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FBwBlobStream.h

#include <iostream>
#include <fstream>
#include <iomanip>
#include <FBwBlob.h>

namespace fbwrap
{

using std::basic_streambuf;
using std::char_traits;


template <typename _CharT, typename _Traits=char_traits<_CharT> >
class  basic_blobbuf : public basic_streambuf<_CharT,_Traits>
{
public:
    typedef _CharT  char_type;
    typedef typename _Traits::int_type  int_type;
    typedef typename _Traits::pos_type  pos_type;
    typedef typename _Traits::off_type  off_type;
private:
    char_type *buffer;
    int buffer_size;
    FBwBlob *blb;
public:
    // Constructor
    basic_blobbuf(FBwBlob *b int size=2048) :
            basic_streambuf<_CharT,_Traits>()
    {
        buffer_size=(size > b->Size())?size:b->Size();
        buffer = new char_type[buffer_size];
        blb=b;
        setp(buffer,buffer+buffer_size);
    }
protected:
    virtual int_type underflow()
    {
        // refill the buffer
        int avail=buffer_size;
        while(aval>=buffer_size)
        {
            int nLen=b->ReadSegment();

            
        setg(buffer,buffer,buffer+i);
        return ret;
    }
    virtual int_type overflow(int_type c)
    {
        char_type *p=pbase();
        while(p<pptr())
        {
            cout << *p++;
        }
        if(!_Traits::eq_int_type(c,_Traits::eof()))
            cout << _Traits::to_char_type(c);
        setp(buffer,buffer+32);
    }
    virtual ~basic_seqbuf()
    {
        if( pptr()>pbase() )
            overflow(_Traits::eof());
        delete[] buffer;
    }
};

template <typename _CharT, typename _Traits=char_traits<_CharT> >
class seq_istream : public basic_istream<_CharT,_Traits>
{
public:
    seq_istream(_CharT limit):
            basic_istream<_CharT,_Traits>(new basic_seqbuf<_CharT,_Traits>(limit))
    {
    }
    virtual ~seq_istream()
    {
        delete rdbuf();
    }
};
template <typename _CharT, typename _Traits=char_traits<_CharT> >
class seq_ostream : public basic_ostream<_CharT,_Traits>
{
public:
    typedef basic_seqbuf<_CharT,_Traits> seqbuf_type;
    seq_ostream(_CharT limit):
            basic_ostream<_CharT,_Traits>(new basic_seqbuf<_CharT,_Traits>(limit))
    {
    }
    virtual ~seq_ostream()
    {
        delete rdbuf();
    }
    void flush()
    {
        seqbuf_type *buf= static_cast<seqbuf_type *>(rdbuf());
        buf->overflow(_Traits::eof());
    }
};

int main()
{
    seq_istream<char> char_seq('z');
    cout << "Testing file bufs" << endl;
    char c;
    cout << "Inicio" << endl;
    for(char_seq >> c;!char_seq.eof();char_seq >> c)
    {
        cout << c;
    }
    cout << endl;
    cout << "FIN DE ARCHIVO" << endl;
    cout << "Probando archivo de salida" << endl;
    seq_ostream<char> oseq('z');
    for(int i=0; i<65;i++)
    {
        oseq << i;
        if( (i%4)==0 )
            oseq << endl;
        else
            oseq << ',';
    }
    oseq.flush();
    return 0;
}

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