56 lines
1.4 KiB
JavaScript
56 lines
1.4 KiB
JavaScript
'use strict';
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// Map of id => function that releases a lock.
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const held = new Map();
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let next_lock_id = 1;
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function processMessage(e) {
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const target = this;
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function respond(data) {
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target.postMessage(Object.assign(data, {rqid: e.data.rqid}));
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}
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switch (e.data.op) {
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case 'request': {
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const controller = new AbortController();
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navigator.locks.request(
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e.data.name, {
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mode: e.data.mode || 'exclusive',
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ifAvailable: e.data.ifAvailable || false,
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signal: e.data.abortImmediately ? controller.signal : undefined,
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}, lock => {
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if (lock === null) {
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respond({ack: 'request', failed: true});
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return;
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}
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let lock_id = next_lock_id++;
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let release;
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const promise = new Promise(r => { release = r; });
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held.set(lock_id, release);
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respond({ack: 'request', lock_id: lock_id});
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return promise;
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}).catch(e => {
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respond({ack: 'request', error: e.name});
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});
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if (e.data.abortImmediately) {
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controller.abort();
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}
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break;
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}
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case 'release':
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held.get(e.data.lock_id)();
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held.delete(e.data.lock_id);
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respond({ack: 'release', lock_id: e.data.lock_id});
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break;
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}
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}
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self.addEventListener('message', processMessage);
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self.addEventListener('connect', ev => {
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// Shared worker case
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ev.ports[0].onmessage = processMessage;
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});
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