git.sur5r.net Git - openldap/blob - servers/slapd/back-bdb/idl.c

   1 /* idl.c - ldap id list handling routines */
   2 /* $OpenLDAP$ */
   3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   4  *
   5  * Copyright 2000-2018 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16
  17 #include "portable.h"
  18
  19 #include <stdio.h>
  20 #include <ac/string.h>
  21
  22 #include "back-bdb.h"
  23 #include "idl.h"
  24
  25 #define IDL_MAX(x,y)    ( (x) > (y) ? (x) : (y) )
  26 #define IDL_MIN(x,y)    ( (x) < (y) ? (x) : (y) )
  27 #define IDL_CMP(x,y)    ( (x) < (y) ? -1 : (x) > (y) )
  28
  29 #define IDL_LRU_DELETE( bdb, e ) do { \
  30         if ( (e) == (bdb)->bi_idl_lru_head ) { \
  31                 if ( (e)->idl_lru_next == (bdb)->bi_idl_lru_head ) { \
  32                         (bdb)->bi_idl_lru_head = NULL; \
  33                 } else { \
  34                         (bdb)->bi_idl_lru_head = (e)->idl_lru_next; \
  35                 } \
  36         } \
  37         if ( (e) == (bdb)->bi_idl_lru_tail ) { \
  38                 if ( (e)->idl_lru_prev == (bdb)->bi_idl_lru_tail ) { \
  39                         assert( (bdb)->bi_idl_lru_head == NULL ); \
  40                         (bdb)->bi_idl_lru_tail = NULL; \
  41                 } else { \
  42                         (bdb)->bi_idl_lru_tail = (e)->idl_lru_prev; \
  43                 } \
  44         } \
  45         (e)->idl_lru_next->idl_lru_prev = (e)->idl_lru_prev; \
  46         (e)->idl_lru_prev->idl_lru_next = (e)->idl_lru_next; \
  47 } while ( 0 )
  48
  49 static int
  50 bdb_idl_entry_cmp( const void *v_idl1, const void *v_idl2 )
  51 {
  52         const bdb_idl_cache_entry_t *idl1 = v_idl1, *idl2 = v_idl2;
  53         int rc;
  54
  55         if ((rc = SLAP_PTRCMP( idl1->db, idl2->db ))) return rc;
  56         if ((rc = idl1->kstr.bv_len - idl2->kstr.bv_len )) return rc;
  57         return ( memcmp ( idl1->kstr.bv_val, idl2->kstr.bv_val , idl1->kstr.bv_len ) );
  58 }
  59
  60 #if IDL_DEBUG > 0
  61 static void idl_check( ID *ids )
  62 {
  63         if( BDB_IDL_IS_RANGE( ids ) ) {
  64                 assert( BDB_IDL_RANGE_FIRST(ids) <= BDB_IDL_RANGE_LAST(ids) );
  65         } else {
  66                 ID i;
  67                 for( i=1; i < ids[0]; i++ ) {
  68                         assert( ids[i+1] > ids[i] );
  69                 }
  70         }
  71 }
  72
  73 #if IDL_DEBUG > 1
  74 static void idl_dump( ID *ids )
  75 {
  76         if( BDB_IDL_IS_RANGE( ids ) ) {
  77                 Debug( LDAP_DEBUG_ANY,
  78                         "IDL: range ( %ld - %ld )\n",
  79                         (long) BDB_IDL_RANGE_FIRST( ids ),
  80                         (long) BDB_IDL_RANGE_LAST( ids ) );
  81
  82         } else {
  83                 ID i;
  84                 Debug( LDAP_DEBUG_ANY, "IDL: size %ld", (long) ids[0], 0, 0 );
  85
  86                 for( i=1; i<=ids[0]; i++ ) {
  87                         if( i % 16 == 1 ) {
  88                                 Debug( LDAP_DEBUG_ANY, "\n", 0, 0, 0 );
  89                         }
  90                         Debug( LDAP_DEBUG_ANY, "  %02lx", (long) ids[i], 0, 0 );
  91                 }
  92
  93                 Debug( LDAP_DEBUG_ANY, "\n", 0, 0, 0 );
  94         }
  95
  96         idl_check( ids );
  97 }
  98 #endif /* IDL_DEBUG > 1 */
  99 #endif /* IDL_DEBUG > 0 */
 100
 101 unsigned bdb_idl_search( ID *ids, ID id )
 102 {
 103 #define IDL_BINARY_SEARCH 1
 104 #ifdef IDL_BINARY_SEARCH
 105         /*
 106          * binary search of id in ids
 107          * if found, returns position of id
 108          * if not found, returns first postion greater than id
 109          */
 110         unsigned base = 0;
 111         unsigned cursor = 1;
 112         int val = 0;
 113         unsigned n = ids[0];
 114
 115 #if IDL_DEBUG > 0
 116         idl_check( ids );
 117 #endif
 118
 119         while( 0 < n ) {
 120                 unsigned pivot = n >> 1;
 121                 cursor = base + pivot + 1;
 122                 val = IDL_CMP( id, ids[cursor] );
 123
 124                 if( val < 0 ) {
 125                         n = pivot;
 126
 127                 } else if ( val > 0 ) {
 128                         base = cursor;
 129                         n -= pivot + 1;
 130
 131                 } else {
 132                         return cursor;
 133                 }
 134         }
 135
 136         if( val > 0 ) {
 137                 ++cursor;
 138         }
 139         return cursor;
 140
 141 #else
 142         /* (reverse) linear search */
 143         int i;
 144
 145 #if IDL_DEBUG > 0
 146         idl_check( ids );
 147 #endif
 148
 149         for( i=ids[0]; i; i-- ) {
 150                 if( id > ids[i] ) {
 151                         break;
 152                 }
 153         }
 154
 155         return i+1;
 156 #endif
 157 }
 158
 159 int bdb_idl_insert( ID *ids, ID id )
 160 {
 161         unsigned x;
 162
 163 #if IDL_DEBUG > 1
 164         Debug( LDAP_DEBUG_ANY, "insert: %04lx at %d\n", (long) id, x, 0 );
 165         idl_dump( ids );
 166 #elif IDL_DEBUG > 0
 167         idl_check( ids );
 168 #endif
 169
 170         if (BDB_IDL_IS_RANGE( ids )) {
 171                 /* if already in range, treat as a dup */
 172                 if (id >= BDB_IDL_RANGE_FIRST(ids) && id <= BDB_IDL_RANGE_LAST(ids))
 173                         return -1;
 174                 if (id < BDB_IDL_RANGE_FIRST(ids))
 175                         ids[1] = id;
 176                 else if (id > BDB_IDL_RANGE_LAST(ids))
 177                         ids[2] = id;
 178                 return 0;
 179         }
 180
 181         x = bdb_idl_search( ids, id );
 182         assert( x > 0 );
 183
 184         if( x < 1 ) {
 185                 /* internal error */
 186                 return -2;
 187         }
 188
 189         if ( x <= ids[0] && ids[x] == id ) {
 190                 /* duplicate */
 191                 return -1;
 192         }
 193
 194         if ( ++ids[0] >= BDB_IDL_DB_MAX ) {
 195                 if( id < ids[1] ) {
 196                         ids[1] = id;
 197                         ids[2] = ids[ids[0]-1];
 198                 } else if ( ids[ids[0]-1] < id ) {
 199                         ids[2] = id;
 200                 } else {
 201                         ids[2] = ids[ids[0]-1];
 202                 }
 203                 ids[0] = NOID;
 204
 205         } else {
 206                 /* insert id */
