The Tor Browser: gfx/src/nsRegion.h@97036ab72558 (annotated)

gfx/src/nsRegion.h@97036ab72558 (annotated)

gfx/src/nsRegion.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.

 /* 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 nsRegion_h__
 #define nsRegion_h__
 #include <stddef.h>                     // for size_t
 #include <stdint.h>                     // for uint32_t, uint64_t
 #include <sys/types.h>                  // for int32_t
 #include "gfxCore.h"                    // for NS_GFX
 #include "nsCoord.h"                    // for nscoord
 #include "nsError.h"                    // for nsresult
 #include "nsPoint.h"                    // for nsIntPoint, nsPoint
 #include "nsRect.h"                     // for nsIntRect, nsRect
 #include "nsMargin.h"                   // for nsIntMargin
 #include "nsStringGlue.h"               // for nsCString
 #include "xpcom-config.h"               // for CPP_THROW_NEW
 class nsIntRegion;
 #include "pixman.h"
 /* For information on the internal representation look at pixman-region.c
  *
  * This replaces an older homebrew implementation of nsRegion. The
  * representation used here may use more rectangles than nsRegion however, the
  * representation is canonical.  This means that there's no need for an
  * Optimize() method because for a paticular region there is only one
  * representation. This means that nsIntRegion will have more predictable
  * performance characteristics than the old nsRegion and should not become
  * degenerate.
  *
  * The pixman region code originates from X11 which has spread to a variety of
  * projects including Qt, Gtk, Wine. It should perform reasonably well.
  */
 class nsRegionRectIterator;
 class nsRegion
 {
   friend class nsRegionRectIterator;
 public:
   nsRegion () { pixman_region32_init(&mImpl); }
   nsRegion (const nsRect& aRect) { pixman_region32_init_rect(&mImpl,
                                                                     aRect.x,
                                                                     aRect.y,
                                                                     aRect.width,
                                                                     aRect.height); }
   nsRegion (const nsRegion& aRegion) { pixman_region32_init(&mImpl); pixman_region32_copy(&mImpl,aRegion.Impl()); }
  ~nsRegion () { pixman_region32_fini(&mImpl); }
   nsRegion& operator = (const nsRect& aRect) { Copy (aRect); return *this; }
   nsRegion& operator = (const nsRegion& aRegion) { Copy (aRegion); return *this; }
   bool operator==(const nsRegion& aRgn) const
   {
     return IsEqual(aRgn);
   }
   void Swap(nsRegion* aOther)
   {
     pixman_region32_t tmp = mImpl;
     mImpl = aOther->mImpl;
     aOther->mImpl = tmp;
   }
   static
   nsresult InitStatic()
   {
     return NS_OK;
   }
   static
   void ShutdownStatic() {}
   nsRegion& And(const nsRegion& aRgn1,   const nsRegion& aRgn2)
   {
     pixman_region32_intersect(&mImpl, aRgn1.Impl(), aRgn2.Impl());
     return *this;
   }
   nsRegion& And(const nsRect& aRect, const nsRegion& aRegion)
   {
     return And(aRegion, aRect);
   }
   nsRegion& And(const nsRegion& aRegion, const nsRect& aRect)
   {
     pixman_region32_intersect_rect(&mImpl, aRegion.Impl(), aRect.x, aRect.y, aRect.width, aRect.height);
     return *this;
   }
   nsRegion& And(const nsRect& aRect1, const nsRect& aRect2)
   {
     nsRect TmpRect;
     TmpRect.IntersectRect(aRect1, aRect2);
     return Copy(TmpRect);
   }
   nsRegion& Or(const nsRegion& aRgn1, const nsRegion& aRgn2)
   {
     pixman_region32_union(&mImpl, aRgn1.Impl(), aRgn2.Impl());
     return *this;
   }
   nsRegion& Or(const nsRegion& aRegion, const nsRect& aRect)
   {
     pixman_region32_union_rect(&mImpl, aRegion.Impl(), aRect.x, aRect.y, aRect.width, aRect.height);
     return *this;
   }
   nsRegion& Or(const nsRect& aRect, const nsRegion& aRegion)
   {
     return  Or(aRegion, aRect);
   }
   nsRegion& Or(const nsRect& aRect1, const nsRect& aRect2)
   {
     Copy (aRect1);
     return Or (*this, aRect2);
   }
   nsRegion& Xor(const nsRegion& aRgn1,   const nsRegion& aRgn2)
   {
     // this could be implemented better if pixman had direct
     // support for xoring regions.
