bcoin-zeromq

A zeromq plugin for bcoin

Motivation

Some bitcoin applications (such as bitcore-node) currently hook to bitcoin core's zeromq sockets to fetch incoming blocks and transactions. This plugin aims to bring such functionality to bcoin.

Usage

Currently bcoin provides no funcionality to install and load global plugins, so in order to use this one you'll need to run it from a dedicated project directory:

mkdir mynode
cd mynode && npm init
npm install --save bcoin bcoin-zeromq

Then just create index.js with the following contents to load the node:

const FullNode = require('bcoin/lib/node/fullnode')
const ZeroMQ = require('bcoin-zeromq')

const ZMQ_ADDRESS = 'tcp://127.0.0.1:28332'

const node = new FullNode({
  db: 'memory',
  zmqPubRawTx: ZMQ_ADDRESS,
  zmqPubHashTx: ZMQ_ADDRESS,
  zmqPubRawBlock: ZMQ_ADDRESS,
  zmqPubHashBlock: ZMQ_ADDRESS
})

node.use(ZeroMQ)

node.open()
  .then(() => node.connect())
  .then(() => node.startSync())

A subscriber may then start receiving block and transaction data. Here's an example using zeromq:

const zeromq = require('zeromq')

const ZMQ_ADDRESS = 'tcp://127.0.0.1:28332'
const ZMQ_TOPIC = 'hashblock'

const subscriber = zeromq.socket('sub')

subscriber.connect(ZMQ_ADDRESS)
subscriber.subscribe(ZMQ_TOPIC)

subscriber.on('message', (topic, msg) => {
  console.log('%s %s', topic, msg)
})