51 lines
1.3 KiB
JavaScript
51 lines
1.3 KiB
JavaScript
// Utilities
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// =========
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// Helper that uses FileReader or FileReaderSync based on context and returns
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// a Promise that resolves with the text or rejects with error.
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function readAsText(blob) {
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if (typeof FileReader !== "undefined") {
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return new Promise(function (resolve, reject) {
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var fs = new FileReader();
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fs.onload = function () {
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resolve(fs.result);
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};
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fs.onerror = reject;
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fs.readAsText(blob);
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});
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} else {
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var fs = new FileReaderSync();
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return Promise.resolve(fs.readAsText(blob));
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}
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}
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function readAsArrayBuffer(blob) {
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if (typeof FileReader !== "undefined") {
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return new Promise(function (resolve, reject) {
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var fs = new FileReader();
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fs.onload = function () {
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resolve(fs.result);
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};
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fs.onerror = reject;
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fs.readAsArrayBuffer(blob);
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});
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} else {
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var fs = new FileReaderSync();
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return Promise.resolve(fs.readAsArrayBuffer(blob));
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}
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}
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function waitForState(worker, state, context) {
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return new Promise(resolve => {
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if (worker.state === state) {
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resolve(context);
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return;
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}
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worker.addEventListener("statechange", function onStateChange() {
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if (worker.state === state) {
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worker.removeEventListener("statechange", onStateChange);
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resolve(context);
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}
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});
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});
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}
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