The Tor Browser: dom/smil/nsSMILCompositor.h@97036ab72558

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.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #ifndef NS_SMILCOMPOSITOR_H_

     7 #define NS_SMILCOMPOSITOR_H_

     9 #include "nsTHashtable.h"

    10 #include "nsString.h"

    11 #include "nsSMILAnimationFunction.h"

    12 #include "nsSMILTargetIdentifier.h"

    13 #include "nsSMILCompositorTable.h"

    14 #include "pldhash.h"

    16 //----------------------------------------------------------------------

    17 // nsSMILCompositor

    18 //

    19 // Performs the composition of the animation sandwich by combining the results

    20 // of a series animation functions according to the rules of SMIL composition

    21 // including prioritising animations.

    23 class nsSMILCompositor : public PLDHashEntryHdr

    24 {

    25 public:

    26   typedef nsSMILTargetIdentifier KeyType;

    27   typedef const KeyType& KeyTypeRef;

    28   typedef const KeyType* KeyTypePointer;

    30   explicit nsSMILCompositor(KeyTypePointer aKey)

    31    : mKey(*aKey),

    32      mForceCompositing(false)

    33   { }

    34   nsSMILCompositor(const nsSMILCompositor& toCopy)

    35     : mKey(toCopy.mKey),

    36       mAnimationFunctions(toCopy.mAnimationFunctions),

    37       mForceCompositing(false)

    38   { }

    39   ~nsSMILCompositor() { }

    41   // PLDHashEntryHdr methods

    42   KeyTypeRef GetKey() const { return mKey; }

    43   bool KeyEquals(KeyTypePointer aKey) const;

    44   static KeyTypePointer KeyToPointer(KeyTypeRef aKey) { return &aKey; }

    45   static PLDHashNumber HashKey(KeyTypePointer aKey);

    46   enum { ALLOW_MEMMOVE = false };

    48   // Adds the given animation function to this Compositor's list of functions

    49   void AddAnimationFunction(nsSMILAnimationFunction* aFunc);

    51   // Composes the attribute's current value with the list of animation

    52   // functions, and assigns the resulting value to this compositor's target

    53   // attribute

    54   void ComposeAttribute();

    56   // Clears animation effects on my target attribute

    57   void ClearAnimationEffects();

    59   // Cycle-collection support

    60   void Traverse(nsCycleCollectionTraversalCallback* aCallback);

    62   // Toggles a bit that will force us to composite (bypassing early-return

    63   // optimizations) when we hit ComposeAttribute.

    64   void ToggleForceCompositing() { mForceCompositing = true; }

    66   // Transfers |aOther|'s mCachedBaseValue to |this|

    67   void StealCachedBaseValue(nsSMILCompositor* aOther) {

    68     mCachedBaseValue = aOther->mCachedBaseValue;

    69   }

    71  private:

    72   // Create a nsISMILAttr for my target, on the heap.  Caller is responsible

    73   // for deallocating the returned object.

    74   nsISMILAttr* CreateSMILAttr();

    76   // Finds the index of the first function that will affect our animation

    77   // sandwich. Also toggles the 'mForceCompositing' flag if it finds that any

    78   // (used) functions have changed.

    79   uint32_t GetFirstFuncToAffectSandwich();

    81   // If the passed-in base value differs from our cached base value, this

    82   // method updates the cached value (and toggles the 'mForceCompositing' flag)

    83   void UpdateCachedBaseValue(const nsSMILValue& aBaseValue);

    85   // Static callback methods

    86   static PLDHashOperator DoComposeAttribute(

    87       nsSMILCompositor* aCompositor, void *aData);

    89   // The hash key (tuple of element/attributeName/attributeType)

    90   KeyType mKey;

    92   // Hash Value: List of animation functions that animate the specified attr

    93   nsTArray<nsSMILAnimationFunction*> mAnimationFunctions;

    95   // Member data for detecting when we need to force-recompose

    96   // ---------------------------------------------------------

    97   // Flag for tracking whether we need to compose. Initialized to false, but

    98   // gets flipped to true if we detect that something has changed.

    99   bool mForceCompositing;

   101   // Cached base value, so we can detect & force-recompose when it changes

   102   // from one sample to the next. (nsSMILAnimationController copies this

   103   // forward from the previous sample's compositor.)

   104   nsAutoPtr<nsSMILValue> mCachedBaseValue;

   105 };

   107 #endif // NS_SMILCOMPOSITOR_H_

The Tor Browser / file revision

dom/smil/nsSMILCompositor.h@97036ab72558

dom/smil/nsSMILCompositor.h