 207                 AC_MEMCPY( &ids[x+1], &ids[x], (ids[0]-x) * sizeof(ID) );
 208                 ids[x] = id;
 209         }
 210
 211 #if IDL_DEBUG > 1
 212         idl_dump( ids );
 213 #elif IDL_DEBUG > 0
 214         idl_check( ids );
 215 #endif
 216
 217         return 0;
 218 }
 219
 220 int bdb_idl_delete( ID *ids, ID id )
 221 {
 222         unsigned x;
 223
 224 #if IDL_DEBUG > 1
 225         Debug( LDAP_DEBUG_ANY, "delete: %04lx at %d\n", (long) id, x, 0 );
 226         idl_dump( ids );
 227 #elif IDL_DEBUG > 0
 228         idl_check( ids );
 229 #endif
 230
 231         if (BDB_IDL_IS_RANGE( ids )) {
 232                 /* If deleting a range boundary, adjust */
 233                 if ( ids[1] == id )
 234                         ids[1]++;
 235                 else if ( ids[2] == id )
 236                         ids[2]--;
 237                 /* deleting from inside a range is a no-op */
 238
 239                 /* If the range has collapsed, re-adjust */
 240                 if ( ids[1] > ids[2] )
 241                         ids[0] = 0;
 242                 else if ( ids[1] == ids[2] )
 243                         ids[1] = 1;
 244                 return 0;
 245         }
 246
 247         x = bdb_idl_search( ids, id );
 248         assert( x > 0 );
 249
 250         if( x <= 0 ) {
 251                 /* internal error */
 252                 return -2;
 253         }
 254
 255         if( x > ids[0] || ids[x] != id ) {
 256                 /* not found */
 257                 return -1;
 258
 259         } else if ( --ids[0] == 0 ) {
 260                 if( x != 1 ) {
 261                         return -3;
 262                 }
 263
 264         } else {
 265                 AC_MEMCPY( &ids[x], &ids[x+1], (1+ids[0]-x) * sizeof(ID) );
 266         }
 267
 268 #if IDL_DEBUG > 1
 269         idl_dump( ids );
 270 #elif IDL_DEBUG > 0
 271         idl_check( ids );
 272 #endif
 273
 274         return 0;
 275 }
 276
 277 static char *
 278 bdb_show_key(
 279         DBT             *key,
 280         char            *buf )
 281 {
 282         if ( key->size == 4 /* LUTIL_HASH_BYTES */ ) {
 283                 unsigned char *c = key->data;
 284                 sprintf( buf, "[%02x%02x%02x%02x]", c[0], c[1], c[2], c[3] );
 285                 return buf;
 286         } else {
 287                 return key->data;
 288         }
 289 }
 290
 291 /* Find a db/key pair in the IDL cache. If ids is non-NULL,
 292  * copy the cached IDL into it, otherwise just return the status.
 293  */
 294 int
 295 bdb_idl_cache_get(
 296         struct bdb_info *bdb,
 297         DB                      *db,
 298         DBT                     *key,
 299         ID                      *ids )
 300 {
 301         bdb_idl_cache_entry_t idl_tmp;
 302         bdb_idl_cache_entry_t *matched_idl_entry;
 303         int rc = LDAP_NO_SUCH_OBJECT;
 304
 305         DBT2bv( key, &idl_tmp.kstr );
 306         idl_tmp.db = db;
 307         ldap_pvt_thread_rdwr_rlock( &bdb->bi_idl_tree_rwlock );
 308         matched_idl_entry = avl_find( bdb->bi_idl_tree, &idl_tmp,
 309                                       bdb_idl_entry_cmp );
 310         if ( matched_idl_entry != NULL ) {
 311                 if ( matched_idl_entry->idl && ids )
 312                         BDB_IDL_CPY( ids, matched_idl_entry->idl );
 313                 matched_idl_entry->idl_flags |= CACHE_ENTRY_REFERENCED;
 314                 if ( matched_idl_entry->idl )
 315                         rc = LDAP_SUCCESS;
 316                 else
 317                         rc = DB_NOTFOUND;
 318         }
 319         ldap_pvt_thread_rdwr_runlock( &bdb->bi_idl_tree_rwlock );
 320
 321         return rc;
 322 }
 323
 324 void
 325 bdb_idl_cache_put(
 326         struct bdb_info *bdb,
 327         DB                      *db,
 328         DBT                     *key,
 329         ID                      *ids,
 330         int                     rc )
 331 {
 332         bdb_idl_cache_entry_t idl_tmp;
 333         bdb_idl_cache_entry_t *ee, *eprev;
 334
 335         if ( rc == DB_NOTFOUND || BDB_IDL_IS_ZERO( ids ))
 336                 return;
 337
 338         DBT2bv( key, &idl_tmp.kstr );
 339
 340         ee = (bdb_idl_cache_entry_t *) ch_malloc(
 341                 sizeof( bdb_idl_cache_entry_t ) );
 342         ee->db = db;
 343         ee->idl = (ID*) ch_malloc( BDB_IDL_SIZEOF ( ids ) );
 344         BDB_IDL_CPY( ee->idl, ids );
 345
 346         ee->idl_lru_prev = NULL;
 347         ee->idl_lru_next = NULL;
 348         ee->idl_flags = 0;
 349         ber_dupbv( &ee->kstr, &idl_tmp.kstr );
 350         ldap_pvt_thread_rdwr_wlock( &bdb->bi_idl_tree_rwlock );
 351         if ( avl_insert( &bdb->bi_idl_tree, (caddr_t) ee,
 352                 bdb_idl_entry_cmp, avl_dup_error ))
 353         {
 354                 ch_free( ee->kstr.bv_val );
 355                 ch_free( ee->idl );
 356                 ch_free( ee );
 357                 ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
 358                 return;
 359         }
 360         ldap_pvt_thread_mutex_lock( &bdb->bi_idl_tree_lrulock );
 361         /* LRU_ADD */
 362         if ( bdb->bi_idl_lru_head ) {
 363                 assert( bdb->bi_idl_lru_tail != NULL );
 364                 assert( bdb->bi_idl_lru_head->idl_lru_prev != NULL );
 365                 assert( bdb->bi_idl_lru_head->idl_lru_next != NULL );
 366
 367                 ee->idl_lru_next = bdb->bi_idl_lru_head;
 368                 ee->idl_lru_prev = bdb->bi_idl_lru_head->idl_lru_prev;
 369                 bdb->bi_idl_lru_head->idl_lru_prev->idl_lru_next = ee;
 370                 bdb->bi_idl_lru_head->idl_lru_prev = ee;
 371         } else {
 372                 ee->idl_lru_next = ee->idl_lru_prev = ee;
 373                 bdb->bi_idl_lru_tail = ee;
 374         }
 375         bdb->bi_idl_lru_head = ee;
 376
 377         if ( bdb->bi_idl_cache_size >= bdb->bi_idl_cache_max_size ) {
 378                 int i;
 379                 eprev = bdb->bi_idl_lru_tail;
 380                 for ( i = 0; (ee = eprev) != NULL && i < 10; i++ ) {
 381                         eprev = ee->idl_lru_prev;
 382                         if ( eprev == ee ) {
 383                                 eprev = NULL;
 384                         }
 385                         if ( ee->idl_flags & CACHE_ENTRY_REFERENCED ) {
 386                                 ee->idl_flags ^= CACHE_ENTRY_REFERENCED;
