stream.h

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/*****************************************************************************
* Multiscale Universal Interface Code Coupling Library                       *
*                                                                            *
* Copyright (C) 2019 Y. H. Tang, S. Kudo, X. Bian, Z. Li, G. E. Karniadakis  *
*                                                                            *
* This software is jointly licensed under the Apache License, Version 2.0    *
* and the GNU General Public License version 3, you may use it according     *
* to either.                                                                 *
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* ** Apache License, version 2.0 **                                          *
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* http://www.apache.org/licenses/LICENSE-2.0                                 *
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* ** GNU General Public License, version 3 **                                *
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*****************************************************************************/
 
#ifndef MUI_STREAM_H_
#define MUI_STREAM_H_
 
#include <memory>
#include <algorithm>
 
#include "../general/endian_traits.h"
 
namespace mui {
 
class istream {
public:
    virtual ~istream() {}
    virtual void read( char* ptr, std::size_t size ) = 0;
};
 
class ostream {
public:
    virtual ~ostream() {}
    virtual void write( const char* ptr, std::size_t size ) = 0;
};
 
class iostream : public istream, public ostream {
public:
    virtual ~iostream() {}
};
 
template<template<typename T, typename =std::allocator<T> > class Seq,
         typename Alloc=std::allocator<char> >
class container_stream: public iostream {
public:
    ~container_stream() {}
    void read( char* ptr, std::size_t size ){
        if( content.size() < size ) throw("");
        std::copy_n(content.begin(),size,ptr);
        content.erase(content.begin(),content.begin()+size);
    }
    void write( const char* ptr, std::size_t size ){
        content.insert(content.end(),ptr,ptr+size);
    }
    Seq<char,Alloc>& data() { return content; }
    const Seq<char,Alloc>& data() const { return content; }
private:
    Seq<char,Alloc> content;
};
 
/*
 * inputiterator_stream is a istream from InputIterator
 */
template<typename ConstInputIterator>
class iitr_stream: public istream {
public:
    iitr_stream( const iitr_stream& ) = default;
    iitr_stream( ConstInputIterator cur_ )
        : cur(cur_) {}
    ~iitr_stream() {}
    void read( char* ptr, std::size_t sz ) {
        std::copy_n(cur,sz,ptr);
        std::advance(cur,sz);
    }
 
    ConstInputIterator current() const { return cur; }
private:
    ConstInputIterator cur;
};
 
template<typename ConstInputIterator>
iitr_stream<ConstInputIterator> make_istream(ConstInputIterator begin)
{
    return iitr_stream<ConstInputIterator>(begin);
}
 
/*
 * outputiterator_stream is a ouput_stream to OutputIterator
 */
template<typename OutputIterator>
class oitr_stream: public ostream {
public:
    oitr_stream( const oitr_stream& ) = default;
    oitr_stream( OutputIterator begin ) : cur(begin) {}
    ~oitr_stream() {}
    void write( const char* ptr, std::size_t sz ) {
        cur = std::copy_n(ptr,sz,cur);
    }
 
    OutputIterator current() const { return cur; }
private:
    OutputIterator cur;
};
 
template<typename OutputIterator>
oitr_stream<OutputIterator> make_ostream(OutputIterator cur)
{
    return oitr_stream<OutputIterator>(cur);
}
 
/*
 * ocount_stream can be used for calculate the size of serialized data.
 */
class ocount_stream : public ostream {
public:
    ocount_stream(std::size_t off=0u) : sum(off) {}
    ~ocount_stream() {}
 
    std::size_t size() const { return sum; }
    void write( const char*, std::size_t size ) { sum += size; }
private:
    std::size_t sum;
};
 
inline std::size_t streamed_size() { return 0u; }
 
template<typename T, typename... Args>
std::size_t streamed_size( const T& a, const Args&... args )
{
    ocount_stream stream;
    stream << a;
    return stream.size() + streamed_size(args...);
}
 
  // Use SFINAE to enable this only for types we marked as not
  // requiring endian conversion
  template<typename T,
       typename std::enable_if<endian_traits<T>::convert == false>::type* = nullptr>
  istream& operator>>(istream& stream, T& dest) {
    stream.read(reinterpret_cast<char*>(&dest), sizeof(T));
    return stream;
  }
 
  // Use SFINAE to enable this only for types we marked as requiring
  // endian conversion
  template<typename T,
       typename std::enable_if<endian_traits<T>::convert == true>::type* = nullptr>
  istream& operator>>(istream& stream, T& dest) {
    detail::endian_converter<sizeof(T)> conv;
    stream.read(conv.data.buf, sizeof(T));
    conv.betoh();
    std::memcpy(reinterpret_cast<char*>(&dest),
        conv.data.buf, sizeof(T));
    return stream;
  }
 
  // Use SFINAE to enable this only for types we marked as not
  // requiring endian conversion
  template<typename T,
       typename std::enable_if<endian_traits<T>::convert == false>::type* = nullptr>
  ostream& operator<<(ostream& stream, const T& src) {
    stream.write(reinterpret_cast<const char*>(&src), sizeof(T));
    return stream;
  }
 
  // Use SFINAE to enable this only for types we marked as requiring
  // endian conversion
  template<typename T,
       typename std::enable_if<endian_traits<T>::convert == true>::type* = nullptr>
  ostream& operator<<(ostream& stream, const T& src) {
    detail::endian_converter<sizeof(T)> conv;
    std::memcpy(conv.data.buf,
        reinterpret_cast<const char*>(&src), sizeof(T));
    conv.htobe();
    stream.write(conv.data.buf, sizeof(T));
    return stream;
  }
 
template<typename F, typename S>
istream& operator>> ( istream& stream, std::pair<F,S>& pair )
{
    stream >> pair.first >> pair.second;
    return stream;
}
template<typename F, typename S>
ostream& operator<< ( ostream& stream, const std::pair<F,S>& pair )
{
    stream << pair.first << pair.second;
    return stream;
}
 
template<typename T>
istream& operator>> ( istream& stream, std::complex<T>& cx )
{
    T r, i;
    stream >> r >> i;
    cx.real(r);
    cx.imag(i);
    return stream;
}
template<typename T>
ostream& operator<< ( ostream& stream, const std::complex<T>& cx )
{
    stream << cx.real() << cx.imag();
    return stream;
}
 
}
 
#endif