50 lines
1.7 KiB
JavaScript
50 lines
1.7 KiB
JavaScript
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// SPDX-License-Identifier: Apache-2.0
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//
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// Analysis worker: the browser's AnalysisResultsManager worker thread.
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//
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// Holds each loaded track's mono signal (transferred in, never copied) and runs
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// one metric at a time on request, so a 10-minute spectrogram never blocks the
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// page. Everything stays in this tab's memory; closing the tab frees it.
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//
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// Messages in: {type: 'load', trackId, mono, sampleRate}
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// {type: 'compute', reqId, trackId, metricId}
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// {type: 'drop', trackId}
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// Messages out: {type: 'result', reqId, trackId, metricId, data, ms}
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// {type: 'error', reqId, trackId, metricId, message}
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import { COMPUTE, transferables } from './dsp.js';
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const tracks = new Map(); // trackId -> {mono, sampleRate, memo}
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self.onmessage = (event) => {
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const msg = event.data;
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if (msg.type === 'load') {
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tracks.set(msg.trackId, { mono: msg.mono, sampleRate: msg.sampleRate, memo: {} });
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return;
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}
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if (msg.type === 'drop') {
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tracks.delete(msg.trackId);
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return;
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}
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if (msg.type !== 'compute') return;
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const { reqId, trackId, metricId } = msg;
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const track = tracks.get(trackId);
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const compute = COMPUTE[metricId];
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if (!track || !compute) {
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self.postMessage({
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type: 'error', reqId, trackId, metricId,
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message: track ? `unknown metric ${metricId}` : 'track is no longer loaded',
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});
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return;
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}
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try {
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const t0 = performance.now();
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const data = compute(track.mono, track.sampleRate, track.memo);
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const ms = performance.now() - t0;
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self.postMessage({ type: 'result', reqId, trackId, metricId, data, ms }, transferables(data));
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} catch (err) {
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self.postMessage({ type: 'error', reqId, trackId, metricId, message: String((err && err.message) || err) });
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}
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};
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