     nsRegion p;
     p.Sub(aRgn1, aRgn2);
     nsRegion q;
     q.Sub(aRgn2, aRgn1);
     return Or(p, q);
   }
   nsRegion& Xor(const nsRegion& aRegion, const nsRect& aRect)
   {
     return Xor(aRegion, nsRegion(aRect));
   }
   nsRegion& Xor(const nsRect& aRect, const nsRegion& aRegion)
   {
     return Xor(nsRegion(aRect), aRegion);
   }
   nsRegion& Xor(const nsRect& aRect1, const nsRect& aRect2)
   {
     return Xor(nsRegion(aRect1), nsRegion(aRect2));
   }
   nsRegion ToAppUnits (nscoord aAppUnitsPerPixel) const;
   nsRegion& Sub(const nsRegion& aRgn1, const nsRegion& aRgn2)
   {
     pixman_region32_subtract(&mImpl, aRgn1.Impl(), aRgn2.Impl());
     return *this;
   }
   nsRegion& Sub(const nsRegion& aRegion, const nsRect& aRect)
   {
     return Sub(aRegion, nsRegion(aRect));
   }
   nsRegion& Sub(const nsRect& aRect, const nsRegion& aRegion)
   {
     return Sub(nsRegion(aRect), aRegion);
   }
   nsRegion& Sub(const nsRect& aRect1, const nsRect& aRect2)
   {
     Copy(aRect1);
     return Sub(*this, aRect2);
   }
   bool Contains (const nsRect& aRect) const
   {
     pixman_box32_t box = RectToBox(aRect);
     return pixman_region32_contains_rectangle(Impl(), &box) == PIXMAN_REGION_IN;
   }
   bool Contains (const nsRegion& aRgn) const;
   bool Intersects (const nsRect& aRect) const;
   void MoveBy (int32_t aXOffset, int32_t aYOffset)
   {
     MoveBy (nsPoint (aXOffset, aYOffset));
   }
   void MoveBy (nsPoint aPt) { pixman_region32_translate(&mImpl, aPt.x, aPt.y); }
   void SetEmpty ()
   {
     pixman_region32_clear(&mImpl);
   }
   nsRegion MovedBy(int32_t aXOffset, int32_t aYOffset) const
   {
     return MovedBy(nsPoint(aXOffset, aYOffset));
   }
   nsRegion MovedBy(const nsPoint& aPt) const
   {
     nsRegion copy(*this);
     copy.MoveBy(aPt);
     return copy;
   }
   nsRegion Intersect(const nsRegion& aOther) const
   {
     nsRegion intersection;
     intersection.And(*this, aOther);
     return intersection;
   }
   void Inflate(const nsMargin& aMargin);
   nsRegion Inflated(const nsMargin& aMargin) const
   {
     nsRegion copy(*this);
     copy.Inflate(aMargin);
     return copy;
   }
   bool IsEmpty () const { return !pixman_region32_not_empty(Impl()); }
   bool IsComplex () const { return GetNumRects() > 1; }
   bool IsEqual (const nsRegion& aRegion) const
   {
     return pixman_region32_equal(Impl(), aRegion.Impl());
   }
   uint32_t GetNumRects () const { return pixman_region32_n_rects(Impl()); }
   const nsRect GetBounds () const { return BoxToRect(mImpl.extents); }
   uint64_t Area () const;
   // Converts this region from aFromAPP, an appunits per pixel ratio, to
   // aToAPP. This applies nsRect::ConvertAppUnitsRoundOut/In to each rect of
   // the region.
   nsRegion ConvertAppUnitsRoundOut (int32_t aFromAPP, int32_t aToAPP) const;
   nsRegion ConvertAppUnitsRoundIn (int32_t aFromAPP, int32_t aToAPP) const;
   nsRegion& ScaleRoundOut(float aXScale, float aYScale);
   nsRegion& ScaleInverseRoundOut(float aXScale, float aYScale);
   nsIntRegion ScaleToOutsidePixels (float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
   nsIntRegion ScaleToInsidePixels (float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
   nsIntRegion ScaleToNearestPixels (float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
   nsIntRegion ToOutsidePixels (nscoord aAppUnitsPerPixel) const;
   nsIntRegion ToNearestPixels (nscoord aAppUnitsPerPixel) const;
   /**
    * Gets the largest rectangle contained in the region.
