mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2025-11-04 07:10:57 +00:00
41 lines
1.4 KiB
C
41 lines
1.4 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
|
||
|
|
*
|
||
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
||
|
|
*/
|
||
|
|
|
||
|
|
#pragma once
|
||
|
|
|
||
|
|
#include <AK/BuiltinWrappers.h>
|
||
|
|
#include <LibCore/System.h>
|
||
|
|
#include <LibWeb/WebIDL/Types.h>
|
||
|
|
|
||
|
|
namespace Web::HTML {
|
||
|
|
|
||
|
|
class NavigatorDeviceMemoryMixin {
|
||
|
|
public:
|
||
|
|
// https://www.w3.org/TR/device-memory/#computing-device-memory-value
|
||
|
|
WebIDL::Double device_memory() const
|
||
|
|
{
|
||
|
|
// The value is calculated by using the actual device memory in MiB then rounding it to the
|
||
|
|
// nearest number where only the most signicant bit can be set and the rest are zeros
|
||
|
|
// (nearest power of two).
|
||
|
|
auto memory_in_bytes = Core::System::physical_memory_bytes();
|
||
|
|
auto memory_in_mib = memory_in_bytes / MiB;
|
||
|
|
auto required_bits = AK::count_required_bits(memory_in_mib);
|
||
|
|
auto lower_memory_in_mib = static_cast<u64>(1) << (required_bits - 1);
|
||
|
|
auto upper_memory_in_mib = static_cast<u64>(1) << required_bits;
|
||
|
|
auto rounded_memory_in_mib = upper_memory_in_mib - memory_in_mib <= memory_in_mib - lower_memory_in_mib
|
||
|
|
? upper_memory_in_mib
|
||
|
|
: lower_memory_in_mib;
|
||
|
|
|
||
|
|
// Then dividing that number by 1024.0 to get the value in GiB.
|
||
|
|
auto memory_in_gib = static_cast<WebIDL::Double>(rounded_memory_in_mib) / 1024.0;
|
||
|
|
|
||
|
|
// An upper bound and a lower bound should be set on the list of values.
|
||
|
|
return AK::clamp(memory_in_gib, 1.0, 4.0);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
}
|