 387                                 continue;
 388                         }
 389                         if ( avl_delete( &bdb->bi_idl_tree, (caddr_t) ee,
 390                                     bdb_idl_entry_cmp ) == NULL ) {
 391                                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_cache_put: "
 392                                         "AVL delete failed\n",
 393                                         0, 0, 0 );
 394                         }
 395                         IDL_LRU_DELETE( bdb, ee );
 396                         i++;
 397                         --bdb->bi_idl_cache_size;
 398                         ch_free( ee->kstr.bv_val );
 399                         ch_free( ee->idl );
 400                         ch_free( ee );
 401                 }
 402                 bdb->bi_idl_lru_tail = eprev;
 403                 assert( bdb->bi_idl_lru_tail != NULL
 404                         || bdb->bi_idl_lru_head == NULL );
 405         }
 406         bdb->bi_idl_cache_size++;
 407         ldap_pvt_thread_mutex_unlock( &bdb->bi_idl_tree_lrulock );
 408         ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
 409 }
 410
 411 void
 412 bdb_idl_cache_del(
 413         struct bdb_info *bdb,
 414         DB                      *db,
 415         DBT                     *key )
 416 {
 417         bdb_idl_cache_entry_t *matched_idl_entry, idl_tmp;
 418         DBT2bv( key, &idl_tmp.kstr );
 419         idl_tmp.db = db;
 420         ldap_pvt_thread_rdwr_wlock( &bdb->bi_idl_tree_rwlock );
 421         matched_idl_entry = avl_find( bdb->bi_idl_tree, &idl_tmp,
 422                                       bdb_idl_entry_cmp );
 423         if ( matched_idl_entry != NULL ) {
 424                 if ( avl_delete( &bdb->bi_idl_tree, (caddr_t) matched_idl_entry,
 425                                     bdb_idl_entry_cmp ) == NULL ) {
 426                         Debug( LDAP_DEBUG_ANY, "=> bdb_idl_cache_del: "
 427                                 "AVL delete failed\n",
 428                                 0, 0, 0 );
 429                 }
 430                 --bdb->bi_idl_cache_size;
 431                 ldap_pvt_thread_mutex_lock( &bdb->bi_idl_tree_lrulock );
 432                 IDL_LRU_DELETE( bdb, matched_idl_entry );
 433                 ldap_pvt_thread_mutex_unlock( &bdb->bi_idl_tree_lrulock );
 434                 free( matched_idl_entry->kstr.bv_val );
 435                 if ( matched_idl_entry->idl )
 436                         free( matched_idl_entry->idl );
 437                 free( matched_idl_entry );
 438         }
 439         ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
 440 }
 441
 442 void
 443 bdb_idl_cache_add_id(
 444         struct bdb_info *bdb,
 445         DB                      *db,
 446         DBT                     *key,
 447         ID                      id )
 448 {
 449         bdb_idl_cache_entry_t *cache_entry, idl_tmp;
 450         DBT2bv( key, &idl_tmp.kstr );
 451         idl_tmp.db = db;
 452         ldap_pvt_thread_rdwr_wlock( &bdb->bi_idl_tree_rwlock );
 453         cache_entry = avl_find( bdb->bi_idl_tree, &idl_tmp,
 454                                       bdb_idl_entry_cmp );
 455         if ( cache_entry != NULL ) {
 456                 if ( !BDB_IDL_IS_RANGE( cache_entry->idl ) &&
 457                         cache_entry->idl[0] < BDB_IDL_DB_MAX ) {
 458                         size_t s = BDB_IDL_SIZEOF( cache_entry->idl ) + sizeof(ID);
 459                         cache_entry->idl = ch_realloc( cache_entry->idl, s );
 460                 }
 461                 bdb_idl_insert( cache_entry->idl, id );
 462         }
 463         ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
 464 }
 465
 466 void
 467 bdb_idl_cache_del_id(
 468         struct bdb_info *bdb,
 469         DB                      *db,
 470         DBT                     *key,
 471         ID                      id )
 472 {
 473         bdb_idl_cache_entry_t *cache_entry, idl_tmp;
 474         DBT2bv( key, &idl_tmp.kstr );
 475         idl_tmp.db = db;
 476         ldap_pvt_thread_rdwr_wlock( &bdb->bi_idl_tree_rwlock );
 477         cache_entry = avl_find( bdb->bi_idl_tree, &idl_tmp,
 478                                       bdb_idl_entry_cmp );
 479         if ( cache_entry != NULL ) {
 480                 bdb_idl_delete( cache_entry->idl, id );
 481                 if ( cache_entry->idl[0] == 0 ) {
 482                         if ( avl_delete( &bdb->bi_idl_tree, (caddr_t) cache_entry,
 483                                                 bdb_idl_entry_cmp ) == NULL ) {
 484                                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_cache_del: "
 485                                         "AVL delete failed\n",
 486                                         0, 0, 0 );
 487                         }
 488                         --bdb->bi_idl_cache_size;
 489                         ldap_pvt_thread_mutex_lock( &bdb->bi_idl_tree_lrulock );
 490                         IDL_LRU_DELETE( bdb, cache_entry );
 491                         ldap_pvt_thread_mutex_unlock( &bdb->bi_idl_tree_lrulock );
 492                         free( cache_entry->kstr.bv_val );
 493                         free( cache_entry->idl );
 494                         free( cache_entry );
 495                 }
 496         }
 497         ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
 498 }
 499
 500 int
 501 bdb_idl_fetch_key(
 502         BackendDB       *be,
 503         DB                      *db,
 504         DB_TXN          *txn,
 505         DBT                     *key,
 506         ID                      *ids,
 507         DBC                     **saved_cursor,
 508         int                     get_flag )
 509 {
 510         struct bdb_info *bdb = (struct bdb_info *) be->be_private;
 511         int rc;
 512         DBT data, key2, *kptr;
 513         DBC *cursor;
 514         ID *i;
 515         void *ptr;
 516         size_t len;
 517         int rc2;
 518         int flags = bdb->bi_db_opflags | DB_MULTIPLE;
 519         int opflag;
 520
 521         /* If using BerkeleyDB 4.0, the buf must be large enough to
 522          * grab the entire IDL in one get(), otherwise BDB will leak
 523          * resources on subsequent get's.  We can safely call get()
 524          * twice - once for the data, and once to get the DB_NOTFOUND
 525          * result meaning there's no more data. See ITS#2040 for details.
