text: /* -*- 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/. */
  
  #include "nspr.h"
  #include "prlog.h"
  
  #include "nsDocLoader.h"
  #include "nsCURILoader.h"
  #include "nsNetUtil.h"
  #include "nsIHttpChannel.h"
  #include "nsIWebProgressListener2.h"
  
  #include "nsIServiceManager.h"
  #include "nsXPIDLString.h"
  
  #include "nsIURL.h"
  #include "nsCOMPtr.h"
  #include "nscore.h"
  #include "nsWeakPtr.h"
  #include "nsAutoPtr.h"
  
  #include "nsIDOMWindow.h"
  
  #include "nsIStringBundle.h"
  #include "nsIScriptSecurityManager.h"
  
  #include "nsITransport.h"
  #include "nsISocketTransport.h"
  
  #include "nsIDOMDocument.h"
  #include "nsIDocument.h"
  #include "nsPresContext.h"
  #include "nsIAsyncVerifyRedirectCallback.h"
  
  static NS_DEFINE_CID(kThisImplCID, NS_THIS_DOCLOADER_IMPL_CID);
  
  #if defined(PR_LOGGING)
  //
  // Log module for nsIDocumentLoader logging...
  //
  // To enable logging (see prlog.h for full details):
  //
  //    set NSPR_LOG_MODULES=DocLoader:5
  //    set NSPR_LOG_FILE=nspr.log
  //
  // this enables PR_LOG_DEBUG level information and places all output in
  // the file nspr.log
  //
  PRLogModuleInfo* gDocLoaderLog = nullptr;
  #endif /* PR_LOGGING */
  
  
  #if defined(DEBUG)
  void GetURIStringFromRequest(nsIRequest* request, nsACString &name)
  {
      if (request)
          request->GetName(name);
      else
          name.AssignLiteral("???");
  }
  #endif /* DEBUG */
  
  struct nsStatusInfo : public PRCList
  {
    nsString mStatusMessage;
    nsresult mStatusCode;
    // Weak mRequest is ok; we'll be told if it decides to go away.
    nsIRequest * const mRequest;
  
    nsStatusInfo(nsIRequest *aRequest) :
      mRequest(aRequest)
    {
      MOZ_COUNT_CTOR(nsStatusInfo);
      PR_INIT_CLIST(this);
    }
    ~nsStatusInfo()
    {
      MOZ_COUNT_DTOR(nsStatusInfo);
      PR_REMOVE_LINK(this);
    }
  };
  
  struct nsRequestInfo : public PLDHashEntryHdr
  {
    nsRequestInfo(const void *key)
      : mKey(key), mCurrentProgress(0), mMaxProgress(0), mUploading(false)
      , mLastStatus(nullptr)
    {
      MOZ_COUNT_CTOR(nsRequestInfo);
    }
  
    ~nsRequestInfo()
    {
      MOZ_COUNT_DTOR(nsRequestInfo);
    }
  
    nsIRequest* Request() {
      return static_cast<nsIRequest*>(const_cast<void*>(mKey));
    }
  
    const void* mKey; // Must be first for the pldhash stubs to work
    int64_t mCurrentProgress;
    int64_t mMaxProgress;
    bool mUploading;
  
    nsAutoPtr<nsStatusInfo> mLastStatus;
  };
  
  
  static bool
  RequestInfoHashInitEntry(PLDHashTable *table, PLDHashEntryHdr *entry,
                           const void *key)
  {
    // Initialize the entry with placement new
    new (entry) nsRequestInfo(key);
    return true;
  }
  
  static void
  RequestInfoHashClearEntry(PLDHashTable *table, PLDHashEntryHdr *entry)
  {
    nsRequestInfo* info = static_cast<nsRequestInfo *>(entry);
    info->~nsRequestInfo();
  }
  
  struct nsListenerInfo {
    nsListenerInfo(nsIWeakReference *aListener, unsigned long aNotifyMask) 
      : mWeakListener(aListener),
        mNotifyMask(aNotifyMask)
    {
    }
  
    // Weak pointer for the nsIWebProgressListener...
    nsWeakPtr mWeakListener;
  
    // Mask indicating which notifications the listener wants to receive.
    unsigned long mNotifyMask;
  };
  
  
  nsDocLoader::nsDocLoader()
    : mParent(nullptr),
      mListenerInfoList(8),
      mCurrentSelfProgress(0),
      mMaxSelfProgress(0),
      mCurrentTotalProgress(0),
      mMaxTotalProgress(0),
      mCompletedTotalProgress(0),
      mIsLoadingDocument(false),
      mIsRestoringDocument(false),
      mDontFlushLayout(false),
      mIsFlushingLayout(false)
  {
  #if defined(PR_LOGGING)
    if (nullptr == gDocLoaderLog) {
        gDocLoaderLog = PR_NewLogModule("DocLoader");
    }
  #endif /* PR_LOGGING */
  
    static PLDHashTableOps hash_table_ops =
    {
      PL_DHashAllocTable,
      PL_DHashFreeTable,
      PL_DHashVoidPtrKeyStub,
      PL_DHashMatchEntryStub,
      PL_DHashMoveEntryStub,
      RequestInfoHashClearEntry,
      PL_DHashFinalizeStub,
      RequestInfoHashInitEntry
    };
  
    if (!PL_DHashTableInit(&mRequestInfoHash, &hash_table_ops, nullptr,
                           sizeof(nsRequestInfo), 16)) {
      mRequestInfoHash.ops = nullptr;
    }
  
    ClearInternalProgress();
  
    PR_INIT_CLIST(&mStatusInfoList);
  
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: created.\n", this));
  }
  
  nsresult
  nsDocLoader::SetDocLoaderParent(nsDocLoader *aParent)
  {
    mParent = aParent;
    return NS_OK; 
  }
  
  nsresult
  nsDocLoader::Init()
  {
    if (!mRequestInfoHash.ops) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
  
    nsresult rv = NS_NewLoadGroup(getter_AddRefs(mLoadGroup), this);
    if (NS_FAILED(rv)) return rv;
  
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: load group %x.\n", this, mLoadGroup.get()));
  
    return NS_OK;
  }
  
  nsDocLoader::~nsDocLoader()
  {
  		/*
  			|ClearWeakReferences()| here is intended to prevent people holding weak references
  			from re-entering this destructor since |QueryReferent()| will |AddRef()| me, and the
  			subsequent |Release()| will try to destroy me.  At this point there should be only
  			weak references remaining (otherwise, we wouldn't be getting destroyed).
  
