webapi-eca/js-coffee/server.js

// Generated by CoffeeScript 1.6.3
/*
Rules Server
============
>This is the main module that is used to run the whole server:
>
>     node server [log_type http_port]
>
>Valid `log_type`'s are:
>
>- `0`: standard I/O output (default)
>- `1`: log file (server.log)
>- `2`: silent
>
>`http_port` can be set to use another port, than defined in the 
>[config](config.html) file, to listen to, e.g. used by the test suite.
>
>---
*/


(function() {
  'use strict';
  /* Grab all required modules*/

  var adminCmds, args, conf, db, engine, handleAdminCommands, http_listener, init, log, mm, path, procCmds, shutDown;

  path = require('path');

  log = require('./logging');

  conf = require('./config');

  db = require('./db_interface');

  engine = require('./engine');

  http_listener = require('./http_listener');

  mm = require('./module_manager');

  args = {};

  procCmds = {};

  /* Prepare the admin commands that are issued via HTTP requests.*/


  adminCmds = {
    'loadrules': mm.loadRulesFromFS,
    'loadaction': mm.loadActionModuleFromFS,
    'loadactions': mm.loadActionModulesFromFS,
    'loadevent': mm.loadEventModuleFromFS,
    'loadevents': mm.loadEventModulesFromFS,
    'loadusers': http_listener.loadUsers,
    'shutdown': shutDown
  };

  /*
  Error handling of the express port listener requires special attention,
  thus we have to catch the process error, which is issued if
  the port is already in use.
  */


  process.on('uncaughtException', function(err) {
    switch (err.errno) {
      case 'EADDRINUSE':
        err.addInfo = 'http_port already in use, shutting down!';
        log.error('RS', err);
        shutDown();
        break;
      default:
        log.error(err);
    }
    return null;
  });

  /*
  ## Initialize the Server
  This function is invoked right after the module is loaded and starts the server.
  */


  init = function() {
    log.print('RS', 'STARTING SERVER');
    /* Check whether the config file is ready, which is required to start the server.*/

    if (!conf.isReady()) {
      log.error('RS', 'Config file not ready!');
      process.exit();
    }
    /* Fetch the `log_type` argument and post a log about which log type is used.*/

    if (process.argv.length > 2) {
      args.logType = parseInt(process.argv[2]) || 0;
      switch (args.logType) {
        case 0:
          log.print('RS', 'Log type set to standard I/O output');
          break;
        case 1:
          log.print('RS', 'Log type set to file output');
          break;
        case 2:
          log.print('RS', 'Log type set to silent');
          break;
        default:
          log.print('RS', 'Unknown log type, using standard I/O');
      }
      log(args);
    } else {
      log.print('RS', 'No log method argument provided, using standard I/O');
    }
    /* Fetch the `http_port` argument*/

    if (process.argv.length > 3) {
      args.http_port = parseInt(process.argv[3]);
    } else {
      log.print('RS', 'No HTTP port passed, using standard port from config file');
    }
    db(args);
    /* We only proceed with the initialization if the DB is ready*/

    return db.isConnected(function(err, result) {
      if (!err) {
        /* Initialize all required modules with the args object.*/

        log.print('RS', 'Initialzing engine');
        engine(args);
        log.print('RS', 'Initialzing http listener');
        http_listener(args);
        log.print('RS', 'Initialzing module manager');
        mm(args);
        log.print('RS', 'Initialzing DB');
        /* Distribute handlers between modules to link the application.*/

        log.print('RS', 'Passing handlers to engine');
        engine.addDBLinkAndLoadActionsAndRules(db);
        log.print('RS', 'Passing handlers to http listener');
        http_listener.addHandlers(db, handleAdminCommands, engine.pushEvent);
        log.print('RS', 'Passing handlers to module manager');
        return mm.addHandlers(db, engine.loadActionModule, engine.addRule);
      }
    });
  };

  /*
  admin commands handler receives all command arguments and an answerHandler
  object that eases response handling to the HTTP request issuer.
  */


  handleAdminCommands = function(args, answHandler) {
    var fAnsw, _name;
    if (args && args.cmd) {
      if (typeof adminCmds[_name = args.cmd] === "function") {
        adminCmds[_name](args, answHandler);
      }
    } else {
      log.print('RS', 'No command in request');
    }
    /*
    The fAnsw function receives an answerHandler object as an argument when called
    and returns an anonymous function
    */

    fAnsw = function(ah) {
      /*
      The anonymous function checks whether the answerHandler was already used to
      issue an answer, if no answer was provided we answer with an error message
      */

      return function() {
        if (!ah.isAnswered()) {
          return ah.answerError('Not handled...');
        }
      };
    };
    /*
    Delayed function call of the anonymous function that checks the answer handler
    */

    return setTimeout(fAnsw(answHandler), 2000);
  };

  /*
  Shuts down the server.
  @param {Object} args
  @param {Object} answHandler
  */


  shutDown = function(args, answHandler) {
    if (answHandler != null) {
      answHandler.answerSuccess('Goodbye!');
    }
    log.print('RS', 'Received shut down command!');
    if (engine != null) {
      engine.shutDown();
    }
    return http_listener != null ? http_listener.shutDown() : void 0;
  };

  /*
  ## Process Commands
  
  When the server is run as a child process, this function handles messages
  from the parent process (e.g. the testing suite)
  */


  process.on('message', function(cmd) {
    return typeof procCmds[cmd] === "function" ? procCmds[cmd]() : void 0;
  });

  /*
  The die command redirects to the shutDown function.
  */


  procCmds.die = shutDown;

  /*
  *Start initialization*
  */


  init();

}).call(this);