docs(examples): Peer and Content Routing 1 and 2 (#107)

examples/peer-and-content-routing/2.js

@@ -0,0 +1,75 @@
+'use strict'
+
+const libp2p = require('libp2p')
+const TCP = require('libp2p-tcp')
+const Multiplex = require('libp2p-multiplex')
+const SECIO = require('libp2p-secio')
+const PeerInfo = require('peer-info')
+const CID = require('cids')
+const KadDHT = require('libp2p-kad-dht')
+
+const waterfall = require('async/waterfall')
+const parallel = require('async/parallel')
+
+class MyBundle extends libp2p {
+  constructor (peerInfo) {
+    const modules = {
+      transport: [new TCP()],
+      connection: {
+        muxer: [Multiplex],
+        crypto: [SECIO]
+      },
+      // we add the DHT module that will enable Peer and Content Routing
+      DHT: KadDHT
+    }
+    super(modules, peerInfo)
+  }
+}
+
+function createNode (callback) {
+  let node
+
+  waterfall([
+    (cb) => PeerInfo.create(cb),
+    (peerInfo, cb) => {
+      peerInfo.multiaddrs.add('/ip4/0.0.0.0/tcp/0')
+      node = new MyBundle(peerInfo)
+      node.start(cb)
+    }
+  ], (err) => callback(err, node))
+}
+
+parallel([
+  (cb) => createNode(cb),
+  (cb) => createNode(cb),
+  (cb) => createNode(cb)
+], (err, nodes) => {
+  if (err) { throw err }
+
+  const node1 = nodes[0]
+  const node2 = nodes[1]
+  const node3 = nodes[2]
+
+  parallel([
+    (cb) => node1.dial(node2.peerInfo, cb),
+    (cb) => node2.dial(node3.peerInfo, cb),
+    // Set up of the cons might take time
+    (cb) => setTimeout(cb, 100)
+  ], (err) => {
+    if (err) { throw err }
+
+    const cid = new CID('QmTp9VkYvnHyrqKQuFPiuZkiX9gPcqj6x5LJ1rmWuSySnL')
+
+    node1.contentRouting.provide(cid, (err) => {
+      if (err) { throw err }
+
+      console.log('Node %s is providing %s', node1.peerInfo.id.toB58String(), cid.toBaseEncodedString())
+
+      node3.contentRouting.findProviders(cid, 5000, (err, providers) => {
+        if (err) { throw err }
+
+        console.log('Found provider:', providers[0].id.toB58String())
+      })
+    })
+  })
+})