iot-sol/node_modules/hope-workflow/lib/engine.js

Intel(r) IoT Services Orchestration Layer - HTML5 IDE + Node.js middleware to create and host distributed IoT Apps in minutes

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var B = require("hope-base");
var _ = require("lodash");

var log = B.log.for_category("workflow/engine");


var Workflow = require("./workflow");

var NodeImplService = require("./node_impl_service");

var EventEmitter = require("events").EventEmitter;


/**
 * @param {Object} config it should contains em and mnode
 */
function Engine(config) {
  this.config = config || {};

  this.workflows = {};
  // a quick lookup table for nodes
  // updated in workflow install / uninstall
  this.nodes = {};


  this.event = new EventEmitter();

}

Engine.create$ = function(config) {
  // TODO: so far we hard code this, while in the future,
  // it should be created via assemble$
  B.check(config.em && config.mnode, "workflow/engine", 
    "Need em (entity_manager) and mnode to initialize the workflow engine");
  var engine = new Engine(config);
  return NodeImplService.create$(engine, config.em, config.mnode).then(function(impl) {
    engine.default_node_impl = impl;
  }).then(function() {
    return engine;
  });
};


Engine.prototype.ensure_get_workflow = function(graph_id) {
  return B.check(this.workflows[graph_id], "Graph not found:", graph_id);
};

Engine.prototype.load = function(graph_json, specs) {
  B.check_warn(!this.workflows[graph_json.id], "workflow/engine", 
    "Workflow would be reloaded for", graph_json.id);
  log("load graph", graph_json.id);
  var w = new Workflow(this, graph_json, specs);
  w.load();
  this.workflows[w.id] = w;
  this.event.emit("workflow_load", {
    id: w.id
  });
  return w;
};

Engine.prototype.start$ = function(graph_json, specs, tracing) {
  // the engine would ensure there is no existing workflow is running first
  var f = this.workflows[graph_json.id];
  if (f) {
    B.check(!f.is_started(), "workflow/engine", 
      "Workfload already started. Please stop it first", graph_json.id);
  }
  // then it would reload (since graph might updated and start)
  f = this.load(graph_json, specs);

  var self = this;
  f.event.on("debug", function(data) {
    self.event.emit("debug", data);
  });

  return f.start$(tracing);
};


Engine.prototype.stop$ = function(graph_id) {
  return this.ensure_get_workflow(graph_id).stop$();
};

Engine.prototype.pause$ = function(graph_id) {
  return this.ensure_get_workflow(graph_id).disable$();
};


Engine.prototype.resume$ = function(graph_id) {
  return this.ensure_get_workflow(graph_id).enable$();
};

Engine.prototype.get_status = function(graph_id) {
  var f = this.workflows[graph_id];
  if (!f) {
    return "unloaded";
  }
  return f.status;
};

Engine.prototype.get_trace = function(graph_id) {
  return this.ensure_get_workflow(graph_id).trace;
};

Engine.prototype.get_debug_trace = function(graph_id) {
  var f = this.workflows[graph_id];
  if (!f) {
    return [];
  }
  return this.ensure_get_workflow(graph_id).debug_trace;
};

Engine.prototype.set_debug_for_node = function(graph_id, node_id, is_debug) {
  return this.ensure_get_workflow(graph_id).set_debug_for_node(node_id, is_debug);
};


Engine.prototype.has_started_workflows = function() {
  var self = this;
  var res = false;
  _.forEach(self.workflows, function(v) {
    if (v.is_started()) {
      res = true;
      return false;
    }
  });
  return res;
};
module.exports = Engine;