Beispiel #1
0
    /**
     * This dispatches the particular methods this class provides.
     * Currently, the only invokable method is:
     * "Start". 
     */
    public void HandleRpc(ISender caller, string method, IList args, object req_state) {
      int part_idx = method.IndexOf(':');
      if( part_idx == -1 ) {
        if (method == "Start") {
          IDictionary ht = (IDictionary) args[0];
          MapReduceArgs mr_args = new MapReduceArgs(ht);
          string task_name = mr_args.TaskName;
          MapReduceTask task;
          if (_name_to_task.TryGetValue(task_name, out task)) {
            MapReduceComputation mr = new MapReduceComputation(_node, req_state, task, mr_args);
            mr.Start();
          } 
          else {
            throw new AdrException(-32608, "No mapreduce task with name: " + task_name);          
          }
        }
        else if( method == "AddHandler" ) {
          //Make sure this is local:
          ISender tmp_call = caller;
          bool islocal = tmp_call is Node;
          while(!islocal && tmp_call is IWrappingSender) {
            tmp_call =  ((IWrappingSender)tmp_call).WrappedSender;
            islocal = tmp_call is Node;
          }
          if( !islocal ) {
            throw new AdrException(-32601, "AddHandler only valid for local callers");
          }
          SubscribeTask(new RpcMapReduceTask(_node, (IDictionary)args[0]));
          _rpc.SendResult(req_state, null);
        }
        else {
          throw new AdrException(-32601, "No Handler for method: " + method);
        }
      }
      else {
        //This is a reference to a specific part of a task:
        string part = method.Substring(0, part_idx);
        string task_name = method.Substring(part_idx + 1);
        MapReduceTask task;
        if(false == _name_to_task.TryGetValue(task_name, out task)) {
          throw new AdrException(-32608, "No mapreduce task with name: " + task_name);          
        }
        if( part == "tree" ) {
          var mra = new MapReduceArgs((IDictionary)args[0]);

          var tree_res = new Channel(1, req_state);
          tree_res.CloseEvent += this.HandleTree;
          task.GenerateTree(tree_res, mra);
        }
        else if( part == "reduce" ) {
          //Prepare the RpcResult:
          var rres_d = (IDictionary)args[2];
          ISender send = SenderFactory.CreateInstance(_node, (string)rres_d["sender"]);
          var rres = new RpcResult(send, rres_d["result"]);
          
          Channel reduce_res = new Channel(1, req_state);
          reduce_res.CloseEvent += this.HandleReduce;
          task.Reduce(reduce_res, args[0], args[1], rres);
        }
        else if( part == "map" ) {
          Channel map_res = new Channel(1, req_state);
          map_res.CloseEvent += this.HandleMap;
          task.Map(map_res, args[0]);
        }
        else {
          throw new AdrException(-32608,
              String.Format("No mapreduce task({0}) part with name: {1}", task_name, part));          
        }
      }
    }
Beispiel #2
0
 /**
  * Starts a map-reduce computation. 
  * @param task map reduce task to start.
  * @param args arguments for the map-reduce task. 
  * @param req_state RPC related state for the invocation.
  */
 protected void Start(MapReduceTask task, MapReduceArgs args, object req_state) {
   MapReduceComputation mr = new MapReduceComputation(_node, req_state, task, args);
   mr.Start();
 }