hagent/lib/server-agent.js

HTTP agent for whistle

var https = require('https');
var getServer = require('./get-server').create(createHttpsServer, 41500);

var MAX_SERVERS = 220;
var TIMEOUT = 6000;
var DELAY = 100;
var NUM_RE = /^\d+$/;

function createHttpsServer(options, listener) {
  var server = https.createServer(options);
  if (typeof listener === 'function') {
    server.on('request', listener);
  } else if (listener) {
    Object.keys(listener).forEach(function(name) {
      server.on(name, listener[name]);
    });
  }
  return server;
}

function ServerAgent() {
  this._cache = {};
  this._serverCount = 0;
}

var proto = ServerAgent.prototype;

proto.existsServer = function(hostname) {
  return this._cache[hostname];
};
proto.createServer = function createServer(hostname, listener, callback, timeout, requestTimeout) {
  var self = this;
  var cache = self._cache;

  var promise = cache[hostname];
  var resolve;

  if (!promise) {
    cache[hostname] = promise = new Promise(function(rsl) { // eslint-disable-line
      resolve = rsl;
    });
  }

  promise.then(callback);

  if (!resolve) {
    return ;
  }

  self.freeServer();
  var cert = self.createCertificate(hostname);
  getServer(cert, listener, function(server, port) {
    var removeServer = function() {
      self.removeServer(hostname);
    };
    server.on('error', removeServer);
    promise.server = server;
    promise.cert = cert;
    var timer = setTimeout(removeServer, TIMEOUT);
    server.once('tlsClientError', removeServer);
    server.once('secureConnection', function() {
      clearTimeout(timer);
    });
    if (NUM_RE.test(timeout)) {
      server.timeout = timeout;
    }
    if (NUM_RE.test(requestTimeout)) {
      server.requestTimeout = requestTimeout;
    }
    resolve(port);
  });
  self._serverCount++;

  return self;
};

proto.removeServer = function removeServer(hostname) {
  var self = this;
  var cache = self._cache;
  var promise = cache[hostname];
  if (!promise) {
    return;
  }
  delete cache[hostname];
  --self._serverCount;
  setTimeout(function() {
    try {
      promise.server.close();
    } catch(e) {} //重复关闭会导致异常
  }, TIMEOUT);
};

proto.freeServer = function() {
  var self = this;
  if (self._serverCount < MAX_SERVERS) {
    return;
  }

  var cache = self._cache;
  for (var i in cache) {
    destroy(i);
  }

  function destroy(hostname) {
    var promise = cache[hostname];
    if (promise._pending) {
      return;
    }
    promise._pending = true;
    promise.then(function(port) {
      var server = promise.server;
      server.getConnections(function(err, count) {
        promise._pending = false;
        if (!err && !count && self._serverCount > MAX_SERVERS) {
          delete cache[hostname];
          --self._serverCount;
          try {
            server.close();
          } catch(e) {} //重复关闭会导致异常
        }
      });
    });
  }
};

proto.destroy = function destroy() {
  var cache = this._cache;
  this._cache = {};
  this._serverCount = 0;
  for (var i in cache) {
    var promise = cache[i];
    promise.then(function() {
      setTimeout(function() {
        try {
          promise.server.close();
        } catch(e) {} //重复关闭会导致异常
      }, DELAY);
    });
  }
};

module.exports = ServerAgent;