is now Small Technology Foundation.
Commit 3e16f0bb authored by Aral Balkan's avatar Aral Balkan

Add a binary version of the native replication test script

(Useful for connecting to hyperdb hypercores, for example.)
parent a56c2e33
// Hypha: A native client for testing replication of a single hypercore.
const hypercore = require('hypercore')
const ram = require('random-access-memory')
const hyperswarm = require('@hyperswarm/network')
const { pipeline } = require('stream')
const { discoveryKey } = require('hypercore/lib/crypto')
const swarm = hyperswarm()
// Basic argument validation.
if (process.argv.length !== 3) {
console.log(`Usage: node index.js <read key to replicate>`)
const readKeyInHex = process.argv[2]
console.log(`\nAttempting to find and replicate hypercore with read key:\n${readKeyInHex}\n`)
const readKeyBuffer = Buffer.from(readKeyInHex, 'hex')
const discoveryKeyBuffer = discoveryKey(readKeyBuffer)
const discoveryKeyInHex = discoveryKeyBuffer.toString('hex')
// Create the local hypercore instance
const localCore = hypercore((filename) => ram(filename), readKeyBuffer, {
createIfMissing: false,
overwrite: false,
valueEncoding: 'binary',
onwrite: (index, data, peer, next) => {
// console.log(`Feed: [onWrite] index = ${index}, peer = ${peer}, data:`)
// console.log(data)
const localReadStream = localCore.createReadStream({live: true})
localReadStream.on('data', (data) => {
console.log('[Replicate]', data.toString('utf8'))
localCore.on('ready', () => {
console.log('Local core ready.')
// HACK: Just for now, make sure we only connect once
let connected = false
// Join the swarm
swarm.join(discoveryKeyBuffer, {
lookup: true, // find and connect to peers.
announce: true // optional: announce self as a connection target.
swarm.on('connection', (remoteNativeStream, details) => {
// HACK: only handle first connection
if (connected) return
connected = true
console.log(`Joined swarm for read key ${readKeyInHex}, discovery key ${discoveryKeyInHex}`)
// Replicate!
console.log('About to replicate!')
// Create the local replication stream.
const localReplicationStream = localCore.replicate({
// TODO: why is Jim’s shopping list example setting encrypt to false?
// The encryption of __what__ does this affect?
// (I haven’t even tested this yet with it set to true to limit the variables.)
encrypt: false,
live: true
(error) => {
console.log(`Pipe closed for ${readKeyInHex}`, error && error.message)
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