external/bsd/openldap/dist/servers/slapd/back-meta/dncache.c

   1 /* $OpenLDAP: pkg/ldap/servers/slapd/back-meta/dncache.c,v 1.16.2.3 2008/02/11 23:26:47 kurt Exp $ */
   2 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   3  *
   4  * Copyright 1999-2008 The OpenLDAP Foundation.
   5  * Portions Copyright 2001-2003 Pierangelo Masarati.
   6  * Portions Copyright 1999-2003 Howard Chu.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted only as authorized by the OpenLDAP
  11  * Public License.
  12  *
  13  * A copy of this license is available in the file LICENSE in the
  14  * top-level directory of the distribution or, alternatively, at
  15  * <http://www.OpenLDAP.org/license.html>.
  16  */
  17 /* ACKNOWLEDGEMENTS:
  18  * This work was initially developed by the Howard Chu for inclusion
  19  * in OpenLDAP Software and subsequently enhanced by Pierangelo
  20  * Masarati.
  21  */
  22
  23 #include "portable.h"
  24
  25 #include <stdio.h>
  26 #include <ac/string.h>
  27
  28 #include "slap.h"
  29 #include "../back-ldap/back-ldap.h"
  30 #include "back-meta.h"
  31
  32 /*
  33  * The dncache, at present, maps an entry to the target that holds it.
  34  */
  35
  36 typedef struct metadncacheentry_t {
  37         struct berval   dn;
  38         int             target;
  39
  40         time_t          lastupdated;
  41 } metadncacheentry_t;
  42
  43 /*
  44  * meta_dncache_cmp
  45  *
  46  * compares two struct metadncacheentry; used by avl stuff
  47  * FIXME: modify avl stuff to delete an entry based on cmp
  48  * (e.g. when ttl expired?)
  49  */
  50 int
  51 meta_dncache_cmp(
  52         const void      *c1,
  53         const void      *c2 )
  54 {
  55         metadncacheentry_t      *cc1 = ( metadncacheentry_t * )c1;
  56         metadncacheentry_t      *cc2 = ( metadncacheentry_t * )c2;
  57
  58         /*
  59          * case sensitive, because the dn MUST be normalized
  60          */
  61         return ber_bvcmp( &cc1->dn, &cc2->dn);
  62 }
  63
  64 /*
  65  * meta_dncache_dup
  66  *
  67  * returns -1 in case a duplicate struct metadncacheentry has been inserted;
  68  * used by avl stuff
  69  */
  70 int
  71 meta_dncache_dup(
  72         void            *c1,
  73         void            *c2 )
  74 {
  75         metadncacheentry_t      *cc1 = ( metadncacheentry_t * )c1;
  76         metadncacheentry_t      *cc2 = ( metadncacheentry_t * )c2;
  77
  78         /*
  79          * case sensitive, because the dn MUST be normalized
  80          */
  81         return ( ber_bvcmp( &cc1->dn, &cc2->dn ) == 0 ) ? -1 : 0;
  82 }
  83
  84 /*
  85  * meta_dncache_get_target
  86  *
  87  * returns the target a dn belongs to, or -1 in case the dn is not
  88  * in the cache
  89  */
  90 int
  91 meta_dncache_get_target(
  92         metadncache_t   *cache,
  93         struct berval   *ndn )
  94 {
  95         metadncacheentry_t      tmp_entry,
  96                                 *entry;
  97         int                     target = META_TARGET_NONE;
  98
  99         assert( cache != NULL );
 100         assert( ndn != NULL );
 101
 102         tmp_entry.dn = *ndn;
 103         ldap_pvt_thread_mutex_lock( &cache->mutex );
 104         entry = ( metadncacheentry_t * )avl_find( cache->tree,
 105                         ( caddr_t )&tmp_entry, meta_dncache_cmp );
 106
 107         if ( entry != NULL ) {
 108
 109                 /*
 110                  * if cache->ttl < 0, cache never expires;
 111                  * if cache->ttl = 0 no cache is used; shouldn't get here
 112                  * else, cache is used with ttl
 113                  */
 114                 if ( cache->ttl < 0 ) {
 115                         target = entry->target;
