The Tor Browser: layout/style/Loader.h@8bccb770b82d (annotated)

layout/style/Loader.h@8bccb770b82d (annotated)

layout/style/Loader.h

Wed, 31 Dec 2014 13:27:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 13:27:57 +0100
branch: TOR_BUG_3246
changeset 6: 8bccb770b82d
permissions: -rw-r--r--

Ignore runtime configuration files generated during quality assurance.

 /* -*- 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/. */
 /* loading of CSS style sheets using the network APIs */
 #ifndef mozilla_css_Loader_h
 #define mozilla_css_Loader_h
 #include "nsIPrincipal.h"
 #include "nsAString.h"
 #include "nsAutoPtr.h"
 #include "nsCompatibility.h"
 #include "nsDataHashtable.h"
 #include "nsInterfaceHashtable.h"
 #include "nsRefPtrHashtable.h"
 #include "nsTArray.h"
 #include "nsTObserverArray.h"
 #include "nsURIHashKey.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/CORSMode.h"
 #include "mozilla/MemoryReporting.h"
 class nsIAtom;
 class nsICSSLoaderObserver;
 class nsCSSStyleSheet;
 class nsIContent;
 class nsIDocument;
 class nsCSSParser;
 class nsMediaList;
 class nsIStyleSheetLinkingElement;
 class nsCycleCollectionTraversalCallback;
 namespace mozilla {
 namespace dom {
 class Element;
 }
 }
 namespace mozilla {
 class URIPrincipalAndCORSModeHashKey : public nsURIHashKey
 {
 public:
   typedef URIPrincipalAndCORSModeHashKey* KeyType;
   typedef const URIPrincipalAndCORSModeHashKey* KeyTypePointer;
   URIPrincipalAndCORSModeHashKey(const URIPrincipalAndCORSModeHashKey* aKey)
     : nsURIHashKey(aKey->mKey), mPrincipal(aKey->mPrincipal),
       mCORSMode(aKey->mCORSMode)
   {
     MOZ_COUNT_CTOR(URIPrincipalAndCORSModeHashKey);
   }
   URIPrincipalAndCORSModeHashKey(nsIURI* aURI, nsIPrincipal* aPrincipal,
                                  CORSMode aCORSMode)
     : nsURIHashKey(aURI), mPrincipal(aPrincipal), mCORSMode(aCORSMode)
   {
     MOZ_COUNT_CTOR(URIPrincipalAndCORSModeHashKey);
   }
   URIPrincipalAndCORSModeHashKey(const URIPrincipalAndCORSModeHashKey& toCopy)
     : nsURIHashKey(toCopy), mPrincipal(toCopy.mPrincipal),
       mCORSMode(toCopy.mCORSMode)
   {
     MOZ_COUNT_CTOR(URIPrincipalAndCORSModeHashKey);
   }
   ~URIPrincipalAndCORSModeHashKey()
   {
     MOZ_COUNT_DTOR(URIPrincipalAndCORSModeHashKey);
   }
   URIPrincipalAndCORSModeHashKey* GetKey() const {
     return const_cast<URIPrincipalAndCORSModeHashKey*>(this);
   }
   const URIPrincipalAndCORSModeHashKey* GetKeyPointer() const { return this; }
   bool KeyEquals(const URIPrincipalAndCORSModeHashKey* aKey) const {
     if (!nsURIHashKey::KeyEquals(aKey->mKey)) {
       return false;
     }
     if (!mPrincipal != !aKey->mPrincipal) {
       // One or the other has a principal, but not both... not equal
       return false;
     }
     if (mCORSMode != aKey->mCORSMode) {
       // Different CORS modes; we don't match
       return false;
     }
     bool eq;
     return !mPrincipal ||
       (NS_SUCCEEDED(mPrincipal->Equals(aKey->mPrincipal, &eq)) && eq);
   }
   static const URIPrincipalAndCORSModeHashKey*
   KeyToPointer(URIPrincipalAndCORSModeHashKey* aKey) { return aKey; }
   static PLDHashNumber HashKey(const URIPrincipalAndCORSModeHashKey* aKey) {
     return nsURIHashKey::HashKey(aKey->mKey);
   }
   nsIURI* GetURI() const { return nsURIHashKey::GetKey(); }
   enum { ALLOW_MEMMOVE = true };
 protected:
   nsCOMPtr<nsIPrincipal> mPrincipal;
   CORSMode mCORSMode;
 };
 namespace css {
 class SheetLoadData;
 class ImportRule;
 /***********************************************************************
  * Enum that describes the state of the sheet returned by CreateSheet. *
  ***********************************************************************/
 enum StyleSheetState {
   eSheetStateUnknown = 0,
   eSheetNeedsParser,
   eSheetPending,
   eSheetLoading,
   eSheetComplete
 };
 class Loader MOZ_FINAL {
 public:
   Loader();
   Loader(nsIDocument*);
  private:
   // Private destructor, to discourage deletion outside of Release():
   ~Loader();
  public:
   NS_INLINE_DECL_REFCOUNTING(Loader)
   void DropDocumentReference(); // notification that doc is going away
   void SetCompatibilityMode(nsCompatibility aCompatMode)
   { mCompatMode = aCompatMode; }
   nsCompatibility GetCompatibilityMode() { return mCompatMode; }
   nsresult SetPreferredSheet(const nsAString& aTitle);
   // XXXbz sort out what the deal is with events!  When should they fire?
