akirattii’s gists

akirattii / async-iterator-example.js

Created November 13, 2018 04:39

NodeJS v10: An example of Async-Iterator with Stream API

	const fs = require("fs");

	const inputFilePath = process.argv[2];
	console.log("file:", inputFilePath);

	async function main(inputFilePath) {
	const readStream = fs.createReadStream(inputFilePath, { encoding: 'utf8', highWaterMark: 1024 });

	// NOTE: Async-Iterator starts with NodeJS v10, but it's experimental yet. (Current latest LTS version: v10.13.0)
	for await (const chunk of readStream) {

akirattii / chart.js-simple-stock-chart-example.html

Created October 4, 2018 00:54

[Chart.js] Simple stock chart example

	<!DOCTYPE html>
	<html>

	<head>
	<meta charset="utf-8">
	<title>Char.js Simple Stock Chart Example</title>
	</head>

	<body>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.bundle.min.js" integrity="sha256-XF29CBwU1MWLaGEnsELogU6Y6rcc5nCkhhx89nFMIDQ=" crossorigin="anonymous"></script>

akirattii / parsePaymentURIScheme.js

Created August 28, 2018 03:13

JS: How to parse Payments URI Scheme

	/**
	* Payments URI Scheme Parser
	* @param {String} - eg. "bitcoin:1XXX?amount=123&comment=%66%77"
	* @see also: https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki
	*/
	function parsePaymentURIScheme(s) {
	const tmp = s.match(/^(\w+)\:(\w+)\??(.+)?/);
	const protocol = (tmp && tmp.length >= 1) ? tmp[1] : null;
	const address = (tmp && tmp.length >= 2) ? tmp[2] : null;
	const qstr = (tmp && tmp.length >= 3) ? tmp[3] : null;

akirattii / generate-entropy-on-mouse-moving.js

Created August 26, 2018 23:07

JS: How to generate a random entropy by mouse-moving on browser

	// const entropy = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]
	const entropy = [];
	let captureStart = false;

	/**
	* Mouse Moving Entropy Generator on browser.
	* Returns an entropy which is 16 bytes long array of unsigned char integer (0-255).
	*/
	$(document).on("mousemove", "html", function(e) {
	const MAX_LEN = 16; // size of entropy's array

akirattii / aes-encrypt-decrypt.js

Last active August 21, 2018 03:56

NodeJS: aes-encrypt / aes-decrypt by using string password. (Browser compatible and I think as a secure way at this point ...)

	const aesjs = require('aes-js');
	const pbkdf2 = require('pbkdf2');

	const password = "mySecretPassword";
	const message = "HelloWorld!";

	const encrypted = encrypt(message, password);
	console.log("encrypted:", encrypted); // 3ed20b7c474c96af513d1c
	const decrypted = decrypt(encrypted, password);
	console.log("decrypted:", decrypted); // HelloWorld!

akirattii / ripple-tx-validation-check-memo.md

Last active August 17, 2018 02:19

Ripple: How to validate a tx's result after submitting it. (private memo)

// submit tx:
submitTx(signedTx, (err, res) => {
  if (err) throw err;
  // Check if `engine_result` is "tesSUCCESS": 
  if (res.engine_result !== "tesSUCCESS") {
    // the tx's failed immediately.
    return;
  }
  const txhash = res.tx_json.hash;

akirattii / ripple-understand-rippled-book_offers-request-response.md

Created August 17, 2018 01:16

Ripple: Understand rippled `book_offers` request & response

Request example (on TestNet)

{
  "id": 4,
  "command": "book_offers",
  "taker": "r9cZA1mLK5R5Am25ArfXFmqgNwjZgnfk59",
  "taker_gets": {
    "currency": "XRP"

akirattii / WsClient.js

Created August 10, 2018 07:24

NodeJS: WebSocket Client (Browser-compatible)

	/*
	websocket client module (supports either NodeJS and browser)

	NOTE:
	`browserify` makes this websocket client lib browser-compatible.

	# Usage
	```
	const onmessage = function(e) {
	console.log("onmessage:", e);

akirattii / RpcClient.js

Last active July 11, 2018 03:13

NodeJS: RPC Client module class (either callback and async/await available)

	// Simple JSON RPC Client
	const request = require("request");
	const requestAsync = require("request-promise");
	// const axios = require("axios");

	module.exports = class RpcClient {

	constructor({
	url,
	jsonrpc = "2.0",

akirattii / getCounterwalletAddress.js

Created July 3, 2018 00:12

[Counterparty] Get Counterwallet's addresses from passphrase by using bitcore-lib

	/*
	* Usage:
	* $ node ./getCounterwalletAddress.js "<livenet_or_testnet>" <derived_index> "<passphrase of 12 words>"
	*/
	const network = process.argv[2]; // "testnet" or "livenet"
	const index = process.argv[3]; // derived address's index
	const passphrase = process.argv[4]; // passphrase

	// Mnemonic function inspired by:
	// Mnemonic.js v. 1.0.0

Akira TANAKA akirattii

Ripple: Understand rippled book_offers request & response

Request example (on TestNet)

Ripple: Understand rippled `book_offers` request & response