C++ 将文件数据一次性加载进内存实例代码

 /**************** 将模型整个读入内存  ********************/
  std::ifstream infile(detModFile,std::ios::binary);
  if (!infile.is_open()) 
  { 
    printf( "connot open the model file: %s\n",detModFile); 
    return -1; 
  } 
  std::filebuf *pbuf = infile.rdbuf(); 
  // 获取文件大小
  long filesize = static_cast<long>((pbuf->pubseekoff (0,std::ios::end,std::ios::in))); 
  pbuf->pubseekpos (0,std::ios::in);
  unsigned char* modelptr = new unsigned char[filesize]; 
  // 读入文件内容
  pbuf->sgetn ((char*)modelptr,filesize); 
  infile.close();   

  // 获取模型个数
  int model_num;
  int p_offset = 0;
  memcpy(&model_num,modelptr,sizeof(int));
  p_offset += sizeof(int);

  //获取每个模型大小
  std::vector<int> each_size(model_num);
  int model_size;
  for (int i = 0; i < model_num; i++)
  {
    memcpy(&model_size,modelptr+p_offset,sizeof(int));
    p_offset += sizeof(int);
    each_size[i] = model_size;
  }