 116
 117                 } else {
 118                         if ( entry->lastupdated+cache->ttl > slap_get_time() ) {
 119                                 target = entry->target;
 120                         }
 121                 }
 122         }
 123         ldap_pvt_thread_mutex_unlock( &cache->mutex );
 124
 125         return target;
 126 }
 127
 128 /*
 129  * meta_dncache_update_entry
 130  *
 131  * updates target and lastupdated of a struct metadncacheentry if exists,
 132  * otherwise it gets created; returns -1 in case of error
 133  */
 134 int
 135 meta_dncache_update_entry(
 136         metadncache_t   *cache,
 137         struct berval   *ndn,
 138         int             target )
 139 {
 140         metadncacheentry_t      *entry,
 141                                 tmp_entry;
 142         time_t                  curr_time = 0L;
 143         int                     err = 0;
 144
 145         assert( cache != NULL );
 146         assert( ndn != NULL );
 147
 148         /*
 149          * if cache->ttl < 0, cache never expires;
 150          * if cache->ttl = 0 no cache is used; shouldn't get here
 151          * else, cache is used with ttl
 152          */
 153         if ( cache->ttl > 0 ) {
 154                 curr_time = slap_get_time();
 155         }
 156
 157         tmp_entry.dn = *ndn;
 158
 159         ldap_pvt_thread_mutex_lock( &cache->mutex );
 160         entry = ( metadncacheentry_t * )avl_find( cache->tree,
 161                         ( caddr_t )&tmp_entry, meta_dncache_cmp );
 162
 163         if ( entry != NULL ) {
 164                 entry->target = target;
 165                 entry->lastupdated = curr_time;
 166
 167         } else {
 168                 entry = ch_malloc( sizeof( metadncacheentry_t ) + ndn->bv_len + 1 );
 169                 if ( entry == NULL ) {
 170                         err = -1;
 171                         goto error_return;
 172                 }
 173
 174                 entry->dn.bv_len = ndn->bv_len;
 175                 entry->dn.bv_val = (char *)&entry[ 1 ];
 176                 AC_MEMCPY( entry->dn.bv_val, ndn->bv_val, ndn->bv_len );
 177                 entry->dn.bv_val[ ndn->bv_len ] = '\0';
 178
 179                 entry->target = target;
 180                 entry->lastupdated = curr_time;
 181
 182                 err = avl_insert( &cache->tree, ( caddr_t )entry,
 183                                 meta_dncache_cmp, meta_dncache_dup );
 184         }
 185
 186 error_return:;
 187         ldap_pvt_thread_mutex_unlock( &cache->mutex );
 188
 189         return err;
 190 }
 191
 192 /*
 193  * meta_dncache_update_entry
 194  *
 195  * updates target and lastupdated of a struct metadncacheentry if exists,
 196  * otherwise it gets created; returns -1 in case of error
 197  */
 198 int
 199 meta_dncache_delete_entry(
 200         metadncache_t   *cache,
 201         struct berval   *ndn )
 202 {
 203         metadncacheentry_t      *entry,
 204                                 tmp_entry;
 205
 206         assert( cache != NULL );
 207         assert( ndn != NULL );
 208
 209         tmp_entry.dn = *ndn;
 210
 211         ldap_pvt_thread_mutex_lock( &cache->mutex );
 212         entry = avl_delete( &cache->tree, ( caddr_t )&tmp_entry,
 213                         meta_dncache_cmp );
 214         ldap_pvt_thread_mutex_unlock( &cache->mutex );
 215
 216         if ( entry != NULL ) {
 217                 meta_dncache_free( ( void * )entry );
 218         }
 219
 220         return 0;
 221 }
 222
 223 /*
 224  * meta_dncache_free
 225  *
 226  * frees an entry
 227  *
 228  */
 229 void
 230 meta_dncache_free(
 231         void            *e )
 232 {
 233         free( e );
 234 }
 235