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         LDBM            db;
  35         struct stat     st;
  36
  37         sprintf( buf, "%s/%s%s", li->li_directory, name, suffix );
  38
  39         Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
  40             flags, li->li_mode );
  41
  42         lru = 0;
  43         ldap_pvt_thread_mutex_lock( &currenttime_mutex );
  44         curtime = currenttime;
  45         ldap_pvt_thread_mutex_unlock( &currenttime_mutex );
  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         if ( stat( buf, &st ) == 0 ) {
 108                 li->li_dbcache[i].dbc_blksize = st.st_blksize;
 109         } else {
 110                 li->li_dbcache[i].dbc_blksize = DEFAULT_BLOCKSIZE;
 111         }
 112         li->li_dbcache[i].dbc_maxids = (li->li_dbcache[i].dbc_blksize /
 113             sizeof(ID)) - ID_BLOCK_IDS_OFFSET;
 114         li->li_dbcache[i].dbc_maxindirect = (SLAPD_LDBM_MIN_MAXIDS /
 115             li->li_dbcache[i].dbc_maxids) + 1;
 116
 117         Debug( LDAP_DEBUG_ARGS,
 118             "ldbm_cache_open (blksize %ld) (maxids %d) (maxindirect %d)\n",
 119             li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
 120             li->li_dbcache[i].dbc_maxindirect );
 121         Debug( LDAP_DEBUG_TRACE, "<= ldbm_cache_open (opened %d)\n", i, 0, 0 );
 122         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 123         return( &li->li_dbcache[i] );
 124 }
 125
 126 void
 127 ldbm_cache_close( Backend *be, struct dbcache *db )
 128 {
 129         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 130
 131         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 132         if ( --db->dbc_refcnt == 0 ) {
 133                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 134         }
 135         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 136 }
 137
 138 void
 139 ldbm_cache_really_close( Backend *be, struct dbcache *db )
 140 {
 141         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 142
 143         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 144         if ( --db->dbc_refcnt == 0 ) {
 145                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 146                 ldbm_close( db->dbc_db );
 147                 free( db->dbc_name );
 148                 db->dbc_name = NULL;
 149         }
 150         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 151 }
 152
 153 void
 154 ldbm_cache_flush_all( Backend *be )
 155 {
 156         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 157         int             i;
 158
 159         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 160         for ( i = 0; i < MAXDBCACHE; i++ ) {
 161                 if ( li->li_dbcache[i].dbc_name != NULL ) {
 162                         Debug( LDAP_DEBUG_TRACE, "ldbm flushing db (%s)\n",
 163                             li->li_dbcache[i].dbc_name, 0, 0 );
 164                         ldbm_sync( li->li_dbcache[i].dbc_db );
 165                 }
 166         }
 167         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 168 }
 169
 170 Datum
 171 ldbm_cache_fetch(
 172     struct dbcache      *db,
 173     Datum               key
 174 )
 175 {
 176         Datum   data;
 177
 178         ldbm_datum_init( data );
 179
 180         data = ldbm_fetch( db->dbc_db, key );
 181
 182         return( data );
 183 }
 184
 185 int
 186 ldbm_cache_store(
 187     struct dbcache      *db,
 188     Datum               key,
 189     Datum               data,
 190     int                 flags
 191 )
 192 {
 193         int     rc;
 194
 195 #ifdef LDBM_DEBUG
 196         Statslog( LDAP_DEBUG_STATS,
 197                 "=> ldbm_cache_store(): key.dptr=%s, key.dsize=%d\n",
 198                 key.dptr, key.dsize, 0, 0, 0 );
 199
 200         Statslog( LDAP_DEBUG_STATS,
 201                 "=> ldbm_cache_store(): key.dptr=0x%08x, data.dptr=0x%0 8x\n",
 202                 key.dptr, data.dptr, 0, 0, 0 );
 203
 204         Statslog( LDAP_DEBUG_STATS,
 205                 "=> ldbm_cache_store(): data.dptr=%s, data.dsize=%d\n",
 206                 data.dptr, data.dsize, 0, 0, 0 );
 207
 208         Statslog( LDAP_DEBUG_STATS,
 209                 "=> ldbm_cache_store(): flags=0x%08x\n",
 210                 flags, 0, 0, 0, 0 );
 211 #endif /* LDBM_DEBUG */
 212
 213         rc = ldbm_store( db->dbc_db, key, data, flags );
 214
 215         return( rc );
 216 }
 217
 218 int
 219 ldbm_cache_delete(
 220     struct dbcache      *db,
 221     Datum               key
 222 )
 223 {
 224         int     rc;
 225
 226         rc = ldbm_delete( db->dbc_db, key );
 227
 228         return( rc );
 229 }