51 lines
1.8 KiB
JavaScript
51 lines
1.8 KiB
JavaScript
const type = 'application/javascript';
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/**
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*
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* @param {string} originalWorkerUrl
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* @param {{
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* useBlob?: boolean
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* skipSameOrigin?: boolean
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* }} options
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* @returns {Promise<string>}
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*/
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async function getCrossOriginWorkerURL (originalWorkerUrl, options = {}) {
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const skipSameOrigin = options.skipSameOrigin || true;
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const useBlob = options.useBlob || true;
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// 本来就是同源的，不需要额外进行处理，直接返回
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if (!originalWorkerUrl.includes('://') || originalWorkerUrl.includes(window.location.origin)) {
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return originalWorkerUrl;
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}
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// 获取 worker 的 js 代码
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const res = await fetch(originalWorkerUrl);
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const workerJsCode = await res.text();
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// worker 所在的文件夹 url
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const workerPath = new URL(originalWorkerUrl).href.split('/');
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workerPath.pop();
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// 给 importScripts 的每一个引入的js文件增加 workerPath 组成绝对路径
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const importScriptsFix = `const _importScripts = importScripts;
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const _fixImports = (url) => new URL(url, '${workerPath.join('/') + '/'}').href;
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importScripts = (...urls) => _importScripts(...urls.map(_fixImports));
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`;
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// 以 MIME 协议组成 blob，从而进行装载
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let resultURL = `data:${type},` + encodeURIComponent(importScriptsFix + workerJsCode);
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if (useBlob) {
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// 在外面再套一层 importScripts，这样第二次请求得到的 worker 就不是 blob worker 了
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// 直接使用 createObjectURL 请求一个 worker 的源码是不行的，因为这样得到的 blob worker
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// 会有原本 worker 的 feature 无法使用
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resultURL = URL.createObjectURL(
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new Blob([`importScripts("${resultURL}")`], { type })
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);
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}
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return resultURL;
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}
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export {
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getCrossOriginWorkerURL
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} |