C++ (Cpp) lwmqtt_read_data Examples

Example #1

File: helpers.c Project: sandeepmistry/arduino-mqtt

lwmqtt_err_t lwmqtt_read_string(uint8_t **buf, const uint8_t *buf_end, lwmqtt_string_t *str) {
  // read length
  uint16_t len;
  lwmqtt_err_t err = lwmqtt_read_num(buf, buf_end, &len);
  if (err != LWMQTT_SUCCESS) {
    return err;
  }

  // read data
  err = lwmqtt_read_data(buf, buf_end, (uint8_t **)&str->data, len);
  if (err != LWMQTT_SUCCESS) {
    return err;
  }

  // set length
  str->len = len;

  return LWMQTT_SUCCESS;
}

Example #2

File: packet.c Project: 256dpi/arduino-mqtt

lwmqtt_err_t lwmqtt_decode_publish(uint8_t *buf, size_t buf_len, bool *dup, uint16_t *packet_id, lwmqtt_string_t *topic,
                                   lwmqtt_message_t *msg) {
  // prepare pointer
  uint8_t *buf_ptr = buf;
  uint8_t *buf_end = buf + buf_len;

  // read header
  uint8_t header;
  lwmqtt_err_t err = lwmqtt_read_byte(&buf_ptr, buf_end, &header);
  if (err != LWMQTT_SUCCESS) {
    return err;
  }

  // check packet type
  if (lwmqtt_read_bits(header, 4, 4) != LWMQTT_PUBLISH_PACKET) {
    return LWMQTT_MISSING_OR_WRONG_PACKET;
  }

  // get dup
  *dup = lwmqtt_read_bits(header, 3, 1) == 1;

  // get retained
  msg->retained = lwmqtt_read_bits(header, 0, 1) == 1;

  // get qos
  switch (lwmqtt_read_bits(header, 1, 2)) {
    case 0:
      msg->qos = LWMQTT_QOS0;
      break;
    case 1:
      msg->qos = LWMQTT_QOS1;
      break;
    case 2:
      msg->qos = LWMQTT_QOS2;
      break;
    default:
      msg->qos = LWMQTT_QOS0;
      break;
  }

  // read remaining length
  uint32_t rem_len;
  err = lwmqtt_read_varnum(&buf_ptr, buf_end, &rem_len);
  if (err != LWMQTT_SUCCESS) {
    return err;
  }

  // check remaining length (topic length)
  if (rem_len < 2) {
    return LWMQTT_REMAINING_LENGTH_MISMATCH;
  }

  // check buffer capacity
  if ((uint32_t)(buf_end - buf_ptr) < rem_len) {
    return LWMQTT_BUFFER_TOO_SHORT;
  }

  // reset buf end
  buf_end = buf_ptr + rem_len;

  // read topic
  err = lwmqtt_read_string(&buf_ptr, buf_end, topic);
  if (err != LWMQTT_SUCCESS) {
    return err;
  }

  // read packet id if qos is at least 1
  if (msg->qos > 0) {
    err = lwmqtt_read_num(&buf_ptr, buf_end, packet_id);
    if (err != LWMQTT_SUCCESS) {
      return err;
    }
  } else {
    *packet_id = 0;
  }

  // set payload length
  msg->payload_len = buf_end - buf_ptr;

  // read payload
  err = lwmqtt_read_data(&buf_ptr, buf_end, &msg->payload, buf_end - buf_ptr);
  if (err != LWMQTT_SUCCESS) {
    return err;
  }

  return LWMQTT_SUCCESS;
}