WrapIStreamBufferImpl.h

#ifndef __PBIO_API__PBIO__STL_WRAPS_IMPLS__WRAP_ISTREAM_BUFFER_IMPL_H_
#define __PBIO_API__PBIO__STL_WRAPS_IMPLS__WRAP_ISTREAM_BUFFER_IMPL_H_



#include <cstring>
#include <istream>

#include "pbio/stl_wraps/WrapIStream.h"

namespace pbio
{
namespace stl_wraps
{

class WrapIStreamBufferImpl : public WrapIStream
{
public:
    WrapIStreamBufferImpl(
        const char* const data,
        const int size):
        _data(data),
        _size(size),
        _pos(0)
    {
        // nothing else
    }

    virtual void read(char* buf, uint64_t size)
    {
        const uint64_t copy_size = std::min<uint64_t>(size, _size - _pos);

        if(copy_size > 0)
        {
            memcpy(buf, _data + _pos, copy_size);
            _pos += copy_size;
        }

        if(size > copy_size)
        {
            memset(buf + copy_size, 0, size - copy_size);
        }
    }

private:

    const char* const _data;
    const int _size;
    int _pos;

};

}  // stl_wraps namespace
}  // pbio namespace


#endif  // __PBIO_API__PBIO__STL_WRAPS_IMPLS__WRAP_ISTREAM_BUFFER_IMPL_H_