#ifndef _XGBOOST_STREAM_H_
#define _XGBOOST_STREAM_H_

#include <cstdio>
/*!
 * \file xgboost_stream.h
 * \brief general stream interface for serialization
 * \author Tianqi Chen: tianqi.tchen@gmail.com
 */
namespace xgboost{
    namespace utils{
        /*! \brief interface of stream I/O, used to serialize model */
        class IStream{
        public:
            /*! 
             * \brief read data from stream
             * \param ptr pointer to memory buffer
             * \param size size of block
             * \return usually is the size of data readed
             */
            virtual size_t Read( void *ptr, size_t size ) = 0;        
            /*! 
             * \brief write data to stream
             * \param ptr pointer to memory buffer
             * \param size size of block
             */
            virtual void Write( const void *ptr, size_t size ) = 0;
            /*! \brief virtual destructor */
            virtual ~IStream( void ){}
        };

        /*! \brief implementation of file i/o stream */
        class FileStream: public IStream{
        private:
            FILE *fp;
        public:        
            FileStream( FILE *fp ){
                this->fp = fp;
            }
            virtual size_t Read( void *ptr, size_t size ){
                return fread( ptr, size, 1, fp );
            }
            virtual void Write( const void *ptr, size_t size ){
                fwrite( ptr, size, 1, fp );
            }
            inline void Close( void ){
                fclose( fp );
            }
        };
    };
};
#endif