    * @param aContainingRect if non-empty, we choose a rectangle that
    * maximizes the area intersecting with aContainingRect (and break ties by
    * then choosing the largest rectangle overall)
    */
   nsRect GetLargestRectangle (const nsRect& aContainingRect = nsRect()) const;
   /**
    * Make sure the region has at most aMaxRects by adding area to it
    * if necessary. The simplified region will be a superset of the
    * original region. The simplified region's bounding box will be
    * the same as for the current region.
    */
   void SimplifyOutward (uint32_t aMaxRects);
   /**
    * Simplify the region by adding at most aThreshold area between spans of
    * rects.  The simplified region will be a superset of the original region.
    * The simplified region's bounding box will be the same as for the current
    * region.
    */
   void SimplifyOutwardByArea(uint32_t aThreshold);
   /**
    * Make sure the region has at most aMaxRects by removing area from
    * it if necessary. The simplified region will be a subset of the
    * original region.
    */
   void SimplifyInward (uint32_t aMaxRects);
   nsCString ToString() const;
 private:
   pixman_region32_t mImpl;
   nsIntRegion ToPixels(nscoord aAppUnitsPerPixel, bool aOutsidePixels) const;
   nsRegion& Copy (const nsRegion& aRegion)
   {
     pixman_region32_copy(&mImpl, aRegion.Impl());
     return *this;
   }
   nsRegion& Copy (const nsRect& aRect)
   {
     // pixman needs to distinguish between an empty region and a region
     // with one rect so that it can return a different number of rectangles.
     // Empty rect: data = empty_box
     //     1 rect: data = null
     //    >1 rect: data = rects
     if (aRect.IsEmpty()) {
       pixman_region32_clear(&mImpl);
     } else {
       pixman_box32_t box = RectToBox(aRect);
       pixman_region32_reset(&mImpl, &box);
     }
     return *this;
   }
   static inline pixman_box32_t RectToBox(const nsRect &aRect)
   {
     pixman_box32_t box = { aRect.x, aRect.y, aRect.XMost(), aRect.YMost() };
     return box;
   }
   static inline pixman_box32_t RectToBox(const nsIntRect &aRect)
   {
     pixman_box32_t box = { aRect.x, aRect.y, aRect.XMost(), aRect.YMost() };
     return box;
   }
   static inline nsRect BoxToRect(const pixman_box32_t &aBox)
   {
     return nsRect(aBox.x1, aBox.y1,
                   aBox.x2 - aBox.x1,
                   aBox.y2 - aBox.y1);
   }
   pixman_region32_t* Impl() const
   {
     return const_cast<pixman_region32_t*>(&mImpl);
   }
 };
 class NS_GFX nsRegionRectIterator
 {
   const nsRegion*  mRegion;
   int i;
   int n;
   nsRect rect;
   pixman_box32_t *boxes;
 public:
   nsRegionRectIterator (const nsRegion& aRegion)
   {
     mRegion = &aRegion;
     i = 0;
     boxes = pixman_region32_rectangles(aRegion.Impl(), &n);
   }
   const nsRect* Next ()
   {
     if (i == n)
       return nullptr;
     rect = nsRegion::BoxToRect(boxes[i]);
     i++;
     return &rect;
   }
   const nsRect* Prev ()
   {
     if (i == -1)
       return nullptr;
     rect = nsRegion::BoxToRect(boxes[i]);
     i--;
     return &rect;
   }
   void Reset ()
   {
     i = 0;
   }
 };
 /**
  * nsIntRegions use int32_t coordinates and nsIntRects.
