mirror of https://github.com/gchq/CyberChef.git
55 lines
1.3 KiB
JavaScript
Executable File
55 lines
1.3 KiB
JavaScript
Executable File
/**
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* Web Worker to load large amounts of data without locking up the UI.
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*
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* @author n1474335 [n1474335@gmail.com]
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* @copyright Crown Copyright 2017
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* @license Apache-2.0
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*/
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/**
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* Respond to message from parent thread.
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*/
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self.addEventListener("message", function(e) {
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const r = e.data;
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if (Object.prototype.hasOwnProperty.call(r, "file")) {
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self.loadFile(r.file);
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}
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});
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/**
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* Loads a file object into an ArrayBuffer, then transfers it back to the parent thread.
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*
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* @param {File} file
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*/
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self.loadFile = function(file) {
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const reader = new FileReader();
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const data = new Uint8Array(file.size);
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let offset = 0;
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const CHUNK_SIZE = 10485760; // 10MiB
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const seek = function() {
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if (offset >= file.size) {
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self.postMessage({"progress": 100});
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self.postMessage({"fileBuffer": data.buffer}, [data.buffer]);
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return;
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}
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self.postMessage({"progress": Math.round(offset / file.size * 100)});
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const slice = file.slice(offset, offset + CHUNK_SIZE);
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reader.readAsArrayBuffer(slice);
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};
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reader.onload = function(e) {
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data.set(new Uint8Array(reader.result), offset);
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offset += CHUNK_SIZE;
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seek();
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};
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reader.onerror = function(e) {
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self.postMessage({"error": reader.error.message});
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};
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seek();
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};
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