block_manager.h

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/***************************************************************************
 * include/stxxl/bits/mng/block_manager.h
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2002-2007 Roman Dementiev <[email protected]>
 * Copyright (C) 2007, 2009 Johannes Singler <[email protected]>
 * Copyright (C) 2008-2010 Andreas Beckmann <[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_MNG_BLOCK_MANAGER_HEADER
#define STXXL_MNG_BLOCK_MANAGER_HEADER

#include <stxxl/bits/config.h>

#include <memory>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <map>
#include <algorithm>
#include <string>
#include <cstdlib>

#if STXXL_MSVC
#include <memory.h>
#endif

#include <stxxl/bits/defines.h>
#include <stxxl/bits/deprecated.h>
#include <stxxl/bits/io/request.h>
#include <stxxl/bits/io/file.h>
#include <stxxl/bits/io/create_file.h>
#include <stxxl/bits/noncopyable.h>
#include <stxxl/bits/singleton.h>
#include <stxxl/bits/mng/bid.h>
#include <stxxl/bits/mng/disk_allocator.h>
#include <stxxl/bits/mng/block_alloc.h>
#include <stxxl/bits/mng/config.h>
#include <stxxl/bits/common/utils.h>
#include <stxxl/bits/common/simple_vector.h>

STXXL_BEGIN_NAMESPACE

#ifndef STXXL_MNG_COUNT_ALLOCATION
#define STXXL_MNG_COUNT_ALLOCATION 1
#endif // STXXL_MNG_COUNT_ALLOCATION

//! \defgroup mnglayer Block Management Layer
//! Group of classes which help controlling external memory space,
//! managing disks, and allocating and deallocating blocks of external storage
//! \{

//! Block manager class.
//!
//! Manages allocation and deallocation of blocks in multiple/single disk setting
//! \remarks is a singleton
class block_manager : public singleton<block_manager>
{
 friend class singleton<block_manager>;

 disk_allocator** disk_allocators;
 file** disk_files;

 size_t ndisks;
 block_manager();

#if STXXL_MNG_COUNT_ALLOCATION
 //! total requested allocation in bytes
 uint64 m_total_allocation;

 //! currently allocated bytes
 uint64 m_current_allocation;

 //! maximum number of bytes allocated during program run.
 uint64 m_maximum_allocation;
#endif // STXXL_MNG_COUNT_ALLOCATION

protected:
 template <class BIDType, class DiskAssignFunctor, class BIDIteratorClass>
 void new_blocks_int(
 const unsigned_type nblocks,
 const DiskAssignFunctor& functor,
 unsigned_type offset,
 BIDIteratorClass out);

public:
 //! return total number of bytes available in all disks
 uint64 get_total_bytes() const;

 //! Return total number of free disk allocations
 uint64 get_free_bytes() const;

 //! Allocates new blocks.
 //!
 //! Allocates new blocks according to the strategy
 //! given by \b functor and stores block identifiers
 //! to the range [ \b bidbegin, \b bidend)
 //! Allocation will be lined up with previous partial allocations
 //! of \b offset blocks.
 //! \param functor object of model of \b allocation_strategy concept
 //! \param bidbegin bidirectional BID iterator object
 //! \param bidend bidirectional BID iterator object
 //! \param offset advance for \b functor to line up partial allocations
 template <class DiskAssignFunctor, class BIDIteratorClass>
 void new_blocks(
 const DiskAssignFunctor& functor,
 BIDIteratorClass bidbegin,
 BIDIteratorClass bidend,
 unsigned_type offset = 0)
 {
 typedef typename std::iterator_traits<BIDIteratorClass>::value_type bid_type;
 new_blocks_int<bid_type>(std::distance(bidbegin, bidend), functor, offset, bidbegin);
 }

 //! Allocates new blocks according to the strategy
 //! given by \b functor and stores block identifiers
 //! to the output iterator \b out
 //! Allocation will be lined up with previous partial allocations
 //! of \b offset blocks.
 //! \param nblocks the number of blocks to allocate
 //! \param functor object of model of \b allocation_strategy concept
 //! \param out iterator object of OutputIterator concept
 //! \param offset advance for \b functor to line up partial allocations
 //!
 //! The \c BlockType template parameter defines the type of block to allocate
 template <class BlockType, class DiskAssignFunctor, class BIDIteratorClass>
 void new_blocks(
 const unsigned_type nblocks,
 const DiskAssignFunctor& functor,
 BIDIteratorClass out,
 unsigned_type offset = 0)
 {
 typedef typename BlockType::bid_type bid_type;
 new_blocks_int<bid_type>(nblocks, functor, offset, out);
 }

