33 lines
1.6 KiB
TypeScript
33 lines
1.6 KiB
TypeScript
/** Poll visible page content without overlapping requests. Fleet watches use their own monitor. */
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export function pollVisible(task: (signal: AbortSignal) => unknown | Promise<unknown>, interval: number, immediate = true): () => void {
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let stopped = false;
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let running = false;
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let timer: ReturnType<typeof setTimeout> | undefined;
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let controller: AbortController | undefined;
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let failures = 0;
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const visible = () => document.visibilityState !== 'hidden';
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const run = async () => {
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if (stopped || running || !visible()) return;
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clearTimeout(timer);
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running = true;
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controller = new AbortController();
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const timeout = setTimeout(() => controller?.abort(), 30_000);
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try { failures = await task(controller.signal) === false ? failures + 1 : 0; }
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catch (error) { if (!controller.signal.aborted) { failures++; console.error('Page refresh failed', error); } }
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finally {
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clearTimeout(timeout);
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controller = undefined;
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running = false;
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if (!stopped && visible()) timer = setTimeout(run, interval * Math.min(8, 2 ** failures));
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}
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};
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const visibility = () => {
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clearTimeout(timer);
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if (!visible()) controller?.abort();
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if (document.visibilityState !== 'hidden') void run();
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};
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document.addEventListener('visibilitychange', visibility);
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if (immediate) void run(); else timer = setTimeout(run, interval);
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return () => { stopped = true; clearTimeout(timer); controller?.abort(); document.removeEventListener('visibilitychange', visibility); };
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}
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