#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