52 lines
1.4 KiB
HTML
52 lines
1.4 KiB
HTML
<!DOCTYPE html>
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<title>Helper IFrame</title>
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<script>
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'use strict';
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// Map of lock_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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self.addEventListener('message', e => {
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function respond(data) {
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parent.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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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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}, 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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});
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break;
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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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case 'client_id':
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navigator.locks.request(e.data.name, async lock => {
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const lock_state = await navigator.locks.query();
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const held_lock =
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lock_state.held.filter(l => l.name === lock.name)[0];
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respond({ack: 'client_id', client_id: held_lock.clientId});
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});
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break;
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}
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});
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</script>
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