dynatrace-cordova-outsystems-plugin/node_modules/tunnel-agent/index.js

This plugin gives you the ability to use the Dynatrace instrumentation in your hybrid application (Cordova, Ionic, ..). It uses the Mobile Agent, the JavaScript Agent and the Javascript Bridge. The Mobile Agent will give you all device specific values con

'use strict'

var net = require('net')
  , tls = require('tls')
  , http = require('http')
  , https = require('https')
  , events = require('events')
  , assert = require('assert')
  , util = require('util')
  , Buffer = require('safe-buffer').Buffer
  ;

exports.httpOverHttp = httpOverHttp
exports.httpsOverHttp = httpsOverHttp
exports.httpOverHttps = httpOverHttps
exports.httpsOverHttps = httpsOverHttps


function httpOverHttp(options) {
  var agent = new TunnelingAgent(options)
  agent.request = http.request
  return agent
}

function httpsOverHttp(options) {
  var agent = new TunnelingAgent(options)
  agent.request = http.request
  agent.createSocket = createSecureSocket
  agent.defaultPort = 443
  return agent
}

function httpOverHttps(options) {
  var agent = new TunnelingAgent(options)
  agent.request = https.request
  return agent
}

function httpsOverHttps(options) {
  var agent = new TunnelingAgent(options)
  agent.request = https.request
  agent.createSocket = createSecureSocket
  agent.defaultPort = 443
  return agent
}


function TunnelingAgent(options) {
  var self = this
  self.options = options || {}
  self.proxyOptions = self.options.proxy || {}
  self.maxSockets = self.options.maxSockets || http.Agent.defaultMaxSockets
  self.requests = []
  self.sockets = []

  self.on('free', function onFree(socket, host, port) {
    for (var i = 0, len = self.requests.length; i < len; ++i) {
      var pending = self.requests[i]
      if (pending.host === host && pending.port === port) {
        // Detect the request to connect same origin server,
        // reuse the connection.
        self.requests.splice(i, 1)
        pending.request.onSocket(socket)
        return
      }
    }
    socket.destroy()
    self.removeSocket(socket)
  })
}
util.inherits(TunnelingAgent, events.EventEmitter)

TunnelingAgent.prototype.addRequest = function addRequest(req, options) {
  var self = this

   // Legacy API: addRequest(req, host, port, path)
  if (typeof options === 'string') {
    options = {
      host: options,
      port: arguments[2],
      path: arguments[3]
    };
  }

  if (self.sockets.length >= this.maxSockets) {
    // We are over limit so we'll add it to the queue.
    self.requests.push({host: options.host, port: options.port, request: req})
    return
  }

  // If we are under maxSockets create a new one.
  self.createConnection({host: options.host, port: options.port, request: req})
}

TunnelingAgent.prototype.createConnection = function createConnection(pending) {
  var self = this

  self.createSocket(pending, function(socket) {
    socket.on('free', onFree)
    socket.on('close', onCloseOrRemove)
    socket.on('agentRemove', onCloseOrRemove)
    pending.request.onSocket(socket)

    function onFree() {
      self.emit('free', socket, pending.host, pending.port)
    }

    function onCloseOrRemove(err) {
      self.removeSocket(socket)
      socket.removeListener('free', onFree)
      socket.removeListener('close', onCloseOrRemove)
      socket.removeListener('agentRemove', onCloseOrRemove)
    }
  })
}

TunnelingAgent.prototype.createSocket = function createSocket(options, cb) {
  var self = this
  var placeholder = {}
  self.sockets.push(placeholder)

  var connectOptions = mergeOptions({}, self.proxyOptions,
    { method: 'CONNECT'
    , path: options.host + ':' + options.port
    , agent: false
    }
  )
  if (connectOptions.proxyAuth) {
    connectOptions.headers = connectOptions.headers || {}
    connectOptions.headers['Proxy-Authorization'] = 'Basic ' +
        Buffer.from(connectOptions.proxyAuth).toString('base64')
  }

  debug('making CONNECT request')
  var connectReq = self.request(connectOptions)
  connectReq.useChunkedEncodingByDefault = false // for v0.6
  connectReq.once('response', onResponse) // for v0.6
  connectReq.once('upgrade', onUpgrade)   // for v0.6
  connectReq.once('connect', onConnect)   // for v0.7 or later
  connectReq.once('error', onError)
  connectReq.end()

  function onResponse(res) {
    // Very hacky. This is necessary to avoid http-parser leaks.
    res.upgrade = true
  }

  function onUpgrade(res, socket, head) {
    // Hacky.
    process.nextTick(function() {
      onConnect(res, socket, head)
    })
  }

  function onConnect(res, socket, head) {
    connectReq.removeAllListeners()
    socket.removeAllListeners()

    if (res.statusCode === 200) {
      assert.equal(head.length, 0)
      debug('tunneling connection has established')
      self.sockets[self.sockets.indexOf(placeholder)] = socket
      cb(socket)
    } else {
      debug('tunneling socket could not be established, statusCode=%d', res.statusCode)
      var error = new Error('tunneling socket could not be established, ' + 'statusCode=' + res.statusCode)
      error.code = 'ECONNRESET'
      options.request.emit('error', error)
      self.removeSocket(placeholder)
    }
  }

  function onError(cause) {
    connectReq.removeAllListeners()

    debug('tunneling socket could not be established, cause=%s\n', cause.message, cause.stack)
    var error = new Error('tunneling socket could not be established, ' + 'cause=' + cause.message)
    error.code = 'ECONNRESET'
    options.request.emit('error', error)
    self.removeSocket(placeholder)
  }
}

TunnelingAgent.prototype.removeSocket = function removeSocket(socket) {
  var pos = this.sockets.indexOf(socket)
  if (pos === -1) return

  this.sockets.splice(pos, 1)

  var pending = this.requests.shift()
  if (pending) {
    // If we have pending requests and a socket gets closed a new one
    // needs to be created to take over in the pool for the one that closed.
    this.createConnection(pending)
  }
}

function createSecureSocket(options, cb) {
  var self = this
  TunnelingAgent.prototype.createSocket.call(self, options, function(socket) {
    // 0 is dummy port for v0.6
    var secureSocket = tls.connect(0, mergeOptions({}, self.options,
      { servername: options.host
      , socket: socket
      }
    ))
    self.sockets[self.sockets.indexOf(socket)] = secureSocket
    cb(secureSocket)
  })
}


function mergeOptions(target) {
  for (var i = 1, len = arguments.length; i < len; ++i) {
    var overrides = arguments[i]
    if (typeof overrides === 'object') {
      var keys = Object.keys(overrides)
      for (var j = 0, keyLen = keys.length; j < keyLen; ++j) {
        var k = keys[j]
        if (overrides[k] !== undefined) {
          target[k] = overrides[k]
        }
      }
    }
  }
  return target
}


var debug
if (process.env.NODE_DEBUG && /\btunnel\b/.test(process.env.NODE_DEBUG)) {
  debug = function() {
    var args = Array.prototype.slice.call(arguments)
    if (typeof args[0] === 'string') {
      args[0] = 'TUNNEL: ' + args[0]
    } else {
      args.unshift('TUNNEL:')
    }
    console.error.apply(console, args)
  }
} else {
  debug = function() {}
}
exports.debug = debug // for test