deep-framework/vendor/aws-xray-sdk/lib/segment_emitter.js

DEEP Framework

var dgram = require('dgram');

var logger = require('./logger');

var DEFAULT_ADDRESS = '127.0.0.1';
var DEFAULT_PORT = 2000;
var PROTOCOL_HEADER = '{"format": "json", "version": 1}';
var PROTOCOL_DELIMITER = '\n';

/**
 * Segment emitter module.
 * @module SegmentEmitter
 */

var SegmentEmitter = {
  socket: dgram.createSocket('udp4'),
  daemonAddress: DEFAULT_ADDRESS,
  daemonPort: DEFAULT_PORT,

  /**
   * Returns the formatted segment JSON string.
   */

  format: function format(segment) {
    return PROTOCOL_HEADER + PROTOCOL_DELIMITER + segment.toString();
  },

  /**
   * Creates a UPD socket connection and send the formatted segment.
   * @param {Segment} segment - The segment to send to the daemon.
   */

  send: function send(segment) {
    var socket = this.socket;
    var client = socket || dgram.createSocket('udp4');
    var data = this.format(segment);
    var message = new Buffer(data);

    if (message.length > 64000) {
      logger.warn('Segment too large to send. Max size is 64 KB.');
      return;
    }

    client.send(message, 0, message.length, this.daemonPort, this.daemonAddress, function(err) {
      if (err)
        logger.error('Error occured sending segment: ', err);
      else
        logger.info('UDP message sent: ' + segment);

      if (!socket)
        client.close();
    });
  },

  /**
   * Configures the address and/or port the daemon is expected to be on.
   * @param {string} address - Address of the daemon the segments should be sent to.  Should be formatted as an IPv4 address.
   * @module SegmentEmitter
   * @function setDaemonAddress
   */

  setDaemonAddress: function setDaemonAddress(address) {
    if (!process.env.AWS_XRAY_DAEMON_ADDRESS) {
      processAddress(address);
    }
  },

  /**
   * Forces the segment emitter to create a new socket on send, and close it on complete.
   * @module SegmentEmitter
   * @function disableReusableSocket
   */

  disableReusableSocket: function() {
    delete this.socket;
  }
};

var processAddress = function processAddress(rawAddress) {
  var splitAddress = rawAddress.split(':');

  if (splitAddress[0] && splitAddress[0].indexOf('.') !== -1)
    SegmentEmitter.daemonAddress = splitAddress[0];

  if (splitAddress[1])
    SegmentEmitter.daemonPort = parseInt(splitAddress[1]);

  logger.info('Configured daemon address to ' + SegmentEmitter.daemonAddress + ':' + SegmentEmitter.daemonPort);
};

if (process.env.AWS_XRAY_DAEMON_ADDRESS)
  processAddress(process.env.AWS_XRAY_DAEMON_ADDRESS);

module.exports = SegmentEmitter;