simdisk_file.h

/***************************************************************************
 *  include/stxxl/bits/io/simdisk_file.h
 *
 *  Part of the STXXL. See http://stxxl.sourceforge.net
 *
 *  Copyright (C) 2002-2003 Roman Dementiev <[email protected]>
 *
 *  Distributed under the Boost Software License, Version 1.0.
 *  (See accompanying file LICENSE_1_0.txt or copy at
 *  http://www.boost.org/LICENSE_1_0.txt)
 **************************************************************************/

#ifndef STXXL_SIMDISK_FILE_HEADER
#define STXXL_SIMDISK_FILE_HEADER

#ifndef STXXL_HAVE_SIMDISK_FILE
#ifdef STXXL_BOOST_CONFIG
 #include <boost/config.hpp>
#endif

#ifndef BOOST_MSVC
// mmap call does not exist in Windows
 #define STXXL_HAVE_SIMDISK_FILE 1
#else
 #define STXXL_HAVE_SIMDISK_FILE 0
#endif
#endif

#if STXXL_HAVE_SIMDISK_FILE

#include <set>
#include <cmath>
#include <sys/mman.h>

#include <stxxl/bits/io/ufs_file_base.h>
#include <stxxl/bits/io/disk_queued_file.h>


__STXXL_BEGIN_NAMESPACE


 #define AVERAGE_SPEED (15 * 1024 * 1024)

class DiskGeometry : private noncopyable
{
    struct Zone
    {
        // manufactured data
#if 0
        int last_cyl;
        int sect_per_track;
#endif
        // derived data
        int first_sector;
        int sectors;
        double sustained_data_rate;  // in MiB/s
        inline Zone(int _first_sector) : first_sector(_first_sector)
        { }                          // constructor for zone search

        inline Zone(
#if 0
            int _last_cyl,
            int _sect_per_track,
#endif
            int _first_sector,
            int _sectors,
            double _rate) :
#if 0
            last_cyl(_last_cyl),
            sect_per_track(_sect_per_track),
#endif
            first_sector(_first_sector),
            sectors(_sectors),
            sustained_data_rate(_rate)
        { }
    };
    struct ZoneCmp
    {
        inline bool operator () (const Zone & a, const Zone & b) const
        {
            return a.first_sector < b.first_sector;
        }
    };

protected:
    int nsurfaces;
    int bytes_per_sector;
    double cmd_ovh;                     // in s
    double seek_time;                   // in s
    double rot_latency;                 // in s
    double head_switch_time;            // in s
    double cyl_switch_time;             // in s
    double revolution_time;             // in s
    double interface_speed;             // in byte/s
    std::set<Zone, ZoneCmp> zones;

    void add_zone(int & first_cyl, int last_cyl,
                  int sec_per_track, int & first_sect);

public:
    inline DiskGeometry()
    { }
    double get_delay(file::offset_type offset, file::size_type size);                // returns delay in s

    inline ~DiskGeometry()
    { }
};


class IC35L080AVVA07 : public DiskGeometry              // IBM series 120GXP
{
public:
    IC35L080AVVA07();
};

class sim_disk_file : public ufs_file_base, public disk_queued_file, public IC35L080AVVA07
{
public:
    inline sim_disk_file(const std::string & filename, int mode, int queue_id = DEFAULT_QUEUE, int allocator_id = NO_ALLOCATOR) : ufs_file_base(filename, mode), disk_queued_file(queue_id, allocator_id)
    {
        std::cout << "Please, make sure that '" << filename <<
        "' is resided on swap memory partition!" <<
        std::endl;
    }
    void serve(const request * req) throw (io_error);
    void set_size(offset_type newsize);
    const char * io_type() const;
};


__STXXL_END_NAMESPACE

#endif  // #if STXXL_HAVE_SIMDISK_FILE

#endif  // !STXXL_SIMDISK_FILE_HEADER