peers: handle maxAge option (#186)

* docs: document bucket timeout option

* peers: handle maxAge option

handle option maxAge to remove stale peers from peercache

README.md

@@ -81,7 +81,9 @@ If `opts` is specified, then the default options (shown below) will be overridde
   host: false,     // host of local peer, if specified then announces get added to local table (String, disabled by default)
   concurrency: 16, // k-rpc option to specify maximum concurrent UDP requests allowed (Number, 16 by default)
   hash: Function,  // custom hash function to use (Function, SHA1 by default),
-  krpc: krpc()     // optional k-rpc instance
+  krpc: krpc(),     // optional k-rpc instance
+  timeBucketOutdated: 900000, // check buckets every 15min
+  maxAge: Infinity  // optional setting for announced peers to time out
 }
 ```
 

client.js

@@ -25,7 +25,10 @@ function DHT (opts) {
 
   this._tables = LRU({maxAge: ROTATE_INTERVAL, max: opts.maxTables || 1000})
   this._values = LRU(opts.maxValues || 1000)
-  this._peers = new PeerStore(opts.maxPeers || 10000)
+  this._peers = new PeerStore({
+    maxAge: opts.maxAge || Infinity,
+    max: opts.maxPeers || 10000
+  })
 
   this._secrets = null
   this._hash = opts.hash || sha1
@@ -778,10 +781,11 @@ function toNode (node) {
   }
 }
 
-function PeerStore (max) {
-  this.max = max || 10000
+function PeerStore (opts) {
+  this.max = opts.max || 10000
+  this.maxAge = opts.maxAge || Infinity
   this.used = 0
-  this.peers = LRU(Infinity)
+  this.peers = LRU({max: Infinity, maxAge: this.maxAge})
 }
 
 PeerStore.prototype.add = function (key, peer) {
@@ -790,7 +794,7 @@ PeerStore.prototype.add = function (key, peer) {
   if (!peers) {
     peers = {
       values: [],
-      map: LRU(Infinity)
+      map: LRU({max: Infinity, maxAge: this.maxAge})
     }
     this.peers.set(key, peers)
   }

test/announce.js

@@ -60,3 +60,67 @@ test('announce with implied port', function (t) {
     })
   })
 })
+
+test('`announce` with {host: "127.0.0.1"} and no cache timeout', function (t) {
+  t.plan(2)
+  var dht1 = new DHT({ bootstrap: false, maxAge: Infinity })
+  var infoHash = common.randomId()
+
+  dht1.listen(function () {
+    var dht2 = new DHT({ bootstrap: '127.0.0.1:' + dht1.address().port, maxAge: Infinity })
+    var cnt = 0
+
+    dht1.on('peer', function (peer) {
+      cnt++
+    })
+
+    dht1.once('announce', function (peer) {
+      t.deepEqual(peer, {host: '127.0.0.1', port: 1337})
+
+      dht1.lookup(infoHash, (er, count) => {
+
+        setTimeout(function () {
+          dht1.lookup(infoHash, (er, c) => {
+            t.equal(cnt, 2, 'finds peers two times')
+            dht1.destroy()
+            dht2.destroy()
+          })
+        }, 100)
+      })
+    })
+
+    dht2.announce(infoHash, 1337)
+  })
+})
+
+test('`announce` with {host: "127.0.0.1"} and cache timeout', function (t) {
+  t.plan(2)
+  var dht1 = new DHT({ bootstrap: false, maxAge: 50 })
+  var infoHash = common.randomId()
+
+  dht1.listen(function () {
+    var dht2 = new DHT({ bootstrap: '127.0.0.1:' + dht1.address().port, maxAge: 50 })
+    var cnt = 0
+
+    dht1.on('peer', function (peer) {
+      cnt++
+    })
+
+    dht1.once('announce', function (peer) {
+      t.deepEqual(peer, {host: '127.0.0.1', port: 1337})
+
+      dht1.lookup(infoHash, (er, count) => {
+
+        setTimeout(function () {
+          dht1.lookup(infoHash, (er, c) => {
+            t.equal(cnt, 1, 'just found a peer one time')
+            dht1.destroy()
+            dht2.destroy()
+          })
+        }, 100)
+      })
+    })
+
+    dht2.announce(infoHash, 1337)
+  })
+})