Read bitcoin blocks from disk with bcoin

reading-blocks-bcoin.js

// original: https://gist.github.com/braydonf/e9572bb40c084691fa20

'use strict';

const path = require('path');
const {Block, Network} = require('bcoin');
const fs = require('bfile');
const bufio = require('bufio');

(async function() {
  const network = Network.get('main');    
  const location = '/home/user/.bitcoin/blocks'
  const regexp = /^blk\d{5}\.dat$/;
  const files = (await fs.readdir(location)).filter((f) => regexp.test(f))

  for (const file of files) {
    const data = await fs.readFile(path.resolve(location, file));
    const reader = bufio.read(data);
    let magic = null;
    let size = 0;

    while (reader.left() >= 4) {
      magic = reader.readU32();
      if (magic !== network.magic) {
        reader.seek(4);
        continue;
      }

      size = reader.readU32();

      const block = Block.fromReader(reader);
      const hash = block.rhash('hex');

      console.log(`File: ${file} Block: ${hash} Size: ${size}`);
    }
  }
})();