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

   1 /* ldbmcache.c - maintain a cache of open ldbm files */
   2 /* $OpenLDAP$ */
   3 /*
   4  * Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
   5  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   6  */
   7
   8 #include "portable.h"
   9
  10 #include <stdio.h>
  11
  12 #include <ac/errno.h>
  13 #include <ac/socket.h>
  14 #include <ac/string.h>
  15 #include <ac/time.h>
  16 #include <sys/stat.h>
  17
  18 #include "slap.h"
  19 #include "back-ldbm.h"
  20
  21 DBCache *
  22 ldbm_cache_open(
  23     Backend     *be,
  24     const char  *name,
  25     const char  *suffix,
  26     int         flags
  27 )
  28 {
  29         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
  30         int             i, lru;
  31         time_t          oldtime, curtime;
  32         char            buf[MAXPATHLEN];
  33 #ifdef HAVE_ST_BLKSIZE
  34         struct stat     st;
  35 #endif
  36
  37         sprintf( buf, "%s" LDAP_DIRSEP "%s%s",
  38                 li->li_directory, name, suffix );
  39
  40         if( li->li_dblocking ) {
  41                 flags |= LDBM_LOCKING;
  42         } else {
  43                 flags |= LDBM_NOLOCKING;
  44         }
  45
  46         if( li->li_dbwritesync ) {
  47                 flags |= LDBM_SYNC;
  48         } else {
  49                 flags |= LDBM_NOSYNC;
  50         }
  51
  52         Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
  53             flags, li->li_mode );
  54
  55         lru = 0;
  56         curtime = slap_get_time();
  57         oldtime = curtime;
  58
  59         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
  60         for ( i = 0; i < MAXDBCACHE && li->li_dbcache[i].dbc_name != NULL;
  61             i++ ) {
  62                 /* already open - return it */
  63                 if ( strcmp( li->li_dbcache[i].dbc_name, buf ) == 0 ) {
  64                         li->li_dbcache[i].dbc_refcnt++;
  65                         Debug( LDAP_DEBUG_TRACE,
  66                             "<= ldbm_cache_open (cache %d)\n", i, 0, 0 );
  67                         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
  68                         return( &li->li_dbcache[i] );
  69                 }
  70
  71                 /* keep track of lru db */
  72                 if ( li->li_dbcache[i].dbc_lastref < oldtime &&
  73                     li->li_dbcache[i].dbc_refcnt == 0 ) {
  74                         lru = i;
  75                         oldtime = li->li_dbcache[i].dbc_lastref;
  76                 }
  77         }
  78
  79         /* no empty slots, not already open - close lru and use that slot */
  80         if ( i == MAXDBCACHE ) {
  81                 i = lru;
  82                 if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
  83                         Debug( LDAP_DEBUG_ANY,
  84                             "ldbm_cache_open no unused db to close - waiting\n",
  85                             0, 0, 0 );
  86                         lru = -1;
  87                         while ( lru == -1 ) {
  88                                 ldap_pvt_thread_cond_wait( &li->li_dbcache_cv,
  89                                     &li->li_dbcache_mutex );
  90                                 for ( i = 0; i < MAXDBCACHE; i++ ) {
  91                                         if ( li->li_dbcache[i].dbc_refcnt
  92                                             == 0 ) {
  93                                                 lru = i;
  94                                                 break;
  95                                         }
  96                                 }
  97                         }
  98                         i = lru;
  99                 }
 100                 ldbm_close( li->li_dbcache[i].dbc_db );
 101                 free( li->li_dbcache[i].dbc_name );
 102                 li->li_dbcache[i].dbc_name = NULL;
 103         }
 104
 105         if ( (li->li_dbcache[i].dbc_db = ldbm_open( buf, flags, li->li_mode,
 106             li->li_dbcachesize )) == NULL ) {
 107                 int err = errno;
 108                 Debug( LDAP_DEBUG_TRACE,
 109                     "<= ldbm_cache_open NULL \"%s\" errno=%d reason=\"%s\")\n",
 110                     buf, err, err > -1 && err < sys_nerr ?