   /**
    * Load an inline style sheet.  If a successful result is returned and
    * *aCompleted is false, then aObserver is guaranteed to be notified
    * asynchronously once the sheet is marked complete.  If an error is
    * returned, or if *aCompleted is true, aObserver will not be notified.  In
    * addition to parsing the sheet, this method will insert it into the
    * stylesheet list of this CSSLoader's document.
    *
    * @param aElement the element linking to the stylesheet.  This must not be
    *                 null and must implement nsIStyleSheetLinkingElement.
    * @param aBuffer the stylesheet data
    * @param aLineNumber the line number at which the stylesheet data started.
    * @param aTitle the title of the sheet.
    * @param aMedia the media string for the sheet.
    * @param aObserver the observer to notify when the load completes.
    *        May be null.
    * @param [out] aCompleted whether parsing of the sheet completed.
    * @param [out] aIsAlternate whether the stylesheet ended up being an
    *        alternate sheet.
    */
   nsresult LoadInlineStyle(nsIContent* aElement,
                            const nsAString& aBuffer,
                            uint32_t aLineNumber,
                            const nsAString& aTitle,
                            const nsAString& aMedia,
                            mozilla::dom::Element* aScopeElement,
                            nsICSSLoaderObserver* aObserver,
                            bool* aCompleted,
                            bool* aIsAlternate);
   /**
    * Load a linked (document) stylesheet.  If a successful result is returned,
    * aObserver is guaranteed to be notified asynchronously once the sheet is
    * loaded and marked complete.  If an error is returned, aObserver will not
    * be notified.  In addition to loading the sheet, this method will insert it
    * into the stylesheet list of this CSSLoader's document.
    *
    * @param aElement the element linking to the the stylesheet.  May be null.
    * @param aURL the URL of the sheet.
    * @param aTitle the title of the sheet.
    * @param aMedia the media string for the sheet.
    * @param aHasAlternateRel whether the rel for this link included
    *        "alternate".
    * @param aCORSMode the CORS mode for this load.
    * @param aObserver the observer to notify when the load completes.
    *                  May be null.
    * @param [out] aIsAlternate whether the stylesheet actually ended up beinga
    *        an alternate sheet.  Note that this need not match
    *        aHasAlternateRel.
    */
   nsresult LoadStyleLink(nsIContent* aElement,
                          nsIURI* aURL,
                          const nsAString& aTitle,
                          const nsAString& aMedia,
                          bool aHasAlternateRel,
                          CORSMode aCORSMode,
                          nsICSSLoaderObserver* aObserver,
                          bool* aIsAlternate);
   /**
    * Load a child (@import-ed) style sheet.  In addition to loading the sheet,
    * this method will insert it into the child sheet list of aParentSheet.  If
    * there is no sheet currently being parsed and the child sheet is not
    * complete when this method returns, then when the child sheet becomes
    * complete aParentSheet will be QIed to nsICSSLoaderObserver and
    * asynchronously notified, just like for LoadStyleLink.  Note that if the
    * child sheet is already complete when this method returns, no
    * nsICSSLoaderObserver notification will be sent.
