30 lines
1.1 KiB
TypeScript
30 lines
1.1 KiB
TypeScript
/// SPDX-License-Identifier: GPL-3.0-or-later
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/// SPDX-FileCopyrightText: Copyright © 2016-2021 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
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// Wake detector - notices when something (such as
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// suspension/sleeping!) has caused periodic activities to be
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// interrupted, and warns others about it. Inspired by
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// http://blog.alexmaccaw.com/javascript-wake-event
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import { Ref, Turn, Observe } from "@syndicate-lang/core";
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export message type WakeEvent();
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export function boot(ds: Ref, period0?: number) {
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const period = period0 ?? 10000;
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at ds {
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during Observe({ "pattern": :pattern WakeEvent() }) => spawn named 'WakeDetector' {
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const facet = Turn.activeFacet;
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let mostRecentTrigger = +(new Date());
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const timerId = setInterval(() => facet.turn(() => {
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const now = +(new Date());
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if (now - mostRecentTrigger > period * 1.5) {
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send message WakeEvent();
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}
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mostRecentTrigger = now;
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}), period);
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on stop clearInterval(timerId);
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}
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}
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}
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