 111                     sys_errlist[err] : "unknown" );
 112                 ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 113                 return( NULL );
 114         }
 115         li->li_dbcache[i].dbc_name = ch_strdup( buf );
 116         li->li_dbcache[i].dbc_refcnt = 1;
 117         li->li_dbcache[i].dbc_lastref = curtime;
 118         li->li_dbcache[i].dbc_dirty = 0;
 119 #ifdef HAVE_ST_BLKSIZE
 120         if ( stat( buf, &st ) == 0 ) {
 121                 li->li_dbcache[i].dbc_blksize = st.st_blksize;
 122         } else
 123 #endif
 124         {
 125                 li->li_dbcache[i].dbc_blksize = DEFAULT_BLOCKSIZE;
 126         }
 127         li->li_dbcache[i].dbc_maxids = (li->li_dbcache[i].dbc_blksize /
 128             sizeof(ID)) - ID_BLOCK_IDS_OFFSET;
 129         li->li_dbcache[i].dbc_maxindirect = ( SLAPD_LDBM_MIN_MAXIDS /
 130             li->li_dbcache[i].dbc_maxids ) + 1;
 131
 132         assert( li->li_dbcache[i].dbc_maxindirect < 256 );
 133
 134         Debug( LDAP_DEBUG_ARGS,
 135             "ldbm_cache_open (blksize %ld) (maxids %d) (maxindirect %d)\n",
 136             li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
 137             li->li_dbcache[i].dbc_maxindirect );
 138         Debug( LDAP_DEBUG_TRACE, "<= ldbm_cache_open (opened %d)\n", i, 0, 0 );
 139         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 140         return( &li->li_dbcache[i] );
 141 }
 142
 143 void
 144 ldbm_cache_close( Backend *be, DBCache *db )
 145 {
 146         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 147
 148         if( li->li_dbwritesync && db->dbc_dirty ) {
 149                 ldbm_sync( db->dbc_db );
 150                 db->dbc_dirty = 0;
 151         }
 152
 153         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 154         if ( --db->dbc_refcnt == 0 ) {
 155                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 156         }
 157         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 158 }
 159
 160 void
 161 ldbm_cache_really_close( Backend *be, DBCache *db )
 162 {
 163         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 164
 165         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 166         if ( --db->dbc_refcnt == 0 ) {
 167                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 168                 ldbm_close( db->dbc_db );
 169                 free( db->dbc_name );
 170                 db->dbc_name = NULL;
 171         }
 172         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 173 }
 174
 175 void
 176 ldbm_cache_flush_all( Backend *be )
 177 {
 178         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 179         int             i;
 180
 181         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 182         for ( i = 0; i < MAXDBCACHE; i++ ) {
 183                 if ( li->li_dbcache[i].dbc_name != NULL ) {
 184                         Debug( LDAP_DEBUG_TRACE, "ldbm flushing db (%s)\n",
 185                             li->li_dbcache[i].dbc_name, 0, 0 );
 186                         ldbm_sync( li->li_dbcache[i].dbc_db );
 187                         li->li_dbcache[i].dbc_dirty = 0;
 188                         if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
 189                                 Debug( LDAP_DEBUG_TRACE,
 190                                        "refcnt = %d, couldn't close db (%s)\n",
 191                                        li->li_dbcache[i].dbc_refcnt,
 192                                        li->li_dbcache[i].dbc_name, 0 );
 193                         } else {
 194                                 Debug( LDAP_DEBUG_TRACE,
 195                                        "ldbm closing db (%s)\n",
 196                                        li->li_dbcache[i].dbc_name, 0, 0 );
 197                                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 198                                 ldbm_close( li->li_dbcache[i].dbc_db );
 199                                 free( li->li_dbcache[i].dbc_name );
 200                                 li->li_dbcache[i].dbc_name = NULL;
 201                         }
 202                 }
 203         }
 204         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 205 }
 206
 207 Datum
 208 ldbm_cache_fetch(
 209     DBCache     *db,
 210     Datum               key
 211 )
 212 {
 213         Datum   data;
 214
 215         return ldbm_fetch( db->dbc_db, key );
 216
 217         return( data );
 218 }
 219
 220 int
 221 ldbm_cache_store(
 222     DBCache     *db,
 223     Datum               key,
 224     Datum               data,
 225     int                 flags
 226 )
 227 {
 228         int     rc;
 229
 230 #ifdef LDBM_DEBUG
 231         Statslog( LDAP_DEBUG_STATS,
 232                 "=> ldbm_cache_store(): key.dptr=%s, key.dsize=%d\n",
 233                 key.dptr, key.dsize, 0, 0, 0 );
 234
 235         Statslog( LDAP_DEBUG_STATS,
 236                 "=> ldbm_cache_store(): key.dptr=0x%08x, data.dptr=0x%0 8x\n",
 237                 key.dptr, data.dptr, 0, 0, 0 );
 238
 239         Statslog( LDAP_DEBUG_STATS,
 240                 "=> ldbm_cache_store(): data.dptr=%s, data.dsize=%d\n",
 241                 data.dptr, data.dsize, 0, 0, 0 );
 242
 243         Statslog( LDAP_DEBUG_STATS,
 244                 "=> ldbm_cache_store(): flags=0x%08x\n",
 245                 flags, 0, 0, 0, 0 );
 246 #endif /* LDBM_DEBUG */
 247
 248         db->dbc_dirty = 1;
 249         rc = ldbm_store( db->dbc_db, key, data, flags );
 250
 251         return( rc );
 252 }
 253
 254 int
 255 ldbm_cache_delete(
 256     DBCache     *db,
 257     Datum               key
 258 )
 259 {
 260         int     rc;
 261
 262         db->dbc_dirty = 1;
 263         rc = ldbm_delete( db->dbc_db, key );
 264
 265         return( rc );
 266 }