    *
    * @param aParentSheet the parent of this child sheet
    * @param aURL the URL of the child sheet
    * @param aMedia the already-parsed media list for the child sheet
    * @param aRule the @import rule importing this child.  This is used to
    *              properly order the child sheet list of aParentSheet.
    */
   nsresult LoadChildSheet(nsCSSStyleSheet* aParentSheet,
                           nsIURI* aURL,
                           nsMediaList* aMedia,
                           ImportRule* aRule);
   /**
    * Synchronously load and return the stylesheet at aURL.  Any child sheets
    * will also be loaded synchronously.  Note that synchronous loads over some
    * protocols may involve spinning up a new event loop, so use of this method
    * does NOT guarantee not receiving any events before the sheet loads.  This
    * method can be used to load sheets not associated with a document.
    *
    * @param aURL the URL of the sheet to load
    * @param aEnableUnsafeRules whether unsafe rules are enabled for this
    * sheet load
    * Unsafe rules are rules that can violate key Gecko invariants if misused.
    * In particular, most anonymous box pseudoelements must be very carefully
    * styled or we will have severe problems. Therefore unsafe rules should
    * never be enabled for stylesheets controlled by untrusted sites; preferably
    * unsafe rules should only be enabled for agent sheets.
    * @param aUseSystemPrincipal if true, give the resulting sheet the system
    * principal no matter where it's being loaded from.
    * @param [out] aSheet the loaded, complete sheet.
    *
    * NOTE: At the moment, this method assumes the sheet will be UTF-8, but
    * ideally it would allow arbitrary encodings.  Callers should NOT depend on
    * non-UTF8 sheets being treated as UTF-8 by this method.
    *
    * NOTE: A successful return from this method doesn't indicate anything about
    * whether the data could be parsed as CSS and doesn't indicate anything
    * about the status of child sheets of the returned sheet.
    */
   nsresult LoadSheetSync(nsIURI* aURL, bool aEnableUnsafeRules,
                          bool aUseSystemPrincipal,
                          nsCSSStyleSheet** aSheet);
   /**
    * As above, but aUseSystemPrincipal and aEnableUnsafeRules are assumed false.
    */
   nsresult LoadSheetSync(nsIURI* aURL, nsCSSStyleSheet** aSheet) {
     return LoadSheetSync(aURL, false, false, aSheet);
   }
   /**
    * Asynchronously load the stylesheet at aURL.  If a successful result is
    * returned, aObserver is guaranteed to be notified asynchronously once the
    * sheet is loaded and marked complete.  This method can be used to load
    * sheets not associated with a document.
    *
    * @param aURL the URL of the sheet to load
    * @param aOriginPrincipal the principal to use for security checks.  This
    *                         can be null to indicate that these checks should
    *                         be skipped.
    * @param aCharset the encoding to use for converting the sheet data
    *        from bytes to Unicode.  May be empty to indicate that the
    *        charset of the CSSLoader's document should be used.  This
    *        is only used if neither the network transport nor the
    *        sheet itself indicate an encoding.
    * @param aObserver the observer to notify when the load completes.
    *                  Must not be null.
    * @param [out] aSheet the sheet to load. Note that the sheet may well
    *              not be loaded by the time this method returns.
    */
   nsresult LoadSheet(nsIURI* aURL,
                      nsIPrincipal* aOriginPrincipal,
                      const nsCString& aCharset,
                      nsICSSLoaderObserver* aObserver,
                      nsCSSStyleSheet** aSheet);
   /**
    * Same as above, to be used when the caller doesn't care about the
    * not-yet-loaded sheet.
    */
   nsresult LoadSheet(nsIURI* aURL,
                      nsIPrincipal* aOriginPrincipal,
                      const nsCString& aCharset,
                      nsICSSLoaderObserver* aObserver,
                      CORSMode aCORSMode = CORS_NONE);
   /**
    * Stop loading all sheets.  All nsICSSLoaderObservers involved will be
    * notified with NS_BINDING_ABORTED as the status, possibly synchronously.
    */
   nsresult Stop(void);
   /**
    * nsresult Loader::StopLoadingSheet(nsIURI* aURL), which notifies the
    * nsICSSLoaderObserver with NS_BINDING_ABORTED, was removed in Bug 556446.
    * It can be found in revision 2c44a32052ad.
    */
   /**
    * Whether the loader is enabled or not.
