LCOV - code coverage report
Current view: directory - objdir/dist/include - nsScriptLoader.h (source / functions) Found Hit Coverage
Test: app.info Lines: 33 2 6.1 %
Date: 2012-06-02 Functions: 8 1 12.5 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2                 : /* ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is Mozilla.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is
      18                 :  * Netscape Communications.
      19                 :  * Portions created by the Initial Developer are Copyright (C) 2001
      20                 :  * the Initial Developer. All Rights Reserved.
      21                 :  *
      22                 :  * Contributor(s):
      23                 :  *   Vidur Apparao <vidur@netscape.com> (original author)
      24                 :  *
      25                 :  * Alternatively, the contents of this file may be used under the terms of
      26                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      27                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      28                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      29                 :  * of those above. If you wish to allow use of your version of this file only
      30                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      31                 :  * use your version of this file under the terms of the MPL, indicate your
      32                 :  * decision by deleting the provisions above and replace them with the notice
      33                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      34                 :  * the provisions above, a recipient may use your version of this file under
      35                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      36                 :  *
      37                 :  * ***** END LICENSE BLOCK ***** */
      38                 : 
      39                 : /*
      40                 :  * A class that handles loading and evaluation of <script> elements.
      41                 :  */
      42                 : 
      43                 : #ifndef __nsScriptLoader_h__
      44                 : #define __nsScriptLoader_h__
      45                 : 
      46                 : #include "nsCOMPtr.h"
      47                 : #include "nsIScriptElement.h"
      48                 : #include "nsIURI.h"
      49                 : #include "nsCOMArray.h"
      50                 : #include "nsTArray.h"
      51                 : #include "nsAutoPtr.h"
      52                 : #include "nsIDocument.h"
      53                 : #include "nsIStreamLoader.h"
      54                 : 
      55                 : class nsScriptLoadRequest;
      56                 : 
      57                 : //////////////////////////////////////////////////////////////
      58                 : // Script loader implementation
      59                 : //////////////////////////////////////////////////////////////
      60                 : 
      61                 : class nsScriptLoader : public nsIStreamLoaderObserver
      62                 : {
      63                 :   friend class nsScriptRequestProcessor;
      64                 : public:
      65                 :   nsScriptLoader(nsIDocument* aDocument);
      66                 :   virtual ~nsScriptLoader();
      67                 : 
      68                 :   NS_DECL_ISUPPORTS
      69                 :   NS_DECL_NSISTREAMLOADEROBSERVER
      70                 : 
      71                 :   /**
      72                 :    * The loader maintains a weak reference to the document with
      73                 :    * which it is initialized. This call forces the reference to
      74                 :    * be dropped.
      75                 :    */
      76                 :   void DropDocumentReference()
      77                 :   {
      78                 :     mDocument = nsnull;
      79                 :   }
      80                 : 
      81                 :   /**
      82                 :    * Add an observer for all scripts loaded through this loader.
      83                 :    *
      84                 :    * @param aObserver observer for all script processing.
      85                 :    */
      86               0 :   nsresult AddObserver(nsIScriptLoaderObserver* aObserver)
      87                 :   {
      88               0 :     return mObservers.AppendObject(aObserver) ? NS_OK :
      89               0 :       NS_ERROR_OUT_OF_MEMORY;
      90                 :   }
      91                 : 
      92                 :   /**
      93                 :    * Remove an observer.
      94                 :    *
      95                 :    * @param aObserver observer to be removed
      96                 :    */
      97               0 :   void RemoveObserver(nsIScriptLoaderObserver* aObserver)
      98                 :   {
      99               0 :     mObservers.RemoveObject(aObserver);
     100               0 :   }
     101                 :   
     102                 :   /**
     103                 :    * Process a script element. This will include both loading the 
     104                 :    * source of the element if it is not inline and evaluating
     105                 :    * the script itself.
     106                 :    *
     107                 :    * If the script is an inline script that can be executed immediately
     108                 :    * (i.e. there are no other scripts pending) then ScriptAvailable
     109                 :    * and ScriptEvaluated will be called before the function returns.
