void
ImageBitmap::SetPictureRect(const IntRect& aRect, ErrorResult& aRv)
{
gfx::IntRect rect = aRect;
// fix up negative dimensions
if (rect.width < 0) {
CheckedInt32 checkedX = CheckedInt32(rect.x) + rect.width;
if (!checkedX.isValid()) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return;
}
rect.x = checkedX.value();
rect.width = -(rect.width);
}
if (rect.height < 0) {
CheckedInt32 checkedY = CheckedInt32(rect.y) + rect.height;
if (!checkedY.isValid()) {
aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return;
}
rect.y = checkedY.value();
rect.height = -(rect.height);
}
mPictureRect = rect;
}
void
gfxXlibSurface::TakePixmap()
{
NS_ASSERTION(!mPixmapTaken, "I already own the Pixmap!");
mPixmapTaken = true;
// The bit depth returned from Cairo is technically int, but this is
// the last place we'd be worried about that scenario.
unsigned int bitDepth = cairo_xlib_surface_get_depth(CairoSurface());
MOZ_ASSERT((bitDepth % 8) == 0, "Memory used not recorded correctly");
// Divide by 8 because surface_get_depth gives us the number of *bits* per
// pixel.
gfxIntSize size = GetSize();
CheckedInt32 totalBytes = CheckedInt32(size.width) * CheckedInt32(size.height) * (bitDepth/8);
// Don't do anything in the "else" case. We could add INT32_MAX, but that
// would overflow the memory used counter. It would also mean we tried for
// a 2G image. For now, we'll just assert,
MOZ_ASSERT(totalBytes.isValid(),"Did not expect to exceed 2Gb image");
if (totalBytes.isValid()) {
RecordMemoryUsed(totalBytes.value());
}
}
size_t
BufferSizeFromStrideAndHeight(int32_t aStride,
int32_t aHeight,
int32_t aExtraBytes)
{
if (MOZ_UNLIKELY(aHeight <= 0)) {
return 0;
}
// We limit the length returned to values that can be represented by int32_t
// because we don't want to allocate buffers any bigger than that. This
// allows for a buffer size of over 2 GiB which is already rediculously
// large and will make the process janky. (Note the choice of the signed type
// is deliberate because we specifically don't want the returned value to
// overflow if someone stores the buffer length in an int32_t variable.)
CheckedInt32 requiredBytes =
CheckedInt32(aStride) * CheckedInt32(aHeight) + CheckedInt32(aExtraBytes);
if (MOZ_UNLIKELY(!requiredBytes.isValid())) {
gfxWarning() << "Buffer size too big; returning zero";
return 0;
}
return requiredBytes.value();
}
