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674075f79e
This reduces the number of compilation jobs when System.h changes from about 750 to 60. (There are still a large number of linker jobs.)
34 lines
1.3 KiB
C++
34 lines
1.3 KiB
C++
/*
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* Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <AK/BuiltinWrappers.h>
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#include <LibCore/System.h>
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#include <LibWeb/HTML/NavigatorDeviceMemory.h>
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namespace Web::HTML {
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// https://www.w3.org/TR/device-memory/#computing-device-memory-value
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WebIDL::Double NavigatorDeviceMemoryMixin::device_memory() const
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{
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// The value is calculated by using the actual device memory in MiB then rounding it to the nearest number where
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// only the most significant bit can be set and the rest are zeros (nearest power of two).
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auto memory_in_bytes = Core::System::physical_memory_bytes();
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auto memory_in_mib = memory_in_bytes / MiB;
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auto required_bits = AK::count_required_bits(memory_in_mib);
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auto lower_memory_in_mib = static_cast<u64>(1) << (required_bits - 1);
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auto upper_memory_in_mib = static_cast<u64>(1) << required_bits;
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auto rounded_memory_in_mib = upper_memory_in_mib - memory_in_mib <= memory_in_mib - lower_memory_in_mib
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? upper_memory_in_mib
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: lower_memory_in_mib;
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// Then dividing that number by 1024.0 to get the value in GiB.
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auto memory_in_gib = static_cast<WebIDL::Double>(rounded_memory_in_mib) / 1024.0;
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// An upper bound and a lower bound should be set on the list of values.
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return AK::clamp(memory_in_gib, 1.0, 4.0);
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}
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}
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