VILLASnode/lib/api.cpp

/* REST-API-releated functions.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#include <villas/api.hpp>
#include <villas/api/request.hpp>
#include <villas/api/session.hpp>
#include <villas/compat.hpp>
#include <villas/node/config.hpp>
#include <villas/node/memory.hpp>
#include <villas/utils.hpp>
#include <villas/web.hpp>

using namespace villas;
using namespace villas::node;
using namespace villas::node::api;

InvalidMethod::InvalidMethod(Request *req)
    : BadRequest("The '{}' API endpoint does not support {} requests",
                 req->factory->getName(),
                 Session::methodToString(req->method)) {}

Api::Api(SuperNode *sn)
    : logger(Log::get("api")), state(State::INITIALIZED), super_node(sn) {}

Api::~Api() {
  if (state == State::STARTED)
    stop();
}

void Api::start() {
  assert(state != State::STARTED);

  logger->info("Starting sub-system");

  running = true;
  thread = std::thread(&Api::worker, this);

  state = State::STARTED;
}

void Api::stop() {
  assert(state == State::STARTED);

  logger->info("Stopping sub-system");

  for (Session *s : sessions)
    s->shutdown();

  for (int i = 0; i < 2 && sessions.size() > 0; i++) {
    logger->info("Waiting for {} sessions to terminate", sessions.size());
    usleep(1 * 1e6);
  }

  running = false;
  pending.push(nullptr); // unblock thread
  thread.join();

  state = State::STOPPED;
}

void Api::worker() {
  logger->info("Started worker");

  // Process pending requests
  while (running) {
    Session *s = pending.pop();
    if (s) {
      // Check that the session is still alive
      auto it = std::find(sessions.begin(), sessions.end(), s);
      if (it != sessions.end())
        s->execute();
    }
  }

  logger->info("Stopped worker");
}