  			An alternative would be incrementing our refcount (consider it a compressed flag
  			saying "Don't re-destroy.").  I haven't yet decided which is better. [scc]
  		*/
    // XXXbz now that NS_IMPL_RELEASE stabilizes by setting refcount to 1, is
    // this needed?
    ClearWeakReferences();
  
    Destroy();
  
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG,
           ("DocLoader:%p: deleted.\n", this));
  
    if (mRequestInfoHash.ops) {
      PL_DHashTableFinish(&mRequestInfoHash);
    }
  }
  
  
  /*
   * Implementation of ISupports methods...
   */
  NS_IMPL_THREADSAFE_ADDREF(nsDocLoader)
  NS_IMPL_THREADSAFE_RELEASE(nsDocLoader)
  
  NS_INTERFACE_MAP_BEGIN(nsDocLoader)
     NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIRequestObserver)
     NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
     NS_INTERFACE_MAP_ENTRY(nsIDocumentLoader)
     NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
     NS_INTERFACE_MAP_ENTRY(nsIWebProgress)
     NS_INTERFACE_MAP_ENTRY(nsIProgressEventSink)   
     NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
     NS_INTERFACE_MAP_ENTRY(nsIChannelEventSink)
     NS_INTERFACE_MAP_ENTRY(nsISecurityEventSink)
     NS_INTERFACE_MAP_ENTRY(nsISupportsPriority)
     if (aIID.Equals(kThisImplCID))
       foundInterface = static_cast<nsIDocumentLoader *>(this);
     else
  NS_INTERFACE_MAP_END
  
  
  /*
   * Implementation of nsIInterfaceRequestor methods...
   */
  NS_IMETHODIMP nsDocLoader::GetInterface(const nsIID& aIID, void** aSink)
  {
    nsresult rv = NS_ERROR_NO_INTERFACE;
  
    NS_ENSURE_ARG_POINTER(aSink);
  
    if(aIID.Equals(NS_GET_IID(nsILoadGroup))) {
      *aSink = mLoadGroup;
      NS_IF_ADDREF((nsISupports*)*aSink);
      rv = NS_OK;
    } else {
      rv = QueryInterface(aIID, aSink);
    }
  
    return rv;
  }
  
  /* static */
  already_AddRefed<nsDocLoader>
  nsDocLoader::GetAsDocLoader(nsISupports* aSupports)
  {
    if (!aSupports) {
      return nullptr;
    }
    
    nsDocLoader* ptr;
    CallQueryInterface(aSupports, &ptr);
    return ptr;
  }
  
  /* static */
  nsresult
  nsDocLoader::AddDocLoaderAsChildOfRoot(nsDocLoader* aDocLoader)
  {
    nsresult rv;
    nsCOMPtr<nsIDocumentLoader> docLoaderService =
      do_GetService(NS_DOCUMENTLOADER_SERVICE_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);
  
    nsRefPtr<nsDocLoader> rootDocLoader = GetAsDocLoader(docLoaderService);
    NS_ENSURE_TRUE(rootDocLoader, NS_ERROR_UNEXPECTED);
  
    return rootDocLoader->AddChildLoader(aDocLoader);
  }
  
  NS_IMETHODIMP
  nsDocLoader::Stop(void)
  {
    nsresult rv = NS_OK;
    int32_t count, i;
  
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: Stop() called\n", this));
  
    count = mChildList.Count();
  
    nsCOMPtr<nsIDocumentLoader> loader;
    for (i=0; i < count; i++) {
      loader = ChildAt(i);
  
      if (loader) {
        (void) loader->Stop();
      }
    }
  
    if (mLoadGroup)
      rv = mLoadGroup->Cancel(NS_BINDING_ABORTED);
  
    // Don't report that we're flushing layout so IsBusy returns false after a
    // Stop call.
    mIsFlushingLayout = false;
  
    // Clear out mChildrenInOnload.  We want to make sure to fire our
    // onload at this point, and there's no issue with mChildrenInOnload
    // after this, since mDocumentRequest will be null after the
    // DocLoaderIsEmpty() call.
    mChildrenInOnload.Clear();
  
    // Make sure to call DocLoaderIsEmpty now so that we reset mDocumentRequest,
    // etc, as needed.  We could be getting into here from a subframe onload, in
    // which case the call to DocLoaderIsEmpty() is coming but hasn't quite
    // happened yet, Canceling the loadgroup did nothing (because it was already
    // empty), and we're about to start a new load (which is what triggered this
    // Stop() call).
  
    // XXXbz If the child frame loadgroups were requests in mLoadgroup, I suspect
    // we wouldn't need the call here....
  
    NS_ASSERTION(!IsBusy(), "Shouldn't be busy here");
    DocLoaderIsEmpty(false);
    
    return rv;
  }       
  
  
  bool
  nsDocLoader::IsBusy()
  {
    nsresult rv;
  
    //
    // A document loader is busy if either:
    //
    //   1. One of its children is in the middle of an onload handler.  Note that
    //      the handler may have already removed this child from mChildList!
    //   2. It is currently loading a document and either has parts of it still
    //      loading, or has a busy child docloader.
    //   3. It's currently flushing layout in DocLoaderIsEmpty().
    //
  
    if (mChildrenInOnload.Count() || mIsFlushingLayout) {
      return true;
    }
  
    /* Is this document loader busy? */
    if (!mIsLoadingDocument) {
      return false;
    }
    
    bool busy;
    rv = mLoadGroup->IsPending(&busy);
    if (NS_FAILED(rv)) {
      return false;
    }
    if (busy) {
      return true;
    }
  
    /* check its child document loaders... */
    int32_t count, i;
  
    count = mChildList.Count();
  
    for (i=0; i < count; i++) {
      nsIDocumentLoader* loader = ChildAt(i);
  
      // This is a safe cast, because we only put nsDocLoader objects into the
      // array
      if (loader && static_cast<nsDocLoader*>(loader)->IsBusy())
        return true;
    }
  
    return false;
  }
  
  NS_IMETHODIMP
  nsDocLoader::GetContainer(nsISupports** aResult)
  {
     NS_ADDREF(*aResult = static_cast<nsIDocumentLoader*>(this));
  
     return NS_OK;
  }
  
  NS_IMETHODIMP
  nsDocLoader::GetLoadGroup(nsILoadGroup** aResult)
  {
    nsresult rv = NS_OK;
  
    if (nullptr == aResult) {
      rv = NS_ERROR_NULL_POINTER;
    } else {
      *aResult = mLoadGroup;
      NS_IF_ADDREF(*aResult);
    }
    return rv;
  }
  
  void
  nsDocLoader::Destroy()
  {
    Stop();
  
    // Remove the document loader from the parent list of loaders...
    if (mParent) 
    {
      mParent->RemoveChildLoader(this);
    }
  
    // Release all the information about network requests...
    ClearRequestInfoHash();
  
    // Release all the information about registered listeners...
    int32_t count = mListenerInfoList.Count();
    for(int32_t i = 0; i < count; i++) {
      nsListenerInfo *info =
        static_cast<nsListenerInfo*>(mListenerInfoList.ElementAt(i));
  
      delete info;
    }
  
    mListenerInfoList.Clear();
    mListenerInfoList.Compact();
  
    mDocumentRequest = 0;
  
    if (mLoadGroup)
      mLoadGroup->SetGroupObserver(nullptr);
  
    DestroyChildren();
  }
  
  void
  nsDocLoader::DestroyChildren()
  {
    int32_t i, count;
    
    count = mChildList.Count();
    // if the doc loader still has children...we need to enumerate the
    // children and make them null out their back ptr to the parent doc
    // loader
    for (i=0; i < count; i++)
    {
      nsIDocumentLoader* loader = ChildAt(i);
  
      if (loader) {
        // This is a safe cast, as we only put nsDocLoader objects into the
        // array
        static_cast<nsDocLoader*>(loader)->SetDocLoaderParent(nullptr);
      }
    }
    mChildList.Clear();
  }
  
  NS_IMETHODIMP
  nsDocLoader::OnStartRequest(nsIRequest *request, nsISupports *aCtxt)
  {
    // called each time a request is added to the group.
  
