feat: add pubsub to libp2p

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)
+    }
+  }
+}