 526          * This bug is fixed in BDB 4.1 so a smaller buffer will work if
 527          * stack space is too limited.
 528          *
 529          * configure now requires Berkeley DB 4.1.
 530          */
 531 #if DB_VERSION_FULL < 0x04010000
 532 #       define BDB_ENOUGH 5
 533 #else
 534         /* We sometimes test with tiny IDLs, and BDB always wants buffers
 535          * that are at least one page in size.
 536          */
 537 # if BDB_IDL_DB_SIZE < 4096
 538 #   define BDB_ENOUGH 2048
 539 # else
 540 #       define BDB_ENOUGH 1
 541 # endif
 542 #endif
 543         ID buf[BDB_IDL_DB_SIZE*BDB_ENOUGH];
 544
 545         char keybuf[16];
 546
 547         Debug( LDAP_DEBUG_ARGS,
 548                 "bdb_idl_fetch_key: %s\n",
 549                 bdb_show_key( key, keybuf ), 0, 0 );
 550
 551         assert( ids != NULL );
 552
 553         if ( saved_cursor && *saved_cursor ) {
 554                 opflag = DB_NEXT;
 555         } else if ( get_flag == LDAP_FILTER_GE ) {
 556                 opflag = DB_SET_RANGE;
 557         } else if ( get_flag == LDAP_FILTER_LE ) {
 558                 opflag = DB_FIRST;
 559         } else {
 560                 opflag = DB_SET;
 561         }
 562
 563         /* only non-range lookups can use the IDL cache */
 564         if ( bdb->bi_idl_cache_size && opflag == DB_SET ) {
 565                 rc = bdb_idl_cache_get( bdb, db, key, ids );
 566                 if ( rc != LDAP_NO_SUCH_OBJECT ) return rc;
 567         }
 568
 569         DBTzero( &data );
 570
 571         data.data = buf;
 572         data.ulen = sizeof(buf);
 573         data.flags = DB_DBT_USERMEM;
 574
 575         /* If we're not reusing an existing cursor, get a new one */
 576         if( opflag != DB_NEXT ) {
 577                 rc = db->cursor( db, txn, &cursor, bdb->bi_db_opflags );
 578                 if( rc != 0 ) {
 579                         Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
 580                                 "cursor failed: %s (%d)\n", db_strerror(rc), rc, 0 );
 581                         return rc;
 582                 }
 583         } else {
 584                 cursor = *saved_cursor;
 585         }
 586
 587         /* If this is a LE lookup, save original key so we can determine
 588          * when to stop. If this is a GE lookup, save the key since it
 589          * will be overwritten.
 590          */
 591         if ( get_flag == LDAP_FILTER_LE || get_flag == LDAP_FILTER_GE ) {
 592                 DBTzero( &key2 );
 593                 key2.flags = DB_DBT_USERMEM;
 594                 key2.ulen = sizeof(keybuf);
 595                 key2.data = keybuf;
 596                 key2.size = key->size;
 597                 AC_MEMCPY( keybuf, key->data, key->size );
 598                 kptr = &key2;
 599         } else {
 600                 kptr = key;
 601         }
 602         len = key->size;
 603         rc = cursor->c_get( cursor, kptr, &data, flags | opflag );
 604
 605         /* skip presence key on range inequality lookups */
 606         while (rc == 0 && kptr->size != len) {
 607                 rc = cursor->c_get( cursor, kptr, &data, flags | DB_NEXT_NODUP );
 608         }
 609         /* If we're doing a LE compare and the new key is greater than
 610          * our search key, we're done
 611          */
 612         if (rc == 0 && get_flag == LDAP_FILTER_LE && memcmp( kptr->data,
 613                 key->data, key->size ) > 0 ) {
 614                 rc = DB_NOTFOUND;
 615         }
 616         if (rc == 0) {
 617                 i = ids;
 618                 while (rc == 0) {
 619                         u_int8_t *j;
 620
 621                         DB_MULTIPLE_INIT( ptr, &data );
 622                         while (ptr) {
 623                                 DB_MULTIPLE_NEXT(ptr, &data, j, len);
 624                                 if (j) {
 625                                         ++i;
 626                                         BDB_DISK2ID( j, i );
 627                                 }
 628                         }
 629                         rc = cursor->c_get( cursor, key, &data, flags | DB_NEXT_DUP );
 630                 }
 631                 if ( rc == DB_NOTFOUND ) rc = 0;
 632                 ids[0] = i - ids;
 633                 /* On disk, a range is denoted by 0 in the first element */
 634                 if (ids[1] == 0) {
 635                         if (ids[0] != BDB_IDL_RANGE_SIZE) {
 636                                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
 637                                         "range size mismatch: expected %d, got %ld\n",
 638                                         BDB_IDL_RANGE_SIZE, ids[0], 0 );
 639                                 cursor->c_close( cursor );
 640                                 return -1;
 641                         }
 642                         BDB_IDL_RANGE( ids, ids[2], ids[3] );
 643                 }
 644                 data.size = BDB_IDL_SIZEOF(ids);
 645         }
 646
 647         if ( saved_cursor && rc == 0 ) {
 648                 if ( !*saved_cursor )
 649                         *saved_cursor = cursor;
 650                 rc2 = 0;
 651         }
 652         else
 653                 rc2 = cursor->c_close( cursor );
 654         if (rc2) {
 655                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
 656                         "close failed: %s (%d)\n", db_strerror(rc2), rc2, 0 );
 657                 return rc2;
 658         }
 659
 660         if( rc == DB_NOTFOUND ) {
 661                 return rc;
 662
 663         } else if( rc != 0 ) {
 664                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
 665                         "get failed: %s (%d)\n",
 666                         db_strerror(rc), rc, 0 );
 667                 return rc;
 668
 669         } else if ( data.size == 0 || data.size % sizeof( ID ) ) {
 670                 /* size not multiple of ID size */
 671                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
 672                         "odd size: expected %ld multiple, got %ld\n",
 673                         (long) sizeof( ID ), (long) data.size, 0 );
 674                 return -1;
 675
 676         } else if ( data.size != BDB_IDL_SIZEOF(ids) ) {
 677                 /* size mismatch */
 678                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
 679                         "get size mismatch: expected %ld, got %ld\n",
 680                         (long) ((1 + ids[0]) * sizeof( ID )), (long) data.size, 0 );
 681                 return -1;
 682         }
 683
 684         if ( bdb->bi_idl_cache_max_size ) {
 685                 bdb_idl_cache_put( bdb, db, key, ids, rc );
 686         }
 687
 688         return rc;
 689 }
 690
 691
 692 int
 693 bdb_idl_insert_key(
 694         BackendDB       *be,
 695         DB                      *db,
 696         DB_TXN          *tid,
 697         DBT                     *key,
 698         ID                      id )
 699 {
 700         struct bdb_info *bdb = (struct bdb_info *) be->be_private;
 701         int     rc;
 702         DBT data;
 703         DBC *cursor;
 704         ID lo, hi, nlo, nhi, nid;
 705         char *err;
 706
 707         {
 708                 char buf[16];
 709                 Debug( LDAP_DEBUG_ARGS,
 710                         "bdb_idl_insert_key: %lx %s\n",
 711                         (long) id, bdb_show_key( key, buf ), 0 );
 712         }
 713
 714         assert( id != NOID );
 715
 716         DBTzero( &data );
 717         data.size = sizeof( ID );
 718         data.ulen = data.size;
 719         data.flags = DB_DBT_USERMEM;
 720
 721         BDB_ID2DISK( id, &nid );
 722
 723         rc = db->cursor( db, tid, &cursor, bdb->bi_db_opflags );
 724         if ( rc != 0 ) {
 725                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_insert_key: "
 726                         "cursor failed: %s (%d)\n", db_strerror(rc), rc, 0 );
 727                 return rc;
 728         }
 729         data.data = &nlo;
 730         /* Fetch the first data item for this key, to see if it
 731          * exists and if it's a range.