  */
 class NS_GFX nsIntRegion
 {
   friend class nsIntRegionRectIterator;
   friend class nsRegion;
 public:
   nsIntRegion () {}
   nsIntRegion (const nsIntRect& aRect) : mImpl (ToRect(aRect)) {}
   nsIntRegion (const nsIntRegion& aRegion) : mImpl (aRegion.mImpl) {}
   nsIntRegion& operator = (const nsIntRect& aRect) { mImpl = ToRect (aRect); return *this; }
   nsIntRegion& operator = (const nsIntRegion& aRegion) { mImpl = aRegion.mImpl; return *this; }
   bool operator==(const nsIntRegion& aRgn) const
   {
     return IsEqual(aRgn);
   }
   void Swap(nsIntRegion* aOther)
   {
     mImpl.Swap(&aOther->mImpl);
   }
   nsIntRegion& And  (const nsIntRegion& aRgn1,   const nsIntRegion& aRgn2)
   {
     mImpl.And (aRgn1.mImpl, aRgn2.mImpl);
     return *this;
   }
   nsIntRegion& And  (const nsIntRegion& aRegion, const nsIntRect& aRect)
   {
     mImpl.And (aRegion.mImpl, ToRect (aRect));
     return *this;
   }
   nsIntRegion& And  (const nsIntRect& aRect, const nsIntRegion& aRegion)
   {
     return  And  (aRegion, aRect);
   }
   nsIntRegion& And  (const nsIntRect& aRect1, const nsIntRect& aRect2)
   {
     nsIntRect TmpRect;
     TmpRect.IntersectRect (aRect1, aRect2);
     mImpl = ToRect (TmpRect);
     return *this;
   }
   nsIntRegion& Or   (const nsIntRegion& aRgn1,   const nsIntRegion& aRgn2)
   {
     mImpl.Or (aRgn1.mImpl, aRgn2.mImpl);
     return *this;
   }
   nsIntRegion& Or   (const nsIntRegion& aRegion, const nsIntRect& aRect)
   {
     mImpl.Or (aRegion.mImpl, ToRect (aRect));
     return *this;
   }
   nsIntRegion& Or   (const nsIntRect& aRect, const nsIntRegion& aRegion)
   {
     return  Or   (aRegion, aRect);
   }
   nsIntRegion& Or   (const nsIntRect& aRect1, const nsIntRect& aRect2)
   {
     mImpl = ToRect (aRect1);
     return Or (*this, aRect2);
   }
   nsIntRegion& Xor  (const nsIntRegion& aRgn1,   const nsIntRegion& aRgn2)
   {
     mImpl.Xor (aRgn1.mImpl, aRgn2.mImpl);
     return *this;
   }
   nsIntRegion& Xor  (const nsIntRegion& aRegion, const nsIntRect& aRect)
   {
     mImpl.Xor (aRegion.mImpl, ToRect (aRect));
     return *this;
   }
   nsIntRegion& Xor  (const nsIntRect& aRect, const nsIntRegion& aRegion)
   {
     return  Xor  (aRegion, aRect);
   }
   nsIntRegion& Xor  (const nsIntRect& aRect1, const nsIntRect& aRect2)
   {
     mImpl = ToRect (aRect1);
     return Xor (*this, aRect2);
   }
   nsIntRegion& Sub  (const nsIntRegion& aRgn1,   const nsIntRegion& aRgn2)
   {
     mImpl.Sub (aRgn1.mImpl, aRgn2.mImpl);
     return *this;
   }
   nsIntRegion& Sub  (const nsIntRegion& aRegion, const nsIntRect& aRect)
   {
     mImpl.Sub (aRegion.mImpl, ToRect (aRect));
     return *this;
   }
   nsIntRegion& Sub  (const nsIntRect& aRect, const nsIntRegion& aRegion)
   {
     return Sub (nsIntRegion (aRect), aRegion);
   }
   nsIntRegion& Sub  (const nsIntRect& aRect1, const nsIntRect& aRect2)
   {
     mImpl = ToRect (aRect1);
     return Sub (*this, aRect2);
   }
   bool Contains (const nsIntRect& aRect) const
   {
     return mImpl.Contains (ToRect (aRect));
   }
   bool Contains (const nsIntRegion& aRgn) const
   {
     return mImpl.Contains (aRgn.mImpl);
   }
   bool Intersects (const nsIntRect& aRect) const
   {
     return mImpl.Intersects (ToRect (aRect));
   }
   void MoveBy (int32_t aXOffset, int32_t aYOffset)
   {
     MoveBy (nsIntPoint (aXOffset, aYOffset));
   }
