ladybird/Userland/Libraries/LibWeb/HighResolutionTime/TimeOrigin.cpp

/*
 * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
 * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/Time.h>
#include <LibWeb/HTML/Scripting/Environments.h>
#include <LibWeb/HighResolutionTime/TimeOrigin.h>

namespace Web::HighResolutionTime {

// https://w3c.github.io/hr-time/#dfn-get-time-origin-timestamp
DOMHighResTimeStamp get_time_origin_timestamp(JS::Object const& global)
{
    // FIXME: Implement this.
    (void)global;
    return 0;
}

// https://w3c.github.io/hr-time/#dfn-coarsen-time
DOMHighResTimeStamp coarsen_time(DOMHighResTimeStamp timestamp, bool cross_origin_isolated_capability)
{
    // FIXME: Implement this.
    (void)cross_origin_isolated_capability;
    return timestamp;
}

// https://w3c.github.io/hr-time/#dfn-relative-high-resolution-time
DOMHighResTimeStamp relative_high_resolution_time(DOMHighResTimeStamp time, JS::Object const& global)
{
    // 1. Let coarse time be the result of calling coarsen time with time and global's relevant settings object's cross-origin isolated capability.
    auto coarse_time = coarsen_time(time, HTML::relevant_settings_object(global).cross_origin_isolated_capability() == HTML::CanUseCrossOriginIsolatedAPIs::Yes);

    // 2. Return the relative high resolution coarse time for coarse time and global.
    return relative_high_resolution_coarsen_time(coarse_time, global);
}

// https://w3c.github.io/hr-time/#dfn-relative-high-resolution-coarse-time
DOMHighResTimeStamp relative_high_resolution_coarsen_time(DOMHighResTimeStamp coarsen_time, JS::Object const& global)
{
    // The relative high resolution coarse time given a DOMHighResTimeStamp coarseTime and a global object global, is the difference between coarseTime and the result of calling get time origin timestamp with global.
    return coarsen_time - get_time_origin_timestamp(global);
}

// https://w3c.github.io/hr-time/#dfn-coarsened-shared-current-time
DOMHighResTimeStamp coarsened_shared_current_time(bool cross_origin_isolated_capability)
{
    // The coarsened shared current time given an optional boolean crossOriginIsolatedCapability (default false), must return the result of calling coarsen time with the unsafe shared current time and crossOriginIsolatedCapability.
    return coarsen_time(unsafe_shared_current_time(), cross_origin_isolated_capability);
}

// https://w3c.github.io/hr-time/#dfn-unsafe-shared-current-time
DOMHighResTimeStamp unsafe_shared_current_time()
{
    // The unsafe shared current time must return the current value of the shared monotonic clock.
    return Time::now_monotonic().to_nanoseconds() / 1e6;
}

}