 732          */
 733         rc = cursor->c_get( cursor, key, &data, DB_SET );
 734         err = "c_get";
 735         if ( rc == 0 ) {
 736                 if ( nlo != 0 ) {
 737                         /* not a range, count the number of items */
 738                         db_recno_t count;
 739                         rc = cursor->c_count( cursor, &count, 0 );
 740                         if ( rc != 0 ) {
 741                                 err = "c_count";
 742                                 goto fail;
 743                         }
 744                         if ( count >= BDB_IDL_DB_MAX ) {
 745                         /* No room, convert to a range */
 746                                 DBT key2 = *key;
 747                                 db_recno_t i;
 748
 749                                 key2.dlen = key2.ulen;
 750                                 key2.flags |= DB_DBT_PARTIAL;
 751
 752                                 BDB_DISK2ID( &nlo, &lo );
 753                                 data.data = &nhi;
 754
 755                                 rc = cursor->c_get( cursor, &key2, &data, DB_NEXT_NODUP );
 756                                 if ( rc != 0 && rc != DB_NOTFOUND ) {
 757                                         err = "c_get next_nodup";
 758                                         goto fail;
 759                                 }
 760                                 if ( rc == DB_NOTFOUND ) {
 761                                         rc = cursor->c_get( cursor, key, &data, DB_LAST );
 762                                         if ( rc != 0 ) {
 763                                                 err = "c_get last";
 764                                                 goto fail;
 765                                         }
 766                                 } else {
 767                                         rc = cursor->c_get( cursor, key, &data, DB_PREV );
 768                                         if ( rc != 0 ) {
 769                                                 err = "c_get prev";
 770                                                 goto fail;
 771                                         }
 772                                 }
 773                                 BDB_DISK2ID( &nhi, &hi );
 774                                 /* Update hi/lo if needed, then delete all the items
 775                                  * between lo and hi
 776                                  */
 777                                 if ( id < lo ) {
 778                                         lo = id;
 779                                         nlo = nid;
 780                                 } else if ( id > hi ) {
 781                                         hi = id;
 782                                         nhi = nid;
 783                                 }
 784                                 data.data = &nid;
 785                                 /* Don't fetch anything, just position cursor */
 786                                 data.flags = DB_DBT_USERMEM | DB_DBT_PARTIAL;
 787                                 data.dlen = data.ulen = 0;
 788                                 rc = cursor->c_get( cursor, key, &data, DB_SET );
 789                                 if ( rc != 0 ) {
 790                                         err = "c_get 2";
 791                                         goto fail;
 792                                 }
 793                                 rc = cursor->c_del( cursor, 0 );
 794                                 if ( rc != 0 ) {
 795                                         err = "c_del range1";
 796                                         goto fail;
 797                                 }
 798                                 /* Delete all the records */
 799                                 for ( i=1; i<count; i++ ) {
 800                                         rc = cursor->c_get( cursor, &key2, &data, DB_NEXT_DUP );
 801                                         if ( rc != 0 ) {
 802                                                 err = "c_get next_dup";
 803                                                 goto fail;
 804                                         }
 805                                         rc = cursor->c_del( cursor, 0 );
 806                                         if ( rc != 0 ) {
 807                                                 err = "c_del range";
 808                                                 goto fail;
 809                                         }
 810                                 }
 811                                 /* Store the range marker */
 812                                 data.size = data.ulen = sizeof(ID);
 813                                 data.flags = DB_DBT_USERMEM;
 814                                 nid = 0;
 815                                 rc = cursor->c_put( cursor, key, &data, DB_KEYFIRST );
 816                                 if ( rc != 0 ) {
 817                                         err = "c_put range";
 818                                         goto fail;
 819                                 }
 820                                 nid = nlo;
 821                                 rc = cursor->c_put( cursor, key, &data, DB_KEYLAST );
 822                                 if ( rc != 0 ) {
 823                                         err = "c_put lo";
 824                                         goto fail;
 825                                 }
 826                                 nid = nhi;
 827                                 rc = cursor->c_put( cursor, key, &data, DB_KEYLAST );
 828                                 if ( rc != 0 ) {
 829                                         err = "c_put hi";
 830                                         goto fail;
 831                                 }
 832                         } else {
 833                         /* There's room, just store it */
 834                                 goto put1;
 835                         }
 836                 } else {
 837                         /* It's a range, see if we need to rewrite
 838                          * the boundaries
 839                          */
 840                         hi = id;
 841                         data.data = &nlo;
 842                         rc = cursor->c_get( cursor, key, &data, DB_NEXT_DUP );
 843                         if ( rc != 0 ) {
 844                                 err = "c_get lo";
 845                                 goto fail;
 846                         }
 847                         BDB_DISK2ID( &nlo, &lo );
 848                         if ( id > lo ) {
 849                                 data.data = &nhi;
 850                                 rc = cursor->c_get( cursor, key, &data, DB_NEXT_DUP );
 851                                 if ( rc != 0 ) {
 852                                         err = "c_get hi";
 853                                         goto fail;
 854                                 }
 855                                 BDB_DISK2ID( &nhi, &hi );
 856                         }
 857                         if ( id < lo || id > hi ) {
 858                                 /* Delete the current lo/hi */
 859                                 rc = cursor->c_del( cursor, 0 );
 860                                 if ( rc != 0 ) {
 861                                         err = "c_del";
 862                                         goto fail;
 863                                 }
 864                                 data.data = &nid;
 865                                 rc = cursor->c_put( cursor, key, &data, DB_KEYFIRST );
 866                                 if ( rc != 0 ) {
 867                                         err = "c_put lo/hi";
 868                                         goto fail;
 869                                 }
 870                         }
 871                 }
 872         } else if ( rc == DB_NOTFOUND ) {
 873 put1:           data.data = &nid;
 874                 rc = cursor->c_put( cursor, key, &data, DB_NODUPDATA );
 875                 /* Don't worry if it's already there */
 876                 if ( rc != 0 && rc != DB_KEYEXIST ) {
 877                         err = "c_put id";
 878                         goto fail;
 879                 }
 880         } else {
 881                 /* initial c_get failed, nothing was done */
 882 fail:
 883                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_insert_key: "
 884                         "%s failed: %s (%d)\n", err, db_strerror(rc), rc );
 885                 cursor->c_close( cursor );
 886                 return rc;
 887         }
 888         /* If key was added (didn't already exist) and using IDL cache,
 889          * update key in IDL cache.
