openldap/servers/slapd/back-monitor/cache.c

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/* cache.c - routines to maintain an in-core cache of entries */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
2004-01-02 03:15:16 +08:00
* Copyright 2001-2004 The OpenLDAP Foundation.
2003-12-09 01:41:40 +08:00
* Portions Copyright 2001-2003 Pierangelo Masarati.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/* ACKNOWLEDGEMENTS:
* This work was initially developed by Pierangelo Masarati for inclusion
* in OpenLDAP Software.
*/
#include "portable.h"
#include <stdio.h>
#include "ac/string.h"
#include "slap.h"
#include "back-monitor.h"
/*
* compares entries based on the dn
*/
int
monitor_cache_cmp(
const void *c1,
const void *c2
)
{
struct monitorcache *cc1 = ( struct monitorcache * )c1;
struct monitorcache *cc2 = ( struct monitorcache * )c2;
/*
* case sensitive, because the dn MUST be normalized
*/
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return ber_bvcmp( &cc1->mc_ndn, &cc2->mc_ndn );
}
/*
* checks for duplicate entries
*/
int
monitor_cache_dup(
void *c1,
void *c2
)
{
struct monitorcache *cc1 = ( struct monitorcache * )c1;
struct monitorcache *cc2 = ( struct monitorcache * )c2;
/*
* case sensitive, because the dn MUST be normalized
*/
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return ber_bvcmp( &cc1->mc_ndn, &cc2->mc_ndn ) == 0 ? -1 : 0;
}
/*
* adds an entry to the cache and inits the mutex
*/
int
monitor_cache_add(
struct monitorinfo *mi,
Entry *e
)
{
struct monitorcache *mc;
struct monitorentrypriv *mp;
int rc;
assert( mi != NULL );
assert( e != NULL );
mp = ( struct monitorentrypriv *)e->e_private;
ldap_pvt_thread_mutex_init( &mp->mp_mutex );
mc = ( struct monitorcache * )ch_malloc( sizeof( struct monitorcache ) );
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mc->mc_ndn = e->e_nname;
mc->mc_e = e;
ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
rc = avl_insert( &mi->mi_cache, ( caddr_t )mc,
monitor_cache_cmp, monitor_cache_dup );
ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
return rc;
}
/*
* locks the entry (no r/w)
*/
int
monitor_cache_lock(
Entry *e
)
{
struct monitorentrypriv *mp;
assert( e != NULL );
assert( e->e_private != NULL );
mp = ( struct monitorentrypriv * )e->e_private;
ldap_pvt_thread_mutex_lock( &mp->mp_mutex );
return( 0 );
}
/*
* gets an entry from the cache based on the normalized dn
* with mutex locked
*/
int
monitor_cache_get(
struct monitorinfo *mi,
struct berval *ndn,
Entry **ep
)
{
struct monitorcache tmp_mc, *mc;
assert( mi != NULL );
assert( ndn != NULL );
assert( ep != NULL );
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tmp_mc.mc_ndn = *ndn;
ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
mc = ( struct monitorcache * )avl_find( mi->mi_cache,
( caddr_t )&tmp_mc, monitor_cache_cmp );
if ( mc != NULL ) {
/* entry is returned with mutex locked */
monitor_cache_lock( mc->mc_e );
ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
*ep = mc->mc_e;
return( 0 );
}
ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
*ep = NULL;
return( -1 );
}
/*
* If the entry exists in cache, it is returned in locked status;
* otherwise, if the parent exists, if it may generate volatile
* descendants an attempt to generate the required entry is
* performed and, if successful, the entry is returned
*/
int
monitor_cache_dn2entry(
Operation *op,
struct berval *ndn,
Entry **ep,
Entry **matched
)
{
struct monitorinfo *mi = (struct monitorinfo *)op->o_bd->be_private;
int rc;
struct berval p_ndn = BER_BVNULL;
Entry *e_parent;
struct monitorentrypriv *mp;
assert( mi != NULL );
assert( ndn != NULL );
assert( ep != NULL );
assert( matched != NULL );
*matched = NULL;
rc = monitor_cache_get( mi, ndn, ep );
if ( !rc && *ep != NULL ) {
return( 0 );
}
/* try with parent/ancestors */
if ( BER_BVISNULL( ndn ) ) {
BER_BVSTR( &p_ndn, "" );
} else {
dnParent( ndn, &p_ndn );
}
rc = monitor_cache_dn2entry( op, &p_ndn, &e_parent, matched );
if ( rc || e_parent == NULL ) {
return( -1 );
}
mp = ( struct monitorentrypriv * )e_parent->e_private;
rc = -1;
if ( mp->mp_flags & MONITOR_F_VOLATILE_CH ) {
/* parent entry generates volatile children */
rc = monitor_entry_create( op, ndn, e_parent, ep );
}
if ( !rc ) {
monitor_cache_release( mi, e_parent );
} else {
*matched = e_parent;
}
return( rc );
}
/*
* releases the lock of the entry; if it is marked as volatile, it is
* destroyed.
*/
int
monitor_cache_release(
struct monitorinfo *mi,
Entry *e
)
{
struct monitorentrypriv *mp;
assert( mi != NULL );
assert( e != NULL );
assert( e->e_private != NULL );
mp = ( struct monitorentrypriv * )e->e_private;
if ( mp->mp_flags & MONITOR_F_VOLATILE ) {
struct monitorcache *mc, tmp_mc;
/* volatile entries do not return to cache */
ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
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tmp_mc.mc_ndn = e->e_nname;
mc = avl_delete( &mi->mi_cache,
( caddr_t )&tmp_mc, monitor_cache_cmp );
ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
ch_free( mc );
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ldap_pvt_thread_mutex_unlock( &mp->mp_mutex );
ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
ch_free( mp );
e->e_private = NULL;
entry_free( e );
return( 0 );
}
ldap_pvt_thread_mutex_unlock( &mp->mp_mutex );
return( 0 );
}