add libp2p-ping to aleph nodes

package.json

@@ -37,6 +37,7 @@
     "knex": "^0.12.6",
     "levelup": "^1.3.3",
     "libp2p-crypto": "git://github.com/libp2p/js-libp2p-crypto.git#c45bdf602e765411d9d5fc2fddd45b31830f08e8",
+    "libp2p-ping": "^0.3.0",
     "libp2p-secio": "0.6.4",
     "libp2p-spdy": "0.10.1",
     "libp2p-swarm": "0.26.2",

src/peer/libp2p_node.js

@@ -10,6 +10,7 @@ const PeerId = require('peer-id')
 const PeerInfo = require('peer-info')
 const PeerBook = require('peer-book')
 const multiaddr = require('multiaddr')
+const Ping = require('libp2p-ping')
 const mafmt = require('mafmt')
 const Abortable = require('pull-abortable')
 const { promiseTimeout } = require('./util')
@@ -62,6 +63,8 @@ class P2PNode {
       this.peerBook.removeByB58String(peerInfo.id.toB58String())
     })
 
+    Ping.mount(this.swarm)
+
     this.abortables = new Set()
   }
 
@@ -227,6 +230,22 @@ class P2PNode {
   unhandle (protocol: string): any {
     return this.swarm.unhandle(protocol)
   }
+
+  ping (peer: PeerInfo): Promise<number> {
+    const pingPromise = new Promise((resolve, reject) => {
+      const p = new Ping(this.swarm, peer)
+      p.on('error', err => {
+        p.stop()
+        reject(err)
+      })
+
+      p.on('ping', latency => {
+        p.stop()
+        resolve(latency)
+      })
+    })
+    return promiseTimeout(this.dialTimeout, pingPromise)
+  }
 }
 
 module.exports = P2PNode

src/peer/node.js

@@ -192,23 +192,37 @@ class MediachainNode {
     return this.lookup(peer)
   }
 
-  openConnection (peer: PeerInfo | PeerId | string, protocol: string): Promise<Connection> {
+  _resolvePeer (peer: PeerInfo | PeerId | string): Promise<PeerInfo> {
     return this._lookupIfNeeded(peer)
       .then(maybePeer => {
         if (!maybePeer) throw new Error(`Unable to locate peer ${peer}`)
         return maybePeer
       })
+  }
+
+  openConnection (peer: PeerInfo | PeerId | string, protocol: string): Promise<Connection> {
+    return this._resolvePeer(peer)
       .then(peerInfo => this.p2p.dialByPeerInfo(peerInfo, protocol))
   }
 
-  ping (peer: PeerInfo | PeerId | string): Promise<boolean> {
-    return this.openConnection(peer, PROTOCOLS.node.ping)
+  ping (peer: PeerInfo | PeerId | string): Promise<number> {
+    let timestamp: number
+    let latency: number
+
+    return this._resolvePeer(peer)
+      .then(peerInfo => this.p2p.ping(peerInfo))
+
+      // fall-back to deprecated mediachain ping protocol if remote node
+      // doesn't support libp2p ping
+      .catch(_err => this.openConnection(peer, PROTOCOLS.node.ping))
       .then((conn: Connection) => pullToPromise(
         pull.values([{}]),
         protoStreamEncode(pb.node.Ping),
+        pull.through(() => { timestamp = Date.now() }),
         conn,
+        pull.through(() => { latency = Date.now() - timestamp }),
         protoStreamDecode(pb.node.Pong),
-        pull.map(_ => { return true })
+        pull.map(_ => { return latency })
       ))
   }
 

test/ping_test.js

@@ -7,11 +7,12 @@ const PeerInfo = require('peer-info')
 const Multiaddr = require('multiaddr')
 
 describe('Ping', function () {
-  let p1, p2, invalidPeer
+  let p1, p2, p3, invalidPeer
 
   before(() => Promise.all([
     makeNode().then(_p1 => { p1 = _p1 }),
     makeNode().then(_p2 => { p2 = _p2 }),
+    makeNode().then(_p3 => { p3 = _p3 }),
     getTestNodeId().then(id => {
       invalidPeer = PeerInfo(id)
       invalidPeer.multiaddr.add(Multiaddr('/ip4/1.2.3.4/tcp/4321'))
@@ -21,7 +22,22 @@ describe('Ping', function () {
   it('pings another node directly by PeerInfo', () => {
     return Promise.all([p1.start(), p2.start()])  // start both peers
       .then(() => p1.ping(p2.peerInfo))
-      .then(result => assert(result))
+      .then(result => assert(result != null))
+  })
+
+  it('uses the libp2p-ping protocol (if possible)', () => {
+    return Promise.all([p1.start(), p2.start()])  // start both peers
+      .then(() => p1.p2p.ping(p2.peerInfo))
+      .then(result => assert.equal(typeof result, 'number', 'libp2p-ping should return latency in ms'))
+  })
+
+  it('falls back to mediachain ping if libp2p-ping fails', () => {
+    p3.p2p.ping = () => Promise.reject(new Error('I only support artisanal, hand-crafted ping protocols!'))
+    return Promise.all([p1.start(), p3.start()])
+      .then(() => p2.ping(p3.peerInfo))
+      .then(result => {
+        assert(result != null)
+      })
   })
 
   it('fails to ping a non-existent node', () => {