The Tor Browser: gfx/thebes/gfxUtils.h@97036ab72558 (annotated)

gfx/thebes/gfxUtils.h@97036ab72558 (annotated)

gfx/thebes/gfxUtils.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: 4 -*-
  * 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 GFX_UTILS_H
 #define GFX_UTILS_H
 #include "gfxTypes.h"
 #include "GraphicsFilter.h"
 #include "imgIContainer.h"
 #include "mozilla/gfx/2D.h"
 #include "mozilla/RefPtr.h"
 class gfxDrawable;
 class nsIntRegion;
 struct nsIntRect;
 namespace mozilla {
 namespace layers {
 class PlanarYCbCrData;
 }
 }
 class gfxUtils {
 public:
     typedef mozilla::gfx::DataSourceSurface DataSourceSurface;
     typedef mozilla::gfx::IntPoint IntPoint;
     typedef mozilla::gfx::Matrix Matrix;
     typedef mozilla::gfx::SourceSurface SourceSurface;
     typedef mozilla::gfx::SurfaceFormat SurfaceFormat;
     /*
      * Premultiply or Unpremultiply aSourceSurface, writing the result
      * to aDestSurface or back into aSourceSurface if aDestSurface is null.
      *
      * If aDestSurface is given, it must have identical format, dimensions, and
      * stride as the source.
      *
      * If the source is not gfxImageFormat::ARGB32, no operation is performed.  If
      * aDestSurface is given, the data is copied over.
      */
     static void PremultiplyImageSurface(gfxImageSurface *aSourceSurface,
                                         gfxImageSurface *aDestSurface = nullptr);
     static void UnpremultiplyImageSurface(gfxImageSurface *aSurface,
                                           gfxImageSurface *aDestSurface = nullptr);
     static mozilla::TemporaryRef<DataSourceSurface> UnpremultiplyDataSurface(DataSourceSurface* aSurface);
     static void ConvertBGRAtoRGBA(gfxImageSurface *aSourceSurface,
                                   gfxImageSurface *aDestSurface = nullptr);
     static void ConvertBGRAtoRGBA(uint8_t* aData, uint32_t aLength);
     /**
      * Draw something drawable while working around limitations like bad support
      * for EXTEND_PAD, lack of source-clipping, or cairo / pixman bugs with
      * extreme user-space-to-image-space transforms.
      *
      * The input parameters here usually come from the output of our image
      * snapping algorithm in nsLayoutUtils.cpp.
      * This method is split from nsLayoutUtils::DrawPixelSnapped to allow for
      * adjusting the parameters. For example, certain images with transparent
      * margins only have a drawable subimage. For those images, imgFrame::Draw
      * will tweak the rects and transforms that it gets from the pixel snapping
      * algorithm before passing them on to this method.
      */
     static void DrawPixelSnapped(gfxContext*      aContext,
                                  gfxDrawable*     aDrawable,
                                  const gfxMatrix& aUserSpaceToImageSpace,
                                  const gfxRect&   aSubimage,
                                  const gfxRect&   aSourceRect,
                                  const gfxRect&   aImageRect,
                                  const gfxRect&   aFill,
                                  const gfxImageFormat aFormat,
                                  GraphicsFilter aFilter,
                                  uint32_t         aImageFlags = imgIContainer::FLAG_NONE);
     /**
      * Clip aContext to the region aRegion.
      */
     static void ClipToRegion(gfxContext* aContext, const nsIntRegion& aRegion);
     /**
      * Clip aTarget to the region aRegion.
      */
     static void ClipToRegion(mozilla::gfx::DrawTarget* aTarget, const nsIntRegion& aRegion);
     /**
      * Clip aContext to the region aRegion, snapping the rectangles.
      */
     static void ClipToRegionSnapped(gfxContext* aContext, const nsIntRegion& aRegion);
     /**
      * Clip aTarget to the region aRegion, snapping the rectangles.
