95 lines
2.2 KiB
JavaScript
95 lines
2.2 KiB
JavaScript
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/**
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* Endian operations.
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*
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* @author n1474335 [n1474335@gmail.com]
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* @copyright Crown Copyright 2016
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* @license Apache-2.0
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*
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* @namespace
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*/
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var Endian = {
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/**
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* @constant
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* @default
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*/
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DATA_FORMAT: ["Hex", "Raw"],
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/**
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* @constant
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* @default
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*/
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WORD_LENGTH: 4,
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/**
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* @constant
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* @default
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*/
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PAD_INCOMPLETE_WORDS: true,
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/**
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* Swap endianness operation.
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*
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* @param {string} input
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* @param {Object[]} args
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* @returns {string}
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*/
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run_swap_endianness: function(input, args) {
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var data_format = args[0],
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word_length = args[1],
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pad_incomplete_words = args[2],
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data = [],
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result = [],
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words = [],
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i = 0,
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j = 0;
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if (word_length <= 0) {
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return "Word length must be greater than 0";
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}
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// Convert input to raw data based on specified data format
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switch (data_format) {
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case "Hex":
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data = Utils.from_hex(input);
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break;
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case "Raw":
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data = Utils.str_to_byte_array(input);
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break;
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default:
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data = input;
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}
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// Split up into words
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for (i = 0; i < data.length; i += word_length) {
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var word = data.slice(i, i + word_length);
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// Pad word if too short
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if (pad_incomplete_words && word.length < word_length){
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for (j = word.length; j < word_length; j++) {
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word.push(0);
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}
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}
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words.push(word);
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}
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// Swap endianness and flatten
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for (i = 0; i < words.length; i++) {
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j = words[i].length;
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while (j--) {
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result.push(words[i][j]);
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}
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}
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// Convert data back to specified data format
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switch (data_format) {
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case "Hex":
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return Utils.to_hex(result);
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case "Raw":
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return Utils.byte_array_to_utf8(result);
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default:
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return result;
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}
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},
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};
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