  #ifdef PR_LOGGING
    if (PR_LOG_TEST(gDocLoaderLog, PR_LOG_DEBUG)) {
      nsAutoCString name;
      request->GetName(name);
  
      uint32_t count = 0;
      if (mLoadGroup)
        mLoadGroup->GetActiveCount(&count);
  
      PR_LOG(gDocLoaderLog, PR_LOG_DEBUG,
             ("DocLoader:%p: OnStartRequest[%p](%s) mIsLoadingDocument=%s, %u active URLs",
              this, request, name.get(),
              (mIsLoadingDocument ? "true" : "false"),
              count));
    }
  #endif /* PR_LOGGING */
    bool bJustStartedLoading = false;
  
    nsLoadFlags loadFlags = 0;
    request->GetLoadFlags(&loadFlags);
  
    if (!mIsLoadingDocument && (loadFlags & nsIChannel::LOAD_DOCUMENT_URI)) {
        bJustStartedLoading = true;
        mIsLoadingDocument = true;
        ClearInternalProgress(); // only clear our progress if we are starting a new load....
    }
  
    //
    // Create a new nsRequestInfo for the request that is starting to
    // load...
    //
    AddRequestInfo(request);
  
    //
    // Only fire a doStartDocumentLoad(...) if the document loader
    // has initiated a load...  Otherwise, this notification has
    // resulted from a request being added to the load group.
    //
    if (mIsLoadingDocument) {
      if (loadFlags & nsIChannel::LOAD_DOCUMENT_URI) {
        //
        // Make sure that the document channel is null at this point...
        // (unless its been redirected)
        //
        NS_ASSERTION((loadFlags & nsIChannel::LOAD_REPLACE) ||
                     !(mDocumentRequest.get()),
                     "Overwriting an existing document channel!");
  
        // This request is associated with the entire document...
        mDocumentRequest = request;
        mLoadGroup->SetDefaultLoadRequest(request); 
  
        // Only fire the start document load notification for the first
        // document URI...  Do not fire it again for redirections
        //
        if (bJustStartedLoading) {
          // Update the progress status state
          mProgressStateFlags = nsIWebProgressListener::STATE_START;
  
          // Fire the start document load notification
          doStartDocumentLoad();
          return NS_OK;
        }
      } 
    }
  
    NS_ASSERTION(!mIsLoadingDocument || mDocumentRequest,
                 "mDocumentRequest MUST be set for the duration of a page load!");
  
    doStartURLLoad(request);
  
    return NS_OK;
  }
  
  NS_IMETHODIMP
  nsDocLoader::OnStopRequest(nsIRequest *aRequest, 
                             nsISupports *aCtxt,
                             nsresult aStatus)
  {
    nsresult rv = NS_OK;
  
  #ifdef PR_LOGGING
    if (PR_LOG_TEST(gDocLoaderLog, PR_LOG_DEBUG)) {
      nsAutoCString name;
      aRequest->GetName(name);
  
      uint32_t count = 0;
      if (mLoadGroup)
        mLoadGroup->GetActiveCount(&count);
  
      PR_LOG(gDocLoaderLog, PR_LOG_DEBUG,
             ("DocLoader:%p: OnStopRequest[%p](%s) status=%x mIsLoadingDocument=%s, %u active URLs",
             this, aRequest, name.get(),
             aStatus, (mIsLoadingDocument ? "true" : "false"),
             count));
    }
  #endif
  
    bool bFireTransferring = false;
  
    //
    // Set the Maximum progress to the same value as the current progress.
    // Since the URI has finished loading, all the data is there.  Also,
    // this will allow a more accurate estimation of the max progress (in case
    // the old value was unknown ie. -1)
    //
    nsRequestInfo *info = GetRequestInfo(aRequest);
    if (info) {
      // Null out mLastStatus now so we don't find it when looking for
      // status from now on.  This destroys the nsStatusInfo and hence
      // removes it from our list.
      info->mLastStatus = nullptr;
  
      int64_t oldMax = info->mMaxProgress;
  
      info->mMaxProgress = info->mCurrentProgress;
      
      //
      // If a request whose content-length was previously unknown has just
      // finished loading, then use this new data to try to calculate a
      // mMaxSelfProgress...
      //
      if ((oldMax < int64_t(0)) && (mMaxSelfProgress < int64_t(0))) {
        mMaxSelfProgress = CalculateMaxProgress();
      }
  
      // As we know the total progress of this request now, save it to be part
      // of CalculateMaxProgress() result. We need to remove the info from the
      // hash, see bug 480713.
      mCompletedTotalProgress += info->mMaxProgress;
      
      //
      // Determine whether a STATE_TRANSFERRING notification should be
      // 'synthesized'.
      //
      // If nsRequestInfo::mMaxProgress (as stored in oldMax) and
      // nsRequestInfo::mCurrentProgress are both 0, then the
      // STATE_TRANSFERRING notification has not been fired yet...
      //
      if ((oldMax == LL_ZERO) && (info->mCurrentProgress == LL_ZERO)) {
        nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
  
        // Only fire a TRANSFERRING notification if the request is also a
        // channel -- data transfer requires a nsIChannel!
        //
        if (channel) {
          if (NS_SUCCEEDED(aStatus)) {
            bFireTransferring = true;
          }
          //
          // If the request failed (for any reason other than being
          // redirected or retargeted), the TRANSFERRING notification can
          // still be fired if a HTTP connection was established to a server.
          //
          else if (aStatus != NS_BINDING_REDIRECTED &&
                   aStatus != NS_BINDING_RETARGETED) {
            //
            // Only if the load has been targeted (see bug 268483)...
            //
            uint32_t lf;
            channel->GetLoadFlags(&lf);
            if (lf & nsIChannel::LOAD_TARGETED) {
              nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aRequest));
              if (httpChannel) {
                uint32_t responseCode;
                rv = httpChannel->GetResponseStatus(&responseCode);
                if (NS_SUCCEEDED(rv)) {
                  //
                  // A valid server status indicates that a connection was
                  // established to the server... So, fire the notification
                  // even though a failure occurred later...
                  //
                  bFireTransferring = true;
                }
              }
            }
          }
        }
      }
    }
  
    if (bFireTransferring) {
      // Send a STATE_TRANSFERRING notification for the request.
      int32_t flags;
      
      flags = nsIWebProgressListener::STATE_TRANSFERRING |
              nsIWebProgressListener::STATE_IS_REQUEST;
      //
      // Move the WebProgress into the STATE_TRANSFERRING state if necessary...
      //
      if (mProgressStateFlags & nsIWebProgressListener::STATE_START) {
        mProgressStateFlags = nsIWebProgressListener::STATE_TRANSFERRING;
  
        // Send STATE_TRANSFERRING for the document too...
        flags |= nsIWebProgressListener::STATE_IS_DOCUMENT;
      }
  
      FireOnStateChange(this, aRequest, flags, NS_OK);
    }
  
    //
    // Fire the OnStateChange(...) notification for stop request
    //
    doStopURLLoad(aRequest, aStatus);
    
    // Clear this request out of the hash to avoid bypass of FireOnStateChange
    // when address of the request is reused.
    RemoveRequestInfo(aRequest);
    