 890          */
 891         if ( !rc && bdb->bi_idl_cache_max_size ) {
 892                 bdb_idl_cache_add_id( bdb, db, key, id );
 893         }
 894         rc = cursor->c_close( cursor );
 895         if( rc != 0 ) {
 896                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_insert_key: "
 897                         "c_close failed: %s (%d)\n",
 898                         db_strerror(rc), rc, 0 );
 899         }
 900         return rc;
 901 }
 902
 903 int
 904 bdb_idl_delete_key(
 905         BackendDB       *be,
 906         DB                      *db,
 907         DB_TXN          *tid,
 908         DBT                     *key,
 909         ID                      id )
 910 {
 911         struct bdb_info *bdb = (struct bdb_info *) be->be_private;
 912         int     rc;
 913         DBT data;
 914         DBC *cursor;
 915         ID lo, hi, tmp, nid, nlo, nhi;
 916         char *err;
 917
 918         {
 919                 char buf[16];
 920                 Debug( LDAP_DEBUG_ARGS,
 921                         "bdb_idl_delete_key: %lx %s\n",
 922                         (long) id, bdb_show_key( key, buf ), 0 );
 923         }
 924         assert( id != NOID );
 925
 926         if ( bdb->bi_idl_cache_size ) {
 927                 bdb_idl_cache_del( bdb, db, key );
 928         }
 929
 930         BDB_ID2DISK( id, &nid );
 931
 932         DBTzero( &data );
 933         data.data = &tmp;
 934         data.size = sizeof( id );
 935         data.ulen = data.size;
 936         data.flags = DB_DBT_USERMEM;
 937
 938         rc = db->cursor( db, tid, &cursor, bdb->bi_db_opflags );
 939         if ( rc != 0 ) {
 940                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_delete_key: "
 941                         "cursor failed: %s (%d)\n", db_strerror(rc), rc, 0 );
 942                 return rc;
 943         }
 944         /* Fetch the first data item for this key, to see if it
 945          * exists and if it's a range.
 946          */
 947         rc = cursor->c_get( cursor, key, &data, DB_SET );
 948         err = "c_get";
 949         if ( rc == 0 ) {
 950                 if ( tmp != 0 ) {
 951                         /* Not a range, just delete it */
 952                         if (tmp != nid) {
 953                                 /* position to correct item */
 954                                 tmp = nid;
 955                                 rc = cursor->c_get( cursor, key, &data, DB_GET_BOTH );
 956                                 if ( rc != 0 ) {
 957                                         err = "c_get id";
 958                                         goto fail;
 959                                 }
 960                         }
 961                         rc = cursor->c_del( cursor, 0 );
 962                         if ( rc != 0 ) {
 963                                 err = "c_del id";
 964                                 goto fail;
 965                         }
 966                 } else {
 967                         /* It's a range, see if we need to rewrite
 968                          * the boundaries
 969                          */
 970                         data.data = &nlo;
 971                         rc = cursor->c_get( cursor, key, &data, DB_NEXT_DUP );
 972                         if ( rc != 0 ) {
 973                                 err = "c_get lo";
 974                                 goto fail;
 975                         }
 976                         BDB_DISK2ID( &nlo, &lo );
 977                         data.data = &nhi;
 978                         rc = cursor->c_get( cursor, key, &data, DB_NEXT_DUP );
 979                         if ( rc != 0 ) {
 980                                 err = "c_get hi";
 981                                 goto fail;
 982                         }
 983                         BDB_DISK2ID( &nhi, &hi );
 984                         if ( id == lo || id == hi ) {
 985                                 if ( id == lo ) {
 986                                         id++;
 987                                         lo = id;
 988                                 } else if ( id == hi ) {
 989                                         id--;
 990                                         hi = id;
 991                                 }
 992                                 if ( lo >= hi ) {
 993                                 /* The range has collapsed... */
 994                                         rc = db->del( db, tid, key, 0 );
 995                                         if ( rc != 0 ) {
 996                                                 err = "del";
 997                                                 goto fail;
 998                                         }
 999                                 } else {
1000                                         if ( id == lo ) {
1001                                                 /* reposition on lo slot */
1002                                                 data.data = &nlo;
1003                                                 cursor->c_get( cursor, key, &data, DB_PREV );
1004                                         }
1005                                         rc = cursor->c_del( cursor, 0 );
1006                                         if ( rc != 0 ) {
1007                                                 err = "c_del";
1008                                                 goto fail;
1009                                         }
1010                                 }
1011                                 if ( lo <= hi ) {
1012                                         BDB_ID2DISK( id, &nid );
1013                                         data.data = &nid;
1014                                         rc = cursor->c_put( cursor, key, &data, DB_KEYFIRST );
1015                                         if ( rc != 0 ) {
1016                                                 err = "c_put lo/hi";
1017                                                 goto fail;
1018                                         }
1019                                 }
1020                         }
1021                 }
1022         } else {
1023                 /* initial c_get failed, nothing was done */
1024 fail:
1025                 if ( rc != DB_NOTFOUND ) {
1026                 Debug( LDAP_DEBUG_ANY, "=> bdb_idl_delete_key: "
1027                         "%s failed: %s (%d)\n", err, db_strerror(rc), rc );
1028                 }
1029                 cursor->c_close( cursor );
1030                 return rc;
1031         }
1032         rc = cursor->c_close( cursor );
1033         if( rc != 0 ) {
1034                 Debug( LDAP_DEBUG_ANY,
1035                         "=> bdb_idl_delete_key: c_close failed: %s (%d)\n",
1036                         db_strerror(rc), rc, 0 );
1037         }
1038
1039         return rc;
1040 }
1041
1042
1043 /*
1044  * idl_intersection - return a = a intersection b
1045  */
1046 int
1047 bdb_idl_intersection(
1048         ID *a,
1049         ID *b )
1050 {
1051         ID ida, idb;
1052         ID idmax, idmin;
1053         ID cursora = 0, cursorb = 0, cursorc;
1054         int swap = 0;
1055
1056         if ( BDB_IDL_IS_ZERO( a ) || BDB_IDL_IS_ZERO( b ) ) {
1057                 a[0] = 0;
1058                 return 0;
1059         }
1060
1061         idmin = IDL_MAX( BDB_IDL_FIRST(a), BDB_IDL_FIRST(b) );
1062         idmax = IDL_MIN( BDB_IDL_LAST(a), BDB_IDL_LAST(b) );
1063         if ( idmin > idmax ) {
1064                 a[0] = 0;
1065                 return 0;
1066         } else if ( idmin == idmax ) {
1067                 a[0] = 1;
1068                 a[1] = idmin;
1069                 return 0;
1070         }
1071
1072         if ( BDB_IDL_IS_RANGE( a ) ) {
1073                 if ( BDB_IDL_IS_RANGE(b) ) {
1074                 /* If both are ranges, just shrink the boundaries */
1075                         a[1] = idmin;
1076                         a[2] = idmax;
1077                         return 0;
1078                 } else {
1079                 /* Else swap so that b is the range, a is a list */
1080                         ID *tmp = a;
1081                         a = b;
1082                         b = tmp;
1083                         swap = 1;
1084                 }
1085         }
1086
1087         /* If a range completely covers the list, the result is
1088          * just the list. If idmin to idmax is contiguous, just
1089          * turn it into a range.
