typescript 로 blockchain 구현하기

dankim·2019년 11월 12일
0

Be proud of yourself

목록 보기
1/3

with Nicolas , thank you.

import * as CryptoJS from "crypto-js";
import { isBlock } from "@babel/types";

class Block {
  public index: number;
  public hash: string;
  public previousHash: string;
  public data: string;
  public timestamp: number;

  static calculateBlockHash = (
    index: number,
    previousHash: string,
    timestamp: number,
    data: string
  ): string => {
    return CryptoJS.SHA256(index + previousHash + timestamp + data).toString();
  };

  static validateStructure = (aBlock: Block): boolean => {
    return (
      typeof aBlock.index === "number" &&
      typeof aBlock.hash === "string" &&
      typeof aBlock.previousHash === "string" &&
      typeof aBlock.timestamp === "number" &&
      typeof aBlock.data === "string"
    );
  };

  constructor(
    index: number,
    hash: string,
    previousHash: string,
    data: string,
    timestamp: number
  ) {
    this.index = index;
    this.hash = hash;
    this.previousHash = previousHash;
    this.data = data;
    this.timestamp = timestamp;
  }
}

const genesisBlock: Block = new Block(0, "asdasdasd", "", "hello", 123456);

let blockchain: Block[] = [genesisBlock];

const getBlockChain = (): Block[] => blockchain;

const getLatestBlock = (): Block => blockchain[blockchain.length - 1];

const getNewTimeStamp = (): number => Math.round(new Date().getTime() / 100);

const createNewBlock = (data: string): Block => {
  const previousBlock: Block = getLatestBlock();
  const newIndex: number = previousBlock.index + 1;
  const newTimeStamp: number = getNewTimeStamp();
  const newHash: string = Block.calculateBlockHash(
    newIndex,
    previousBlock.hash,
    newTimeStamp,
    data
  );
  const newBlock: Block = new Block(
    newIndex,
    newHash,
    previousBlock.hash,
    data,
    newTimeStamp
  );
  addBlock(newBlock);
  return newBlock;
};

const getHashForBlock = (aBlock: Block): string =>
  Block.calculateBlockHash(
    aBlock.index,
    aBlock.previousHash,
    aBlock.timestamp,
    aBlock.data
  );

const isBlockValid = (candidateBlock: Block, previousBlock: Block): boolean => {
  if (
    !Block.validateStructure(candidateBlock) ||
    !Block.validateStructure(previousBlock)
  ) {
    return false;
  } else if (previousBlock.index + 1 !== candidateBlock.index) {
    return false;
  } else if (previousBlock.hash !== candidateBlock.previousHash) {
    return false;
  } else if (getHashForBlock(candidateBlock) !== candidateBlock.hash) {
    return false;
  } else {
    return true;
  }
};

const addBlock = (candidateBlock: Block): void => {
  if (isBlockValid(candidateBlock, getLatestBlock())) {
    blockchain.push(candidateBlock);
  }
};

createNewBlock("second block");
createNewBlock("third block");
createNewBlock("fourth block");
console.log(blockchain);
export {};
profile
Be proud of yourself.

0개의 댓글