openldap/servers/slapd/back-meta/dncache.c
2002-04-03 15:43:41 +00:00

291 lines
7.1 KiB
C

/*
* Copyright 1998-2002 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*
* Copyright 2001, Pierangelo Masarati, All rights reserved. <ando@sys-net.it>
*
* This work has been developed to fulfill the requirements
* of SysNet s.n.c. <http:www.sys-net.it> and it has been donated
* to the OpenLDAP Foundation in the hope that it may be useful
* to the Open Source community, but WITHOUT ANY WARRANTY.
*
* Permission is granted to anyone to use this software for any purpose
* on any computer system, and to alter it and redistribute it, subject
* to the following restrictions:
*
* 1. The author and SysNet s.n.c. are not responsible for the consequences
* of use of this software, no matter how awful, even if they arise from
* flaws in it.
*
* 2. The origin of this software must not be misrepresented, either by
* explicit claim or by omission. Since few users ever read sources,
* credits should appear in the documentation.
*
* 3. Altered versions must be plainly marked as such, and must not be
* misrepresented as being the original software. Since few users
* ever read sources, credits should appear in the documentation.
* SysNet s.n.c. cannot be responsible for the consequences of the
* alterations.
*
* 4. This notice may not be removed or altered.
*
*
* This software is based on the backend back-ldap, implemented
* by Howard Chu <hyc@highlandsun.com>, and modified by Mark Valence
* <kurash@sassafras.com>, Pierangelo Masarati <ando@sys-net.it> and other
* contributors. The contribution of the original software to the present
* implementation is acknowledged in this copyright statement.
*
* A special acknowledgement goes to Howard for the overall architecture
* (and for borrowing large pieces of code), and to Mark, who implemented
* from scratch the attribute/objectclass mapping.
*
* The original copyright statement follows.
*
* Copyright 1999, Howard Chu, All rights reserved. <hyc@highlandsun.com>
*
* Permission is granted to anyone to use this software for any purpose
* on any computer system, and to alter it and redistribute it, subject
* to the following restrictions:
*
* 1. The author is not responsible for the consequences of use of this
* software, no matter how awful, even if they arise from flaws in it.
*
* 2. The origin of this software must not be misrepresented, either by
* explicit claim or by omission. Since few users ever read sources,
* credits should appear in the documentation.
*
* 3. Altered versions must be plainly marked as such, and must not be
* misrepresented as being the original software. Since few users
* ever read sources, credits should appear in the
* documentation.
*
* 4. This notice may not be removed or altered.
*
*/
#include "portable.h"
#include <stdio.h>
#include "slap.h"
#include "../back-ldap/back-ldap.h"
#include "back-meta.h"
/*
* The dncache, at present, maps an entry to the target that holds it.
*/
struct metadncacheentry {
struct berval dn;
int target;
time_t lastupdated;
};
/*
* meta_dncache_cmp
*
* compares two struct metadncacheentry; used by avl stuff
* FIXME: modify avl stuff to delete an entry based on cmp
* (e.g. when ttl expired?)
