      nsresult mStatus;
  };

  // The following notification functions are protected to ensure that (friend
  // class) imgStatusTracker is the only class allowed to send us
  // notifications.

  /* non-virtual imgIDecoderObserver methods */
  void OnStartDecode     ();
  void OnStartContainer  (imgIContainer *aContainer);
  void OnStartFrame      (uint32_t aFrame);
  void OnDataAvailable   (bool aCurrentFrame, const nsIntRect * aRect);
  void OnStopFrame       (uint32_t aFrame);
  void OnStopContainer   (imgIContainer *aContainer);
  void OnStopDecode      (nsresult status, const PRUnichar *statusArg);
  void OnDiscard         ();
  void OnImageIsAnimated ();

  /* non-virtual imgIContainerObserver methods */
  void FrameChanged(imgIContainer *aContainer,
                    const nsIntRect *aDirtyRect);

  /* non-virtual sort-of-nsIRequestObserver methods */
  void OnStartRequest();
  void OnStopRequest(bool aLastPart);

  /* non-virtual imgIOnloadBlocker methods */
  void BlockOnload();
  void UnblockOnload();

  /* Finish up canceling ourselves */
  void DoCancel(nsresult status);

  /* Do the proper refcount management to null out mListener */
  void NullOutListener();

  void DoRemoveFromLoadGroup() {
    RemoveFromLoadGroup(true);
  }

  // Return the imgStatusTracker associated with mOwner and/or mImage. It may
  // live either on mOwner or mImage, depending on whether
  //   (a) we have an mOwner at all
  //   (b) whether mOwner has instantiated its image yet
  imgStatusTracker& GetStatusTracker();

  nsITimedChannel* TimedChannel()
  {
    if (!mOwner)
      return nullptr;
    return mOwner->mTimedChannel;
  }

public:
  NS_FORWARD_SAFE_NSITIMEDCHANNEL(TimedChannel())

private:
  friend class imgCacheValidator;

  // We maintain the following invariant:
  // The proxy is registered at most with a single imgRequest as an observer,
  // and whenever it is, mOwner points to that object. This helps ensure that
  // imgRequestProxy::~imgRequestProxy unregisters the proxy as an observer
  // from whatever request it was registered with (if any). This, in turn,
  // means that imgRequest::mObservers will not have any stale pointers in it.
  nsRefPtr<imgRequest> mOwner;

  // The URI of our request.
  nsCOMPtr<nsIURI> mURI;

  // The image we represent. Is null until data has been received, and is then
  // set by imgRequest.
  nsRefPtr<mozilla::image::Image> mImage;

  // Our principal. Is null until data has been received from the channel, and
  // is then set by imgRequest.
  nsCOMPtr<nsIPrincipal> mPrincipal;

  // mListener is only promised to be a weak ref (see imgILoader.idl),
  // but we actually keep a strong ref to it until we've seen our
  // first OnStopRequest.
  imgIDecoderObserver* mListener;
  nsCOMPtr<nsILoadGroup> mLoadGroup;

  nsLoadFlags mLoadFlags;
  uint32_t    mLockCount;
  uint32_t    mAnimationConsumers;
  bool mCanceled;
  bool mIsInLoadGroup;
  bool mListenerIsStrongRef;
  bool mDecodeRequested;

  // Whether we want to defer our notifications by the non-virtual Observer
  // interfaces as image loads proceed.
  bool mDeferNotifications;

  // We only want to send OnStartContainer once for each proxy, but we might
  // get multiple OnStartContainer calls.
  bool mSentStartContainer;
};

#endif // imgRequestProxy_h__