    //
    // Only fire the DocLoaderIsEmpty(...) if the document loader has initiated a
    // load.  This will handle removing the request from our hashtable as needed.
    //
    if (mIsLoadingDocument) {
      DocLoaderIsEmpty(true);
    }
    
    return NS_OK;
  }
  
  
  nsresult nsDocLoader::RemoveChildLoader(nsDocLoader* aChild)
  {
    nsresult rv = mChildList.RemoveElement(aChild) ? NS_OK : NS_ERROR_FAILURE;
    if (NS_SUCCEEDED(rv)) {
      aChild->SetDocLoaderParent(nullptr);
    }
    return rv;
  }
  
  nsresult nsDocLoader::AddChildLoader(nsDocLoader* aChild)
  {
    nsresult rv = mChildList.AppendElement(aChild) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
    if (NS_SUCCEEDED(rv)) {
      aChild->SetDocLoaderParent(this);
    }
    return rv;
  }
  
  NS_IMETHODIMP nsDocLoader::GetDocumentChannel(nsIChannel ** aChannel)
  {
    if (!mDocumentRequest) {
      *aChannel = nullptr;
      return NS_OK;
    }
    
    return CallQueryInterface(mDocumentRequest, aChannel);
  }
  
  
  void nsDocLoader::DocLoaderIsEmpty(bool aFlushLayout)
  {
    if (mIsLoadingDocument) {
      /* In the unimagineably rude circumstance that onload event handlers
         triggered by this function actually kill the window ... ok, it's
         not unimagineable; it's happened ... this deathgrip keeps this object
         alive long enough to survive this function call. */
      nsCOMPtr<nsIDocumentLoader> kungFuDeathGrip(this);
  
      // Don't flush layout if we're still busy.
      if (IsBusy()) {
        return;
      }
  
      NS_ASSERTION(!mIsFlushingLayout, "Someone screwed up");
  
      // The load group for this DocumentLoader is idle.  Flush if we need to.
      if (aFlushLayout && !mDontFlushLayout) {
        nsCOMPtr<nsIDOMDocument> domDoc = do_GetInterface(GetAsSupports(this));
        nsCOMPtr<nsIDocument> doc = do_QueryInterface(domDoc);
        if (doc) {
          // We start loads from style resolution, so we need to flush out style
          // no matter what.  If we have user fonts, we also need to flush layout,
          // since the reflow is what starts font loads.
          mozFlushType flushType = Flush_Style;
          nsIPresShell* shell = doc->GetShell();
          if (shell) {
            // Be safe in case this presshell is in teardown now
            nsPresContext* presContext = shell->GetPresContext();
            if (presContext && presContext->GetUserFontSet()) {
              flushType = Flush_Layout;
            }
          }
          mDontFlushLayout = mIsFlushingLayout = true;
          doc->FlushPendingNotifications(flushType);
          mDontFlushLayout = mIsFlushingLayout = false;
        }
      }
  
      // And now check whether we're really busy; that might have changed with
      // the layout flush.
      if (!IsBusy()) {
        // Clear out our request info hash, now that our load really is done and
        // we don't need it anymore to CalculateMaxProgress().
        ClearInternalProgress();
  
        PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
               ("DocLoader:%p: Is now idle...\n", this));
  
        nsCOMPtr<nsIRequest> docRequest = mDocumentRequest;
  
        NS_ASSERTION(mDocumentRequest, "No Document Request!");
        mDocumentRequest = 0;
        mIsLoadingDocument = false;
  
        // Update the progress status state - the document is done
        mProgressStateFlags = nsIWebProgressListener::STATE_STOP;
  
  
        nsresult loadGroupStatus = NS_OK; 
        mLoadGroup->GetStatus(&loadGroupStatus);
  
        // 
        // New code to break the circular reference between 
        // the load group and the docloader... 
        // 
        mLoadGroup->SetDefaultLoadRequest(nullptr); 
  
        // Take a ref to our parent now so that we can call DocLoaderIsEmpty() on
        // it even if our onload handler removes us from the docloader tree.
        nsRefPtr<nsDocLoader> parent = mParent;
  
        // Note that if calling ChildEnteringOnload() on the parent returns false
        // then calling our onload handler is not safe.  That can only happen on
        // OOM, so that's ok.
        if (!parent || parent->ChildEnteringOnload(this)) {
          // Do nothing with our state after firing the
          // OnEndDocumentLoad(...). The document loader may be loading a *new*
          // document - if LoadDocument() was called from a handler!
          //
          doStopDocumentLoad(docRequest, loadGroupStatus);
  
          if (parent) {
            parent->ChildDoneWithOnload(this);
          }
        }
      }
    }
  }
  
  void nsDocLoader::doStartDocumentLoad(void)
  {
  
  #if defined(DEBUG)
    nsAutoCString buffer;
  
    GetURIStringFromRequest(mDocumentRequest, buffer);
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: ++ Firing OnStateChange for start document load (...)."
            "\tURI: %s \n",
            this, buffer.get()));
  #endif /* DEBUG */
  
    // Fire an OnStatus(...) notification STATE_START.  This indicates
    // that the document represented by mDocumentRequest has started to
    // load...
    FireOnStateChange(this,
                      mDocumentRequest,
                      nsIWebProgressListener::STATE_START |
                      nsIWebProgressListener::STATE_IS_DOCUMENT |
                      nsIWebProgressListener::STATE_IS_REQUEST |
                      nsIWebProgressListener::STATE_IS_WINDOW |
                      nsIWebProgressListener::STATE_IS_NETWORK,
                      NS_OK);
  }
  
  void nsDocLoader::doStartURLLoad(nsIRequest *request)
  {
  #if defined(DEBUG)
    nsAutoCString buffer;
  
    GetURIStringFromRequest(request, buffer);
      PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
            ("DocLoader:%p: ++ Firing OnStateChange start url load (...)."
             "\tURI: %s\n",
              this, buffer.get()));
  #endif /* DEBUG */
  
    FireOnStateChange(this,
                      request,
                      nsIWebProgressListener::STATE_START |
                      nsIWebProgressListener::STATE_IS_REQUEST,
                      NS_OK);
  }
  
  void nsDocLoader::doStopURLLoad(nsIRequest *request, nsresult aStatus)
  {
  #if defined(DEBUG)
    nsAutoCString buffer;
  
    GetURIStringFromRequest(request, buffer);
      PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
            ("DocLoader:%p: ++ Firing OnStateChange for end url load (...)."
             "\tURI: %s status=%x\n",
              this, buffer.get(), aStatus));
  #endif /* DEBUG */
  
    FireOnStateChange(this,
                      request,
                      nsIWebProgressListener::STATE_STOP |
                      nsIWebProgressListener::STATE_IS_REQUEST,
                      aStatus);
  
    // Fire a status change message for the most recent unfinished
    // request to make sure that the displayed status is not outdated.
    if (!PR_CLIST_IS_EMPTY(&mStatusInfoList)) {
      nsStatusInfo* statusInfo =
        static_cast<nsStatusInfo*>(PR_LIST_HEAD(&mStatusInfoList));
      FireOnStatusChange(this, statusInfo->mRequest,
                         statusInfo->mStatusCode,
                         statusInfo->mStatusMessage.get());
    }
  }
  
  void nsDocLoader::doStopDocumentLoad(nsIRequest *request,
                                           nsresult aStatus)
  {
  #if defined(DEBUG)
    nsAutoCString buffer;
  