    * When disabled, processing of new styles is disabled and an attempt
    * to do so will fail with a return code of
    * NS_ERROR_NOT_AVAILABLE. Note that this DOES NOT disable
    * currently loading styles or already processed styles.
    */
   bool GetEnabled() { return mEnabled; }
   void SetEnabled(bool aEnabled) { mEnabled = aEnabled; }
   /**
    * Get the document we live for. May return null.
    */
   nsIDocument* GetDocument() const { return mDocument; }
   /**
    * Return true if this loader has pending loads (ones that would send
    * notifications to an nsICSSLoaderObserver attached to this loader).
    * If called from inside nsICSSLoaderObserver::StyleSheetLoaded, this will
    * return false if and only if that is the last StyleSheetLoaded
    * notification the CSSLoader knows it's going to send.  In other words, if
    * two sheets load at once (via load coalescing, e.g.), HasPendingLoads()
    * will return true during notification for the first one, and false
    * during notification for the second one.
    */
   bool HasPendingLoads();
   /**
    * Add an observer to this loader.  The observer will be notified
    * for all loads that would have notified their own observers (even
    * if those loads don't have observers attached to them).
    * Load-specific observers will be notified before generic
    * observers.  The loader holds a reference to the observer.
    *
    * aObserver must not be null.
    */
   nsresult AddObserver(nsICSSLoaderObserver* aObserver);
   /**
    * Remove an observer added via AddObserver.
    */
   void RemoveObserver(nsICSSLoaderObserver* aObserver);
   // These interfaces are public only for the benefit of static functions
   // within nsCSSLoader.cpp.
   // IsAlternate can change our currently selected style set if none
   // is selected and aHasAlternateRel is false.
   bool IsAlternate(const nsAString& aTitle, bool aHasAlternateRel);
   typedef nsTArray<nsRefPtr<SheetLoadData> > LoadDataArray;
   // Traverse the cached stylesheets we're holding on to.  This should
   // only be called from the document that owns this loader.
   void TraverseCachedSheets(nsCycleCollectionTraversalCallback& cb);
   // Unlink the cached stylesheets we're holding on to.  Again, this
   // should only be called from the document that owns this loader.
   void UnlinkCachedSheets();
   // Measure our size.
   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
   // Marks all the sheets at the given URI obsolete, and removes them from the
   // cache.
   nsresult ObsoleteSheet(nsIURI* aURI);
 private:
   friend class SheetLoadData;
   static PLDHashOperator
   RemoveEntriesWithURI(URIPrincipalAndCORSModeHashKey* aKey,
                        nsRefPtr<nsCSSStyleSheet> &aSheet,
                        void* aUserData);
   // Note: null aSourcePrincipal indicates that the content policy and
   // CheckLoadURI checks should be skipped.
   nsresult CheckLoadAllowed(nsIPrincipal* aSourcePrincipal,
                             nsIURI* aTargetURI,
                             nsISupports* aContext);
   // For inline style, the aURI param is null, but the aLinkingContent
   // must be non-null then.  The loader principal must never be null
   // if aURI is not null.
   // *aIsAlternate is set based on aTitle and aHasAlternateRel.
   nsresult CreateSheet(nsIURI* aURI,
                        nsIContent* aLinkingContent,
                        nsIPrincipal* aLoaderPrincipal,
                        CORSMode aCORSMode,
                        bool aSyncLoad,
                        bool aHasAlternateRel,
                        const nsAString& aTitle,
                        StyleSheetState& aSheetState,
                        bool *aIsAlternate,
                        nsCSSStyleSheet** aSheet);
   // Pass in either a media string or the nsMediaList from the
   // CSSParser.  Don't pass both.
