Program Listing for File commandhandler.cpp

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// ---------------------------------------------------------------------
// 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;
}