git.sur5r.net Git - openldap/blob - servers/slapd/back-ldbm/dbcache.c

   1 /* ldbmcache.c - maintain a cache of open ldbm files */
   2
   3 #include "portable.h"
   4
   5 #include <stdio.h>
   6
   7 #include <ac/errno.h>
   8 #include <ac/socket.h>
   9 #include <ac/string.h>
  10 #include <ac/time.h>
  11
  12 #include <sys/stat.h>
  13
  14 #ifdef HAVE_SYS_PARAM_H
  15 #include <sys/param.h>
  16 #endif
  17
  18 #include "ldap_defaults.h"
  19 #include "slap.h"
  20 #include "back-ldbm.h"
  21
  22 DBCache *
  23 ldbm_cache_open(
  24     Backend     *be,
  25     char        *name,
  26     char        *suffix,
  27     int         flags
  28 )
  29 {
  30         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
  31         int             i, lru;
  32         time_t          oldtime, curtime;
  33         char            buf[MAXPATHLEN];
  34 #ifdef HAVE_ST_BLKSIZE
  35         struct stat     st;
  36 #endif
  37
  38         sprintf( buf, "%s" LDAP_DIRSEP "%s%s",
  39                 li->li_directory, name, suffix );
  40
  41         Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
  42             flags, li->li_mode );
  43
  44         lru = 0;
  45         curtime = slap_get_time();
  46         oldtime = curtime;
  47
  48         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
  49         for ( i = 0; i < MAXDBCACHE && li->li_dbcache[i].dbc_name != NULL;
  50             i++ ) {
  51                 /* already open - return it */
  52                 if ( strcmp( li->li_dbcache[i].dbc_name, buf ) == 0 ) {
  53                         li->li_dbcache[i].dbc_refcnt++;
  54                         Debug( LDAP_DEBUG_TRACE,
  55                             "<= ldbm_cache_open (cache %d)\n", i, 0, 0 );
  56                         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
  57                         return( &li->li_dbcache[i] );
  58                 }
  59
  60                 /* keep track of lru db */
  61                 if ( li->li_dbcache[i].dbc_lastref < oldtime &&
  62                     li->li_dbcache[i].dbc_refcnt == 0 ) {
  63                         lru = i;
  64                         oldtime = li->li_dbcache[i].dbc_lastref;
  65                 }
  66         }
  67
  68         /* no empty slots, not already open - close lru and use that slot */
  69         if ( i == MAXDBCACHE ) {
  70                 i = lru;
  71                 if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
  72                         Debug( LDAP_DEBUG_ANY,
  73                             "ldbm_cache_open no unused db to close - waiting\n",
  74                             0, 0, 0 );
  75                         lru = -1;
  76                         while ( lru == -1 ) {
  77                                 ldap_pvt_thread_cond_wait( &li->li_dbcache_cv,
  78                                     &li->li_dbcache_mutex );
  79                                 for ( i = 0; i < MAXDBCACHE; i++ ) {
  80                                         if ( li->li_dbcache[i].dbc_refcnt
  81                                             == 0 ) {
  82                                                 lru = i;
  83                                                 break;
  84                                         }
  85                                 }
  86                         }
  87                         i = lru;
  88                 }
  89                 ldbm_close( li->li_dbcache[i].dbc_db );
  90                 free( li->li_dbcache[i].dbc_name );
  91                 li->li_dbcache[i].dbc_name = NULL;
  92         }
  93
  94         if ( (li->li_dbcache[i].dbc_db = ldbm_open( buf, flags, li->li_mode,
  95             li->li_dbcachesize )) == NULL ) {
  96                 int err = errno;
  97                 Debug( LDAP_DEBUG_TRACE,
  98                     "<= ldbm_cache_open NULL \"%s\" errno %d reason \"%s\")\n",
  99                     buf, err, err > -1 && err < sys_nerr ?
