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#ifndef LPC_MEMPOOL_H1103129409_INCLUDE_GUARD_
#define LPC_MEMPOOL_H1103129409_INCLUDE_GUARD_
/* This file is part of indexlib.
* Copyright (C) 2005 Luís Pedro Coelho <[email protected]>
*
* Indexlib is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation and available as file
* GPL_V2 which is distributed along with indexlib.
*
* Indexlib 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of this program with any edition of
* the Qt library by Trolltech AS, Norway (or with modified versions
* of Qt that use the same license as Qt), and distribute linked
* combinations including the two. You must obey the GNU General
* Public License in all respects for all of the code used other than
* Qt. If you modify this file, you may extend this exception to
* your version of the file, but you are not obligated to do so. If
* you do not wish to do so, delete this exception statement from
* your version.
*/
#include "memreference.h"
#include "manager.h"
#include "memreference.h"
#include "thing.h"
#include <cassert>
#include <vector>
#include <memory>
#include <algorithm>
#include <iostream>
/**
* @short implement memory management for things
*
* This class implements memory management for pools of things.
* It uses a simple linked list memory management algorithm and
* it depends on being supplied the right trait for the type held.
*/
template <typename Traits>
struct mempool /* : boost::noncopyable */ {
public:
typedef Traits traits_type;
typedef typename traits_type::value_type data_type;
typedef typename traits_type::pointer data_typeptr;
explicit mempool( std::auto_ptr<memory_manager> source );
/**
* Returns a memory block of size \param s.
* Analogous to malloc()
*/
data_typeptr allocate( unsigned s );
/**
* Makes the memory pointed to by \param p of size \s or allocates a new block of size \s
* and moves the held data.
*
* Analogous to realloc()
* Unlike realloc(), does not support either reallocate( 0, s ) nor reallocate( p, 0 )
*/
data_typeptr reallocate( data_typeptr, unsigned );
/** Releases the memory pointed to by \param p
* Analogous to free()
*/
void deallocate( data_typeptr p );
/** Prints a half-readable description to \param out
* Mainly for debugging
*/
void print( std::ostream& out ) const;
/**
* How big (in bytes) is the memory managed?
*/
unsigned size() const { return manager_->size(); }
private:
/**
* Basically int( log_2( min( x + 1, min_size() ) ) )
*/
static unsigned order_of( unsigned x ) {
assert( x > 0 );
if ( x < traits_type::min_size() ) x = traits_type::min_size();
--x;
unsigned res = 0;
while ( x ) {
++res;
x >>= 1;
}
return res;
}
/**
* @returns order^2
*/
static unsigned order_to_size( unsigned order ) {
return 1 << order;
}
static unsigned size_of( data_typeptr data ) {
return traits_type::size_of( data );
}
enum { min_order_for_free_node = 4 };
friend struct list_node_manager;
struct list_node_manager {
protected:
const mempool* parent_;
public:
explicit list_node_manager( const mempool* p = 0 ):parent_( p ) {}
void* rw_base( unsigned idx ) const {
return parent_->manager_->rw_base( idx );
}
const void* ronly_base( unsigned idx ) const {
return parent_->manager_->ronly_base( idx );
}
};
START_THING( list_node, thing<list_node_manager> )
void set_parent( const mempool* p ) { this->parent_ = p; }
MEMBER( uint16_t, order, 0 )
MEMBER( uint32_t, next, 2 )
MEMBER( uint32_t, prev, 6 )
END_THING( list_node )
list_nodeptr get_node( uint32_t p ) const;
/**
* Get the free list header for a given order
*/
memory_reference<uint32_t> free_list( unsigned order );
uint32_t free_list( unsigned order ) const {
return const_cast<mempool*>( this )->free_list( order );
}
void insert_into_list( uint32_t where, unsigned order );
void remove_from_list( uint32_t where, unsigned order );
void break_up( uint32_t where );
void init_memory();
void fill_into_list( unsigned old_size );
void fill_into_list( unsigned old_size, unsigned order );
bool join( data_typeptr&, unsigned order );
void deallocate( data_typeptr, unsigned order );
std::auto_ptr<memory_manager> manager_;
memory_reference<uint32_t> max_order_;
};
#include "mempool.tcc"
#endif /* LPC_MEMPOOL_H1103129409_INCLUDE_GUARD_ */
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