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'use strict';
// The goal of this file is to normalize SAB
// at least in main -> worker() use cases.
// This still cannot possibly solve the sync
// worker -> main() use case if SharedArrayBuffer
// is not available or usable.
const {CHANNEL} = require('./channel.js');
const {isArray} = Array;
let {SharedArrayBuffer, window} = globalThis;
let {notify, wait, waitAsync} = Atomics;
let postPatched = null;
// This is needed for some version of Firefox
if (!waitAsync) {
waitAsync = buffer => ({
value: new Promise(onmessage => {
// encodeURIComponent('onmessage=({data:b})=>(Atomics.wait(b,0),postMessage(0))')
let w = new Worker('data:application/javascript,onmessage%3D(%7Bdata%3Ab%7D)%3D%3E(Atomics.wait(b%2C0)%2CpostMessage(0))');
w.onmessage = onmessage;
w.postMessage(buffer);
})
});
}
// Monkey-patch SharedArrayBuffer if needed
try {
new SharedArrayBuffer(4);
}
catch (_) {
SharedArrayBuffer = ArrayBuffer;
const ids = new WeakMap;
// patch only main -> worker():async use case
if (window) {
const resolvers = new Map;
const {prototype: {postMessage}} = Worker;
const listener = event => {
const details = event.data?.[CHANNEL];
if (!isArray(details)) {
event.stopImmediatePropagation();
const { id, sb } = details;
resolvers.get(id)(sb);
}
};
postPatched = function (data, ...rest) {
const details = data?.[CHANNEL];
if (isArray(details)) {
const [id, sb] = details;
ids.set(sb, id);
this.addEventListener('message', listener);
}
return postMessage.call(this, data, ...rest);
};
waitAsync = sb => ({
value: new Promise(resolve => {
resolvers.set(ids.get(sb), resolve);
}).then(buff => {
resolvers.delete(ids.get(sb));
ids.delete(sb);
for (let i = 0; i < buff.length; i++) sb[i] = buff[i];
return 'ok';
})
});
}
else {
const as = (id, sb) => ({[CHANNEL]: { id, sb }});
notify = sb => {
postMessage(as(ids.get(sb), sb));
};
addEventListener('message', event => {
const details = event.data?.[CHANNEL];
if (isArray(details)) {
const [id, sb] = details;
ids.set(sb, id);
}
});
}
}
exports.SharedArrayBuffer = SharedArrayBuffer;
exports.isArray = isArray;
exports.notify = notify;
exports.postPatched = postPatched;
exports.wait = wait;
exports.waitAsync = waitAsync;
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