Function parse_time

dds/DCPS/security/AccessControl/XmlUtils.cpp:245–429

#endif // XMLDATETIME_HAS_GETEPOCH

bool parse_time(const XMLCh* in, time_t& value)
{
  xercesc::XMLDateTime xdt(in);
  try {
    xdt.parseDateTime();
  } catch (const xercesc::XMLException& ex) {
    if (security_debug.access_error) {
      ACE_ERROR((LM_ERROR, "(%P|%t) ERROR: {access_error} parse_time: "
        "failed to parse date/time \"%C\": %C\n",
        to_string(in).c_str(), to_string(ex).c_str()));
    }
    return false;
  }

#if XMLDATETIME_HAS_GETEPOCH
  value = xdt.getEpoch();
#else
  /*
   * Doesn't seem like older Xerces' actually have a way to get the information
   * from XMLDateTime, so we have to do it ourselves.
   *
   * For this we'll follow https://www.w3.org/TR/xmlschema-2/#dateTime, which
   * is basically the same as ISO8601.
   * The exceptions are:
   * - We won't accept a negative datetime (-0001 is the year 2BCE), since the
   *   standard library might not be able to handle such a far back and we're
   *   certainly not expecting it.
   * - The Schema spec says that times without timezone info should be
   *   interpreted as "local", but seems it be intentionally vague as what that
   *   means. The DDS Security 1.1 spec explicitly says in 9.4.1.3.2.2 that it
   *   would be UTC. Xerces getEpoch values match up with this in the unit test
   *   for this code, so it's also interpreting them as UTC instead of
   *   something like the local system timezone.
   * - Since we use time_t we will accept but ignore fractional seconds.
   *   NOTE: The security spec is missing fractional seconds in a format
   *   description in a comment in example XML. This comment has been copied
   *   into many permissions files sitting in OpenDDS.
   */

  const std::string str = to_string(in);
  if (str[0] == '-') {
    if (security_debug.access_error) {
      ACE_ERROR((LM_ERROR, "(%P|%t) ERROR: {access_error} parse_time: "
        "date/time can't be negative: \"%C\"\n",
        str.c_str()));
    }
    return false;
  }

  /*
   * After this the expected lexical format given by the Schema spec is:
   *   yyyy '-' mm '-' dd 'T' hh ':' mm ':' ss ('.' s+)? ((('+' | '-') hh ':' mm) | 'Z')?
   * or alternatively as the Security spec says, except with fractional seconds:
   *   CCYY-MM-DDThh:mm:ss[.fffff...][Z|(+|-)hh:mm]
   * See unit tests for this code for examples
   */
  std::tm dttm;
  size_t pos = 0;