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/*----------------------------------------------------------------------------*/
/*ncache.h*/
/*----------------------------------------------------------------------------*/
/*The cache of nodes*/
/*----------------------------------------------------------------------------*/
/*Based on the code of unionfs translator.*/
/*----------------------------------------------------------------------------*/
/*Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc.
Written by Sergiu Ivanov <unlimitedscolobb@gmail.com>.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or * (at your option) any later version.
This program 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.*/
/*----------------------------------------------------------------------------*/
#ifndef __NCACHE_H__
#define __NCACHE_H__
/*----------------------------------------------------------------------------*/
#include <error.h>
#include <hurd/netfs.h>
/*----------------------------------------------------------------------------*/
#include "node.h"
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*--------Macros--------------------------------------------------------------*/
/*The default maximal cache size*/
#define NCACHE_SIZE 256
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*A cache chain*/
struct ncache
{
/*the MRU end of the cache chain*/
node_t * mru;
/*the LRU end of the cache chain*/
node_t * lru;
/*the maximal number of nodes to cache*/
int size_max;
/*the current length of the cache chain*/
int size_current;
/*a lock*/
struct mutex lock;
};/*struct ncache*/
/*----------------------------------------------------------------------------*/
typedef struct ncache ncache_t;
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*--------Global Variables----------------------------------------------------*/
/*The cache size (may be overwritten by the user)*/
extern int cache_size;
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*--------Functions-----------------------------------------------------------*/
/*Initializes the node cache*/
void
ncache_init
(
int size_max
);
/*----------------------------------------------------------------------------*/
/*Looks up the lnode and stores the result in `node`; creates a new entry
in the cache if the lookup fails*/
error_t
ncache_node_lookup
(
lnode_t * lnode, /*search for this*/
node_t ** node /*put the result here*/
);
/*----------------------------------------------------------------------------*/
/*Resets the node cache*/
void
ncache_reset(void);
/*----------------------------------------------------------------------------*/
/*Adds the given node to the cache*/
void
ncache_node_add
(
node_t * node /*the node to add*/
);
/*----------------------------------------------------------------------------*/
#endif /*__NCACHE_H__*/
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