     110                 :    *
     111                 :    * If true is returned the script could not be executed immediately.
     112                 :    * In this case ScriptAvailable is guaranteed to be called at a later
     113                 :    * point (as well as possibly ScriptEvaluated).
     114                 :    *
     115                 :    * @param aElement The element representing the script to be loaded and
     116                 :    *        evaluated.
     117                 :    */
     118                 :   bool ProcessScriptElement(nsIScriptElement* aElement);
     119                 : 
     120                 :   /**
     121                 :    * Gets the currently executing script. This is useful if you want to
     122                 :    * generate a unique key based on the currently executing script.
     123                 :    */
     124                 :   nsIScriptElement* GetCurrentScript()
     125                 :   {
     126                 :     return mCurrentScript;
     127                 :   }
     128                 : 
     129                 :   nsIScriptElement* GetCurrentParserInsertedScript()
     130                 :   {
     131                 :     return mCurrentParserInsertedScript;
     132                 :   }
     133                 : 
     134                 :   /**
     135                 :    * Whether the loader is enabled or not.
     136                 :    * When disabled, processing of new script elements is disabled. 
     137                 :    * Any call to ProcessScriptElement() will return false. Note that
     138                 :    * this DOES NOT disable currently loading or executing scripts.
     139                 :    */
     140               1 :   bool GetEnabled()
     141                 :   {
     142               1 :     return mEnabled;
     143                 :   }
     144               0 :   void SetEnabled(bool aEnabled)
     145                 :   {
     146               0 :     if (!mEnabled && aEnabled) {
     147               0 :       ProcessPendingRequestsAsync();
     148                 :     }
     149               0 :     mEnabled = aEnabled;
     150               0 :   }
     151                 : 
     152                 :   /**
     153                 :    * Add/remove blocker. Blockers will stop scripts from executing, but not
     154                 :    * from loading.
     155                 :    */
     156               0 :   void AddExecuteBlocker()
     157                 :   {
     158               0 :     ++mBlockerCount;
     159               0 :   }
     160                 :   void RemoveExecuteBlocker()
     161                 :   {
     162                 :     if (!--mBlockerCount) {
     163                 :       ProcessPendingRequestsAsync();
     164                 :     }
     165                 :   }
     166                 : 
     167                 :   /**
     168                 :    * Convert the given buffer to a UTF-16 string.
     169                 :    * @param aChannel     Channel corresponding to the data. May be null.
     170                 :    * @param aData        The data to convert
     171                 :    * @param aLength      Length of the data
     172                 :    * @param aHintCharset Hint for the character set (e.g., from a charset
     173                 :    *                     attribute). May be the empty string.
     174                 :    * @param aDocument    Document which the data is loaded for. Must not be
     175                 :    *                     null.
     176                 :    * @param aString      [out] Data as converted to unicode
     177                 :    */
     178                 :   static nsresult ConvertToUTF16(nsIChannel* aChannel, const PRUint8* aData,
     179                 :                                  PRUint32 aLength,
     180                 :                                  const nsAString& aHintCharset,
     181                 :                                  nsIDocument* aDocument, nsString& aString);
     182                 : 
     183                 :   /**
     184                 :    * Processes any pending requests that are ready for processing.
     185                 :    */
     186                 :   void ProcessPendingRequests();
     187                 : 
     188                 :   /**
     189                 :    * Check whether it's OK to load a script from aURI in
     190                 :    * aDocument.
     191                 :    */
     192                 :   static nsresult ShouldLoadScript(nsIDocument* aDocument,
     193                 :                                    nsISupports* aContext,
     194                 :                                    nsIURI* aURI,
     195                 :                                    const nsAString &aType);
     196                 : 
     197                 :   /**
     198                 :    * Check whether it's OK to execute a script loaded via aChannel in
     199                 :    * aDocument.
     200                 :    */
     201                 :   static bool ShouldExecuteScript(nsIDocument* aDocument,
     202                 :                                     nsIChannel* aChannel);
     203                 : 
     204                 :   /**
     205                 :    * Starts deferring deferred scripts and puts them in the mDeferredRequests
     206                 :    * queue instead.
