C++ function will not return

Question

I have a function that I am calling that runs all the way up to where it should return but doesn't return. If I cout something for debugging at the very end of the function, it gets displayed but the function does not return.

fetchData is the function I am referring to. It gets called by outputFile. cout displays "done here" but not "data fetched"

I know this code is messy but can anyone help me figure this out?

Thanks

  //Given an inode return all data of i_block data
  char* fetchData(iNode tempInode){
   char* data;
   data = new char[tempInode.i_size];
   this->currentInodeSize = tempInode.i_size;

   //Loop through blocks to retrieve data
   vector<unsigned int> i_blocks;
   i_blocks.reserve(tempInode.i_blocks);

   this->currentDataPosition = 0;
   cout << "currentDataPosition set to 0" << std::endl;
   cout << "i_blocks:" << tempInode.i_blocks << std::endl;
   int i = 0;
   for(i = 0; i < 12; i++){
    if(tempInode.i_block[i] == 0)
     break;
    i_blocks.push_back(tempInode.i_block[i]);
   }

   appendIndirectData(tempInode.i_block[12], &i_blocks);
   appendDoubleIndirectData(tempInode.i_block[13], &i_blocks);
   appendTripleIndirectData(tempInode.i_block[14], &i_blocks);

   //Loop through all the block addresses to get the actual data
   for(i=0; i < i_blocks.size(); i++){
    appendData(i_blocks[i], data);
   }
   cout << "done here" << std::endl;

   return data;
  }




  void appendData(int block, char* data){
   char* tempBuffer;
   tempBuffer = new char[this->blockSize];

   ifstream file (this->filename, std::ios::binary);
   int entryLocation = block*this->blockSize;
   file.seekg (entryLocation, ios::beg);
   file.read(tempBuffer, this->blockSize);

   //Append this block to data
   for(int i=0; i < this->blockSize; i++){
    data[this->currentDataPosition] = tempBuffer[i];
    this->currentDataPosition++;
   }
   data[this->currentDataPosition] = '\0';
  }

  void outputFile(iNode file, string filename){
   char* data;
   cout << "File Transfer Started" << std::endl;
   data = this->fetchData(file);
   cout << "data fetched" << std::endl;

   char *outputFile = (char*)filename.c_str();
   ofstream myfile;
   myfile.open (outputFile,ios::out|ios::binary);
   int i = 0;
   for(i=0; i < file.i_size; i++){
    myfile << data[i];
   }
   myfile.close();
   cout << "File Transfer Completed" << std::endl;
   return;
  }

Answer 1

Either there's some other line of code in your program that prints "done here", or you're corrupting the stack and affected the return address. But I don't see any buffers on the stack that you could overrun.

Have you tried using a debugger?

Answer 2

Set breakpoints, step through in a debugger, and see where the actual execution starts to differ from what you think should happen.

From a quick look at your code, you should get the second message, but going through in a debugger and seeing what really happens will help more than any theoretical musings on what could be going wrong. It also looks like you'll be leaking memory everywhere, I don't see any deletes to go with your news.

Answer 3

If appendData() keeps appending to i_blocks then the data structure keeps growing and so does i_blocks.size(). This will never exit !!!

   //Loop through all the block addresses to get the actual data
   for(i=0; i < i_blocks.size(); i++){
    appendData(i_blocks[i], data);
   }