diff options
Diffstat (limited to 'unionfs/ncache.c')
| -rw-r--r-- | unionfs/ncache.c | 151 |
1 files changed, 0 insertions, 151 deletions
diff --git a/unionfs/ncache.c b/unionfs/ncache.c deleted file mode 100644 index 4c83ac0e..00000000 --- a/unionfs/ncache.c +++ /dev/null @@ -1,151 +0,0 @@ -/* Hurd unionfs - Copyright (C) 2001, 2002 Free Software Foundation, Inc. - Written by Moritz Schulte <moritz@duesseldorf.ccc.de>. - - 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. */ - -#define _GNU_SOURCE - -#include <hurd/netfs.h> -#include <error.h> -#include <stdlib.h> -#include <assert.h> - -#include "ncache.h" -#include "lib.h" -#include "unionfs.h" - -/* The node cache. */ -ncache_t ncache; - -/* Cache size, may be overwritten by the user. */ -int ncache_size = NCACHE_SIZE; - -/* Initialize the node cache, set the maximum number of allowed nodes - in the cache to SIZE_MAX. */ -void -ncache_init (int size_max) -{ - ncache.mru = NULL; - ncache.lru = NULL; - ncache.size_max = size_max; - ncache.size_current = 0; - mutex_init (&ncache.lock); -} - -/* Remove the given node NODE from the cache. */ -static void -ncache_node_remove (node_t *node) -{ - struct netnode *nn = node->nn; - - if (nn->ncache_next) - nn->ncache_next->nn->ncache_prev = nn->ncache_prev; - if (nn->ncache_prev) - nn->ncache_prev->nn->ncache_next = nn->ncache_next; - if (ncache.mru == node) - ncache.mru = nn->ncache_next; - if (ncache.lru == node) - ncache.lru = nn->ncache_prev; - nn->ncache_next = NULL; - nn->ncache_prev = NULL; - ncache.size_current--; -} - -void -ncache_reset (void) -{ - node_t *node; - - mutex_lock (&ncache.lock); - while ((node = ncache.mru)) - ncache_node_remove (node); - mutex_unlock (&ncache.lock); -} - -/* Lookup the node for the light node LNODE. If it does not exist - anymore in the cache, create a new node. Store the looked up node - in *NODE. */ -error_t -ncache_node_lookup (lnode_t *lnode, node_t **node) -{ - error_t err = 0; - node_t *n; - - if (lnode->node) - { - debug_msg ("ncache_node_lookup for lnode: %s (found in cache)", - lnode->name); - n = lnode->node; - netfs_nref (n); - } - else - { - debug_msg ("ncache_node_lookup for lnode: %s (newly created)", - lnode->name); - err = node_create (lnode, &n); - } - - if (! err) - { - mutex_lock (&n->lock); - *node = n; - } - return err; -} - -/* Add the given node NODE to the node cache; remove - least-recently-used nodes, if needed. */ -void -ncache_node_add (node_t *node) -{ - mutex_lock (&ncache.lock); - - debug_msg ("adding node to cache: %s", node->nn->lnode->name); - - if (ncache.size_max > 0 || ncache.size_current > 0) - { - if (ncache.mru != node) - { - if (node->nn->ncache_next || node->nn->ncache_prev) - /* Node is already in the cache. */ - ncache_node_remove (node); - else - /* Add a reference from the cache. */ - netfs_nref (node); - - node->nn->ncache_next = ncache.mru; - node->nn->ncache_prev = NULL; - if (ncache.mru) - ncache.mru->nn->ncache_prev = node; - if (! ncache.lru) - ncache.lru = node; - ncache.mru = node; - ncache.size_current++; - } - } - - /* Forget the least used nodes. */ - while (ncache.size_current > ncache.size_max) - { - struct node *lru = ncache.lru; - debug_msg ("removing cached node: %s", lru->nn->lnode->name); - ncache_node_remove (lru); - netfs_nrele (lru); - } - - mutex_unlock (&ncache.lock); -} |