   // This method will set the sheet's enabled state based on isAlternate
   void PrepareSheet(nsCSSStyleSheet* aSheet,
                     const nsAString& aTitle,
                     const nsAString& aMediaString,
                     nsMediaList* aMediaList,
                     dom::Element* aScopeElement,
                     bool isAlternate);
   nsresult InsertSheetInDoc(nsCSSStyleSheet* aSheet,
                             nsIContent* aLinkingContent,
                             nsIDocument* aDocument);
   nsresult InsertChildSheet(nsCSSStyleSheet* aSheet,
                             nsCSSStyleSheet* aParentSheet,
                             ImportRule* aParentRule);
   nsresult InternalLoadNonDocumentSheet(nsIURI* aURL,
                                         bool aAllowUnsafeRules,
                                         bool aUseSystemPrincipal,
                                         nsIPrincipal* aOriginPrincipal,
                                         const nsCString& aCharset,
                                         nsCSSStyleSheet** aSheet,
                                         nsICSSLoaderObserver* aObserver,
                                         CORSMode aCORSMode = CORS_NONE);
   // Post a load event for aObserver to be notified about aSheet.  The
   // notification will be sent with status NS_OK unless the load event is
   // canceled at some point (in which case it will be sent with
   // NS_BINDING_ABORTED).  aWasAlternate indicates the state when the load was
   // initiated, not the state at some later time.  aURI should be the URI the
   // sheet was loaded from (may be null for inline sheets).  aElement is the
   // owning element for this sheet.
   nsresult PostLoadEvent(nsIURI* aURI,
                          nsCSSStyleSheet* aSheet,
                          nsICSSLoaderObserver* aObserver,
                          bool aWasAlternate,
                          nsIStyleSheetLinkingElement* aElement);
   // Start the loads of all the sheets in mPendingDatas
   void StartAlternateLoads();
   // Handle an event posted by PostLoadEvent
   void HandleLoadEvent(SheetLoadData* aEvent);
   // Note: LoadSheet is responsible for releasing aLoadData and setting the
   // sheet to complete on failure.
   nsresult LoadSheet(SheetLoadData* aLoadData, StyleSheetState aSheetState);
   // Parse the stylesheet in aLoadData.  The sheet data comes from aInput.
   // Set aCompleted to true if the parse finished, false otherwise (e.g. if the
   // sheet had an @import).  If aCompleted is true when this returns, then
   // ParseSheet also called SheetComplete on aLoadData.
   nsresult ParseSheet(const nsAString& aInput,
                       SheetLoadData* aLoadData,
                       bool& aCompleted);
   // The load of the sheet in aLoadData is done, one way or another.  Do final
   // cleanup, including releasing aLoadData.
   void SheetComplete(SheetLoadData* aLoadData, nsresult aStatus);
   // The guts of SheetComplete.  This may be called recursively on parent datas
   // or datas that had glommed on to a single load.  The array is there so load
   // datas whose observers need to be notified can be added to it.
   void DoSheetComplete(SheetLoadData* aLoadData, nsresult aStatus,
                        LoadDataArray& aDatasToNotify);
   struct Sheets {
     nsRefPtrHashtable<URIPrincipalAndCORSModeHashKey, nsCSSStyleSheet>
                       mCompleteSheets;
     nsDataHashtable<URIPrincipalAndCORSModeHashKey, SheetLoadData*>
                       mLoadingDatas; // weak refs
     nsDataHashtable<URIPrincipalAndCORSModeHashKey, SheetLoadData*>
                       mPendingDatas; // weak refs
   };
   nsAutoPtr<Sheets> mSheets;
   // We're not likely to have many levels of @import...  But likely to have
   // some.  Allocate some storage, what the hell.
   nsAutoTArray<SheetLoadData*, 8> mParsingDatas;
   // The array of posted stylesheet loaded events (SheetLoadDatas) we have.
   // Note that these are rare.
   LoadDataArray     mPostedEvents;
   // Our array of "global" observers
   // XXXbz these are strong refs; should we be cycle collecting CSS loaders?
   nsTObserverArray<nsCOMPtr<nsICSSLoaderObserver> > mObservers;
   // the load data needs access to the document...
   nsIDocument*      mDocument;  // the document we live for
   // Number of datas still waiting to be notified on if we're notifying on a
   // whole bunch at once (e.g. in one of the stop methods).  This is used to
   // make sure that HasPendingLoads() won't return false until we're notifying
   // on the last data we're working with.
   uint32_t          mDatasToNotifyOn;
   nsCompatibility   mCompatMode;
   nsString          mPreferredSheet;  // title of preferred sheet
   bool              mEnabled; // is enabled to load new styles
 #ifdef DEBUG
   bool              mSyncCallback;
 #endif
 };
 } // namespace css
 } // namespace mozilla
 #endif /* mozilla_css_Loader_h */

The Tor Browser / annotate

layout/style/Loader.h@8bccb770b82d (annotated)

layout/style/Loader.h