VILLASnode/lib/nodes/example.cpp

/* An example get started with new implementations of new node-types.
 *
 * This example does not do any particulary useful.
 * It is just a skeleton to get you started with new node-types.
 *
 * 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/exceptions.hpp>
#include <villas/node_compat.hpp>
#include <villas/nodes/example.hpp>
#include <villas/sample.hpp>
#include <villas/super_node.hpp>
#include <villas/utils.hpp>

using namespace villas;
using namespace villas::node;
using namespace villas::utils;

ExampleNode::ExampleNode(const uuid_t &id, const std::string &name)
    : Node(id, name), setting1(72), setting2("something"), state1(0) {}

ExampleNode::~ExampleNode() {}

int ExampleNode::prepare() {
  state1 = setting1;

  if (setting2 == "double")
    state1 *= 2;

  return 0;
}

int ExampleNode::parse(json_t *json) {
  // TODO: Add implementation here. The following is just an example

  const char *setting2_str = nullptr;

  json_error_t err;
  int ret = json_unpack_ex(json, &err, 0, "{ s?: i, s?: s }", "setting1",
                           &setting1, "setting2", &setting2_str);
  if (ret)
    throw ConfigError(json, err, "node-config-node-example");

  if (setting2_str)
    setting2 = setting2_str;

  return 0;
}

int ExampleNode::check() {
  if (setting1 > 100 || setting1 < 0)
    return -1;

  if (setting2.empty() || setting2.size() > 10)
    return -1;

  return 0;
}

int ExampleNode::start() {
  // TODO add implementation here

  start_time = time_now();

  return 0;
}

// int ExampleNode::stop()
// {
// 	// TODO add implementation here
// 	return 0;
// }

// int ExampleNode::pause()
// {
// 	// TODO add implementation here
// 	return 0;
// }

// int ExampleNode::resume()
// {
// 	// TODO add implementation here
// 	return 0;
// }

// int ExampleNode::restart()
// {
// 	// TODO add implementation here
// 	return 0;
// }

// int ExampleNode::reverse()
// {
// 	// TODO add implementation here
// 	return 0;
// }

// std::vector<int> ExampleNode::getPollFDs()
// {
// 	// TODO add implementation here
// 	return {};
// }

// std::vector<int> ExampleNode::getNetemFDs()
// {
// 	// TODO add implementation here
// 	return {};
// }

// struct villas::node::memory::Type * ExampleNode::getMemoryType()
// {
//	// TODO add implementation here
// }

const std::string &ExampleNode::getDetails() {
  details = fmt::format("setting1={}, setting2={}", setting1, setting2);
  return details;
}

int ExampleNode::_read(struct Sample *smps[], unsigned cnt) {
  int read;
  struct timespec now;

  // TODO: Add implementation here. The following is just an example

  assert(cnt >= 1 && smps[0]->capacity >= 1);

  now = time_now();

  smps[0]->data[0].f = time_delta(&now, &start_time);

  /* Dont forget to set other flags in struct Sample::flags
   * E.g. for sequence no, timestamps... */
  smps[0]->flags = (int)SampleFlags::HAS_DATA;
  smps[0]->signals = getInputSignals(false);

  read = 1; // The number of samples read

  return read;
}

int ExampleNode::_write(struct Sample *smps[], unsigned cnt) {
  int written;

  // TODO: Add implementation here.

  written = 0; // The number of samples written

  return written;
}

// Register node
static char n[] = "example";
static char d[] = "An example for staring new node-type implementations";
static NodePlugin<ExampleNode, n, d,
                  (int)NodeFactory::Flags::SUPPORTS_READ |
                      (int)NodeFactory::Flags::SUPPORTS_WRITE |
                      (int)NodeFactory::Flags::SUPPORTS_POLL |
                      (int)NodeFactory::Flags::HIDDEN>
    p;