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, empty;
  31         time_t          oldtime, curtime;
  32         char            buf[MAXPATHLEN];
  33 #ifdef HAVE_ST_BLKSIZE
  34         struct stat     st;
  35 #endif
  36
  37         if (li->li_envdirok)
  38                 sprintf( buf, "%s%s", name, suffix );
  39         else
  40                 sprintf( buf, "%s" LDAP_DIRSEP "%s%s",
  41                         li->li_directory, name, suffix );
  42
  43         if( li->li_dblocking ) {
  44                 flags |= LDBM_LOCKING;
  45         } else {
  46                 flags |= LDBM_NOLOCKING;
  47         }
  48
  49         if( li->li_dbwritesync && global_backendsyncfreq == 0) {
  50                 flags |= LDBM_SYNC;
  51         } else {
  52                 flags |= LDBM_NOSYNC;
  53         }
  54
  55 #ifdef NEW_LOGGING
  56         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
  57                    "ldbm_cache_open: \"%s\", %d, %o\n", buf, flags, li->li_mode ));
  58 #else
  59         Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
  60             flags, li->li_mode );
  61 #endif
  62
  63
  64         curtime = slap_get_time();
  65         empty = MAXDBCACHE;
  66
  67         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
  68         do {
  69                 lru = 0;
  70                 oldtime = curtime;
  71                 for ( i = 0; i < MAXDBCACHE; i++ ) {
  72                         /* see if this slot is free */
  73                         if ( li->li_dbcache[i].dbc_name == NULL) {
  74                                 if (empty == MAXDBCACHE)
  75                                         empty = i;
  76                                 continue;
  77                         }
  78
  79                         if ( strcmp( li->li_dbcache[i].dbc_name, buf ) == 0 ) {
  80                                 /* already open - return it */
  81                                 if (li->li_dbcache[i].dbc_flags != flags
  82                                         && li->li_dbcache[i].dbc_refcnt == 0)
  83                                 {
  84                                         /* we don't want to use an open cache with different
  85                                          * permissions (esp. if we need write but the open
  86                                          * cache is read-only).  So close this one if
  87                                          * possible, and re-open below.
  88                                          *
  89                                          * FIXME:  what about the case where the refcount
  90                                          * is > 0?  right now, we're using it anyway and
  91                                          * just praying.  Can there be more than one open
  92                                          * cache to the same db?
  93                                          *
  94                                          * Also, it's really only necessary to compare the
  95                                          * read-only flag, instead of all of the flags,
  96                                          * but for now I'm checking all of them.
  97                                          */
  98                                         lru = i;
  99                                         empty = MAXDBCACHE;
 100                                         break;
 101                                 }
 102                                 li->li_dbcache[i].dbc_refcnt++;
 103 #ifdef NEW_LOGGING
 104                                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 105                                            "ldbm_cache_open: cache %d\n", i ));
 106 #else
 107                                 Debug( LDAP_DEBUG_TRACE,
 108                                     "<= ldbm_cache_open (cache %d)\n", i, 0, 0 );
 109 #endif
 110
 111                                 ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 112                                 return( &li->li_dbcache[i] );
 113                         }
 114
 115                         /* keep track of lru db */
 116                         if ( li->li_dbcache[i].dbc_lastref < oldtime
 117                                 && li->li_dbcache[i].dbc_refcnt == 0 )
 118                         {
 119                                 lru = i;
 120                                 oldtime = li->li_dbcache[i].dbc_lastref;
 121                         }
 122                 }
 123
 124                 i = empty;
 125                 if ( i == MAXDBCACHE ) {
 126                         /* no empty slots, not already open - close lru and use that slot */
 127                         if ( li->li_dbcache[lru].dbc_refcnt == 0 ) {
 128                                 i = lru;
 129                                 ldbm_close( li->li_dbcache[i].dbc_db );
 130                                 free( li->li_dbcache[i].dbc_name );
 131                                 li->li_dbcache[i].dbc_name = NULL;
 132                         } else {
 133 #ifdef NEW_LOGGING
 134                                 LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 135                                            "ldbm_cache_open: no unused db to close - waiting\n" ));
 136 #else
 137                                 Debug( LDAP_DEBUG_ANY,
 138                                     "ldbm_cache_open no unused db to close - waiting\n",
 139                                     0, 0, 0 );
 140 #endif
 141
 142                                 ldap_pvt_thread_cond_wait( &li->li_dbcache_cv,
 143                                             &li->li_dbcache_mutex );
 144                                 /* after waiting for a free slot, go back to square
 145                                  * one: look for an open cache for this db, or an
 146                                  * empty slot, or an unref'ed cache, or wait again.
