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/******************************************************************************
IrstLM: IRST Language Model Toolkit
Copyright (C) 2006 Marcello Federico, ITC-irst Trento, Italy
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
******************************************************************************/
// An efficient memory manager
// by M. Federico
// Copyright Marcello Federico, ITC-irst, 1998
#ifndef MF_MEMPOOL_H
#define MF_MEMPOOL_H
#ifndef NULL
const int NULL=0;
#endif
#include <iostream> // std::ostream
//! Memory block
/*! This can be used by:
- mempool to store items of fixed size
- strstack to store strings of variable size
*/
class memnode{
friend class mempool; //!< grant access
friend class strstack; //!< grant access
char *block; //!< block of memory
memnode *next; //!< next block ptr
};
//! Memory pool
/*! A memory pool is composed of:
- a linked list of blocknum memory blocks
- each block might contain up to block_size items
- each item is made of exactly item_size bytes
*/
class mempool{
int block_size; //!< number of entries per block
int item_size; //!< number of bytes per entry
int true_size; //!< number of bytes per block
memnode* block_list; //!< list of blocks
char* free_list; //!< free entry list
int entries; //!< number of stored entries
int blocknum; //!< number of allocated blocks
public:
//! Creates a memory pool
mempool(int is, int bs);
//! Destroys memory pool
~mempool();
//! Prints a map of memory occupancy
void map(std::ostream& co);
//! Allocates a single memory entry
char *allocate();
//! Frees a single memory entry
int free(char* addr);
//! Prints statistics about this mempool
void stat();
//! Returns effectively used memory (bytes)
/*! includes 8 bytes required by each call of new */
int used(){return blocknum * (true_size + 8);};
//! Returns amount of wasted memory (bytes)
int wasted(){return used()-(entries * item_size);};
};
//! A stack to store strings
/*!
The stack is composed of
- a list of blocks memnode of fixed size
- attribute blocknum tells the block on top
- attribute idx tells position of the top string
*/
class strstack{
memnode* list; //!< list of memory blocks
int size; //!< size of each block
int idx; //!< index of last stored string
int waste; //!< current waste of memory
int memory; //!< current use of memory
int entries; //!< current number of stored strings
int blocknum; //!< current number of used blocks
public:
strstack(int bs=1000);
~strstack();
char *push(char *s);
char *pop();
char *top();
void stat();
int used(){return memory;}
int wasted(){return waste;}
};
//! Manage multiple memory pools
/*!
This class permits to manage memory pools
with items up to a specified size.
- items within the allowed range are stored in memory pools
- items larger than the limit are allocated with new
*/
class storage{
mempool **poolset; //!< array of memory pools
int setsize; //!< number of memory pools/maximum elem size
int poolsize; //!< size of each block
int newmemory; //!< stores amount of used memory
int newcalls; //!< stores number of allocated blocks
public:
//! Creates storage
storage(int maxsize,int blocksize);
//! Destroys storage
~storage();
//! Allocates memory
char *allocate(int size);
//! Realloc memory
char *reallocate(char *oldptr,int oldsize,int newsize);
//! Frees memory of an entry
int free(char *addr,int size=0);
//! Prints statistics about storage
void stat();
};
#endif
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