The Tor Browser: content/base/public/nsIScriptElement.h@97036ab72558 (annotated)

content/base/public/nsIScriptElement.h@97036ab72558 (annotated)

content/base/public/nsIScriptElement.h

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- 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 nsIScriptElement_h___
 #define nsIScriptElement_h___
 #include "nsISupports.h"
 #include "nsIURI.h"
 #include "nsCOMPtr.h"
 #include "nsIScriptLoaderObserver.h"
 #include "nsWeakPtr.h"
 #include "nsIParser.h"
 #include "nsContentCreatorFunctions.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "mozilla/CORSMode.h"
 #define NS_ISCRIPTELEMENT_IID \
 { 0x491628bc, 0xce7c, 0x4db4, \
  { 0x93, 0x3f, 0xce, 0x1b, 0x75, 0xee, 0x75, 0xce } }
 /**
  * Internal interface implemented by script elements
  */
 class nsIScriptElement : public nsIScriptLoaderObserver {
 public:
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISCRIPTELEMENT_IID)
   nsIScriptElement(mozilla::dom::FromParser aFromParser)
     : mLineNumber(0),
       mAlreadyStarted(false),
       mMalformed(false),
       mDoneAddingChildren(aFromParser == mozilla::dom::NOT_FROM_PARSER ||
                           aFromParser == mozilla::dom::FROM_PARSER_FRAGMENT),
       mForceAsync(aFromParser == mozilla::dom::NOT_FROM_PARSER ||
                   aFromParser == mozilla::dom::FROM_PARSER_FRAGMENT),
       mFrozen(false),
       mDefer(false),
       mAsync(false),
       mExternal(false),
       mParserCreated(aFromParser == mozilla::dom::FROM_PARSER_FRAGMENT ?
                      mozilla::dom::NOT_FROM_PARSER : aFromParser),
                      // Fragment parser-created scripts (if executable)
                      // behave like script-created scripts.
       mCreatorParser(nullptr)
   {
   }
   /**
    * Content type identifying the scripting language. Can be empty, in
    * which case javascript will be assumed.
    */
   virtual void GetScriptType(nsAString& type) = 0;
   /**
    * Location of script source text. Can return null, in which case
    * this is assumed to be an inline script element.
    */
   nsIURI* GetScriptURI()
   {
     NS_PRECONDITION(mFrozen, "Not ready for this call yet!");
     return mUri;
   }
   /**
    * Script source text for inline script elements.
    */
   virtual void GetScriptText(nsAString& text) = 0;
   virtual void GetScriptCharset(nsAString& charset) = 0;
   /**
    * Freezes the return values of GetScriptDeferred(), GetScriptAsync() and
    * GetScriptURI() so that subsequent modifications to the attributes don't
    * change execution behavior.
    */
   virtual void FreezeUriAsyncDefer() = 0;
   /**
    * Is the script deferred. Currently only supported by HTML scripts.
    */
   bool GetScriptDeferred()
   {
     NS_PRECONDITION(mFrozen, "Not ready for this call yet!");
     return mDefer;
   }
   /**
    * Is the script async. Currently only supported by HTML scripts.
    */
   bool GetScriptAsync()
   {
     NS_PRECONDITION(mFrozen, "Not ready for this call yet!");
     return mAsync;
   }
   /**
    * Is the script an external script?
    */
   bool GetScriptExternal()
   {
     NS_PRECONDITION(mFrozen, "Not ready for this call yet!");
     return mExternal;
   }
   /**
    * Returns how the element was created.
    */
   mozilla::dom::FromParser GetParserCreated()
   {
     return mParserCreated;
   }
   void SetScriptLineNumber(uint32_t aLineNumber)
   {
     mLineNumber = aLineNumber;
   }
   uint32_t GetScriptLineNumber()
   {
     return mLineNumber;
   }
   void SetIsMalformed()
   {
     mMalformed = true;
   }
   bool IsMalformed()
   {
     return mMalformed;
   }
   void PreventExecution()
   {
     mAlreadyStarted = true;
   }
   void LoseParserInsertedness()
   {
     mFrozen = false;
     mUri = nullptr;
     mCreatorParser = nullptr;
     mParserCreated = mozilla::dom::NOT_FROM_PARSER;
     bool async = false;
     nsCOMPtr<nsIDOMHTMLScriptElement> htmlScript = do_QueryInterface(this);
     if (htmlScript) {
       htmlScript->GetAsync(&async);
     }
     mForceAsync = !async;
   }
   void SetCreatorParser(nsIParser* aParser)
   {
     mCreatorParser = do_GetWeakReference(aParser);
   }
   /**
    * Unblocks the creator parser
