91 lines
2.1 KiB
JavaScript
91 lines
2.1 KiB
JavaScript
// Sshwifty - A Web SSH client
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//
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// Copyright (C) 2019 Rui NI <nirui@gmx.com>
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as
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// published by the Free Software Foundation, either version 3 of the
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// License, or (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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import Exception from "./exception.js";
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import * as reader from "../stream/reader.js";
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export const MAX = 0x3fff;
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export const MAX_BYTES = 2;
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const integerHasNextBit = 0x80;
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const integerValueCutter = 0x7f;
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export class Integer {
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/**
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* constructor
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*
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* @param {number} num Integer number
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*
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*/
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constructor(num) {
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this.num = num;
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}
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/**
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* Marshal integer to buffer
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*
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* @returns {Uint8Array} Integer buffer
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*
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* @throws {Exception} When number is too large
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*
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*/
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marshal() {
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if (this.num > MAX) {
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throw new Exception("Integer number cannot be greater than 0x3fff");
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}
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if (this.num <= integerValueCutter) {
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return new Uint8Array([this.num & integerValueCutter]);
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}
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return new Uint8Array([
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(this.num >> 7) | integerHasNextBit,
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this.num & integerValueCutter
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]);
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}
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/**
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* Parse the reader to build an Integer
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*
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* @param {reader.Reader} rd Data reader
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*
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*/
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async unmarshal(rd) {
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for (let i = 0; i < MAX_BYTES; i++) {
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let r = await reader.readOne(rd);
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this.num |= r[0] & integerValueCutter;
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if ((integerHasNextBit & r[0]) == 0) {
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return;
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}
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this.num <<= 7;
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}
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}
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/**
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* Return the value of the number
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*
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* @returns {number} The integer value
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*
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*/
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value() {
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return this.num;
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}
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}
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