 100                     sys_errlist[err] : "unknown" );
 101                 ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 102                 return( NULL );
 103         }
 104         li->li_dbcache[i].dbc_name = ch_strdup( buf );
 105         li->li_dbcache[i].dbc_refcnt = 1;
 106         li->li_dbcache[i].dbc_lastref = curtime;
 107 #ifdef HAVE_ST_BLKSIZE
 108         if ( stat( buf, &st ) == 0 ) {
 109                 li->li_dbcache[i].dbc_blksize = st.st_blksize;
 110         } else
 111 #endif
 112         {
 113                 li->li_dbcache[i].dbc_blksize = DEFAULT_BLOCKSIZE;
 114         }
 115         li->li_dbcache[i].dbc_maxids = (li->li_dbcache[i].dbc_blksize /
 116             sizeof(ID)) - ID_BLOCK_IDS_OFFSET;
 117         li->li_dbcache[i].dbc_maxindirect = (SLAPD_LDBM_MIN_MAXIDS /
 118             li->li_dbcache[i].dbc_maxids) + 1;
 119
 120         Debug( LDAP_DEBUG_ARGS,
 121             "ldbm_cache_open (blksize %ld) (maxids %d) (maxindirect %d)\n",
 122             li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
 123             li->li_dbcache[i].dbc_maxindirect );
 124         Debug( LDAP_DEBUG_TRACE, "<= ldbm_cache_open (opened %d)\n", i, 0, 0 );
 125         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 126         return( &li->li_dbcache[i] );
 127 }
 128
 129 void
 130 ldbm_cache_close( Backend *be, DBCache *db )
 131 {
 132         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 133
 134         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 135         if ( --db->dbc_refcnt == 0 ) {
 136                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 137         }
 138         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 139 }
 140
 141 void
 142 ldbm_cache_really_close( Backend *be, DBCache *db )
 143 {
 144         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 145
 146         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 147         if ( --db->dbc_refcnt == 0 ) {
 148                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 149                 ldbm_close( db->dbc_db );
 150                 free( db->dbc_name );
 151                 db->dbc_name = NULL;
 152         }
 153         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 154 }
 155
 156 void
 157 ldbm_cache_flush_all( Backend *be )
 158 {
 159         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 160         int             i;
 161
 162         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 163         for ( i = 0; i < MAXDBCACHE; i++ ) {
 164                 if ( li->li_dbcache[i].dbc_name != NULL ) {
 165                         Debug( LDAP_DEBUG_TRACE, "ldbm flushing db (%s)\n",
 166                             li->li_dbcache[i].dbc_name, 0, 0 );
 167                         ldbm_sync( li->li_dbcache[i].dbc_db );
 168 #ifdef SLAP_CLEANUP
 169                         if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
 170                                 Debug( LDAP_DEBUG_TRACE,
 171                                        "refcnt = %d, couldn't close db (%s)\n",
 172                                        li->li_dbcache[i].dbc_refcnt,
 173                                        li->li_dbcache[i].dbc_name, 0 );
 174                         } else {
 175                                 Debug( LDAP_DEBUG_TRACE,
 176                                        "ldbm closing db (%s)\n",
 177                                        li->li_dbcache[i].dbc_name, 0, 0 );
 178                                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 179                                 ldbm_close( li->li_dbcache[i].dbc_db );
 180                                 free( li->li_dbcache[i].dbc_name );
 181                                 li->li_dbcache[i].dbc_name = NULL;
 182                         }
 183 #endif /* SLAP_CLEANUP */
 184                 }
 185         }
 186         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 187 }
 188
 189 Datum
 190 ldbm_cache_fetch(
 191     DBCache     *db,
 192     Datum               key
 193 )
 194 {
 195         Datum   data;
 196
 197         ldbm_datum_init( data );
 198
 199         data = ldbm_fetch( db->dbc_db, key );
 200
 201         return( data );
 202 }
 203
 204 int
 205 ldbm_cache_store(
 206     DBCache     *db,
 207     Datum               key,
 208     Datum               data,
 209     int                 flags
 210 )
 211 {
 212         int     rc;
 213
 214 #ifdef LDBM_DEBUG
 215         Statslog( LDAP_DEBUG_STATS,
 216                 "=> ldbm_cache_store(): key.dptr=%s, key.dsize=%d\n",
 217                 key.dptr, key.dsize, 0, 0, 0 );
 218
 219         Statslog( LDAP_DEBUG_STATS,
 220                 "=> ldbm_cache_store(): key.dptr=0x%08x, data.dptr=0x%0 8x\n",
 221                 key.dptr, data.dptr, 0, 0, 0 );
 222
 223         Statslog( LDAP_DEBUG_STATS,
 224                 "=> ldbm_cache_store(): data.dptr=%s, data.dsize=%d\n",
 225                 data.dptr, data.dsize, 0, 0, 0 );
 226
 227         Statslog( LDAP_DEBUG_STATS,
 228                 "=> ldbm_cache_store(): flags=0x%08x\n",
 229                 flags, 0, 0, 0, 0 );
 230 #endif /* LDBM_DEBUG */
 231
 232         rc = ldbm_store( db->dbc_db, key, data, flags );
 233
 234         return( rc );
 235 }
 236
 237 int
 238 ldbm_cache_delete(
 239     DBCache     *db,
 240     Datum               key
 241 )
 242 {
 243         int     rc;
 244
 245         rc = ldbm_delete( db->dbc_db, key );
 246
 247         return( rc );
 248 }