VILLASnode/common/lib/compat.cpp

/* Compatability for different library versions.
 *
 * 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 <cstring>
#include <jansson.h>
#include <unistd.h>

#include <villas/compat.hpp>

#if JANSSON_VERSION_HEX < 0x020A00
size_t json_dumpb(const json_t *json, char *buffer, size_t size, size_t flags) {
  char *str;
  size_t len;

  str = json_dumps(json, flags);
  if (!str)
    return 0;

  len = strlen(str); // Not \0 terminated
  if (buffer && len <= size)
    memcpy(buffer, str, len);

  free(str);

  return len;
}

static size_t json_loadfd_callback(void *buffer, size_t buflen, void *data) {
  int *fd = (int *)data;

  return (size_t)read(*fd, buffer, buflen);
}

json_t *json_loadfd(int input, size_t flags, json_error_t *error) {
  return json_load_callback(json_loadfd_callback, (void *)&input, flags, error);
}

static int json_dumpfd_callback(const char *buffer, size_t size, void *data) {
#ifdef HAVE_UNISTD_H
  int *dest = (int *)data;

  if (write(*dest, buffer, size) == (ssize_t)size)
    return 0;
#else
  (void)buffer;
  (void)size;
  (void)data;
#endif // HAVE_UNISTD_H

  return -1;
}

int json_dumpfd(const json_t *json, int output, size_t flags) {
  return json_dump_callback(json, json_dumpfd_callback, (void *)&output, flags);
}
#endif // JANSSON_VERSION_HEX < 0x020A00