 147                                  */
 148                         }
 149                 }
 150         } while (i == MAXDBCACHE);
 151
 152         if ( (li->li_dbcache[i].dbc_db = ldbm_open( li->li_dbenv, buf, flags, li->li_mode,
 153             li->li_dbcachesize )) == NULL )
 154         {
 155                 int err = errno;
 156 #ifdef NEW_LOGGING
 157                 LDAP_LOG(( "cache", LDAP_LEVEL_ERR,
 158                            "ldbm_cache_open: \"%s\" failed, errono=%d, reason=%s\n",
 159                            buf, err, err > -1 && err < sys_nerr ? sys_errlist[err] :
 160                            "unknown" ));
 161 #else
 162                 Debug( LDAP_DEBUG_TRACE,
 163                     "<= ldbm_cache_open NULL \"%s\" errno=%d reason=\"%s\")\n",
 164                     buf, err, err > -1 && err < sys_nerr ?
 165                     sys_errlist[err] : "unknown" );
 166 #endif
 167
 168                 ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 169                 return( NULL );
 170         }
 171         li->li_dbcache[i].dbc_name = ch_strdup( buf );
 172         li->li_dbcache[i].dbc_refcnt = 1;
 173         li->li_dbcache[i].dbc_lastref = curtime;
 174         li->li_dbcache[i].dbc_flags = flags;
 175         li->li_dbcache[i].dbc_dirty = 0;
 176 #ifdef HAVE_ST_BLKSIZE
 177         if ( stat( buf, &st ) == 0 ) {
 178                 li->li_dbcache[i].dbc_blksize = st.st_blksize;
 179         } else
 180 #endif
 181         {
 182                 li->li_dbcache[i].dbc_blksize = DEFAULT_BLOCKSIZE;
 183         }
 184         li->li_dbcache[i].dbc_maxids = (li->li_dbcache[i].dbc_blksize /
 185             sizeof(ID)) - ID_BLOCK_IDS_OFFSET;
 186         li->li_dbcache[i].dbc_maxindirect = ( SLAPD_LDBM_MIN_MAXIDS /
 187             li->li_dbcache[i].dbc_maxids ) + 1;
 188
 189         assert( li->li_dbcache[i].dbc_maxindirect < 256 );
 190
 191 #ifdef NEW_LOGGING
 192         LDAP_LOG(( "cache", LDAP_LEVEL_ARGS,
 193                    "ldbm_cache_open: blksize:%ld  maxids:%d  maxindirect:%d\n",
 194                    li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
 195                    li->li_dbcache[i].dbc_maxindirect ));
 196 #else
 197         Debug( LDAP_DEBUG_ARGS,
 198             "ldbm_cache_open (blksize %ld) (maxids %d) (maxindirect %d)\n",
 199             li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
 200             li->li_dbcache[i].dbc_maxindirect );
 201 #endif
 202
 203 #ifdef NEW_LOGGING
 204         LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 205                    "ldbm_cache_open: opened %d\n", i ));
 206 #else
 207         Debug( LDAP_DEBUG_TRACE, "<= ldbm_cache_open (opened %d)\n", i, 0, 0 );
 208 #endif
 209
 210         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 211         return( &li->li_dbcache[i] );
 212 }
 213
 214 void
 215 ldbm_cache_close( Backend *be, DBCache *db )
 216 {
 217         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 218
 219         if( li->li_dbwritesync && db->dbc_dirty ) {
 220                 ldbm_sync( db->dbc_db );
 221                 db->dbc_dirty = 0;
 222         }
 223
 224         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 225         if ( --db->dbc_refcnt <= 0 ) {
 226                 db->dbc_refcnt = 0;
 227                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 228         }
 229         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 230 }
 231
 232 void
 233 ldbm_cache_really_close( Backend *be, DBCache *db )
 234 {
 235         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 236
 237         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 238         if ( --db->dbc_refcnt <= 0 ) {
 239                 db->dbc_refcnt = 0;
 240                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 241                 ldbm_close( db->dbc_db );
 242                 free( db->dbc_name );
 243                 db->dbc_name = NULL;
 244         }
 245         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 246 }
 247
 248 void
 249 ldbm_cache_flush_all( Backend *be )
 250 {
 251         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 252         int             i;
 253
 254         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 255         for ( i = 0; i < MAXDBCACHE; i++ ) {
 256                 if ( li->li_dbcache[i].dbc_name != NULL ) {
 257 #ifdef NEW_LOGGING
 258                         LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 259                                    "ldbm_cache_flush_all: flushing db (%s)\n",