 //! Allocates a new block according to the strategy
 //! given by \b functor and stores the block identifier
 //! to bid.
 //! Allocation will be lined up with previous partial allocations
 //! of \b offset blocks.
 //! \param functor object of model of \b allocation_strategy concept
 //! \param bid BID to store the block identifier
 //! \param offset advance for \b functor to line up partial allocations
 template <typename DiskAssignFunctor, unsigned BLK_SIZE>
 void new_block(const DiskAssignFunctor& functor, BID<BLK_SIZE>& bid, unsigned_type offset = 0)
 {
 new_blocks_int<BID<BLK_SIZE> >(1, functor, offset, &bid);
 }

 //! Deallocates blocks.
 //!
 //! Deallocates blocks in the range [ \b bidbegin, \b bidend)
 //! \param bidbegin iterator object of \b bid_iterator concept
 //! \param bidend iterator object of \b bid_iterator concept
 template <class BIDIteratorClass>
 void delete_blocks(const BIDIteratorClass& bidbegin, const BIDIteratorClass& bidend);

 //! Deallocates a block.
 //! \param bid block identifier
 template <unsigned BLK_SIZE>
 void delete_block(const BID<BLK_SIZE>& bid);

 ~block_manager();

#if STXXL_MNG_COUNT_ALLOCATION
 //! return total requested allocation in bytes
 uint64 get_total_allocation() const
 { return m_total_allocation; }

 //! return currently allocated bytes
 uint64 get_current_allocation() const
 { return m_current_allocation; }

 //! return maximum number of bytes allocated during program run.
 uint64 get_maximum_allocation() const
 { return m_maximum_allocation; }
#endif // STXXL_MNG_COUNT_ALLOCATION
};


template <class BIDType, class DiskAssignFunctor, class OutputIterator>
void block_manager::new_blocks_int(
 const unsigned_type nblocks,
 const DiskAssignFunctor& functor,
 unsigned_type offset,
 OutputIterator out)
{
 typedef BIDType bid_type;
 typedef BIDArray<bid_type::t_size> bid_array_type;

 simple_vector<int_type> bl(ndisks);
 simple_vector<bid_array_type> disk_bids(ndisks);
 simple_vector<file*> disk_ptrs(nblocks);

 bl.memzero();

 for (unsigned_type i = 0; i < nblocks; ++i)
 {
 unsigned_type disk = functor(offset + i);
 disk_ptrs[i] = disk_files[disk];
 bl[disk]++;
 }

 for (unsigned_type i = 0; i < ndisks; ++i)
 {
 if (bl[i])
 {
 disk_bids[i].resize(bl[i]);
 disk_allocators[i]->new_blocks(disk_bids[i]);
 }
 }

 bl.memzero();

 OutputIterator it = out;
 for (unsigned_type i = 0; i != nblocks; ++it, ++i)
 {
 const int disk = disk_ptrs[i]->get_allocator_id();
 bid_type bid(disk_ptrs[i], disk_bids[disk][bl[disk]++].offset);
 *it = bid;
 STXXL_VERBOSE_BLOCK_LIFE_CYCLE("BLC:new " << FMT_BID(bid));
 }

#if STXXL_MNG_COUNT_ALLOCATION
 m_total_allocation += nblocks * BIDType::size;
 m_current_allocation += nblocks * BIDType::size;
 m_maximum_allocation = STXXL_MAX(m_maximum_allocation, m_current_allocation);
#endif // STXXL_MNG_COUNT_ALLOCATION
}


template <unsigned BLK_SIZE>
void block_manager::delete_block(const BID<BLK_SIZE>& bid)
{
 // do not uncomment it
 //assert(bid.storage->get_allocator_id() < config::get_instance()->disks_number());
 if (!bid.is_managed())
 return; // self managed disk
 STXXL_VERBOSE_BLOCK_LIFE_CYCLE("BLC:delete " << FMT_BID(bid));
 assert(bid.storage->get_allocator_id() >= 0);
 disk_allocators[bid.storage->get_allocator_id()]->delete_block(bid);
 disk_files[bid.storage->get_allocator_id()]->discard(bid.offset, bid.size);

#if STXXL_MNG_COUNT_ALLOCATION
 m_current_allocation -= BLK_SIZE;
#endif // STXXL_MNG_COUNT_ALLOCATION
}


template <class BIDIteratorClass>
void block_manager::delete_blocks(
 const BIDIteratorClass& bidbegin,
 const BIDIteratorClass& bidend)
{
 for (BIDIteratorClass it = bidbegin; it != bidend; it++)
 {
 delete_block(*it);
 }
}

// in bytes
#ifndef STXXL_DEFAULT_BLOCK_SIZE
 #define STXXL_DEFAULT_BLOCK_SIZE(type) (2 * 1024 * 1024) // use traits
#endif

//! \}

STXXL_END_NAMESPACE

#endif // !STXXL_MNG_BLOCK_MANAGER_HEADER
// vim: et:ts=4:sw=4