BDSFieldLoaderQueryPoints.cc

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) BDSIM Collaboration, 2001 - 2026.
 
This file is part of BDSIM.
 
BDSIM is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published 
by the Free Software Foundation version 3 of the License.
 
BDSIM is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with BDSIM.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "BDSException.hh"
#include "BDSFieldLoaderQueryPoints.hh"
#include "BDSFourVector.hh"
#include "BDSUtilities.hh"
 
#include "globals.hh"
#include "G4String.hh"
 
#include "CLHEP/Units/SystemOfUnits.h"
 
#include <algorithm>
#include <fstream>
#include <iostream>
#include <map>
#include <regex>
#include <sstream>
#include <string>
#include <vector>
 
#ifdef USE_GZSTREAM
#include "src-external/gzstream/gzstream.h"
#endif
 
template <class T>
BDSFieldLoaderQueryPoints<T>::BDSFieldLoaderQueryPoints()
{;}
 
template <class T>
BDSFieldLoaderQueryPoints<T>::~BDSFieldLoaderQueryPoints()
{;}
 
template <class T>
std::vector<BDSFourVector<G4double>> BDSFieldLoaderQueryPoints<T>::Load(const G4String& fileName,
                                                                        std::vector<G4String>* columnNamesIn) const
{
  G4String functionName = "BDSFieldLoaderQueryPoints::Load> ";
  T file;
 
  file.open(fileName);
  
  // test if file is valid
#ifdef USE_GZSTREAM
  bool validFile = file.rdbuf()->is_open();
#else
  bool validFile = file.is_open();
#endif
 
  if (!validFile)
    {throw BDSException(functionName, "Cannot open file \"" + fileName + "\"");}
  else
    {G4cout << functionName << "loading \"" << fileName << "\"" << G4endl;}
 
  std::string line;
  std::vector<BDSFourVector<G4double>> result;
 
  G4double x = 0;
  G4double y = 0;
  G4double z = 0;
  G4double t = 0;
  std::map<G4String, G4double*> columnNameToVariableAddress = { {"x",&x},
                                                                {"y",&y},
                                                                {"z",&z},
                                                                {"t",&t} };
  std::map<G4String, G4double> columnNameToUnits = { {"x", CLHEP::m},
                                                     {"y", CLHEP::m},
                                                     {"z", CLHEP::m},
                                                     {"t", CLHEP::ns} };
  std::vector<G4double*> values;
  std::vector<G4double> units;
  std::vector<G4String>  columnNamesToPrint;
  G4int nCoordinates = 0;
  G4bool intoData = false;
  G4int lineNo = 1;
  while (std::getline(file, line))
    {
      x = 0;
      y = 0;
      z = 0;
      t = 0;
      
      // skip a line if it's only whitespace
      if (std::all_of(line.begin(), line.end(), isspace))
        {
          lineNo += 1;
          continue;
        }
 
      if (!intoData)
        {
          std::regex columnRow("^\\s*[!\\#]"); // ignore any initial white space and look for '!'
          if (std::regex_search(line, columnRow))
            {
              std::regex afterExclamation("\\s*!\\s*(.+)");
              std::smatch match;
              std::regex_search(line, match, afterExclamation);
              std::string restOfLine = match[1];
 
              if (restOfLine.empty())
                {
                  G4String msg = "Error on line> " + std::to_string(lineNo);
                  msg += ": column specification missing variables";
                  throw BDSException(functionName, msg);
                }
 
              std::vector<G4String> columnNames = BDS::SplitOnWhiteSpace(restOfLine);
              for (const auto& columnName : columnNames)
                {
                  G4String variableName = BDS::LowerCase(columnName);
                  auto search = columnNameToVariableAddress.find(variableName);
                  if (search == columnNameToVariableAddress.end())
                    {
                      G4String msg = "Error on line> " + std::to_string(lineNo) + "> variable name \"";
                      msg += variableName + "\" is not one of 'x', 'y', 'z', 't'";
                      throw BDSException(functionName, msg);
                    }
                  values.push_back(search->second);
                  units.push_back(columnNameToUnits[search->first]);
                  if (std::find(columnNamesToPrint.begin(), columnNamesToPrint.end(), search->first) != columnNamesToPrint.end())
                    {throw BDSException(functionName, "duplicate column name");}
                  columnNamesToPrint.push_back(search->first);
                }
              nCoordinates = (G4int)values.size();
              G4cout << functionName << "assuming " << nCoordinates << " coordinate";
              if (nCoordinates > 1)
                {G4cout << "s";}
              G4cout << " in each  line: (";
              for (const auto& coordName : columnNamesToPrint)
                {G4cout << " " << coordName;}
              G4cout << " )" << G4endl;
              if (columnNamesIn)
                {*columnNamesIn = columnNamesToPrint;}
            }
          intoData = true;
          lineNo += 1;
          continue;
        }
 
      std::vector<G4String> wordsInLine = BDS::SplitOnWhiteSpace(line);
 
      if ((G4int)wordsInLine.size() != nCoordinates)
        {throw BDSException(functionName, "invalid number of coordinates on line " + std::to_string(lineNo));}
 
      for (G4int i = 0; i < (G4int)values.size(); i++)
        {
          G4double coord = 0;
          try
            {coord = std::stod(wordsInLine[i]);}
          catch (std::exception& e)
            {throw BDSException(functionName, "Error on line> " + std::to_string(lineNo) + "> cannot convert to number");}
          (*values[i]) = coord * units[i];
        }
      
      result.emplace_back(BDSFourVector<G4double>(x,y,z,t));
 
      lineNo += 1;
    }
 
  file.close();
 
  G4cout << functionName << "loaded " << result.size() << " points" << G4endl;
 
  return result;
}
 
std::vector<BDSFourVector<G4double>> BDS::LoadFieldQueryPoints(const G4String& fileName,
                                                               std::vector<G4String>* columnNamesIn)
{
  G4String functionName = "BDS::LoadFieldQueryPoints>"; // namespaced functions don't print so well
  
  G4String fullFilePath = BDS::GetFullPath(fileName);
  if (!BDS::FileExists(fullFilePath))
    {throw BDSException(functionName, "no such file: \"" + fullFilePath + "\"");}
 
  std::vector<BDSFourVector<G4double>> result;
  if (fullFilePath.rfind("gz") != std::string::npos)
    {
#ifdef USE_GZSTREAM
      BDSFieldLoaderQueryPoints<igzstream> loader;
      result = loader.Load(fullFilePath, columnNamesIn);
#else
      throw BDSException(functionName, "Compressed file loading - but BDSIM not compiled with ZLIB.");
#endif
    }
  else
    {
      BDSFieldLoaderQueryPoints<std::ifstream> loader;
      result = loader.Load(fullFilePath, columnNamesIn);
    }
  return result;
}
 
template class BDSFieldLoaderQueryPoints<std::ifstream>;
 
#ifdef USE_GZSTREAM
template class BDSFieldLoaderQueryPoints<igzstream>;
#endif