rpn3319

Writing DApps in TestRPC

1. Set up
   • install npm install -g ethereumjs-testrpc http-server
   • install npm install solc [email protected]
2. Writing Smartcontract & deploying code
3. Building UI with html and js
4. Setting npm start script "start": "node deployContract.js && http-server .",
5. Run testrpc, then run npm start

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Standards

• CSS naming convention: http://getbem.com

Snippets

Unit rem tip: Adding font size 62.5% to html to specify 1rem = 10px

Snippet

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console.time(__filename);
const { default: axios } = require('axios');
const fs = require('fs');
const { createInterface } = require('readline');

const file = process.argv[2];
const token = process.argv[3] || 'all';
const dateStart = process.argv[4]
  ? new Date(`${process.argv[4]} 0:0:0`).getTime() / 1000
  : null;

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import * as winston from 'winston';

const { combine, timestamp, prettyPrint, colorize, json } = winston.format;

export const logger = winston.createLogger({
  format: combine(colorize(), json(), timestamp(), prettyPrint()),
  transports: [
    new winston.transports.Console({
      format: winston.format.simple(),
      level: 'info',

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/**
 * Motivation
 *
 * We have a very big array need to be processed in order
 * with a async function and make sure that not blocking
 * other process
 *
 * Solution
 *
 * Using Timers functions of Node.js

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package helper

func IndexOf(input []int, search int) int {
	if len(input) == 0 {
		return -1
	}

	for i, v := range input {
		if v == search {
			return i

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package helper

import (
	"math/rand"
	"time"
)

func Shuffle(arr []int) []int {
	for i := len(arr) - 1; i > 0; i-- {
		rand.Seed(time.Now().UTC().UnixNano())

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version: "3.9"
    
services:
  db:
    image: mysql:5.7
    volumes:
      - db_data:/var/lib/mysql
      - ./docker/my.cnf:/etc/my.cnf
    restart: always
    environment:

rpn3319

Knowledge

• More deeper understand about libuv, why it's run in 4 threads and how to config to improve NodeJS concurrency performance: https://www.sebastienvercammen.be/your-libuv-thread-pool-size-is-too-small/

Libraries and Tools

• nanoid, uuid: Unique string generator:
• node-schedule: run jobs
• concurrently: Run multi commands concurrently
• live-server: run server with live reload capability, useful fast testing html files

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version: '3'

networks:
  workspaces:
    driver: bridge

services:
  zookeeper:
    image: confluentinc/cp-zookeeper:5.3.1
    restart: always