    GetURIStringFromRequest(request, buffer);
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: ++ Firing OnStateChange for end document load (...)."
           "\tURI: %s Status=%x\n",
            this, buffer.get(), aStatus));
  #endif /* DEBUG */
  
    // Firing STATE_STOP|STATE_IS_DOCUMENT will fire onload handlers.
    // Grab our parent chain before doing that so we can still dispatch
    // STATE_STOP|STATE_IS_WINDW_STATE_IS_NETWORK to them all, even if
    // the onload handlers rearrange the docshell tree.
    WebProgressList list;
    GatherAncestorWebProgresses(list);
    
    //
    // Fire an OnStateChange(...) notification indicating the the
    // current document has finished loading...
    //
    int32_t flags = nsIWebProgressListener::STATE_STOP |
                    nsIWebProgressListener::STATE_IS_DOCUMENT;
    for (uint32_t i = 0; i < list.Length(); ++i) {
      list[i]->DoFireOnStateChange(this, request, flags, aStatus);
    }
  
    //
    // Fire a final OnStateChange(...) notification indicating the the
    // current document has finished loading...
    //
    flags = nsIWebProgressListener::STATE_STOP |
            nsIWebProgressListener::STATE_IS_WINDOW |
            nsIWebProgressListener::STATE_IS_NETWORK;
    for (uint32_t i = 0; i < list.Length(); ++i) {
      list[i]->DoFireOnStateChange(this, request, flags, aStatus);
    }
  }
  
  ////////////////////////////////////////////////////////////////////////////////////
  // The following section contains support for nsIWebProgress and related stuff
  ////////////////////////////////////////////////////////////////////////////////////
  
  NS_IMETHODIMP
  nsDocLoader::AddProgressListener(nsIWebProgressListener *aListener,
                                       uint32_t aNotifyMask)
  {
    nsresult rv;
  
    nsListenerInfo* info = GetListenerInfo(aListener);
    if (info) {
      // The listener is already registered!
      return NS_ERROR_FAILURE;
    }
  
    nsWeakPtr listener = do_GetWeakReference(aListener);
    if (!listener) {
      return NS_ERROR_INVALID_ARG;
    }
  
    info = new nsListenerInfo(listener, aNotifyMask);
    if (!info) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
  
    rv = mListenerInfoList.AppendElement(info) ? NS_OK : NS_ERROR_FAILURE;
    return rv;
  }
  
  NS_IMETHODIMP
  nsDocLoader::RemoveProgressListener(nsIWebProgressListener *aListener)
  {
    nsresult rv;
  
    nsListenerInfo* info = GetListenerInfo(aListener);
    if (info) {
      rv = mListenerInfoList.RemoveElement(info) ? NS_OK : NS_ERROR_FAILURE;
      delete info;
    } else {
      // The listener is not registered!
      rv = NS_ERROR_FAILURE;
    }
    return rv;
  }
  
  NS_IMETHODIMP
  nsDocLoader::GetDOMWindow(nsIDOMWindow **aResult)
  {
    return CallGetInterface(this, aResult);
  }
  
  NS_IMETHODIMP
  nsDocLoader::GetIsLoadingDocument(bool *aIsLoadingDocument)
  {
    *aIsLoadingDocument = mIsLoadingDocument;
  
    return NS_OK;
  }
  
  int64_t nsDocLoader::GetMaxTotalProgress()
  {
    int64_t newMaxTotal = 0;
  
    int32_t count = mChildList.Count();
    nsCOMPtr<nsIWebProgress> webProgress;
    for (int32_t i=0; i < count; i++) 
    {
      int64_t individualProgress = 0;
      nsIDocumentLoader* docloader = ChildAt(i);
      if (docloader)
      {
        // Cast is safe since all children are nsDocLoader too
        individualProgress = ((nsDocLoader *) docloader)->GetMaxTotalProgress();
      }
      if (individualProgress < int64_t(0)) // if one of the elements doesn't know it's size
                                           // then none of them do
      {
         newMaxTotal = int64_t(-1);
         break;
      }
      else
       newMaxTotal += individualProgress;
    }
  
    int64_t progress = -1;
    if (mMaxSelfProgress >= int64_t(0) && newMaxTotal >= int64_t(0))
      progress = newMaxTotal + mMaxSelfProgress;
    
    return progress;
  }
  
  ////////////////////////////////////////////////////////////////////////////////////
  // The following section contains support for nsIProgressEventSink which is used to 
  // pass progress and status between the actual request and the doc loader. The doc loader
  // then turns around and makes the right web progress calls based on this information.
  ////////////////////////////////////////////////////////////////////////////////////
  
  NS_IMETHODIMP nsDocLoader::OnProgress(nsIRequest *aRequest, nsISupports* ctxt, 
                                        uint64_t aProgress, uint64_t aProgressMax)
  {
    nsRequestInfo *info;
    int64_t progressDelta = 0;
  
    //
    // Update the RequestInfo entry with the new progress data
    //
    info = GetRequestInfo(aRequest);
    if (info) {
      // suppress sending STATE_TRANSFERRING if this is upload progress (see bug 240053)
      if (!info->mUploading && (int64_t(0) == info->mCurrentProgress) && (int64_t(0) == info->mMaxProgress)) {
        //
        // If we receive an OnProgress event from a toplevel channel that the URI Loader
        // has not yet targeted, then we must suppress the event.  This is necessary to
        // ensure that webprogresslisteners do not get confused when the channel is
        // finally targeted.  See bug 257308.
        //
        nsLoadFlags lf = 0;
        aRequest->GetLoadFlags(&lf);
        if ((lf & nsIChannel::LOAD_DOCUMENT_URI) && !(lf & nsIChannel::LOAD_TARGETED)) {
          PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
              ("DocLoader:%p Ignoring OnProgress while load is not targeted\n", this));
          return NS_OK;
        }
  
        //
        // This is the first progress notification for the entry.  If
        // (aMaxProgress > 0) then the content-length of the data is known,
        // so update mMaxSelfProgress...  Otherwise, set it to -1 to indicate
        // that the content-length is no longer known.
        //
        if (uint64_t(aProgressMax) != UINT64_MAX) {
          mMaxSelfProgress  += int64_t(aProgressMax);
          info->mMaxProgress = int64_t(aProgressMax);
        } else {
          mMaxSelfProgress   =  int64_t(-1);
          info->mMaxProgress =  int64_t(-1);
        }
  
        // Send a STATE_TRANSFERRING notification for the request.
        int32_t flags;
      
        flags = nsIWebProgressListener::STATE_TRANSFERRING | 
                nsIWebProgressListener::STATE_IS_REQUEST;
        //
        // Move the WebProgress into the STATE_TRANSFERRING state if necessary...
        //
        if (mProgressStateFlags & nsIWebProgressListener::STATE_START) {
          mProgressStateFlags = nsIWebProgressListener::STATE_TRANSFERRING;
  
          // Send STATE_TRANSFERRING for the document too...
          flags |= nsIWebProgressListener::STATE_IS_DOCUMENT;
        }
  
        FireOnStateChange(this, aRequest, flags, NS_OK);
      }
  
      // Update the current progress count...
      progressDelta = int64_t(aProgress) - info->mCurrentProgress;
      mCurrentSelfProgress += progressDelta;
  
      info->mCurrentProgress = int64_t(aProgress);
    }
    //
    // The request is not part of the load group, so ignore its progress
    // information...
    //
    else {
  #if defined(DEBUG)
      nsAutoCString buffer;
  
