The Tor Browser: gfx/2d/SourceSurfaceCG.h@97036ab72558 (annotated)

gfx/2d/SourceSurfaceCG.h@97036ab72558 (annotated)

gfx/2d/SourceSurfaceCG.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: 20; 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 _MOZILLA_GFX_SOURCESURFACECG_H
 #define _MOZILLA_GFX_SOURCESURFACECG_H
 #include <ApplicationServices/ApplicationServices.h>
 #include "2D.h"
 class MacIOSurface;
 namespace mozilla {
 namespace gfx {
 CGImageRef
 CreateCGImage(void *aInfo,
               const void *aData,
               const IntSize &aSize,
               int32_t aStride,
               SurfaceFormat aFormat);
 class DrawTargetCG;
 class SourceSurfaceCG : public SourceSurface
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(SourceSurfaceCG)
   SourceSurfaceCG() {}
   SourceSurfaceCG(CGImageRef aImage) : mImage(aImage) {}
   ~SourceSurfaceCG();
   virtual SurfaceType GetType() const { return SurfaceType::COREGRAPHICS_IMAGE; }
   virtual IntSize GetSize() const;
   virtual SurfaceFormat GetFormat() const;
   virtual TemporaryRef<DataSourceSurface> GetDataSurface();
   CGImageRef GetImage() { return mImage; }
   bool InitFromData(unsigned char *aData,
                     const IntSize &aSize,
                     int32_t aStride,
                     SurfaceFormat aFormat);
 private:
   CGImageRef mImage;
   /* It might be better to just use the bitmap info from the CGImageRef to
    * deduce the format to save space in SourceSurfaceCG,
    * for now we just store it in mFormat */
   SurfaceFormat mFormat;
 };
 class DataSourceSurfaceCG : public DataSourceSurface
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DataSourceSurfaceCG)
   DataSourceSurfaceCG() {}
   DataSourceSurfaceCG(CGImageRef aImage);
   ~DataSourceSurfaceCG();
   virtual SurfaceType GetType() const { return SurfaceType::DATA; }
   virtual IntSize GetSize() const;
   virtual SurfaceFormat GetFormat() const { return mFormat; }
   CGImageRef GetImage() { return mImage; }
   bool InitFromData(unsigned char *aData,
                     const IntSize &aSize,
                     int32_t aStride,
                     SurfaceFormat aFormat);
   virtual unsigned char *GetData();
   virtual int32_t Stride() { return CGImageGetBytesPerRow(mImage); }
 private:
   CGContextRef mCg;
   CGImageRef mImage;
   SurfaceFormat mFormat;
   //XXX: we don't need to store mData we can just get it from the CGContext
   void *mData;
   /* It might be better to just use the bitmap info from the CGImageRef to
    * deduce the format to save space in SourceSurfaceCG,
    * for now we just store it in mFormat */
 };
 class SourceSurfaceCGContext : public DataSourceSurface
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DataSourceSurfaceCGContext)
   virtual void DrawTargetWillChange() = 0;
   virtual CGImageRef GetImage() = 0;
 };
 class SourceSurfaceCGBitmapContext : public SourceSurfaceCGContext
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DataSourceSurfaceCGBitmapContext)
   SourceSurfaceCGBitmapContext(DrawTargetCG *);
   ~SourceSurfaceCGBitmapContext();
   virtual SurfaceType GetType() const { return SurfaceType::COREGRAPHICS_CGCONTEXT; }
   virtual IntSize GetSize() const;
   virtual SurfaceFormat GetFormat() const { return mFormat; }
   virtual TemporaryRef<DataSourceSurface> GetDataSurface()
   {
     // This call to DrawTargetWillChange() is needed to make a local copy of
     // the data from mDrawTarget.  If we don't do that, the data can end up
     // getting deleted before the CGImageRef it belongs to.
     //
     // Another reason we need a local copy of the data is that the data in
     // mDrawTarget could change when someone touches the original DrawTargetCG
     // object.  But a SourceSurface object should be immutable.
     //
     // For more information see bug 925448.
     DrawTargetWillChange();
     return this;
   }
   CGImageRef GetImage() { EnsureImage(); return mImage; }
   virtual unsigned char *GetData() { return static_cast<unsigned char*>(mData); }
   virtual int32_t Stride() { return mStride; }
 private:
   //XXX: do the other backends friend their DrawTarget?
   friend class DrawTargetCG;
   virtual void DrawTargetWillChange();
   void EnsureImage() const;
   // We hold a weak reference to these two objects.
   // The cycle is broken by DrawTargetWillChange
   DrawTargetCG *mDrawTarget;
   CGContextRef mCg;
   SurfaceFormat mFormat;
   mutable CGImageRef mImage;
   // mData can be owned by three different things:
   // mImage, mCg or SourceSurfaceCGBitmapContext
   void *mData;
   // The image buffer, if the buffer is owned by this class.
   AlignedArray<uint8_t> mDataHolder;
   int32_t mStride;
   IntSize mSize;
 };
 class SourceSurfaceCGIOSurfaceContext : public SourceSurfaceCGContext
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DataSourceSurfaceCGIOSurfaceContext)
   SourceSurfaceCGIOSurfaceContext(DrawTargetCG *);
   ~SourceSurfaceCGIOSurfaceContext();
   virtual SurfaceType GetType() const { return SurfaceType::COREGRAPHICS_CGCONTEXT; }
   virtual IntSize GetSize() const;
   virtual SurfaceFormat GetFormat() const { return mFormat; }
   CGImageRef GetImage() { EnsureImage(); return mImage; }
   virtual unsigned char *GetData();
   virtual int32_t Stride() { return mStride; }
 private:
   //XXX: do the other backends friend their DrawTarget?
   friend class DrawTargetCG;
   virtual void DrawTargetWillChange();
   void EnsureImage() const;
   SurfaceFormat mFormat;
   mutable CGImageRef mImage;
   MacIOSurface* mIOSurface;
   void *mData;
   int32_t mStride;
   IntSize mSize;
 };
 }
 }
 #endif // _MOZILLA_GFX_SOURCESURFACECG_H

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gfx/2d/SourceSurfaceCG.h@97036ab72558 (annotated)

gfx/2d/SourceSurfaceCG.h