VILLASnode/lib/formats/json_edgeflex.cpp

/* JSON serializtion for edgeFlex project.
 *
 * Author: Manuel Pitz <manuel.pitz@eonerc.rwth-aachen.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#include <cstring>

#include <villas/formats/json_edgeflex.hpp>
#include <villas/timing.hpp>

using namespace villas::node;

int JsonEdgeflexFormat::packSample(json_t **json_smp,
                                   const struct Sample *smp) {
  json_t *json_data, *json_value;
  json_t *json_created = nullptr;

  if (smp->length < 1)
    return -1;

  json_data = json_object();

  for (unsigned i = 0; i < smp->length; i++) {
    auto sig = smp->signals->getByIndex(i);
    if (!sig)
      return -1;

    json_value = smp->data[i].toJson(sig->type);
    json_object_set(json_data, sig->name.c_str(), json_value);
  }

  json_created = json_integer(time_to_double(&smp->ts.origin) * 1e3);
  json_object_set(json_data, "created", json_created);

  *json_smp = json_data;

  return 0;
}

int JsonEdgeflexFormat::unpackSample(json_t *json_smp, struct Sample *smp) {
  int ret;
  const char *key;
  json_t *json_value, *json_created = nullptr;
  json_int_t created = -1;

  if (smp->capacity < 1)
    return -1;

  if (json_typeof(json_smp) != JSON_OBJECT)
    return -1;

  json_object_foreach(json_smp, key, json_value) {
    if (!strcmp(key, "created"))
      json_created = json_incref(json_value);
    else {
      auto idx = signals->getIndexByName(key);
      if (idx < 0) {
        ret = sscanf(key, "signal_%d", &idx);
        if (ret != 1)
          continue;

        if (idx < 0)
          return -1;
      }

      auto sig = signals->getByIndex(idx);

      if (idx < (int)smp->capacity) {
        ret = smp->data[idx].parseJson(sig->type, json_value);
        if (ret)
          return ret;
      }

      if (idx >= (int)smp->length)
        smp->length = idx + 1;
    }
  }

  if (!json_created || !json_is_number(json_created))
    return -1;

  created = json_number_value(json_created);
  smp->ts.origin = time_from_double(created / 1e3);

  smp->flags = (int)SampleFlags::HAS_TS_ORIGIN;
  if (smp->length > 0)
    smp->flags |= (int)SampleFlags::HAS_DATA;

  return 0;
}

// Register format
static char n[] = "json.edgeflex";
static char d[] = "EdgeFlex JSON format";
static FormatPlugin<JsonEdgeflexFormat, n, d,
                    (int)SampleFlags::HAS_TS_ORIGIN |
                        (int)SampleFlags::HAS_SEQUENCE |
                        (int)SampleFlags::HAS_DATA>
    p;