      GetURIStringFromRequest(aRequest, buffer);
      PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
             ("DocLoader:%p OOPS - No Request Info for: %s\n",
              this, buffer.get()));
  #endif /* DEBUG */
  
      return NS_OK;
    }
  
    //
    // Fire progress notifications out to any registered nsIWebProgressListeners
    //
    FireOnProgressChange(this, aRequest, aProgress, aProgressMax, progressDelta,
                         mCurrentTotalProgress, mMaxTotalProgress);
  
    return NS_OK;
  }
  
  NS_IMETHODIMP nsDocLoader::OnStatus(nsIRequest* aRequest, nsISupports* ctxt, 
                                          nsresult aStatus, const PRUnichar* aStatusArg)
  {
    //
    // Fire progress notifications out to any registered nsIWebProgressListeners
    //
    if (aStatus != NS_OK) {
      // Remember the current status for this request
      nsRequestInfo *info;
      info = GetRequestInfo(aRequest);
      if (info) {
        bool uploading = (aStatus == NS_NET_STATUS_WRITING ||
                          aStatus == NS_NET_STATUS_SENDING_TO);
        // If switching from uploading to downloading (or vice versa), then we
        // need to reset our progress counts.  This is designed with HTTP form
        // submission in mind, where an upload is performed followed by download
        // of possibly several documents.
        if (info->mUploading != uploading) {
          mCurrentSelfProgress  = mMaxSelfProgress  = LL_ZERO;
          mCurrentTotalProgress = mMaxTotalProgress = LL_ZERO;
          mCompletedTotalProgress = LL_ZERO;
          info->mUploading = uploading;
          info->mCurrentProgress = LL_ZERO;
          info->mMaxProgress = LL_ZERO;
        }
      }
  
      nsCOMPtr<nsIStringBundleService> sbs =
        mozilla::services::GetStringBundleService();
      if (!sbs)
        return NS_ERROR_FAILURE;
      nsXPIDLString msg;
      nsresult rv = sbs->FormatStatusMessage(aStatus, aStatusArg,
                                             getter_Copies(msg));
      if (NS_FAILED(rv))
        return rv;
  
      // Keep around the message. In case a request finishes, we need to make sure
      // to send the status message of another request to our user to that we
      // don't display, for example, "Transferring" messages for requests that are
      // already done.
      if (info) {
        if (!info->mLastStatus) {
          info->mLastStatus = new nsStatusInfo(aRequest);
        } else {
          // We're going to move it to the front of the list, so remove
          // it from wherever it is now.
          PR_REMOVE_LINK(info->mLastStatus);
        }
        info->mLastStatus->mStatusMessage = msg;
        info->mLastStatus->mStatusCode = aStatus;
        // Put the info at the front of the list
        PR_INSERT_LINK(info->mLastStatus, &mStatusInfoList);
      }
      FireOnStatusChange(this, aRequest, aStatus, msg);
    }
    return NS_OK;
  }
  
  void nsDocLoader::ClearInternalProgress()
  {
    ClearRequestInfoHash();
  
    mCurrentSelfProgress  = mMaxSelfProgress  = LL_ZERO;
    mCurrentTotalProgress = mMaxTotalProgress = LL_ZERO;
    mCompletedTotalProgress = LL_ZERO;
  
    mProgressStateFlags = nsIWebProgressListener::STATE_STOP;
  }
  
  
  void nsDocLoader::FireOnProgressChange(nsDocLoader *aLoadInitiator,
                                         nsIRequest *request,
                                         int64_t aProgress,
                                         int64_t aProgressMax,
                                         int64_t aProgressDelta,
                                         int64_t aTotalProgress,
                                         int64_t aMaxTotalProgress)
  {
    if (mIsLoadingDocument) {
      mCurrentTotalProgress += aProgressDelta;
      mMaxTotalProgress = GetMaxTotalProgress();
  
      aTotalProgress    = mCurrentTotalProgress;
      aMaxTotalProgress = mMaxTotalProgress;
    }
  
  #if defined(DEBUG)
    nsAutoCString buffer;
  
    GetURIStringFromRequest(request, buffer);
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: Progress (%s): curSelf: %d maxSelf: %d curTotal: %d maxTotal %d\n",
            this, buffer.get(), aProgress, aProgressMax, aTotalProgress, aMaxTotalProgress));
  #endif /* DEBUG */
  
    /*
     * First notify any listeners of the new progress info...
     *
     * Operate the elements from back to front so that if items get
     * get removed from the list it won't affect our iteration
     */
    nsCOMPtr<nsIWebProgressListener> listener;
    int32_t count = mListenerInfoList.Count();
  
    while (--count >= 0) {
      nsListenerInfo *info;
  
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(count));
      if (!info || !(info->mNotifyMask & nsIWebProgress::NOTIFY_PROGRESS)) {
        continue;
      }
  
      listener = do_QueryReferent(info->mWeakListener);
      if (!listener) {
        // the listener went away. gracefully pull it out of the list.
        mListenerInfoList.RemoveElementAt(count);
        delete info;
        continue;
      }
  
      // XXX truncates 64-bit to 32-bit
      listener->OnProgressChange(aLoadInitiator,request,
                                 int32_t(aProgress), int32_t(aProgressMax),
                                 int32_t(aTotalProgress), int32_t(aMaxTotalProgress));
    }
  
    mListenerInfoList.Compact();
  
    // Pass the notification up to the parent...
    if (mParent) {
      mParent->FireOnProgressChange(aLoadInitiator, request,
                                    aProgress, aProgressMax,
                                    aProgressDelta,
                                    aTotalProgress, aMaxTotalProgress);
    }
  }
  
  void nsDocLoader::GatherAncestorWebProgresses(WebProgressList& aList)
  {
    for (nsDocLoader* loader = this; loader; loader = loader->mParent) {
      aList.AppendElement(loader);
    }
  }
  
  void nsDocLoader::FireOnStateChange(nsIWebProgress *aProgress,
                                      nsIRequest *aRequest,
                                      int32_t aStateFlags,
                                      nsresult aStatus)
  {
    WebProgressList list;
    GatherAncestorWebProgresses(list);
    for (uint32_t i = 0; i < list.Length(); ++i) {
      list[i]->DoFireOnStateChange(aProgress, aRequest, aStateFlags, aStatus);
    }
  }
  
  void nsDocLoader::DoFireOnStateChange(nsIWebProgress * const aProgress,
                                        nsIRequest * const aRequest,
                                        int32_t &aStateFlags,
                                        const nsresult aStatus)
  {
    //
    // Remove the STATE_IS_NETWORK bit if necessary.
    //
    // The rule is to remove this bit, if the notification has been passed
    // up from a child WebProgress, and the current WebProgress is already
    // active...
    //
    if (mIsLoadingDocument &&
        (aStateFlags & nsIWebProgressListener::STATE_IS_NETWORK) && 
        (this != aProgress)) {
      aStateFlags &= ~nsIWebProgressListener::STATE_IS_NETWORK;
    }
  
    // Add the STATE_RESTORING bit if necessary.
    if (mIsRestoringDocument)
      aStateFlags |= nsIWebProgressListener::STATE_RESTORING;
  
  #if defined(DEBUG)
    nsAutoCString buffer;
  
