decode.h

// :mode=c++:
/*
decode.h - c++ wrapper for a base64 decoding algorithm

This is part of the libb64 project, and has been placed in the public domain.
For details, see http://sourceforge.net/projects/libb64
*/
#ifndef BASE64_DECODE_H
#define BASE64_DECODE_H

#define BUFFERSIZE 16777216

#include <iostream>

namespace base64
{
    extern "C"
    {
        #include "cdecode.h"
    }

    struct decoder
    {
        base64_decodestate _state;
        int _buffersize;

        decoder(int buffersize_in = BUFFERSIZE)
        : _buffersize(buffersize_in)
        {}

        int decode(char value_in)
        {
            return base64_decode_value(value_in);
        }

        int decode(const char* code_in, const int length_in, char* plaintext_out)
        {
            return base64_decode_block(code_in, length_in, plaintext_out, &_state);
        }

        void decode(std::istream& istream_in, std::ostream& ostream_in)
        {
            base64_init_decodestate(&_state);
            //
            const int N = _buffersize;
            char* code = new char[N];
            char* plaintext = new char[N];
            int codelength;
            int plainlength;

            do
            {
                istream_in.read((char*)code, N);
                codelength = istream_in.gcount();
                plainlength = decode(code, codelength, plaintext);
                ostream_in.write((const char*)plaintext, plainlength);
            }
            while (istream_in.good() && codelength > 0);
            //
            base64_init_decodestate(&_state);

            delete [] code;
            delete [] plaintext;
        }
    };

} // namespace base64



#endif // BASE64_DECODE_H