   void MoveBy (nsIntPoint aPt)
   {
     mImpl.MoveBy (aPt.x, aPt.y);
   }
   nsIntRegion MovedBy(int32_t aXOffset, int32_t aYOffset) const
   {
     return MovedBy(nsIntPoint(aXOffset, aYOffset));
   }
   nsIntRegion MovedBy(const nsIntPoint& aPt) const
   {
     nsIntRegion copy(*this);
     copy.MoveBy(aPt);
     return copy;
   }
   nsIntRegion Intersect(const nsIntRegion& aOther) const
   {
     nsIntRegion intersection;
     intersection.And(*this, aOther);
     return intersection;
   }
   void Inflate(const nsIntMargin& aMargin)
   {
     mImpl.Inflate(nsMargin(aMargin.top, aMargin.right, aMargin.bottom, aMargin.left));
   }
   nsIntRegion Inflated(const nsIntMargin& aMargin) const
   {
     nsIntRegion copy(*this);
     copy.Inflate(aMargin);
     return copy;
   }
   void SetEmpty ()
   {
     mImpl.SetEmpty  ();
   }
   bool IsEmpty () const { return mImpl.IsEmpty (); }
   bool IsComplex () const { return mImpl.IsComplex (); }
   bool IsEqual (const nsIntRegion& aRegion) const
   {
     return mImpl.IsEqual (aRegion.mImpl);
   }
   uint32_t GetNumRects () const { return mImpl.GetNumRects (); }
   nsIntRect GetBounds () const { return FromRect (mImpl.GetBounds ()); }
   uint64_t Area () const { return mImpl.Area(); }
   nsRegion ToAppUnits (nscoord aAppUnitsPerPixel) const;
   nsIntRect GetLargestRectangle (const nsIntRect& aContainingRect = nsIntRect()) const
   {
     return FromRect (mImpl.GetLargestRectangle( ToRect(aContainingRect) ));
   }
   nsIntRegion& ScaleRoundOut (float aXScale, float aYScale)
   {
     mImpl.ScaleRoundOut(aXScale, aYScale);
     return *this;
   }
   /**
    * Make sure the region has at most aMaxRects by adding area to it
    * if necessary. The simplified region will be a superset of the
    * original region. The simplified region's bounding box will be
    * the same as for the current region.
    */
   void SimplifyOutward (uint32_t aMaxRects)
   {
     mImpl.SimplifyOutward (aMaxRects);
   }
   void SimplifyOutwardByArea (uint32_t aThreshold)
   {
     mImpl.SimplifyOutwardByArea (aThreshold);
   }
   /**
    * Make sure the region has at most aMaxRects by removing area from
    * it if necessary. The simplified region will be a subset of the
    * original region.
    */
   void SimplifyInward (uint32_t aMaxRects)
   {
     mImpl.SimplifyInward (aMaxRects);
   }
   nsCString ToString() const { return mImpl.ToString(); }
 private:
   nsRegion mImpl;
   static nsRect ToRect(const nsIntRect& aRect)
   {
     return nsRect (aRect.x, aRect.y, aRect.width, aRect.height);
   }
   static nsIntRect FromRect(const nsRect& aRect)
   {
     return nsIntRect (aRect.x, aRect.y, aRect.width, aRect.height);
   }
 };
 class NS_GFX nsIntRegionRectIterator
 {
   nsRegionRectIterator mImpl;
   nsIntRect mTmp;
 public:
   nsIntRegionRectIterator (const nsIntRegion& aRegion) : mImpl (aRegion.mImpl) {}
   const nsIntRect* Next ()
   {
     const nsRect* r = mImpl.Next();
     if (!r)
       return nullptr;
     mTmp = nsIntRegion::FromRect (*r);
     return &mTmp;
   }
   const nsIntRect* Prev ()
   {
     const nsRect* r = mImpl.Prev();
     if (!r)
       return nullptr;
     mTmp = nsIntRegion::FromRect (*r);
     return &mTmp;
   }
   void Reset ()
   {
     mImpl.Reset ();
   }
 };
 #endif

The Tor Browser / annotate

gfx/src/nsRegion.h@97036ab72558 (annotated)

gfx/src/nsRegion.h