    GetURIStringFromRequest(aRequest, buffer);
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: Status (%s): code: %x\n",
           this, buffer.get(), aStateFlags));
  #endif /* DEBUG */
  
    NS_ASSERTION(aRequest, "Firing OnStateChange(...) notification with a NULL request!");
  
    /*                                                                           
     * First notify any listeners of the new state info...
     *
     * Operate the elements from back to front so that if items get
     * get removed from the list it won't affect our iteration
     */
    nsCOMPtr<nsIWebProgressListener> listener;
    int32_t count = mListenerInfoList.Count();
    int32_t notifyMask = (aStateFlags >> 16) & nsIWebProgress::NOTIFY_STATE_ALL;
  
    while (--count >= 0) {
      nsListenerInfo *info;
  
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(count));
      if (!info || !(info->mNotifyMask & notifyMask)) {
        continue;
      }
  
      listener = do_QueryReferent(info->mWeakListener);
      if (!listener) {
        // the listener went away. gracefully pull it out of the list.
        mListenerInfoList.RemoveElementAt(count);
        delete info;
        continue;
      }
  
      listener->OnStateChange(aProgress, aRequest, aStateFlags, aStatus);
    }
  
    mListenerInfoList.Compact();
  }
  
  
  
  void
  nsDocLoader::FireOnLocationChange(nsIWebProgress* aWebProgress,
                                    nsIRequest* aRequest,
                                    nsIURI *aUri,
                                    uint32_t aFlags)
  {
    /*                                                                           
     * First notify any listeners of the new state info...
     *
     * Operate the elements from back to front so that if items get
     * get removed from the list it won't affect our iteration
     */
    nsCOMPtr<nsIWebProgressListener> listener;
    int32_t count = mListenerInfoList.Count();
  
    while (--count >= 0) {
      nsListenerInfo *info;
  
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(count));
      if (!info || !(info->mNotifyMask & nsIWebProgress::NOTIFY_LOCATION)) {
        continue;
      }
  
      listener = do_QueryReferent(info->mWeakListener);
      if (!listener) {
        // the listener went away. gracefully pull it out of the list.
        mListenerInfoList.RemoveElementAt(count);
        delete info;
        continue;
      }
  
      PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, ("DocLoader [%p] calling %p->OnLocationChange", this, listener.get()));
      listener->OnLocationChange(aWebProgress, aRequest, aUri, aFlags);
    }
  
    mListenerInfoList.Compact();
  
    // Pass the notification up to the parent...
    if (mParent) {
      mParent->FireOnLocationChange(aWebProgress, aRequest, aUri, aFlags);
    }
  }
  
  void
  nsDocLoader::FireOnStatusChange(nsIWebProgress* aWebProgress,
                                  nsIRequest* aRequest,
                                  nsresult aStatus,
                                  const PRUnichar* aMessage)
  {
    /*                                                                           
     * First notify any listeners of the new state info...
     *
     * Operate the elements from back to front so that if items get
     * get removed from the list it won't affect our iteration
     */
    nsCOMPtr<nsIWebProgressListener> listener;
    int32_t count = mListenerInfoList.Count();
  
    while (--count >= 0) {
      nsListenerInfo *info;
  
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(count));
      if (!info || !(info->mNotifyMask & nsIWebProgress::NOTIFY_STATUS)) {
        continue;
      }
  
      listener = do_QueryReferent(info->mWeakListener);
      if (!listener) {
        // the listener went away. gracefully pull it out of the list.
        mListenerInfoList.RemoveElementAt(count);
        delete info;
        continue;
      }
  
      listener->OnStatusChange(aWebProgress, aRequest, aStatus, aMessage);
    }
    mListenerInfoList.Compact();
    
    // Pass the notification up to the parent...
    if (mParent) {
      mParent->FireOnStatusChange(aWebProgress, aRequest, aStatus, aMessage);
    }
  }
  
  bool
  nsDocLoader::RefreshAttempted(nsIWebProgress* aWebProgress,
                                nsIURI *aURI,
                                int32_t aDelay,
                                bool aSameURI)
  {
    /*
     * Returns true if the refresh may proceed,
     * false if the refresh should be blocked.
     *
     * First notify any listeners of the refresh attempt...
     *
     * Iterate the elements from back to front so that if items
     * get removed from the list it won't affect our iteration
     */
    bool allowRefresh = true;
    int32_t count = mListenerInfoList.Count();
  
    while (--count >= 0) {
      nsListenerInfo *info;
  
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(count));
      if (!info || !(info->mNotifyMask & nsIWebProgress::NOTIFY_REFRESH)) {
        continue;
      }
  
      nsCOMPtr<nsIWebProgressListener> listener =
        do_QueryReferent(info->mWeakListener);
      if (!listener) {
        // the listener went away. gracefully pull it out of the list.
        mListenerInfoList.RemoveElementAt(count);
        delete info;
        continue;
      }
  
      nsCOMPtr<nsIWebProgressListener2> listener2 =
        do_QueryReferent(info->mWeakListener);
      if (!listener2)
        continue;
  
      bool listenerAllowedRefresh;
      nsresult listenerRV = listener2->OnRefreshAttempted(
          aWebProgress, aURI, aDelay, aSameURI, &listenerAllowedRefresh);
      if (NS_FAILED(listenerRV))
        continue;
  
      allowRefresh = allowRefresh && listenerAllowedRefresh;
    }
  
    mListenerInfoList.Compact();
  
    // Pass the notification up to the parent...
    if (mParent) {
      allowRefresh = allowRefresh &&
        mParent->RefreshAttempted(aWebProgress, aURI, aDelay, aSameURI);
    }
  
    return allowRefresh;
  }
  
  nsListenerInfo * 
  nsDocLoader::GetListenerInfo(nsIWebProgressListener *aListener)
  {
    int32_t i, count;
    nsListenerInfo *info;
  
    nsCOMPtr<nsISupports> listener1 = do_QueryInterface(aListener);
    count = mListenerInfoList.Count();
    for (i=0; i<count; i++) {
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(i));
  
      NS_ASSERTION(info, "There should NEVER be a null listener in the list");
      if (info) {
        nsCOMPtr<nsISupports> listener2 = do_QueryReferent(info->mWeakListener);
        if (listener1 == listener2)
          return info;
      }
    }
    return nullptr;
  }
  
  nsresult nsDocLoader::AddRequestInfo(nsIRequest *aRequest)
  {
    if (!PL_DHashTableOperate(&mRequestInfoHash, aRequest, PL_DHASH_ADD)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
  
    return NS_OK;
  }
  
  void nsDocLoader::RemoveRequestInfo(nsIRequest *aRequest)
  {
    PL_DHashTableOperate(&mRequestInfoHash, aRequest, PL_DHASH_REMOVE);
  }
  
  nsRequestInfo * nsDocLoader::GetRequestInfo(nsIRequest *aRequest)
  {
    nsRequestInfo *info =
      static_cast<nsRequestInfo *>
                 (PL_DHashTableOperate(&mRequestInfoHash, aRequest,
                                          PL_DHASH_LOOKUP));
  
    if (PL_DHASH_ENTRY_IS_FREE(info)) {
      // Nothing found in the hash, return null.
  
      return nullptr;
    }
  
    // Return what we found in the hash...
  
