The Tor Browser: gfx/thebes/gfxRect.cpp@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: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     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 #include "gfxRect.h"

     8 #include "nsMathUtils.h"

    10 static bool

    11 WithinEpsilonOfInteger(gfxFloat aX, gfxFloat aEpsilon)

    12 {

    13     return fabs(NS_round(aX) - aX) <= fabs(aEpsilon);

    14 }

    16 bool

    17 gfxRect::WithinEpsilonOfIntegerPixels(gfxFloat aEpsilon) const

    18 {

    19     NS_ASSERTION(-0.5 < aEpsilon && aEpsilon < 0.5, "Nonsense epsilon value");

    20     return (WithinEpsilonOfInteger(x, aEpsilon) &&

    21             WithinEpsilonOfInteger(y, aEpsilon) &&

    22             WithinEpsilonOfInteger(width, aEpsilon) &&

    23             WithinEpsilonOfInteger(height, aEpsilon));

    24 }

    26 /* Clamp r to CAIRO_COORD_MIN .. CAIRO_COORD_MAX

    27  * these are to be device coordinates.

    28  *

    29  * Cairo is currently using 24.8 fixed point,

    30  * so -2^24 .. 2^24-1 is our valid

    31  */

    33 #define CAIRO_COORD_MAX (16777215.0)

    34 #define CAIRO_COORD_MIN (-16777216.0)

    36 void

    37 gfxRect::Condition()

    38 {

    39     // if either x or y is way out of bounds;

    40     // note that we don't handle negative w/h here

    41     if (x > CAIRO_COORD_MAX) {

    42         x = CAIRO_COORD_MAX;

    43         width = 0.0;

    44     }

    46     if (y > CAIRO_COORD_MAX) {

    47         y = CAIRO_COORD_MAX;

    48         height = 0.0;

    49     }

    51     if (x < CAIRO_COORD_MIN) {

    52         width += x - CAIRO_COORD_MIN;

    53         if (width < 0.0)

    54             width = 0.0;

    55         x = CAIRO_COORD_MIN;

    56     }

    58     if (y < CAIRO_COORD_MIN) {

    59         height += y - CAIRO_COORD_MIN;

    60         if (height < 0.0)

    61             height = 0.0;

    62         y = CAIRO_COORD_MIN;

    63     }

    65     if (x + width > CAIRO_COORD_MAX) {

    66         width = CAIRO_COORD_MAX - x;

    67     }

    69     if (y + height > CAIRO_COORD_MAX) {

    70         height = CAIRO_COORD_MAX - y;

    71     }

    72 }

The Tor Browser / file revision

gfx/thebes/gfxRect.cpp@97036ab72558

gfx/thebes/gfxRect.cpp