feat: add pubsub to libp2p

Author: daviddias

package.json

@@ -38,6 +38,7 @@
   "homepage": "https://github.com/libp2p/js-libp2p",
   "dependencies": {
     "async": "^2.6.0",
+    "libp2p-floodsub": "^0.14.1",
     "libp2p-ping": "~0.6.1",
     "libp2p-switch": "~0.36.1",
     "mafmt": "^4.0.0",

src/error-messages.js

@@ -0,0 +1,3 @@
+'use strict'
+
+exports.NOT_STARTED_YET = 'The libp2p node is not started yet'

src/index.js

@@ -14,6 +14,7 @@ const Ping = require('libp2p-ping')
 const peerRouting = require('./peer-routing')
 const contentRouting = require('./content-routing')
 const dht = require('./dht')
+const pubsub = require('./pubsub')
 const getPeerInfo = require('./get-peer-info')
 
 exports = module.exports
@@ -89,6 +90,7 @@ class Node extends EventEmitter {
     this.peerRouting = peerRouting(this)
     this.contentRouting = contentRouting(this)
     this.dht = dht(this)
+    this.pubsub = pubsub(this)
 
     this._getPeerInfo = getPeerInfo(this)
 
@@ -149,17 +151,29 @@ class Node extends EventEmitter {
         cb()
       },
       (cb) => {
-        // TODO: chicken-and-egg problem:
+        // TODO: chicken-and-egg problem #1:
         // have to set started here because DHT requires libp2p is already started
         this._isStarted = true
         if (this._dht) {
-          return this._dht.start(cb)
+          this._dht.start(cb)
+        } else {
+          cb()
         }
-        cb()
       },
+      (cb) => {
+        // TODO: chicken-and-egg problem #2:
+        // have to set started here because FloodSub requires libp2p is already started
+        if (this._options !== false) {
+          this._floodSub.start(cb)
+        } else {
+          cb()
+        }
+      },
+
       (cb) => {
         // detect which multiaddrs we don't have a transport for and remove them
         const multiaddrs = this.peerInfo.multiaddrs.toArray()
+
         transports.forEach((transport) => {
           multiaddrs.forEach((multiaddr) => {
             if (!multiaddr.toString().match(/\/p2p-circuit($|\/)/) &&
@@ -188,6 +202,11 @@ class Node extends EventEmitter {
     }
 
     series([
+      (cb) => {
+        if (this._floodSub.started) {
+          this._floodSub.stop(cb)
+        }
+      },
       (cb) => {
         if (this._dht) {
           return this._dht.stop(cb)

src/pubsub.js

@@ -0,0 +1,89 @@
+'use strict'
+
+const setImmediate = require('async/setImmediate')
+const NOT_STARTED_YET = require('./error-messages').NOT_STARTED_YET
+const FloodSub = require('libp2p-floodsub')
+
+module.exports = (node) => {
+  const floodSub = new FloodSub(node)
+
+  node._floodSub = floodSub
+
+  return {
+    subscribe: (topic, options, handler, callback) => {
+      if (!node.isStarted()) {
+        return setImmediate(() => callback(new Error(NOT_STARTED_YET)))
+      }
+
+      if (typeof options === 'function') {
+        callback = handler
+        handler = options
+        options = {}
+      }
+
+      function subscribe (cb) {
+        if (floodSub.listenerCount(topic) === 0) {
+          floodSub.subscribe(topic)
+        }
+
+        floodSub.pubsub.on(topic, handler)
+        setImmediate(cb)
+      }
+
+      subscribe(callback)
+    },
+
+    unsubscribe: (topic, handler) => {
+      floodSub.removeListener(topic, handler)
+
+      if (floodSub.listenerCount(topic) === 0) {
+        floodSub.unsubscribe(topic)
+      }
+    },
+
+    publish: (topic, data, callback) => {
+      if (!node.isStarted()) {
+        return setImmediate(() => callback(new Error(NOT_STARTED_YET)))
+      }
+
+      if (!Buffer.isBuffer(data)) {
+        return setImmediate(() => callback(new Error('data must be a Buffer')))
+      }
+
+      floodSub.publish(topic, data)
+
+      setImmediate(() => callback())
+    },
+
+    ls: (callback) => {
+      if (!node.isStarted()) {
+        return setImmediate(() => callback(new Error(NOT_STARTED_YET)))
+      }
+
+      const subscriptions = Array.from(floodSub.subscriptions)
+
+      setImmediate(() => callback(null, subscriptions))
+    },
+
+    peers: (topic, callback) => {
+      if (!node.isStarted()) {
+        return setImmediate(() => callback(new Error(NOT_STARTED_YET)))
+      }
+
+      if (typeof topic === 'function') {
+        callback = topic
+        topic = null
+      }
+
+      const peers = Array.from(floodSub.peers.values())
+        .filter((peer) => topic ? peer.topics.has(topic) : true)
+        .map((peer) => peer.info.id.toB58String())
+
+      setImmediate(() => callback(null, peers))
+    },
+
+    setMaxListeners (n) {
+      return floodSub.setMaxListeners(n)
+    }
+  }
+}

test/node.js

@@ -4,6 +4,7 @@ require('./base')
 require('./transports.node')
 require('./stream-muxing.node')
 require('./peer-discovery.node')
+require('./pubsub.node')
 require('./peer-routing.node')
 require('./content-routing.node')
 require('./circuit-relay.node')

test/pubsub.node.js

@@ -0,0 +1,52 @@
+/* eslint-env mocha */
+/* eslint max-nested-callbacks: ["error", 8] */
+
+'use strict'
+
+const chai = require('chai')
+chai.use(require('dirty-chai'))
+const expect = chai.expect
+const parallel = require('async/parallel')
+const _times = require('lodash.times')
+const utils = require('./utils/node')
+const createNode = utils.createNode
+
+describe('.pubsub', () => {
+  let nodeA
+  let nodeB
+
+  before(function (done) {
+    this.timeout(5 * 1000)
+
+    const tasks = _times(2, () => (cb) => {
+      createNode('/ip4/0.0.0.0/tcp/0', {
+        mdns: false,
+        dht: true
+      }, (err, node) => {
+        expect(err).to.not.exist()
+        node.start((err) => cb(err, node))
+      })
+    })
+
+    parallel(tasks, (err, nodes) => {
+      expect(err).to.not.exist()
+      nodeA = nodes[0]
+      nodeB = nodes[1]
+
+      nodeA.dial(nodeB.peerInfo, done)
+    })
+  })
+
+  after((done) => {
+    parallel([
+      (cb) => nodeA.stop(cb),
+      (cb) => nodeB.stop(cb)
+    ], done)
+  })
+
+  describe('.pubsub on (default)', () => {
+  })
+
+  describe('.pubsub off', () => {
+  })
+})