*/
int
meta_dncache_cmp(
const void *c1,
const void *c2
)
{
struct metadncacheentry *cc1 = ( struct metadncacheentry * )c1;
struct metadncacheentry *cc2 = ( struct metadncacheentry * )c2;
/*
* case sensitive, because the dn MUST be normalized
*/
return ber_bvcmp( &cc1->dn, &cc2->dn);
}
/*
* meta_dncache_dup
*
* returns -1 in case a duplicate struct metadncacheentry has been inserted;
* used by avl stuff
*/
int
meta_dncache_dup(
void *c1,
void *c2
)
{
struct metadncacheentry *cc1 = ( struct metadncacheentry * )c1;
struct metadncacheentry *cc2 = ( struct metadncacheentry * )c2;
/*
* case sensitive, because the dn MUST be normalized
*/
return ( ber_bvcmp( &cc1->dn, &cc2->dn ) == 0 ) ? -1 : 0;
}
/*
* meta_dncache_get_target
*
* returns the target a dn belongs to, or -1 in case the dn is not
* in the cache
*/
int
meta_dncache_get_target(
struct metadncache *cache,
struct berval *ndn
)
{
struct metadncacheentry tmp_entry, *entry;
time_t curr_time;
int target = -1;
assert( cache );
assert( ndn );
tmp_entry.dn = *ndn;
ldap_pvt_thread_mutex_lock( &cache->mutex );
entry = ( struct metadncacheentry * )avl_find( cache->tree,
( caddr_t )&tmp_entry, meta_dncache_cmp );
if ( entry != NULL ) {
/*
* if cache->ttl < 0, cache never expires;
* if cache->ttl = 0 no cache is used; shouldn't get here
* else, cache is used with ttl
*/
if ( cache->ttl < 0 ) {
target = entry->target;
} else {
/*
* Need mutex?
*/
curr_time = time( NULL );
if ( entry->lastupdated+cache->ttl > curr_time ) {
target = entry->target;
}
}
}
ldap_pvt_thread_mutex_unlock( &cache->mutex );
return target;
}
/*
* meta_dncache_update_entry
*
* updates target and lastupdated of a struct metadncacheentry if exists,
* otherwise it gets created; returns -1 in case of error
*/
int
meta_dncache_update_entry(
struct metadncache *cache,
struct berval *ndn,
int target
)
{
struct metadncacheentry *entry, tmp_entry;
time_t curr_time = 0L;
int err = 0;
assert( cache );
assert( ndn );
/*
* if cache->ttl < 0, cache never expires;
* if cache->ttl = 0 no cache is used; shouldn't get here
* else, cache is used with ttl
*/
if ( cache->ttl > 0 ) {
/*
* Need mutex?
*/
curr_time = time( NULL );
}
tmp_entry.dn = *ndn;
ldap_pvt_thread_mutex_lock( &cache->mutex );
entry = ( struct metadncacheentry * )avl_find( cache->tree,
( caddr_t )&tmp_entry, meta_dncache_cmp );
if ( entry != NULL ) {
entry->target = target;
entry->lastupdated = curr_time;
} else {
entry = ch_calloc( sizeof( struct metadncacheentry ), 1 );
if ( entry == NULL ) {
ldap_pvt_thread_mutex_unlock( &cache->mutex );
return -1;
}
ber_dupbv( &entry->dn, ndn );
if ( entry->dn.bv_val == NULL ) {
ldap_pvt_thread_mutex_unlock( &cache->mutex );
return -1;
}
entry->target = target;
entry->lastupdated = curr_time;
err = avl_insert( &cache->tree, ( caddr_t )entry,
meta_dncache_cmp, meta_dncache_dup );
}
ldap_pvt_thread_mutex_unlock( &cache->mutex );
return err;
}
/*
* meta_dncache_update_entry
*
* updates target and lastupdated of a struct metadncacheentry if exists,
* otherwise it gets created; returns -1 in case of error
*/
int
meta_dncache_delete_entry(
struct metadncache *cache,
struct berval *ndn
)
{
struct metadncacheentry *entry, tmp_entry;
assert( cache );
assert( ndn );
tmp_entry.dn = *ndn;
ldap_pvt_thread_mutex_lock( &cache->mutex );
entry = avl_delete( &cache->tree, ( caddr_t )&tmp_entry,
meta_dncache_cmp );
ldap_pvt_thread_mutex_unlock( &cache->mutex );
if ( entry != NULL ) {
meta_dncache_free( ( void * )entry );
}
return 0;
}
/*
* meta_dncache_free
*
* frees an entry
*
*/
void
meta_dncache_free(
void *e
)
{
struct metadncacheentry *entry = ( struct metadncacheentry * )e;
free( entry->dn.bv_val );
}