do not request duplicate txs.

lib/bcoin/peer.js

@@ -537,6 +537,8 @@ Peer.prototype._handleGetAddr = function handleGetAddr() {
 Peer.prototype._handleInv = function handleInv(items) {
   var req, i, block, hash;
 
+  this.emit('inv', items);
+
   // Always request advertised TXs
   var txs = items.filter(function(item) {
     return item.type === 'tx';

lib/bcoin/pool.js

@@ -133,6 +133,11 @@ function Pool(options) {
     invalid: {}
   };
 
+  this.tx = {
+    have: {},
+    count: 0
+  };
+
   this.request = {
     map: {},
     active: 0,
@@ -341,11 +346,9 @@ Pool.prototype._addLoader = function _addLoader() {
     return;
 
   if (!this.options.headers && !this.options.multiplePeers) {
-    this.request = {
-      map: {},
-      active: 0,
-      queue: []
-    };
+    this.request.map = {};
+    this.request.active = 0;
+    this.request.queue = [];
   }
 
   peer = this._createPeer(750 * Math.random(), true);
@@ -833,8 +836,17 @@ Pool.prototype._createPeer = function _createPeer(backoff, priority) {
   peer.on('txs', function(txs) {
     self.emit('txs', txs, peer);
     txs.forEach(function(hash) {
+      hash = utils.toHex(hash);
+      if (self.tx.have[hash])
+        return;
+      self.tx.have[hash] = true;
+      self.tx.count++;
       self._request('tx', hash, peer);
     });
+    if (self.tx.count > 10000) {
+      self.tx.have = {};
+      self.tx.count = 0;
+    }
     self._scheduleRequests();
   });