ebyedataheader.hpp

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#ifndef H_POTTU_EBYEDATAHEADER
#define H_POTTU_EBYEDATAHEADER
 
 
#include <cstdint>
#include <cstring>
#include <cctype>
#include <iostream>
 
namespace pottu {
 
    struct ebyedataheader_t
    {
    char     id[8];
    uint32_t sequence;
    uint16_t stream;
    uint16_t tape;
    uint16_t myEndian;
    uint16_t dataEndian;
    uint32_t dataLen;
 
    
    static ebyedataheader_t createFromMemory( const char *p ) noexcept {
        ebyedataheader_t ret;
        if( sizeof(ebyedataheader_t) == 24 ) {
        // Faster version. It is very likely that this is the one
        // most compilers will do.
        std::memcpy( (void *)&ret, p, 24 );
        } else {
        // Support for unusual memory layout
        std::memcpy( &ret.id,         (const char *)p +  0, 8 );
        std::memcpy( &ret.sequence,   (const char *)p +  8, 4 );
        std::memcpy( &ret.stream,     (const char *)p + 12, 2 );
        std::memcpy( &ret.tape,       (const char *)p + 14, 2 );
        std::memcpy( &ret.myEndian,   (const char *)p + 16, 2 );
        std::memcpy( &ret.dataEndian, (const char *)p + 18, 2 );
        std::memcpy( &ret.dataLen,    (const char *)p + 20, 4 );
        }
        return ret;
    }
 
    
    friend std::ostream &operator<<(std::ostream &os, const ebyedataheader_t &h) {
        os << "(";
 
        for( int i = 0; i < 8; ++i ) {
        os << (int)h.id[i] << "\"";
        if( isascii( h.id[i] ) )
            os << h.id[i];
        os << "\" ";
        }
        
        os << h.sequence << ","
           << h.stream << ","
           << h.tape << ","
           << h.myEndian << ","
           << h.dataEndian << ","
           << h.dataLen << ")";
        return (os);
    }
 
    
    bool isValid() const noexcept {
        return stream == 1 && myEndian == 1 && dataEndian == 1
        && strncmp((const char *)&id, "EBYEDATA", 8) == 0;
    }
    };
 
 
}
 
    
#endif