Method openFile

SRC/database/FileDatastore.cpp:1189–1247

 *******************************************************************/

int
FileDatastore::openFile(char *fileName, FileDatastoreOutputFile *theFileStruct, int dataSize)
{
  fstream *res = new fstream();
  if (res == 0) {
    opserr << "FileDatastore::openFile - out of memory; failed to open file: " << fileName << endln;
    return 0;
  }

  res->open(fileName, ios::in | ios::out | ios::binary); 

  // if file did not exist, need to pass trunc flag to open it
  if (res->bad() == true || res->is_open() == false) {
    // delete & new again for unix gcc compiler to work!
    delete res;
    res = new fstream();
    if (res == 0) {
      opserr << "FileDatastore::openFile - out of memory; failed to open file: " << fileName << endln;
      theFileStruct->theFile = res;
      return -1;
    }
    res->open(fileName, ios::in | ios::out | ios::trunc | ios::binary);   
  }

  if (res->bad() == true || res->is_open() == false) {
    opserr << "FATAL - FileDatastore::openFile() - could not open file " << fileName << endln;
    delete res;
    theFileStruct->theFile = 0;
    return -1;
  }

  // set the position for writing to eof
  res->seekp(0,ios::end);  
  STREAM_POSITION_TYPE fileEnd = res->tellp();
  int maxDataTag = 0;
  
  if (fileEnd == 0 || fileEnd == -1) {
    *(theIntData.dbTag) = maxDataTag;
    res->write(data, sizeof(int));    
    fileEnd = sizeof(int);
    maxDataTag = -1;
  } else {
    res->seekg(0, ios::beg);  
    res->read(data, sizeof(int));
    maxDataTag = *(theIntData.dbTag);
  }

  // move to start of data part
  res->seekp(sizeof(int), ios::beg);
  res->seekg(sizeof(int), ios::beg);

  // fill in the structure data
  theFileStruct->theFile = res;
  theFileStruct->fileEnd = fileEnd;

  theFileStruct->maxDbTag = maxDataTag; 	      

  return 0;