bitcore-lib-zcash/PeerManager.js

require('classtool');

function spec(b) {
  var config = b.config || require('./config');
  var log = b.log || require('./util/log');
  var network = b.network || require('./networks')[config.network];
  var Connection = b.Connection || require('./Connection').createClass(
    {config: config, network: network});
  var Peer = b.Peer || require('./Peer').class();
  var noop = function() {};

  GetAdjustedTime = b.GetAdjustedTime || function () {
    // TODO: Implement actual adjustment
    return Math.floor(new Date().getTime() / 1000);
  };

  function PeerManager() {
    this.active = false;
    this.timer = null;

    this.peers = [];
    this.connections = [];
    this.isConnected = false;
    this.peerDiscovery = false;

    // Move these to the Node's settings object
    this.interval = 5000;
    this.minConnections = 8;
    this.minKnownPeers = 10;
  };
  PeerManager.superclass = b.superclass || require('events').EventEmitter;

  PeerManager.Connection = Connection;

  PeerManager.prototype.start = function() {
    this.active = true;
    if(!this.timer) {
      this.timer = setInterval(this.checkStatus.bind(this), this.interval);
    }
  };

  PeerManager.prototype.stop = function() {
    this.active = false;
    if(this.timer) {
      clearInterval(this.timer);
      this.timer = null;
    }
    for(var i=0; i<this.connections.length; i++) {
      this.connections[i].socket.end();
    };
  };

  PeerManager.prototype.addPeer = function(peer, port) {
    if(peer instanceof Peer) {
      this.peers.push(peer);
    } else if ("string" == typeof peer) {
      this.addPeer(new Peer(peer, port));
    } else {
      log.err('Node.addPeer(): Invalid value provided for peer',
                 {val: peer});
      throw 'Node.addPeer(): Invalid value provided for peer.';
    }
  };

  PeerManager.prototype.checkStatus = function checkStatus() {
    // Make sure we are connected to all forcePeers
    if(this.peers.length) {
      var peerIndex = {};
      this.peers.forEach(function(peer) {
        peerIndex[peer.toString()] = peer;
      });

      // Ignore the ones we're already connected to
      this.connections.forEach(function(conn) {
        var peerName = conn.peer.toString();
        if("undefined" !== peerIndex[peerName]) {
          delete peerIndex[peerName];
        }
      });

      Object.keys(peerIndex).forEach(function(i) {
        this.connectTo(peerIndex[i]);
      }.bind(this));
    }
  };

  PeerManager.prototype.connectTo = function(peer) {
    log.info('connecting to '+peer);
    try {
      return this.addConnection(peer.createConnection(), peer);
    } catch (e) {
      log.err('creating connection',e);
      return null;
    }
  };

  PeerManager.prototype.addConnection = function(socketConn, peer) {
    var conn = new Connection(socketConn, peer);
    this.connections.push(conn);
    this.emit('connection', conn);

    conn.addListener('version', this.handleVersion.bind(this));
    conn.addListener('verack', this.handleReady.bind(this));
    conn.addListener('addr', this.handleAddr.bind(this));
    conn.addListener('getaddr', this.handleGetAddr.bind(this));
    conn.addListener('error', this.handleError.bind(this));
    conn.addListener('disconnect', this.handleDisconnect.bind(this));

    return conn;
  };

  PeerManager.prototype.handleVersion = function(e) {
    if (!e.conn.inbound) {
      // TODO: Advertise our address (if listening)
    }
    // Get recent addresses
    if(this.peerDiscovery &&
        (e.message.version >= 31402 || this.peers.length < 1000)) {
      e.conn.sendGetAddr();
      e.conn.getaddr = true;
    }
  };

  PeerManager.prototype.handleReady = function (e) {
    log.info('connected to '+e.conn.peer.host+':'+e.conn.peer.port);
    this.emit('connect', {
      pm: this,
      conn: e.conn,
      socket: e.socket,
      peer: e.peer
    });

    if(this.isConnected == false) {
      this.emit('netConnected');
      this.isConnected = true;
    }
  };

  PeerManager.prototype.handleAddr = function (e) {
    if(!this.peerDiscovery) return;

    var now = GetAdjustedTime();
    e.message.addrs.forEach(function (addr) {
      try {
        // In case of an invalid time, assume "5 days ago"
        if (addr.time <= 100000000 || addr.time > (now + 10 * 60)) {
          addr.time = now - 5 * 24 * 60 * 60;
        }
        var peer = new Peer(addr.ip, addr.port, addr.services);
        peer.lastSeen = addr.time;

        // TODO: Handle duplicate peers
        this.peers.push(peer);

        // TODO: Handle addr relay
      } catch(e) {
        log.warn("Invalid addr received: "+e.message);
      }
    }.bind(this));
    if (e.message.addrs.length < 1000 ) {
      e.conn.getaddr = false;
    }
  };

  PeerManager.prototype.handleGetAddr = function(e) {
    // TODO: Reply with addr message.
  };

  PeerManager.prototype.handleError = function(e) {
    log.err('unkown error with peer '+e.peer+' (disconnecting): '+e.err);
    this.handleDisconnect.apply(this, [].slice.call(arguments));
  };

  PeerManager.prototype.handleDisconnect = function(e) {
    log.info('disconnected from peer '+e.peer);
    var i = this.connections.indexOf(e.conn);
    if(i != -1) this.connections.splice(i, 1);

    if(!this.connections.length) {
      this.emit('netDisconnected');
      this.isConnected = false;
    }
  };

  PeerManager.prototype.getActiveConnection = function () {
    var activeConnections = this.connections.filter(function (conn) {
      return conn.active;
    });

    if (activeConnections.length) {
      var randomIndex = Math.floor(Math.random()*activeConnections.length);
      var candidate = activeConnections[randomIndex];
      if (candidate.socket.writable) {
        return candidate;
      } else {
        // Socket is not writable, remove it from active connections
        activeConnections.splice(randomIndex, 1);

        // Then try again
        // TODO: This causes an infinite recursion when all connections are dead,
        //       although it shouldn't.
        return this.getActiveConnection();
      }
    } else {
      return null;
    }
  };

  PeerManager.prototype.getActiveConnections = function () {
    return this.connections.slice(0);
  };

  return PeerManager;
};
module.defineClass(spec);