VILLASnode/lib/hooks/shift_seq.cpp

/* Shift sequence number of samples.
 *
 * 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/hook.hpp>
#include <villas/sample.hpp>

namespace villas {
namespace node {

class ShiftSequenceHook : public Hook {

protected:
  int offset;

public:
  using Hook::Hook;

  virtual void parse(json_t *json) {
    json_error_t err;
    int ret;

    assert(state != State::STARTED);

    Hook::parse(json);

    ret = json_unpack_ex(json, &err, 0, "{ s: i }", "offset", &offset);
    if (ret)
      throw ConfigError(json, err, "node-config-hook-shift_seq");

    state = State::PARSED;
  }

  virtual Hook::Reason process(struct Sample *smp) {
    assert(state == State::STARTED);

    smp->sequence += offset;

    return Reason::OK;
  }
};

// Register hook
static char n[] = "shift_seq";
static char d[] = "Shift sequence number of samples";
static HookPlugin<ShiftSequenceHook, n, d,
                  (int)Hook::Flags::NODE_READ | (int)Hook::Flags::PATH>
    p;

} // namespace node
} // namespace villas