I’ve prepared a Nodejs javascript script to (attempt to) fetch block information for an example testnet block (3) from the P2P network, using bitcore-p2p library (which uses the getdata P2P protocol, also this):
let p2p = require('bitcore-p2p')
let Pool = p2p.Pool;
let Networks = require('bitcore-lib').Networks
let Messages = p2p.Messages
let pool = new Pool({network : Networks.testnet})
const endianness = require('endianness')
/* pool will receive "I'm here" peerinv messages from peers, respond with block request" */
let blockrequestcounter = 0
pool.on('peerinv', (peer, message) => {
console.log('peerinv message: ',message)
if (blockrequestcounter < 5) { //limit to 5 requests
let exampleBlockHash = Buffer.from('000000008b896e272758da5297bcd98fdc6d97c9b765ecec401e286dc1fdbe10','hex') // block 3 in testnet
endianness(exampleBlockHash,32) // flips endianness
let message_out = new Messages({network:Networks.testnet}).GetData.forBlock(exampleBlockHash)
peer.sendMessage(message_out)
blockrequestcounter += 1
}
})
/* Monitor other messages from pool peers; */
pool.on('ready', ()=> { console.log('ready')})
pool.on('error', (err) => {console.error('Error: ',err)})
pool.on('inv', (peer, message) => { console.log('Received inv: ',message)})
pool.on('alert', (peer, message) => { console.log('Received alert: ',message)})
pool.on('block', (peer, message) => { console.log('Received block: ',message)})
pool.on('merkleblock', (peer, message) => { console.log('Received merkleblock: ',message)})
pool.on('peermerkleblock', (peer, message) => { console.log('Received peermerkleblock: ',message)})
pool.on('peertx', (peer, message) => { console.log('Received peertx:',message)})
pool.on('getblocks', (peer, message) => { console.log('Received getblocks: ',message)})
pool.on('tx', (peer, message) => { console.log('Received tx: ',message)})
pool.connect()
At present, I get no messages back. I do continue to get “peerinv” messages though.
What is a good way to get block data using bitcore-p2p?
Are there any alternative constructions I could use (at present I’d only like the blockheader, the coinbasetx and its merkle partner (the root of the other transactions)?
