69 lines
1.9 KiB
JavaScript
69 lines
1.9 KiB
JavaScript
'use strict';
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String.prototype.removeEndNullBytes = function() {
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return this.replace(/\0+$/g, '');
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}
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String.prototype.removeStartNullBytes = function() {
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return this.replace(/^\0+/g, '');
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}
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var pluie =
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{
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bin :
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{
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enc : new TextEncoder("utf-8"),
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dec : new TextDecoder("utf-8", {fatal: true}),
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intFromBytes : function(bytes)
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{
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// Big Endian
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for (var i = value = 0, lim = bytes.length; i < lim; i++) {
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value = value * 256 + bytes[i];
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}
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return value;
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},
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bytesFromInt : function(value, size)
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{
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var bytes = new Uint8Array(size);
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while (value) {
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bytes.set([value & 255], --size);
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value >>= 8;;
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}
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return bytes;
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},
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pack : function(size, type, value)
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{
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var packed = null
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if (type == 'n' || type == 'N') {
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// js int max on 32 signed bits
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if (value >= 0 && value <= 2147483647) {
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packed = this.bytesFromInt(value, type == 'n' ? 2 : 4);
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}
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}
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else if (type == 'a') {
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packed = new Uint8Array(size);
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packed.set(this.enc.encode(value), 0);
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}
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return packed;
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},
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unpack : function(size, type, bytes)
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{
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var unpacked = null
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if (type == 'n' || type == 'N') {
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var selByte = bytes.slice(0, size*(type == 'n' ? 2 : 4));
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unpacked = this.intFromBytes(selByte);
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}
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else if (type == 'a') {
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unpacked = this.dec.decode(bytes.slice(0, size)).removeEndNullBytes();
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}
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return unpacked;
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}
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}
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}
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module.exports = pluie.bin;
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