1090          */
1091         if ( BDB_IDL_IS_RANGE( b )
1092                 && BDB_IDL_RANGE_FIRST( b ) <= BDB_IDL_FIRST( a )
1093                 && BDB_IDL_RANGE_LAST( b ) >= BDB_IDL_LLAST( a ) ) {
1094                 if (idmax - idmin + 1 == a[0])
1095                 {
1096                         a[0] = NOID;
1097                         a[1] = idmin;
1098                         a[2] = idmax;
1099                 }
1100                 goto done;
1101         }
1102
1103         /* Fine, do the intersection one element at a time.
1104          * First advance to idmin in both IDLs.
1105          */
1106         cursora = cursorb = idmin;
1107         ida = bdb_idl_first( a, &cursora );
1108         idb = bdb_idl_first( b, &cursorb );
1109         cursorc = 0;
1110
1111         while( ida <= idmax || idb <= idmax ) {
1112                 if( ida == idb ) {
1113                         a[++cursorc] = ida;
1114                         ida = bdb_idl_next( a, &cursora );
1115                         idb = bdb_idl_next( b, &cursorb );
1116                 } else if ( ida < idb ) {
1117                         ida = bdb_idl_next( a, &cursora );
1118                 } else {
1119                         idb = bdb_idl_next( b, &cursorb );
1120                 }
1121         }
1122         a[0] = cursorc;
1123 done:
1124         if (swap)
1125                 BDB_IDL_CPY( b, a );
1126
1127         return 0;
1128 }
1129
1130
1131 /*
1132  * idl_union - return a = a union b
1133  */
1134 int
1135 bdb_idl_union(
1136         ID      *a,
1137         ID      *b )
1138 {
1139         ID ida, idb;
1140         ID cursora = 0, cursorb = 0, cursorc;
1141
1142         if ( BDB_IDL_IS_ZERO( b ) ) {
1143                 return 0;
1144         }
1145
1146         if ( BDB_IDL_IS_ZERO( a ) ) {
1147                 BDB_IDL_CPY( a, b );
1148                 return 0;
1149         }
1150
1151         if ( BDB_IDL_IS_RANGE( a ) || BDB_IDL_IS_RANGE(b) ) {
1152 over:           ida = IDL_MIN( BDB_IDL_FIRST(a), BDB_IDL_FIRST(b) );
1153                 idb = IDL_MAX( BDB_IDL_LAST(a), BDB_IDL_LAST(b) );
1154                 a[0] = NOID;
1155                 a[1] = ida;
1156                 a[2] = idb;
1157                 return 0;
1158         }
1159
1160         ida = bdb_idl_first( a, &cursora );
1161         idb = bdb_idl_first( b, &cursorb );
1162
1163         cursorc = b[0];
1164
1165         /* The distinct elements of a are cat'd to b */
1166         while( ida != NOID || idb != NOID ) {
1167                 if ( ida < idb ) {
1168                         if( ++cursorc > BDB_IDL_UM_MAX ) {
1169                                 goto over;
1170                         }
1171                         b[cursorc] = ida;
1172                         ida = bdb_idl_next( a, &cursora );
1173
1174                 } else {
1175                         if ( ida == idb )
1176                                 ida = bdb_idl_next( a, &cursora );
1177                         idb = bdb_idl_next( b, &cursorb );
1178                 }
1179         }
1180
1181         /* b is copied back to a in sorted order */
1182         a[0] = cursorc;
1183         cursora = 1;
1184         cursorb = 1;
1185         cursorc = b[0]+1;
1186         while (cursorb <= b[0] || cursorc <= a[0]) {
1187                 if (cursorc > a[0])
1188                         idb = NOID;
1189                 else
1190                         idb = b[cursorc];
1191                 if (cursorb <= b[0] && b[cursorb] < idb)
1192                         a[cursora++] = b[cursorb++];
1193                 else {
1194                         a[cursora++] = idb;
1195                         cursorc++;
1196                 }
1197         }
1198
1199         return 0;
1200 }
1201
1202
1203 #if 0
1204 /*
1205  * bdb_idl_notin - return a intersection ~b (or a minus b)
1206  */
1207 int
1208 bdb_idl_notin(
1209         ID      *a,
1210         ID      *b,
1211         ID *ids )
1212 {
1213         ID ida, idb;
1214         ID cursora = 0, cursorb = 0;
1215
1216         if( BDB_IDL_IS_ZERO( a ) ||
1217                 BDB_IDL_IS_ZERO( b ) ||
1218                 BDB_IDL_IS_RANGE( b ) )
1219         {
1220                 BDB_IDL_CPY( ids, a );
1221                 return 0;
1222         }
1223
1224         if( BDB_IDL_IS_RANGE( a ) ) {
1225                 BDB_IDL_CPY( ids, a );
1226                 return 0;
1227         }
1228
1229         ida = bdb_idl_first( a, &cursora ),
1230         idb = bdb_idl_first( b, &cursorb );
1231
1232         ids[0] = 0;
1233
1234         while( ida != NOID ) {
1235                 if ( idb == NOID ) {
1236                         /* we could shortcut this */
1237                         ids[++ids[0]] = ida;
1238                         ida = bdb_idl_next( a, &cursora );
1239
1240                 } else if ( ida < idb ) {
1241                         ids[++ids[0]] = ida;
1242                         ida = bdb_idl_next( a, &cursora );
1243
1244                 } else if ( ida > idb ) {
1245                         idb = bdb_idl_next( b, &cursorb );
1246
1247                 } else {
1248                         ida = bdb_idl_next( a, &cursora );
1249                         idb = bdb_idl_next( b, &cursorb );
1250                 }
1251         }
1252
1253         return 0;
1254 }
1255 #endif
1256
1257 ID bdb_idl_first( ID *ids, ID *cursor )
1258 {
1259         ID pos;
1260
1261         if ( ids[0] == 0 ) {
1262                 *cursor = NOID;
1263                 return NOID;
1264         }
1265
1266         if ( BDB_IDL_IS_RANGE( ids ) ) {
1267                 if( *cursor < ids[1] ) {
1268                         *cursor = ids[1];
1269                 }
1270                 return *cursor;
1271         }
1272
1273         if ( *cursor == 0 )
1274                 pos = 1;
1275         else
1276                 pos = bdb_idl_search( ids, *cursor );
1277
1278         if( pos > ids[0] ) {
1279                 return NOID;
1280         }
1281
1282         *cursor = pos;
1283         return ids[pos];
1284 }
1285
1286 ID bdb_idl_next( ID *ids, ID *cursor )
1287 {
1288         if ( BDB_IDL_IS_RANGE( ids ) ) {
1289                 if( ids[2] < ++(*cursor) ) {
1290                         return NOID;
1291                 }
1292                 return *cursor;
1293         }
1294
1295         if ( ++(*cursor) <= ids[0] ) {
1296                 return ids[*cursor];
1297         }
1298
1299         return NOID;
1300 }
1301
1302 #ifdef BDB_HIER
1303
1304 /* Add one ID to an unsorted list. We ensure that the first element is the
1305  * minimum and the last element is the maximum, for fast range compaction.
