simdisk_file.h

Go to the documentation of this file.

/***************************************************************************
 * include/stxxl/bits/io/simdisk_file.h
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2002-2003 Roman Dementiev <[email protected]>
 * Copyright (C) 2008 Andreas Beckmann <[email protected]>
 * Copyright (C) 2009 Johannes Singler <[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_IO_SIMDISK_FILE_HEADER
#define STXXL_IO_SIMDISK_FILE_HEADER

#include <stxxl/bits/config.h>

#ifndef STXXL_HAVE_SIMDISK_FILE
// use mmap call
#define STXXL_HAVE_SIMDISK_FILE STXXL_HAVE_MMAP_FILE
#endif

#if STXXL_HAVE_SIMDISK_FILE

#include <set>
#include <cmath>

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


STXXL_BEGIN_NAMESPACE

//! \weakgroup fileimpl
//! \{

 #define AVERAGE_SPEED (15 * 1024 * 1024)

class simdisk_geometry : 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 simdisk_geometry()
 { }
 double get_delay(file::offset_type offset, file::size_type size); // returns delay in s

 inline ~simdisk_geometry()
 { }
};


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

//! Implementation of disk emulation.
//! \remark It is emulation of IBM IC35L080AVVA07 disk's timings
class sim_disk_file : public ufs_file_base, public disk_queued_file, public IC35L080AVVA07
{
public:
 //! Constructs file object.
 //! \param filename path of file
 //! \attention filename must be resided at memory disk partition
 //! \param mode open mode, see \c stxxl::file::open_modes
 //! \param queue_id disk queue identifier
 //! \param allocator_id linked disk_allocator
 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_IO_SIMDISK_FILE_HEADER