73 lines
1.9 KiB
JavaScript
73 lines
1.9 KiB
JavaScript
'use strict';
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/* istanbul ignore next */
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var MyPromise = typeof Promise !== 'undefined' ? Promise : require('lie');
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var messageIds = 0;
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function onMessage(self, e) {
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var message = e.data;
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if (!Array.isArray(message) || message.length < 2) {
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// Ignore - this message is not for us.
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return;
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}
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var messageId = message[0];
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var error = message[1];
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var result = message[2];
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var callback = self._callbacks[messageId];
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if (!callback) {
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// Ignore - user might have created multiple PromiseWorkers.
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// This message is not for us.
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return;
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}
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delete self._callbacks[messageId];
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callback(error, result);
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}
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function PromiseWorker(worker) {
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var self = this;
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self._worker = worker;
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self._callbacks = {};
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worker.addEventListener('message', function (e) {
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onMessage(self, e);
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});
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}
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PromiseWorker.prototype.postMessage = function (userMessage, transferList) {
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var self = this;
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var messageId = messageIds++;
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var messageToSend = [messageId, userMessage];
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return new MyPromise(function (resolve, reject) {
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self._callbacks[messageId] = function (error, result) {
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if (error) {
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return reject(new Error(error.message));
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}
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resolve(result);
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};
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/* istanbul ignore if */
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if (typeof self._worker.controller !== 'undefined') {
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// service worker, use MessageChannels because e.source is broken in Chrome < 51:
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// https://bugs.chromium.org/p/chromium/issues/detail?id=543198
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var channel = new MessageChannel();
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channel.port1.onmessage = function (e) {
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onMessage(self, e);
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};
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self._worker.controller.postMessage(messageToSend, [channel.port2].concat(transferList));
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} else {
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// web worker
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self._worker.postMessage(messageToSend, transferList);
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}
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});
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};
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PromiseWorker.prototype.terminate = function () {
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this._worker.terminate();
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}
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module.exports = PromiseWorker; |