Chunk.h

/******************************************************************************
 *
 *  This file is part of the Data Logging Service (DLS).
 *
 *  DLS is free software: you can redistribute it and/or modify it under the
 *  terms of the GNU General Public License as published by the Free Software
 *  Foundation, either version 3 of the License, or (at your option) any later
 *  version.
 *
 *  DLS is distributed in the hope that it will be useful, but WITHOUT ANY
 *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 *  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 *  details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with DLS. If not, see <http://www.gnu.org/licenses/>.
 *
 *****************************************************************************/

#ifndef LibDLSChunkH
#define LibDLSChunkH

/*****************************************************************************/

#include <string>

#include "Exception.h"
#include "Time.h"
#include "Data.h"
#include "globals.h"

/*****************************************************************************/

namespace DlsProto {
    class ChunkInfo;
}

namespace LibDLS {

/*****************************************************************************/

template <class T> class IndexT;
class File;
template <class T> class CompressionT;
class XmlTag;

/*****************************************************************************/

typedef int (*DataCallback)(Data *, void *);

/*************************************************************************/

class DLS_PUBLIC ChunkException:
    public Exception
{
    public:
        ChunkException(const std::string &pmsg):
            Exception(pmsg) {};
};

/*************************************************************************/

class DLS_PUBLIC Chunk
{
    public:
        Chunk();
        Chunk(const DlsProto::ChunkInfo &, ChannelType);
        virtual ~Chunk();

        void import(const std::string &, ChannelType);
        void preload(const std::string &, ChannelType, Time, Time);
        void fetch_range();

        Time start() const { return _start; }
        Time end() const { return _end; }
        bool incomplete() const { return _incomplete; }

        void fetch_data(Time, Time, unsigned int,
                DataCallback, void *,
                unsigned int);

        bool operator<(const Chunk &) const;
        bool operator==(const Chunk &) const;

        void set_chunk_info(DlsProto::ChunkInfo *) const;
        void update_from_chunk_info(const DlsProto::ChunkInfo &);

#ifdef DEBUG_TIMING
        static void reset_timing();
        static void output_timing();
#endif

    protected:
        std::string _dir; 
        double _sample_frequency; 
        unsigned int _meta_reduction; 
        int _format_index; 
        unsigned int _mdct_block_size; 
        Time _start; 
        Time _end; 
        ChannelType _type; 
        bool _incomplete; 
        enum LoadState {
            Empty,
            Pre,
            Full
        } _load_state;

        unsigned int _calc_optimal_level(Time, Time, unsigned int) const;
        Time _time_per_value(unsigned int) const;

        void _fetch_level_data_wrapper(Time, Time,
                MetaType,
                unsigned int,
                Time,
                Data **,
                DataCallback,
                void *,
                unsigned int,
                unsigned int &,
                Time &) const;

        template <class T>
            void _fetch_level_data(Time, Time,
                    MetaType,
                    unsigned int,
                    Time,
                    Data **,
                    DataCallback,
                    void *,
                    unsigned int,
                    unsigned int &,
                    Time &) const;

        template <class T>
            bool _read_tag(
                    IndexT<IndexRecord> &,
                    unsigned int,
                    IndexRecord &,
                    IndexRecord &,
                    bool &,
                    File &,
                    CompressionT<T> *,
                    MetaType,
                    unsigned int,
                    Time,
                    Data **,
                    DataCallback,
                    void *,
                    unsigned int,
                    unsigned int &,
                    Time &
                    ) const;

        template <class T>
            void _process_data_tag(const XmlTag *,
                    Time,
                    MetaType,
                    unsigned int,
                    Time,
                    CompressionT<T> *,
                    Data **,
                    DataCallback,
                    void *,
                    unsigned int,
                    unsigned int &,
                    Time &) const;
};

/*****************************************************************************/

} // namespace

/*****************************************************************************/

#endif