 260                                    li->li_dbcache[i].dbc_name ));
 261 #else
 262                         Debug( LDAP_DEBUG_TRACE, "ldbm flushing db (%s)\n",
 263                             li->li_dbcache[i].dbc_name, 0, 0 );
 264 #endif
 265
 266                         ldbm_sync( li->li_dbcache[i].dbc_db );
 267                         li->li_dbcache[i].dbc_dirty = 0;
 268                         if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
 269 #ifdef NEW_LOGGING
 270                                 LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 271                                            "ldbm_cache_flush_all: couldn't close db (%s), refcnt=%d\n",
 272                                            li->li_dbcache[i].dbc_name, li->li_dbcache[i].dbc_refcnt ));
 273 #else
 274                                 Debug( LDAP_DEBUG_TRACE,
 275                                        "refcnt = %d, couldn't close db (%s)\n",
 276                                        li->li_dbcache[i].dbc_refcnt,
 277                                        li->li_dbcache[i].dbc_name, 0 );
 278 #endif
 279
 280                         } else {
 281 #ifdef NEW_LOGGING
 282                                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 283                                            "ldbm_cache_flush_all: ldbm closing db (%s)\n",
 284                                            li->li_dbcache[i].dbc_name ));
 285 #else
 286                                 Debug( LDAP_DEBUG_TRACE,
 287                                        "ldbm closing db (%s)\n",
 288                                        li->li_dbcache[i].dbc_name, 0, 0 );
 289 #endif
 290
 291                                 ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
 292                                 ldbm_close( li->li_dbcache[i].dbc_db );
 293                                 free( li->li_dbcache[i].dbc_name );
 294                                 li->li_dbcache[i].dbc_name = NULL;
 295                         }
 296                 }
 297         }
 298         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 299 }
 300
 301 void
 302 ldbm_cache_sync( Backend *be )
 303 {
 304         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 305         int             i;
 306
 307         ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 308         for ( i = 0; i < MAXDBCACHE; i++ ) {
 309                 if ( li->li_dbcache[i].dbc_name != NULL && li->li_dbcache[i].dbc_dirty ) {
 310                         Debug(  LDAP_DEBUG_TRACE, "ldbm syncing db (%s)\n",
 311                                 li->li_dbcache[i].dbc_name, 0, 0 );
 312                         ldbm_sync( li->li_dbcache[i].dbc_db );
 313                         li->li_dbcache[i].dbc_dirty = 0;
 314                 }
 315         }
 316         ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
 317 }
 318
 319 Datum
 320 ldbm_cache_fetch(
 321     DBCache     *db,
 322     Datum               key
 323 )
 324 {
 325         Datum   data;
 326
 327         return ldbm_fetch( db->dbc_db, key );
 328
 329         return( data );
 330 }
 331
 332 int
 333 ldbm_cache_store(
 334     DBCache     *db,
 335     Datum               key,
 336     Datum               data,
 337     int                 flags
 338 )
 339 {
 340         int     rc;
 341
 342 #ifdef LDBM_DEBUG
 343         Statslog( LDAP_DEBUG_STATS,
 344                 "=> ldbm_cache_store(): key.dptr=%s, key.dsize=%d\n",
 345                 key.dptr, key.dsize, 0, 0, 0 );
 346
 347         Statslog( LDAP_DEBUG_STATS,
 348                 "=> ldbm_cache_store(): key.dptr=0x%08x, data.dptr=0x%0 8x\n",
 349                 key.dptr, data.dptr, 0, 0, 0 );
 350
 351         Statslog( LDAP_DEBUG_STATS,
 352                 "=> ldbm_cache_store(): data.dptr=%s, data.dsize=%d\n",
 353                 data.dptr, data.dsize, 0, 0, 0 );
 354
 355         Statslog( LDAP_DEBUG_STATS,
 356                 "=> ldbm_cache_store(): flags=0x%08x\n",
 357                 flags, 0, 0, 0, 0 );
 358 #endif /* LDBM_DEBUG */
 359
 360         db->dbc_dirty = 1;
 361         rc = ldbm_store( db->dbc_db, key, data, flags );
 362
 363         return( rc );
 364 }
 365
 366 int
 367 ldbm_cache_delete(
 368     DBCache     *db,
 369     Datum               key
 370 )
 371 {
 372         int     rc;
 373
 374         db->dbc_dirty = 1;
 375         rc = ldbm_delete( db->dbc_db, key );
 376
 377         return( rc );
 378 }