.. _program_listing_file_falcon_commandhandler.cpp:

Program Listing for File commandhandler.cpp
===========================================

|exhale_lsh| :ref:`Return to documentation for file <file_falcon_commandhandler.cpp>` (``falcon/commandhandler.cpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // ---------------------------------------------------------------------
   // This file is part of falcon-core.
   //
   // Copyright (C) 2015, 2016, 2017 Neuro-Electronics Research Flanders
   //
   // Falcon-server is free software: you can redistribute it and/or modify
   // it under the terms of the GNU General Public License as published by
   // the Free Software Foundation, either version 3 of the License, or
   // (at your option) any later version.
   //
   // Falcon-server is distributed in the hope that it will be useful,
   // but WITHOUT ANY WARRANTY; without even the implied warranty of
   // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   // GNU General Public License for more details.
   //
   // You should have received a copy of the GNU General Public License
   // along with falcon-core. If not, see <http://www.gnu.org/licenses/>.
   // ---------------------------------------------------------------------
   #include <deque>
   #include <regex>
   #include <unistd.h>
   
   #include "buildconstant.hpp"
   #include "commandhandler.hpp"
   #include "utilities/filesystem.hpp"
   #include "utilities/zmqutil.hpp"
   #include "yaml-cpp/yaml.h"
   
   using namespace commands;
   
   bool CommandHandler::DelegateGraphCommand(std::deque<std::string> &command,
                                             std::deque<std::string> &reply) {
     // delegate
     s_send_multi(*graph_socket_, command);
     // get reply
     reply = s_blocking_recv_multi(*graph_socket_);
   
     return false;
   }
   
   bool CommandHandler::DelegateResourcesCommand(std::deque<std::string> &command,
                                      std::deque<std::string> &reply) {
   
       std::string resources_type;
   
       if (command[0] == "list") {
   
         if(command.size() == 2)
              resources_type = command[1]+"://";
         else
             resources_type = "resources://";
   
         try{
           std::string resource_path = global_context_->resolve_path(resources_type);
           std::vector<std::string> list_files = getAllFilesInDir(resource_path);
           for (auto const &file : list_files) {
             reply.push_back(std::regex_replace(file,  std::regex(resource_path), resources_type));
           }
   
         } catch (YAML::BadFile &e) {
           reply.push_back("ERR");
           reply.push_back("Unknown resources type requested \"" + resources_type + "\".");
           return false;
         }
   
       } else if (command[0] == "graphs") {
         try {
           std::string graph_path =
                   global_context_->resolve_path(command[1]);
           YAML::Node node;
           node["falcon"]["version"] = "1.0.0";
           node["graph"] = YAML::LoadFile(graph_path);
           YAML::Emitter out;
           out << node;
           reply.push_back(std::string(out.c_str()));
         } catch (YAML::BadFile &e) {
           reply.push_back("ERR");
           reply.push_back("Invalid graph file");
         }
       }
       else{
           // error
           reply.push_back("ERR");
           reply.push_back("Unknown resources command \"" + command[0] + "\".");
       }
       return false;
   }
   
   bool CommandHandler::HandleCommand(std::deque<std::string> &command,
                                      std::deque<std::string> &reply) {
     bool finished = false;
   
     std::deque<std::string> local_command;
     std::deque<std::string> local_reply;
   
     if (command.empty()) {
       return finished;
     }
     if (command[0] == "graph") {
       // delegate
       command.pop_front();
       finished = DelegateGraphCommand(command, reply);
     } else if (command[0] == "resources") {
       command.pop_front();
       finished = DelegateResourcesCommand(command, reply);
     } else if (command[0] == "documentation") {
       local_command.push_back("documentation");
       finished = DelegateGraphCommand(local_command, reply);
     } else if (command[0] == "test") {
       if (command.size() > 1) {
         if (command[1] == "true" || command[1] == "on") {
           global_context_->set_test(true);
           reply.push_back("OK");
         } else if (command[1] == "false" || command[1] == "off") {
           global_context_->set_test(false);
           reply.push_back("OK");
         } else {
           reply.push_back("ERR");
           reply.push_back("Invalid argument for test command");
         }
       } else {
         // toggle test flag
         global_context_->set_test(!global_context_->test());
         reply.push_back("OK");
       }
     } else if (command[0] == "quit" || command[0] == "kill") {
       local_command.push_back("state");
       DelegateGraphCommand(local_command, local_reply);
   
       if (local_reply[0] == "PROCESSING" && command[0] == "quit") {
         // error
         reply.push_back("ERR");
         reply.push_back("Cannot quit while graph is processing.");
       } else {
         if (local_reply[0] == "PROCESSING") {
           local_command.back() = "stop";
           DelegateGraphCommand(local_command, local_reply);
         }
         local_command.back() = "destroy";
         DelegateGraphCommand(local_command, local_reply);
         reply.push_back("OK");
         finished = true;
       }
     } else if (command[0] == "info") {
       local_command.push_back("state");
       DelegateGraphCommand(local_command, local_reply);
   
       YAML::Emitter out;
       out << YAML::BeginMap;
       out << YAML::Key << "Falcon version" << YAML::Value << GIT_REVISION;
       out << YAML::Key << "run_environment_root" << YAML::Value
           << global_context_->storage_context("runroot");
       out << YAML::Key << "resource_root" << YAML::Value
           << global_context_->storage_context("resources");
       out << YAML::Key << "graph_state" << YAML::Value << local_reply[0];
       out << YAML::Key << "default_test_flag" << YAML::Value
           << global_context_->test();
   
       reply.push_back(std::string(out.c_str()));
     } else {
       // error
       reply.push_back("ERR");
       reply.push_back("Unknown command \"" + command[0] + "\".");
     }
     return finished;
   }
   
   
   void CommandHandler::start() {
     if (sources_.size() == 0) {
       return;
     }
   
     // connect to graph thread
     // construct socket here, so that it is automatically destructed when this
     // function ends
     zmq::socket_t socket(global_context_->zmq(), ZMQ_REQ);
     socket.connect("inproc://graph");
   
     // save pointer to socket, so that DelegateGraphCommand can use it
     graph_socket_ = &socket;
   
     bool finished = false;
     std::deque<std::string> command;
     std::deque<std::string> reply;
   
     while (!finished) {
       usleep(100000); // 0.1 second
   
       // iterate through sources
       for (auto &it : sources_) {
         // retrieve command
         command.clear();
   
         if (it->getcommand(command)) {
           reply.clear();
           finished = HandleCommand(command, reply);
           it->sendreply(command, reply);
         }
   
         if (finished) {
           break;
         }
       }
     }
   
     graph_socket_ = nullptr;
   }