     207                 :    */
     208               0 :   void BeginDeferringScripts()
     209                 :   {
     210               0 :     mDeferEnabled = true;
     211               0 :     if (mDocument) {
     212               0 :       mDocument->BlockOnload();
     213                 :     }
     214               0 :   }
     215                 : 
     216                 :   /**
     217                 :    * Notifies the script loader that parsing is done.  If aTerminated is true,
     218                 :    * this will drop any pending scripts that haven't run yet.  Otherwise, it
     219                 :    * will stops deferring scripts and immediately processes the
     220                 :    * mDeferredRequests queue.
     221                 :    *
     222                 :    * WARNING: This function will synchronously execute content scripts, so be
     223                 :    * prepared that the world might change around you.
     224                 :    */
     225                 :   void ParsingComplete(bool aTerminated);
     226                 : 
     227                 :   /**
     228                 :    * Returns the number of pending scripts, deferred or not.
     229                 :    */
     230                 :   PRUint32 HasPendingOrCurrentScripts()
     231                 :   {
     232                 :     return mCurrentScript || mParserBlockingRequest;
     233                 :   }
     234                 : 
     235                 :   /**
     236                 :    * Adds aURI to the preload list and starts loading it.
     237                 :    *
     238                 :    * @param aURI The URI of the external script.
     239                 :    * @param aCharset The charset parameter for the script.
     240                 :    * @param aType The type parameter for the script.
     241                 :    * @param aCrossOrigin The crossorigin attribute for the script.
     242                 :    *                     Void if not present.
     243                 :    */
     244                 :   virtual void PreloadURI(nsIURI *aURI, const nsAString &aCharset,
     245                 :                           const nsAString &aType,
     246                 :                           const nsAString &aCrossOrigin);
     247                 : 
     248                 : private:
     249                 :   /**
     250                 :    * Unblocks the creator parser of the parser-blocking scripts.
     251                 :    */
     252                 :   void UnblockParser(nsScriptLoadRequest* aParserBlockingRequest);
     253                 : 
     254                 :   /**
     255                 :    * Asynchronously resumes the creator parser of the parser-blocking scripts.
     256                 :    */
     257                 :   void ContinueParserAsync(nsScriptLoadRequest* aParserBlockingRequest);
     258                 : 
     259                 : 
     260                 :   /**
     261                 :    * Helper function to check the content policy for a given request.
     262                 :    */
     263                 :   static nsresult CheckContentPolicy(nsIDocument* aDocument,
     264                 :                                      nsISupports *aContext,
     265                 :                                      nsIURI *aURI,
     266                 :                                      const nsAString &aType);
     267                 : 
     268                 :   /**
     269                 :    * Start a load for aRequest's URI.
     270                 :    */
     271                 :   nsresult StartLoad(nsScriptLoadRequest *aRequest, const nsAString &aType);
     272                 : 
     273                 :   /**
     274                 :    * Process any pending requests asynchronously (i.e. off an event) if there
     275                 :    * are any. Note that this is a no-op if there aren't any currently pending
     276                 :    * requests.
     277                 :    *
     278                 :    * This function is virtual to allow cross-library calls to SetEnabled()
     279                 :    */
     280                 :   virtual void ProcessPendingRequestsAsync();
     281                 : 
     282                 :   /**
     283                 :    * If true, the loader is ready to execute scripts, and so are all its
     284                 :    * ancestors.  If the loader itself is ready but some ancestor is not, this
     285                 :    * function will add an execute blocker and ask the ancestor to remove it
     286                 :    * once it becomes ready.
     287                 :    */
     288                 :   bool ReadyToExecuteScripts();
     289                 : 
     290                 :   /**
     291                 :    * Return whether just this loader is ready to execute scripts.