    */
   void UnblockParser()
   {
     nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
     if (parser) {
       parser->UnblockParser();
     }
   }
   /**
    * Attempts to resume parsing asynchronously
    */
   void ContinueParserAsync()
   {
     nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
     if (parser) {
       parser->ContinueInterruptedParsingAsync();
     }
   }
   /**
    * Informs the creator parser that the evaluation of this script is starting
    */
   void BeginEvaluating()
   {
     nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
     if (parser) {
       parser->BeginEvaluatingParserInsertedScript();
     }
   }
   /**
    * Informs the creator parser that the evaluation of this script is ending
    */
   void EndEvaluating()
   {
     nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
     if (parser) {
       parser->EndEvaluatingParserInsertedScript();
     }
   }
   /**
    * Retrieves a pointer to the creator parser if this has one or null if not
    */
   already_AddRefed<nsIParser> GetCreatorParser()
   {
     nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
     return parser.forget();
   }
   /**
    * This method is called when the parser finishes creating the script
    * element's children, if any are present.
    *
    * @return whether the parser will be blocked while this script is being
    *         loaded
    */
   bool AttemptToExecute()
   {
     mDoneAddingChildren = true;
     bool block = MaybeProcessScript();
     if (!mAlreadyStarted) {
       // Need to lose parser-insertedness here to allow another script to cause
       // execution later.
       LoseParserInsertedness();
     }
     return block;
   }
   /**
    * Get the CORS mode of the script element
    */
   virtual mozilla::CORSMode GetCORSMode() const
   {
     /* Default to no CORS */
     return mozilla::CORS_NONE;
   }
   /**
    * Fire an error event
    */
   virtual nsresult FireErrorEvent() = 0;
 protected:
   /**
    * Processes the script if it's in the document-tree and links to or
    * contains a script. Once it has been evaluated there is no way to make it
    * reevaluate the script, you'll have to create a new element. This also means
    * that when adding a src attribute to an element that already contains an
    * inline script, the script referenced by the src attribute will not be
    * loaded.
    *
    * In order to be able to use multiple childNodes, or to use the
    * fallback mechanism of using both inline script and linked script you have
    * to add all attributes and childNodes before adding the element to the
    * document-tree.
    *
    * @return whether the parser will be blocked while this script is being
    *         loaded
    */
   virtual bool MaybeProcessScript() = 0;
   /**
    * The start line number of the script.
    */
   uint32_t mLineNumber;
   /**
    * The "already started" flag per HTML5.
    */
   bool mAlreadyStarted;
   /**
    * The script didn't have an end tag.
    */
   bool mMalformed;
   /**
    * False if parser-inserted but the parser hasn't triggered running yet.
    */
   bool mDoneAddingChildren;
   /**
    * If true, the .async property returns true instead of reflecting the
    * content attribute.
    */
   bool mForceAsync;
   /**
    * Whether src, defer and async are frozen.
    */
   bool mFrozen;
   /**
    * The effective deferredness.
    */
   bool mDefer;
   /**
    * The effective asyncness.
    */
   bool mAsync;
   /**
    * The effective externalness. A script can be external with mUri being null
    * if the src attribute contained an invalid URL string.
    */
   bool mExternal;
   /**
    * Whether this element was parser-created.
    */
   mozilla::dom::FromParser mParserCreated;
   /**
    * The effective src (or null if no src).
    */
   nsCOMPtr<nsIURI> mUri;
   /**
    * The creator parser of a non-defer, non-async parser-inserted script.
    */
   nsWeakPtr mCreatorParser;
 };
 NS_DEFINE_STATIC_IID_ACCESSOR(nsIScriptElement, NS_ISCRIPTELEMENT_IID)
 #endif // nsIScriptElement_h___

The Tor Browser / annotate

content/base/public/nsIScriptElement.h@97036ab72558 (annotated)

content/base/public/nsIScriptElement.h