CGII/framework/include/cgv/utils/big_binary_file.h
2018-05-17 15:50:03 +02:00

74 lines
No EOL
2 KiB
C++

#pragma once
#include <string>
#include "lib_begin.h"
namespace cgv {
namespace utils {
/**
* class to handle files with very large sizes (>=2GB)
* hiding the ugly win32 api calls
*
* linux-support by using 64bit pointer, LFS required in kernel
*/
class CGV_API big_binary_file
{
public:
enum MODE {READ = 1, WRITE = 2, READ_WRITE = 3};
private:
MODE access_mode;
std::string filename;
bool fileopened;
void* file;
public:
///assosiates the new instance to the file filename
big_binary_file(const std::string &filename = "");
///close the file (if it is still opened)
virtual ~big_binary_file();
///open a file in read or write mode
bool open(MODE m, const std::string& file_name = "");
///close the file
void close();
///return true if the file is opened
bool is_open();
///return the size of the file in bytes
long long size();
///read num bytes from the file into the targetbuffer
bool read(unsigned char *targetbuffer,unsigned long num, unsigned long *numread=NULL);
///write num bytes to the file from the sourcebuffer (file must be opened with write access first)
bool write(const unsigned char *sourcebuffer,unsigned long num, unsigned long *numwrote=NULL);
/// read a typedef value
template <typename T>
bool read(T& v) { return read((unsigned char*)(&v),sizeof(T)); }
/// read an array of typed values
template <typename T>
bool read_array(T* a, unsigned int n) { return read((unsigned char*)a,sizeof(T)*n); }
/// write a typedef value
template <typename T>
bool write(const T& v) { return write((const unsigned char*)(&v),sizeof(T)); }
/// write an array of typed values
template <typename T>
bool write_array(const T* a, unsigned int n) { return write((const unsigned char*)a,sizeof(T)*n); }
//set the file pointer to index (position in bytes from the beginning of the file)
bool seek(long long index);
///return the position of the file pointer in bytes
long long position();
};
}
}
#include <cgv/config/lib_end.h>