     292                 :    */
     293                 :   bool SelfReadyToExecuteScripts()
     294                 :   {
     295                 :     return mEnabled && !mBlockerCount;
     296                 :   }
     297                 : 
     298                 :   bool AddPendingChildLoader(nsScriptLoader* aChild) {
     299                 :     return mPendingChildLoaders.AppendElement(aChild) != nsnull;
     300                 :   }
     301                 :   
     302                 :   nsresult ProcessRequest(nsScriptLoadRequest* aRequest);
     303                 :   void FireScriptAvailable(nsresult aResult,
     304                 :                            nsScriptLoadRequest* aRequest);
     305                 :   void FireScriptEvaluated(nsresult aResult,
     306                 :                            nsScriptLoadRequest* aRequest);
     307                 :   nsresult EvaluateScript(nsScriptLoadRequest* aRequest,
     308                 :                           const nsAFlatString& aScript);
     309                 : 
     310                 :   nsresult PrepareLoadedRequest(nsScriptLoadRequest* aRequest,
     311                 :                                 nsIStreamLoader* aLoader,
     312                 :                                 nsresult aStatus,
     313                 :                                 PRUint32 aStringLen,
     314                 :                                 const PRUint8* aString);
     315                 : 
     316                 :   nsIDocument* mDocument;                   // [WEAK]
     317                 :   nsCOMArray<nsIScriptLoaderObserver> mObservers;
     318                 :   nsTArray<nsRefPtr<nsScriptLoadRequest> > mNonAsyncExternalScriptInsertedRequests;
     319                 :   nsTArray<nsRefPtr<nsScriptLoadRequest> > mAsyncRequests;
     320                 :   nsTArray<nsRefPtr<nsScriptLoadRequest> > mDeferRequests;
     321                 :   nsTArray<nsRefPtr<nsScriptLoadRequest> > mXSLTRequests;
     322                 :   nsRefPtr<nsScriptLoadRequest> mParserBlockingRequest;
     323                 : 
     324                 :   // In mRequests, the additional information here is stored by the element.
     325                 :   struct PreloadInfo {
     326                 :     nsRefPtr<nsScriptLoadRequest> mRequest;
     327                 :     nsString mCharset;
     328                 :   };
     329                 : 
     330                 :   struct PreloadRequestComparator {
     331                 :     bool Equals(const PreloadInfo &aPi, nsScriptLoadRequest * const &aRequest)
     332                 :         const
     333                 :     {
     334                 :       return aRequest == aPi.mRequest;
     335                 :     }
     336                 :   };
     337                 :   struct PreloadURIComparator {
     338                 :     bool Equals(const PreloadInfo &aPi, nsIURI * const &aURI) const;
     339                 :   };
     340                 :   nsTArray<PreloadInfo> mPreloads;
     341                 : 
     342                 :   nsCOMPtr<nsIScriptElement> mCurrentScript;
     343                 :   nsCOMPtr<nsIScriptElement> mCurrentParserInsertedScript;
     344                 :   // XXXbz do we want to cycle-collect these or something?  Not sure.
     345                 :   nsTArray< nsRefPtr<nsScriptLoader> > mPendingChildLoaders;
     346                 :   PRUint32 mBlockerCount;
     347                 :   bool mEnabled;
     348                 :   bool mDeferEnabled;
     349                 :   bool mDocumentParsingDone;
     350                 : };
     351                 : 
     352                 : class nsAutoScriptLoaderDisabler
     353                 : {
     354                 : public:
     355               0 :   nsAutoScriptLoaderDisabler(nsIDocument* aDoc)
     356               0 :   {
     357               0 :     mLoader = aDoc->ScriptLoader();
     358               0 :     mWasEnabled = mLoader->GetEnabled();
     359               0 :     if (mWasEnabled) {
     360               0 :       mLoader->SetEnabled(false);
     361                 :     }
     362               0 :   }
     363                 :   
     364               0 :   ~nsAutoScriptLoaderDisabler()
     365               0 :   {
     366               0 :     if (mWasEnabled) {
     367               0 :       mLoader->SetEnabled(true);
     368                 :     }
     369               0 :   }
     370                 :   
     371                 :   bool mWasEnabled;
     372                 :   nsRefPtr<nsScriptLoader> mLoader;
     373                 : };
     374                 : 
     375                 : #endif //__nsScriptLoader_h__

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