Add hack to support N42 messages embedded with another XML message from a specific RSI system.

Author: wcjohns

SpecUtils/SpecFile.h

@@ -500,8 +500,16 @@ bool is_candidate_n42_file( const char * const data, const char * const data_end
  @TODO move this function, and similar ones to a N42 utils header/source
  */
 char *convert_n42_utf16_xml_to_utf8( char * data, char * const data_end );
- 
- 
+
+/** Function converts XML files that look like
+ `<MessageEnvelope... <n42:RadInstrumentData>...</n42:RadInstrumentData></MessageEnvelope>`
+ to
+ `<RadInstrumentData>...<RadInstrumentData>`
+ So they can be parsed as N42 files.
+ */
+bool rsi_portal_xml_to_n42_hack( char* &data, char* &data_end );
+
+
 /** @TODO move this function, and similar ones to a N42 utils header/source
  
  */

src/SpecFile_n42.cpp

@@ -4714,7 +4714,111 @@ namespace SpecUtils
 
  return new_data_end;
  }//convert_n42_utf16_xml_to_utf8
- 
+
+
+ bool rsi_portal_xml_to_n42_hack( char* &data, char* &data_end )
+ {
+ assert( data <= data_end );
+ if( data_end < data )
+ throw logic_error( "Invalid start-end of data" ); //shouldnt ever happen
+
+ const size_t orig_len = (data_end - data);
+ if( orig_len < 1024 )
+ return false;
+
+ // If '<MessageEnvelope' is not found within the first 512 characters, then return false
+ // if '<n42:RadInstrumentData>' is not found within the first 8192 characters, return false.
+ // Go through and replace all instances of "<n42:" with " <"
+ // Go through and replace all instances of "</n42:" with " </"
+ // Make `data` point at the first instance of "<RadInstrumentData>"
+ // Make `data_end` point one position past the first following "</RadInstrumentData>"
+
+ // Define string literals
+ const char message_envelope[] = "<MessageEnvelope";
+ const size_t message_envelope_len = (sizeof(message_envelope) / sizeof(message_envelope[0])) - 1;
+
+ const char rad_instrument_data[] = "<n42:RadInstrumentData>";
+ const size_t rad_instrument_data_len = (sizeof(rad_instrument_data) / sizeof(rad_instrument_data[0])) - 1;
+
+ const char rad_instrument_data_start[] = "<RadInstrumentData>";
+ const size_t rad_instrument_data_start_len = (sizeof(rad_instrument_data_start) / sizeof(rad_instrument_data_start[0])) - 1;
+
+ const char rad_instrument_data_end[] = "</RadInstrumentData>";
+ const size_t rad_instrument_data_end_len = (sizeof(rad_instrument_data_end) / sizeof(rad_instrument_data_end[0])) - 1;
+
+ const char n42_open[] = "<n42:";
+ const size_t n42_open_len = (sizeof(n42_open) / sizeof(n42_open[0])) - 1;
+ const char n42_close[] = "</n42:";
+ const size_t n42_close_len = (sizeof(n42_close) / sizeof(n42_close[0])) - 1;
+ const char replacement_open[] = " <";
+ const size_t replacement_open_len = (sizeof(replacement_open) / sizeof(replacement_open[0])) - 1;
+ const char replacement_close[] = " </";
+ const size_t replacement_close_len = (sizeof(replacement_close) / sizeof(replacement_close[0])) - 1;
+
+ static_assert( sizeof(n42_open) == sizeof(replacement_open), "Mismatch on n42 open str len" );
+ static_assert( sizeof(n42_close) == sizeof(replacement_close), "Mismatch on n42 open str len" );
+
+ // Check for '<MessageEnvelope' within the first 512 characters
+ const size_t envelope_search_len = std::min(size_t(512), orig_len);
+ char * const message_envelope_pos = std::search( data, data + envelope_search_len,
+ message_envelope, message_envelope + message_envelope_len);
+ if( message_envelope_pos == (data + envelope_search_len) )
+ return false;
+
+ // Check for '<n42:RadInstrumentData>' within the first 8192 characters
+ const size_t rad_instrument_search_len = std::min(size_t(8192), orig_len);
+ char *rad_instrument_pos = std::search(data, data + rad_instrument_search_len,
+ rad_instrument_data, rad_instrument_data + rad_instrument_data_len);
+ if( rad_instrument_pos == (data + rad_instrument_search_len) )
+ return false;
+
+ // If we are here, we are probably in the target rsi portal file
+
+ // Replace all instances of "<n42:" with " <"
+ char *pos = data;
+ while( pos < (data_end - n42_open_len) )
+ {
+ pos = std::search(pos, data_end, n42_open, n42_open + n42_open_len);
+ if( pos == data_end )
+ break; // No more occurrences
+ std::memcpy(pos, replacement_open, replacement_open_len);
+ pos += n42_open_len; // Move past the replaced substring
+ }
+
+
+ // Replace all instances of "</n42:" with " <"
+ pos = data;
+ while( pos < (data_end - n42_close_len) )
+ {
+ pos = std::search(pos, data_end, n42_close, n42_close + n42_close_len);
+ if( pos == data_end )
+ break; // No more occurrences
+ std::memcpy(pos, replacement_close, replacement_close_len);
+ pos += n42_close_len; // Move past the replaced substring
+ }
+
+ // Make `data` point at the first instance of "<RadInstrumentData>"
+ char *rad_data_start = std::search(data, data_end,
+ rad_instrument_data_start, rad_instrument_data_start + rad_instrument_data_start_len);
+ assert( rad_data_start < data_end );
+
+ if( rad_data_start == data_end )
+ return false; // "<RadInstrumentData>" not found
+
+ data = rad_data_start;
+
+ // Make `data_end` point one position past the first following "</RadInstrumentData>"
+ char *rad_data_end = std::search(rad_data_start, data_end,
+ rad_instrument_data_end, rad_instrument_data_end + rad_instrument_data_end_len);
+ if( rad_data_end == data_end )
+ return false; // "</RadInstrumentData>" not found
+
+ data_end = rad_data_end + rad_instrument_data_end_len;
+
+ return true;
+ }//bool rsi_portal_xml_to_n42_hack( char* &data, char* &data_end )
+
+
  bool SpecFile::load_from_N42( std::istream &input )
  {
  std::unique_lock<std::recursive_mutex> scoped_lock( mutex_ );
@@ -8867,10 +8971,11 @@ namespace SpecUtils
  reset(); 
 
  data_end = convert_n42_utf16_xml_to_utf8( data, data_end );
+ rsi_portal_xml_to_n42_hack( data, data_end );
 
  // Some times a bunch of null characters can get appended to the end
  // of the file - lets remove them, or rapidxml::parse will fail.
- // TODO: bet yet, we should look for the last '>' character, or even better, the last valid closing tag
+ // TODO: better yet, we should look for the last '>' character, or even better, the last valid closing tag
  while( ((data_end - data) > 2) && ((*(data_end - 1)) == '\0') )
  --data_end;