vide_public/external/healpix/cxxsupport/bstream.h
2012-10-30 13:56:48 -04:00

266 lines
7.3 KiB
C++

/*
* This file is part of libcxxsupport.
*
* libcxxsupport 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; either version 2 of the License, or
* (at your option) any later version.
*
* libcxxsupport 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 libcxxsupport; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* libcxxsupport is being developed at the Max-Planck-Institut fuer Astrophysik
* and financially supported by the Deutsches Zentrum fuer Luft- und Raumfahrt
* (DLR).
*/
/*! \file bstream.h
* Classes for binary I/O with streams
*
* Copyright (C) 2010 Max-Planck-Society
* \author Martin Reinecke
*/
#ifndef PLANCK_BSTREAM_H
#define PLANCK_BSTREAM_H
#include <iostream>
#include <fstream>
#include <algorithm>
#include "datatypes.h"
/*! An object of this class can be cast to a \a bool, which indicates whether
the computer architecture is big-endian (true) or little-endian (false). */
class EndianTest__
{
private:
bool big_end;
public:
EndianTest__()
{
union { uint16 i16; uint8 i8; } tmp;
tmp.i16 = 1;
big_end = (tmp.i8==0);
}
operator bool() const { return big_end; }
};
const EndianTest__ big_endian;
template<size_t size> inline void byteswap_helper__ (char *);
template<> inline void byteswap_helper__<1> (char *)
{}
template<> inline void byteswap_helper__<2> (char *val)
{
using namespace std;
swap (val[0],val[1]);
}
template<> inline void byteswap_helper__<4> (char *val)
{
using namespace std;
swap (val[0],val[3]); swap (val[1],val[2]);
}
template<> inline void byteswap_helper__<8> (char *val)
{
using namespace std;
swap (val[0],val[7]); swap (val[1],val[6]);
swap (val[2],val[5]); swap (val[3],val[4]);
}
/*! Performs an endianness conversion on \a val.
\note \a T must be a primitive data type! */
template<typename T> inline void byteswap (T &val)
{ byteswap_helper__<sizeof(T)> (reinterpret_cast<char *> (&val)); }
const bool file_is_lsb=big_endian, file_is_msb=!big_endian,
file_is_natural=false;
/*! Class for writing binary data to a stream. */
class bostream
{
private:
std::ostream &s;
bool doswap;
public:
/*! Creates a new object which is attached to \a s_ and performs
endianness conversion if \a doswap_==true. */
bostream (std::ostream &s_, bool doswap_=false)
: s(s_), doswap(doswap_) {}
/*! Writes a binary representation of \a num objects of type \a T
(stored in \a data) to the attached stream. Endianness conversion
is performed if requested in the constructor.
\note \a T must be a primitive data type! */
template<typename T> bostream &put (const T *data, size_t num)
{
if ((sizeof(T)>1) && doswap)
for (size_t m=0; m<num; ++m)
{
T tmp=data[m];
byteswap (tmp);
s.write (reinterpret_cast<const char *> (&tmp), sizeof(T));
}
else
s.write (reinterpret_cast<const char *> (data), num*sizeof(T));
return *this;
}
/*! Writes a binary representation of \a data to the attached stream.
Endianness conversion is performed if requested in the constructor.
\note \a T must be a primitive data type! */
template<typename T> bostream &operator<< (const T &data)
{
put(&data,1);
return *this;
}
bool getSwap() const
{ return doswap; }
void setSwap(bool newswap)
{ doswap=newswap; }
void flipSwap()
{ doswap=!doswap; }
};
/*! Class for reading binary data from a stream. */
class bistream
{
private:
std::istream &s;
bool doswap;
public:
/*! Creates a new object which is attached to \a s_ and performs
endianness conversion if \a doswap_==true. */
bistream (std::istream &s_, bool doswap_=false)
: s(s_), doswap(doswap_) {}
/*! Reads a binary representation of \a num objects of type \a T
from the attached stream and stores them in \a data. Endianness
conversion is performed if requested in the constructor.
\note \a T must be a primitive data type! */
template<typename T> bistream &get (T *data, size_t num)
{
s.read (reinterpret_cast<char *> (data), num*sizeof(T));
if ((sizeof(T)>1) && doswap)
for (size_t m=0; m<num; ++m)
byteswap (data[m]);
return *this;
}
/*! Reads a binary representation of \a data from the attached stream.
Endianness conversion is performed if requested in the constructor.
\note \a T must be a primitive data type! */
template<typename T> bistream &operator>> (T &data)
{
get (&data,1);
return *this;
}
bool getSwap() const
{ return doswap; }
void setSwap(bool newswap)
{ doswap=newswap; }
void flipSwap()
{ doswap=!doswap; }
};
class bofstream: public std::ofstream
{
private:
bool doswap;
public:
/*! */
bofstream (const char *fname, bool doswap_)
: std::ofstream(fname,std::ios::binary), doswap(doswap_) {}
template<typename T> bofstream &operator<< (const T &data)
{
if (doswap)
{
T tmp = data;
byteswap (tmp);
write (reinterpret_cast<const char *> (&tmp), sizeof(T));
}
else
write (reinterpret_cast<const char *> (&data), sizeof(T));
return *this;
}
template<typename T> bofstream &put (const T *data, size_t num)
{
if (doswap)
for (size_t m=0; m<num; ++m)
{
T tmp=data[m];
byteswap (tmp);
write (reinterpret_cast<const char *> (&tmp), sizeof(T));
}
else
write (reinterpret_cast<const char *> (data), num*sizeof(T));
return *this;
}
bool getSwap() const
{ return doswap; }
void setSwap(bool newswap)
{ doswap=newswap; }
void flipSwap()
{ doswap=!doswap; }
};
class bifstream: public std::ifstream
{
private:
bool doswap;
public:
/*! */
bifstream ()
: doswap(false) {}
bifstream (const char *fname, bool doswap_)
: std::ifstream(fname,std::ios::binary), doswap(doswap_) {}
void open (const char *fname, bool doswap_)
{
doswap=doswap_;
std::ifstream::open(fname,std::ios::binary);
}
template<typename T> bifstream &operator>> (T &data)
{
read (reinterpret_cast<char *> (&data), sizeof(T));
if (doswap) byteswap (data);
return *this;
}
template<typename T> bifstream &get (T *data, size_t num)
{
read (reinterpret_cast<char *> (data), num*sizeof(T));
if (doswap)
for (size_t m=0; m<num; ++m)
byteswap (data[m]);
return *this;
}
void rewind()
{ seekg(0,std::ios::beg); }
void skip(std::streamoff nbytes)
{ seekg(nbytes,std::ios::cur); }
bool getSwap() const
{ return doswap; }
void setSwap(bool newswap)
{ doswap=newswap; }
void flipSwap()
{ doswap=!doswap; }
};
#endif