    return info;
  }
  
  // PLDHashTable enumeration callback that just removes every entry
  // from the hash.
  static PLDHashOperator
  RemoveInfoCallback(PLDHashTable *table, PLDHashEntryHdr *hdr, uint32_t number,
                     void *arg)
  {
    return PL_DHASH_REMOVE;
  }
  
  void nsDocLoader::ClearRequestInfoHash(void)
  {
    if (!mRequestInfoHash.ops || !mRequestInfoHash.entryCount) {
      // No hash, or the hash is empty, nothing to do here then...
  
      return;
    }
  
    PL_DHashTableEnumerate(&mRequestInfoHash, RemoveInfoCallback, nullptr);
  }
  
  // PLDHashTable enumeration callback that calculates the max progress.
  static PLDHashOperator
  CalcMaxProgressCallback(PLDHashTable *table, PLDHashEntryHdr *hdr,
                          uint32_t number, void *arg)
  {
    const nsRequestInfo *info = static_cast<const nsRequestInfo *>(hdr);
    int64_t *max = static_cast<int64_t *>(arg);
  
    if (info->mMaxProgress < info->mCurrentProgress) {
      *max = int64_t(-1);
  
      return PL_DHASH_STOP;
    }
  
    *max += info->mMaxProgress;
  
    return PL_DHASH_NEXT;
  }
  
  int64_t nsDocLoader::CalculateMaxProgress()
  {
    int64_t max = mCompletedTotalProgress;
    PL_DHashTableEnumerate(&mRequestInfoHash, CalcMaxProgressCallback, &max);
    return max;
  }
  
  NS_IMETHODIMP nsDocLoader::AsyncOnChannelRedirect(nsIChannel *aOldChannel,
                                                    nsIChannel *aNewChannel,
                                                    uint32_t aFlags,
                                                    nsIAsyncVerifyRedirectCallback *cb)
  {
    if (aOldChannel)
    {
      nsLoadFlags loadFlags = 0;
      int32_t stateFlags = nsIWebProgressListener::STATE_REDIRECTING |
                           nsIWebProgressListener::STATE_IS_REQUEST;
  
      aOldChannel->GetLoadFlags(&loadFlags);
      // If the document channel is being redirected, then indicate that the
      // document is being redirected in the notification...
      if (loadFlags & nsIChannel::LOAD_DOCUMENT_URI)
      {
        stateFlags |= nsIWebProgressListener::STATE_IS_DOCUMENT;
  
  #if defined(DEBUG)
        nsCOMPtr<nsIRequest> request(do_QueryInterface(aOldChannel));
        NS_ASSERTION(request == mDocumentRequest, "Wrong Document Channel");
  #endif /* DEBUG */
      }
  
      OnRedirectStateChange(aOldChannel, aNewChannel, aFlags, stateFlags);
      FireOnStateChange(this, aOldChannel, stateFlags, NS_OK);
    }
  
    cb->OnRedirectVerifyCallback(NS_OK);
    return NS_OK;
  }
  
  /*
   * Implementation of nsISecurityEventSink method...
   */
  
  NS_IMETHODIMP nsDocLoader::OnSecurityChange(nsISupports * aContext,
                                              uint32_t aState)
  {
    //
    // Fire progress notifications out to any registered nsIWebProgressListeners.  
    //
    
    nsCOMPtr<nsIRequest> request = do_QueryInterface(aContext);
    nsIWebProgress* webProgress = static_cast<nsIWebProgress*>(this);
  
    /*                                                                           
     * First notify any listeners of the new state info...
     *
     * Operate the elements from back to front so that if items get
     * get removed from the list it won't affect our iteration
     */
    nsCOMPtr<nsIWebProgressListener> listener;
    int32_t count = mListenerInfoList.Count();
  
    while (--count >= 0) {
      nsListenerInfo *info;
  
      info = static_cast<nsListenerInfo*>(mListenerInfoList.SafeElementAt(count));
      if (!info || !(info->mNotifyMask & nsIWebProgress::NOTIFY_SECURITY)) {
        continue;
      }
  
      listener = do_QueryReferent(info->mWeakListener);
      if (!listener) {
        // the listener went away. gracefully pull it out of the list.
        mListenerInfoList.RemoveElementAt(count);
        delete info;
        continue;
      }
  
      listener->OnSecurityChange(webProgress, request, aState);
    }
  
    mListenerInfoList.Compact();
  
    // Pass the notification up to the parent...
    if (mParent) {
      mParent->OnSecurityChange(aContext, aState);
    }
    return NS_OK;
  }
  
  /*
   * Implementation of nsISupportsPriority methods...
   *
   * The priority of the DocLoader _is_ the priority of its LoadGroup.
   *
   * XXX(darin): Once we start storing loadgroups in loadgroups, this code will
   * go away. 
   */
  
  NS_IMETHODIMP nsDocLoader::GetPriority(int32_t *aPriority)
  {
    nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(mLoadGroup);
    if (p)
      return p->GetPriority(aPriority);
  
    *aPriority = 0;
    return NS_OK;
  }
  
  NS_IMETHODIMP nsDocLoader::SetPriority(int32_t aPriority)
  {
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: SetPriority(%d) called\n", this, aPriority));
  
    nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(mLoadGroup);
    if (p)
      p->SetPriority(aPriority);
  
    int32_t count = mChildList.Count();
  
    nsDocLoader *loader;
    for (int32_t i=0; i < count; i++) {
      loader = static_cast<nsDocLoader*>(ChildAt(i));
      if (loader) {
        loader->SetPriority(aPriority);
      }
    }
  
    return NS_OK;
  }
  
  NS_IMETHODIMP nsDocLoader::AdjustPriority(int32_t aDelta)
  {
    PR_LOG(gDocLoaderLog, PR_LOG_DEBUG, 
           ("DocLoader:%p: AdjustPriority(%d) called\n", this, aDelta));
  
    nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(mLoadGroup);
    if (p)
      p->AdjustPriority(aDelta);
  
    int32_t count = mChildList.Count();
  
    nsDocLoader *loader;
    for (int32_t i=0; i < count; i++) {
      loader = static_cast<nsDocLoader*>(ChildAt(i));
      if (loader) {
        loader->AdjustPriority(aDelta);
      }
    }
  
    return NS_OK;
  }
  
  
  
  
  #if 0
  void nsDocLoader::DumpChannelInfo()
  {
    nsChannelInfo *info;
    int32_t i, count;
    int32_t current=0, max=0;
  
    
    printf("==== DocLoader=%x\n", this);
  
    count = mChannelInfoList.Count();
    for(i=0; i<count; i++) {
      info = (nsChannelInfo *)mChannelInfoList.ElementAt(i);
  
  #if defined(DEBUG)
      nsAutoCString buffer;
      nsresult rv = NS_OK;
      if (info->mURI) {
        rv = info->mURI->GetSpec(buffer);
      }
  
      printf("  [%d] current=%d  max=%d [%s]\n", i,
             info->mCurrentProgress, 
             info->mMaxProgress, buffer.get());
  #endif /* DEBUG */
  
      current += info->mCurrentProgress;
      if (max >= 0) {
        if (info->mMaxProgress < info->mCurrentProgress) {
          max = -1;
        } else {
          max += info->mMaxProgress;
        }
      }
    }
  
    printf("\nCurrent=%d   Total=%d\n====\n", current, max);
  }
  #endif /* 0 */
  