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 "ldapconfig.h"
  19 #include "slap.h"
  20 #include "back-ldbm.h"
  21
  22 struct 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%s%s%s", li->li_directory, DEFAULT_DIRSEP, name, suffix );
  39
  40         Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
  41             flags, li->li_mode );
  42
  43         lru = 0;
  44         ldap_pvt_thread_mutex_lock( &currenttime_mutex );
  45         curtime = currenttime;
  46         ldap_pvt_thread_mutex_unlock( &currenttime_mutex );
  47         oldtime = curtime;
  48
  49         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
  50         for ( i = 0; i < MAXDBCACHE && li->li_dbcache[i].dbc_name != NULL;
  51             i++ ) {
  52                 /* already open - return it */
  53                 if ( strcmp( li->li_dbcache[i].dbc_name, buf ) == 0 ) {
  54                         li->li_dbcache[i].dbc_refcnt++;
  55                         Debug( LDAP_DEBUG_TRACE,
  56                             "<= ldbm_cache_open (cache %d)\n", i, 0, 0 );
  57                         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
  58                         return( &li->li_dbcache[i] );
  59                 }
  60
  61                 /* keep track of lru db */
  62                 if ( li->li_dbcache[i].dbc_lastref < oldtime &&
  63                     li->li_dbcache[i].dbc_refcnt == 0 ) {
  64                         lru = i;
  65                         oldtime = li->li_dbcache[i].dbc_lastref;
  66                 }
  67         }
  68
  69         /* no empty slots, not already open - close lru and use that slot */
  70         if ( i == MAXDBCACHE ) {
  71                 i = lru;
  72                 if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
  73                         Debug( LDAP_DEBUG_ANY,
  74                             "ldbm_cache_open no unused db to close - waiting\n",
  75                             0, 0, 0 );
  76                         lru = -1;
  77                         while ( lru == -1 ) {
  78                                 ldap_pvt_thread_cond_wait( &li->li_dbcache_cv,
  79                                     &li->li_dbcache_mutex );
  80                                 for ( i = 0; i < MAXDBCACHE; i++ ) {
  81                                         if ( li->li_dbcache[i].dbc_refcnt
  82                                             == 0 ) {
  83                                                 lru = i;
  84                                                 break;
  85                                         }
  86                                 }
  87                         }
  88                         i = lru;
  89                 }
  90                 ldbm_close( li->li_dbcache[i].dbc_db );
  91                 free( li->li_dbcache[i].dbc_name );
  92                 li->li_dbcache[i].dbc_name = NULL;
  93         }
  94
  95         if ( (li->li_dbcache[i].dbc_db = ldbm_open( buf, flags, li->li_mode,
  96             li->li_dbcachesize )) == NULL ) {
  97                 Debug( LDAP_DEBUG_TRACE,
  98                     "<= ldbm_cache_open NULL \"%s\" errno %d reason \"%s\")\n",
  99                     buf, errno, errno > -1 && errno < sys_nerr ?
 100                     sys_errlist[errno] : "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, struct 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, struct 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                 }
 169         }
 170         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 171 }
 172
 173 Datum
 174 ldbm_cache_fetch(
 175     struct dbcache      *db,
 176     Datum               key
 177 )
 178 {
 179         Datum   data;
 180
 181         ldbm_datum_init( data );
 182
 183         data = ldbm_fetch( db->dbc_db, key );
 184
 185         return( data );
 186 }
 187
 188 int
 189 ldbm_cache_store(
 190     struct dbcache      *db,
 191     Datum               key,
 192     Datum               data,
 193     int                 flags
 194 )
 195 {
 196         int     rc;
 197
 198 #ifdef LDBM_DEBUG
 199         Statslog( LDAP_DEBUG_STATS,
 200                 "=> ldbm_cache_store(): key.dptr=%s, key.dsize=%d\n",
 201                 key.dptr, key.dsize, 0, 0, 0 );
 202
 203         Statslog( LDAP_DEBUG_STATS,
 204                 "=> ldbm_cache_store(): key.dptr=0x%08x, data.dptr=0x%0 8x\n",
 205                 key.dptr, data.dptr, 0, 0, 0 );
 206
 207         Statslog( LDAP_DEBUG_STATS,
 208                 "=> ldbm_cache_store(): data.dptr=%s, data.dsize=%d\n",
 209                 data.dptr, data.dsize, 0, 0, 0 );
 210
 211         Statslog( LDAP_DEBUG_STATS,
 212                 "=> ldbm_cache_store(): flags=0x%08x\n",
 213                 flags, 0, 0, 0, 0 );
 214 #endif /* LDBM_DEBUG */
 215
 216         rc = ldbm_store( db->dbc_db, key, data, flags );
 217
 218         return( rc );
 219 }
 220
 221 int
 222 ldbm_cache_delete(
 223     struct dbcache      *db,
 224     Datum               key
 225 )
 226 {
 227         int     rc;
 228
 229         rc = ldbm_delete( db->dbc_db, key );
 230
 231         return( rc );
 232 }