apla-blockchain-tools/lib/convert.js

Module contains a number of tools to work with Apla Blockchain

"use strict";
// MIT License
//
// Copyright (c) 2016-2018 AplaProject
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

/*
 * Package: apla-blockchain-tools
 * Author: Anton Zuev
 * mail: a.zuev@apla.io
 * Company: apla.io
 */

let { Uint64BE } = require('int64-buffer');

let convert = {
    MONEY_POWER: 18,

    /**
     *
     * @param hex {string}
     * @return {ArrayBuffer}
     */
    toArrayBuffer: (hex) => {
        const uint8 = new Uint8Array(hex.match(/[\da-f]{2}/gi).map(h =>
            parseInt(h, 16)
        ));

        return uint8.buffer;
    },

    /**
     *
     * @param length {number}
     * @return {Uint8Array}
     */
    encodeLength: (length) => {
        if (length >= 0 && length < 128) {
            const value = new Uint8Array(1);
            value[0] = length;
            return value;
        }

        const buffer = (new Uint64BE(length)).buffer;
        let i = 1;
        while (buffer[i] === 0 && i < buffer.length) {
            i++;
        }
        let offset = buffer.length - i;

        const uint8 = new Uint8Array(1 + offset);
        uint8[0] = 128 | offset;
        for (let n = 1; i <= buffer.length; n++ , i++) {
            uint8[n] = buffer[i];
        }

        return uint8;
    },

    /**
     *
     * @param a {Uint8Array | ArrayBuffer}
     * @param b {Uint8Array | ArrayBuffer}
     * @return {ArrayBuffer}
     */
    concatBuffer: (a, b) => {
        if (a instanceof ArrayBuffer) {
            a = new Uint8Array(a);
        }

        if (b instanceof ArrayBuffer) {
            b = new Uint8Array(b);
        }

        const uint8 = new Uint8Array(a.length + b.length);

        uint8.set(a, 0);
        uint8.set(b, a.length);

        return uint8.buffer;
    },

    /**
     *
     * @param buffer {Uint8Array | ArrayBuffer}
     * @return {ArrayBuffer}
     */
    encodeLengthPlusData: (buffer) => {
        if (buffer instanceof ArrayBuffer) {
            buffer = new Uint8Array(buffer);
        }
        return convert.concatBuffer(convert.encodeLength(buffer.length), buffer);
    },

    /**
     *
     * @param value {number | string}
     * @return {*}
     */
    toMoney: (value) => {
        const match = /([\d]+)((\.|,)([\d]+))?/.exec(String(value));
        if (!match) {
            return null;
        }
        const integer = match[1];
        const fraction = match[4] || '';
        let result = integer;
        for (let i = 0; i < convert.MONEY_POWER; i++) {
            const val = fraction.length <= i ? '0' : fraction[i];
            result += val;
        }
        if (fraction.length > convert.MONEY_POWER) {
            result = result + `.${fraction.slice(convert.MONEY_POWER, convert.MONEY_POWER * 2)}`;
        }
        return result;
    },


    /**
     *
     * @param {Array} value
     * @return {ArrayBuffer}
     */
    arrayToArrayBuffer: (value) => {
        let r = new ArrayBuffer(value.length);
        for (let i = 0; i < value.length; i++){
            r[i] = value[i];
        }
        return r;
    },

};

module.exports = convert;