      */
     static void ClipToRegionSnapped(mozilla::gfx::DrawTarget* aTarget, const nsIntRegion& aRegion);
     /**
      * Create a path consisting of rectangles in |aRegion|.
      */
     static void PathFromRegion(gfxContext* aContext, const nsIntRegion& aRegion);
     /**
      * Create a path consisting of rectangles in |aRegion|, snapping the rectangles.
      */
     static void PathFromRegionSnapped(gfxContext* aContext, const nsIntRegion& aRegion);
     /*
      * Convert image format to depth value
      */
     static int ImageFormatToDepth(gfxImageFormat aFormat);
     /**
      * Return the transform matrix that maps aFrom to the rectangle defined by
      * aToTopLeft/aToTopRight/aToBottomRight. aFrom must be
      * nonempty and the destination rectangle must be axis-aligned.
      */
     static gfxMatrix TransformRectToRect(const gfxRect& aFrom,
                                          const gfxPoint& aToTopLeft,
                                          const gfxPoint& aToTopRight,
                                          const gfxPoint& aToBottomRight);
     static Matrix TransformRectToRect(const gfxRect& aFrom,
                                       const IntPoint& aToTopLeft,
                                       const IntPoint& aToTopRight,
                                       const IntPoint& aToBottomRight);
     /**
      * If aIn can be represented exactly using an nsIntRect (i.e.
      * integer-aligned edges and coordinates in the int32_t range) then we
      * set aOut to that rectangle, otherwise return failure.
     */
     static bool GfxRectToIntRect(const gfxRect& aIn, nsIntRect* aOut);
     /**
      * Return the smallest power of kScaleResolution (2) greater than or equal to
      * aVal.
      */
     static gfxFloat ClampToScaleFactor(gfxFloat aVal);
     /**
      * Helper function for ConvertYCbCrToRGB that finds the
      * RGB buffer size and format for given YCbCrImage.
      * @param aSuggestedFormat will be set to gfxImageFormat::RGB24
      *   if the desired format is not supported.
      * @param aSuggestedSize will be set to the picture size from aData
      *   if either the suggested size was {0,0}
      *   or simultaneous scaling and conversion is not supported.
      */
     static void
     GetYCbCrToRGBDestFormatAndSize(const mozilla::layers::PlanarYCbCrData& aData,
                                    gfxImageFormat& aSuggestedFormat,
                                    gfxIntSize& aSuggestedSize);
     /**
      * Convert YCbCrImage into RGB aDestBuffer
      * Format and Size parameters must have
      *   been passed to GetYCbCrToRGBDestFormatAndSize
      */
     static void
     ConvertYCbCrToRGB(const mozilla::layers::PlanarYCbCrData& aData,
                       const gfxImageFormat& aDestFormat,
                       const gfxIntSize& aDestSize,
                       unsigned char* aDestBuffer,
                       int32_t aStride);
     /**
      * Creates a copy of aSurface, but having the SurfaceFormat aFormat.
      *
      * This function always creates a new surface. Do not call it if aSurface's
      * format is the same as aFormat. Such a non-conversion would just be an
      * unnecessary and wasteful copy (this function asserts to prevent that).
      *
      * This function is intended to be called by code that needs to access the
      * pixel data of the surface, but doesn't want to have lots of branches
      * to handle different pixel data formats (code which would become out of
      * date if and when new formats are added). Callers can use this function
      * to copy the surface to a specified format so that they only have to
      * handle pixel data in that one format.
      *
      * WARNING: There are format conversions that will not be supported by this
      * function. It very much depends on what the Moz2D backends support. If
      * the temporary B8G8R8A8 DrawTarget that this function creates has a
      * backend that supports DrawSurface() calls passing a surface with
      * aSurface's format it will work. Otherwise it will not.
