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/*
Unix SMB/CIFS implementation.
In-memory cache
Copyright (C) Volker Lendecke 2007-2008
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 3 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef __MEMCACHE_H__
#define __MEMCACHE_H__
#include "includes.h"
struct memcache;
/*
* A memcache can store different subkeys with overlapping keys, the
* memcache_number becomes part of the key. Feel free to add caches of your
* own here.
*
* If you add talloc type caches, also note this in the switch statement in
* memcache_is_talloc().
*/
enum memcache_number {
STAT_CACHE,
GETWD_CACHE,
GETPWNAM_CACHE, /* talloc */
MANGLE_HASH2_CACHE,
PDB_GETPWSID_CACHE, /* talloc */
SINGLETON_CACHE_TALLOC, /* talloc */
SINGLETON_CACHE
};
/*
* Create a memcache structure. max_size is in bytes, if you set it 0 it will
* not forget anything.
*/
struct memcache *memcache_init(TALLOC_CTX *mem_ctx, size_t max_size);
/*
* If you set this global memcache, use it as the default cache when NULL is
* passed to the memcache functions below. This is a workaround for many
* situations where passing the cache everywhere would be a big hassle.
*/
void memcache_set_global(struct memcache *cache);
/*
* Add a data blob to the cache
*/
void memcache_add(struct memcache *cache, enum memcache_number n,
DATA_BLOB key, DATA_BLOB value);
/*
* Add a talloc object to the cache. The difference to memcache_add() is that
* when the objects is to be discared, talloc_free is called for it. Also
* talloc_move() ownership of the object to the cache.
*
* Please note that the current implementation has a fixed relationship
* between what cache subtypes store talloc objects and which ones store plain
* blobs. We can fix this, but for now we don't have a mixed use of blobs vs
* talloc objects in the cache types.
*/
void memcache_add_talloc(struct memcache *cache, enum memcache_number n,
DATA_BLOB key, void *ptr);
/*
* Delete an object from the cache
*/
void memcache_delete(struct memcache *cache, enum memcache_number n,
DATA_BLOB key);
/*
* Look up an object from the cache. Memory still belongs to the cache, so
* make a copy of it if needed.
*/
bool memcache_lookup(struct memcache *cache, enum memcache_number n,
DATA_BLOB key, DATA_BLOB *value);
/*
* Look up an object from the cache. Memory still belongs to the cache, so
* make a copy of it if needed.
*/
void *memcache_lookup_talloc(struct memcache *cache, enum memcache_number n,
DATA_BLOB key);
/*
* Flush a complete cache subset.
*/
void memcache_flush(struct memcache *cache, enum memcache_number n);
#endif
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