      *
      *                      *** IMPORTANT PERF NOTE ***
      *
      * This function exists partly because format conversion is fraught with
      * non-obvious performance hazards, so we don't want Moz2D consumers to be
      * doing their own format conversion. Do not try to do so, or at least read
      * the comments in this functions implemtation. That said, the copy that
      * this function carries out has a cost and, although this function tries
      * to avoid perf hazards such as expensive uploads to/readbacks from the
      * GPU, it can't guarantee that it always successfully does so. Perf
      * critical code that can directly handle the common formats that it
      * encounters in a way that is cheaper than a copy-with-format-conversion
      * should consider doing so, and only use this function as a fallback to
      * handle other formats.
      *
      * XXXjwatt it would be nice if SourceSurface::GetDataSurface took a
      * SurfaceFormat argument (with a default argument meaning "use the
      * existing surface's format") and returned a DataSourceSurface in that
      * format. (There would then be an issue of callers maybe failing to
      * realize format conversion may involve expensive copying/uploading/
      * readback.)
      */
     static mozilla::TemporaryRef<DataSourceSurface>
     CopySurfaceToDataSourceSurfaceWithFormat(SourceSurface* aSurface,
                                              SurfaceFormat aFormat);
     static const uint8_t sUnpremultiplyTable[256*256];
     static const uint8_t sPremultiplyTable[256*256];
 #ifdef MOZ_DUMP_PAINTING
     /**
      * Writes a binary PNG file.
      */
     static void WriteAsPNG(mozilla::gfx::DrawTarget* aDT, const char* aFile);
     /**
      * Write as a PNG encoded Data URL to stdout.
      */
     static void DumpAsDataURL(mozilla::gfx::DrawTarget* aDT);
     /**
      * Copy a PNG encoded Data URL to the clipboard.
      */
     static void CopyAsDataURL(mozilla::gfx::DrawTarget* aDT);
     static bool sDumpPaintList;
     static bool sDumpPainting;
     static bool sDumpPaintingToFile;
     static FILE* sDumpPaintFile;
     /**
      * Writes a binary PNG file.
      * Expensive. Creates a DataSourceSurface, then a DrawTarget, then passes to DrawTarget overloads
      */
     static void WriteAsPNG(mozilla::RefPtr<mozilla::gfx::SourceSurface> aSourceSurface, const char* aFile);
     /**
      * Write as a PNG encoded Data URL to stdout.
      * Expensive. Creates a DataSourceSurface, then a DrawTarget, then passes to DrawTarget overloads
      */
     static void DumpAsDataURL(mozilla::RefPtr<mozilla::gfx::SourceSurface> aSourceSurface);
     /**
      * Copy a PNG encoded Data URL to the clipboard.
      * Expensive. Creates a DataSourceSurface, then a DrawTarget, then passes to DrawTarget overloads
      */
     static void CopyAsDataURL(mozilla::RefPtr<mozilla::gfx::SourceSurface> aSourceSurface);
 #endif
 };
 namespace mozilla {
 namespace gfx {
 /* These techniques are suggested by "Bit Twiddling Hacks"
  */
 /**
  * Returns true if |aNumber| is a power of two
  * 0 is incorreclty considered a power of two
  */
 static inline bool
 IsPowerOfTwo(int aNumber)
 {
     return (aNumber & (aNumber - 1)) == 0;
 }
 /**
  * Returns the first integer greater than |aNumber| which is a power of two
  * Undefined for |aNumber| < 0
  */
 static inline int
 NextPowerOfTwo(int aNumber)
 {
 #if defined(__arm__)
     return 1 << (32 - __builtin_clz(aNumber - 1));
 #else
     --aNumber;
     aNumber |= aNumber >> 1;
     aNumber |= aNumber >> 2;
     aNumber |= aNumber >> 4;
     aNumber |= aNumber >> 8;
     aNumber |= aNumber >> 16;
     return ++aNumber;
 #endif
 }
 } // namespace gfx
 } // namespace mozilla
 #endif

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gfx/thebes/gfxUtils.h@97036ab72558 (annotated)

gfx/thebes/gfxUtils.h