1306  *   this means IDLs up to length 3 are always sorted...
1307  */
1308 int bdb_idl_append_one( ID *ids, ID id )
1309 {
1310         if (BDB_IDL_IS_RANGE( ids )) {
1311                 /* if already in range, treat as a dup */
1312                 if (id >= BDB_IDL_RANGE_FIRST(ids) && id <= BDB_IDL_RANGE_LAST(ids))
1313                         return -1;
1314                 if (id < BDB_IDL_RANGE_FIRST(ids))
1315                         ids[1] = id;
1316                 else if (id > BDB_IDL_RANGE_LAST(ids))
1317                         ids[2] = id;
1318                 return 0;
1319         }
1320         if ( ids[0] ) {
1321                 ID tmp;
1322
1323                 if (id < ids[1]) {
1324                         tmp = ids[1];
1325                         ids[1] = id;
1326                         id = tmp;
1327                 }
1328                 if ( ids[0] > 1 && id < ids[ids[0]] ) {
1329                         tmp = ids[ids[0]];
1330                         ids[ids[0]] = id;
1331                         id = tmp;
1332                 }
1333         }
1334         ids[0]++;
1335         if ( ids[0] >= BDB_IDL_UM_MAX ) {
1336                 ids[0] = NOID;
1337                 ids[2] = id;
1338         } else {
1339                 ids[ids[0]] = id;
1340         }
1341         return 0;
1342 }
1343
1344 /* Append sorted list b to sorted list a. The result is unsorted but
1345  * a[1] is the min of the result and a[a[0]] is the max.
1346  */
1347 int bdb_idl_append( ID *a, ID *b )
1348 {
1349         ID ida, idb, tmp, swap = 0;
1350
1351         if ( BDB_IDL_IS_ZERO( b ) ) {
1352                 return 0;
1353         }
1354
1355         if ( BDB_IDL_IS_ZERO( a ) ) {
1356                 BDB_IDL_CPY( a, b );
1357                 return 0;
1358         }
1359
1360         if ( b[0] == 1 ) {
1361                 return bdb_idl_append_one( a, BDB_IDL_FIRST( b ));
1362         }
1363
1364         ida = BDB_IDL_LAST( a );
1365         idb = BDB_IDL_LAST( b );
1366         if ( BDB_IDL_IS_RANGE( a ) || BDB_IDL_IS_RANGE(b) ||
1367                 a[0] + b[0] >= BDB_IDL_UM_MAX ) {
1368                 a[2] = IDL_MAX( ida, idb );
1369                 a[1] = IDL_MIN( a[1], b[1] );
1370                 a[0] = NOID;
1371                 return 0;
1372         }
1373
1374         if ( ida > idb ) {
1375                 swap = idb;
1376                 a[a[0]] = idb;
1377                 b[b[0]] = ida;
1378         }
1379
1380         if ( b[1] < a[1] ) {
1381                 tmp = a[1];
1382                 a[1] = b[1];
1383         } else {
1384                 tmp = b[1];
1385         }
1386         a[0]++;
1387         a[a[0]] = tmp;
1388
1389         {
1390                 int i = b[0] - 1;
1391                 AC_MEMCPY(a+a[0]+1, b+2, i * sizeof(ID));
1392                 a[0] += i;
1393         }
1394         if ( swap ) {
1395                 b[b[0]] = swap;
1396         }
1397         return 0;
1398 }
1399
1400 #if 1
1401
1402 /* Quicksort + Insertion sort for small arrays */
1403
1404 #define SMALL   8
1405 #define SWAP(a,b)       itmp=(a);(a)=(b);(b)=itmp
1406
1407 void
1408 bdb_idl_sort( ID *ids, ID *tmp )
1409 {
1410         int *istack = (int *)tmp;
1411         int i,j,k,l,ir,jstack;
1412         ID a, itmp;
1413
1414         if ( BDB_IDL_IS_RANGE( ids ))
1415                 return;
1416
1417         ir = ids[0];
1418         l = 1;
1419         jstack = 0;
1420         for(;;) {
1421                 if (ir - l < SMALL) {   /* Insertion sort */
1422                         for (j=l+1;j<=ir;j++) {
1423                                 a = ids[j];
1424                                 for (i=j-1;i>=1;i--) {
1425                                         if (ids[i] <= a) break;
1426                                         ids[i+1] = ids[i];
1427                                 }
1428                                 ids[i+1] = a;
1429                         }
1430                         if (jstack == 0) break;
1431                         ir = istack[jstack--];
1432                         l = istack[jstack--];
1433                 } else {
1434                         k = (l + ir) >> 1;      /* Choose median of left, center, right */
1435                         SWAP(ids[k], ids[l+1]);
1436                         if (ids[l] > ids[ir]) {
1437                                 SWAP(ids[l], ids[ir]);
1438                         }
1439                         if (ids[l+1] > ids[ir]) {
1440                                 SWAP(ids[l+1], ids[ir]);
1441                         }
1442                         if (ids[l] > ids[l+1]) {
1443                                 SWAP(ids[l], ids[l+1]);
1444                         }
1445                         i = l+1;
1446                         j = ir;
1447                         a = ids[l+1];
1448                         for(;;) {
1449                                 do i++; while(ids[i] < a);
1450                                 do j--; while(ids[j] > a);
1451                                 if (j < i) break;
1452                                 SWAP(ids[i],ids[j]);
1453                         }
1454                         ids[l+1] = ids[j];
1455                         ids[j] = a;
1456                         jstack += 2;
1457                         if (ir-i+1 >= j-l) {
1458                                 istack[jstack] = ir;
1459                                 istack[jstack-1] = i;
1460                                 ir = j-1;
1461                         } else {
1462                                 istack[jstack] = j-1;
1463                                 istack[jstack-1] = l;
1464                                 l = i;
1465                         }
1466                 }
1467         }
1468 }
1469
1470 #else
1471
1472 /* 8 bit Radix sort + insertion sort
1473  *
1474  * based on code from http://www.cubic.org/docs/radix.htm
1475  * with improvements by ebackes@symas.com and hyc@symas.com
1476  *
1477  * This code is O(n) but has a relatively high constant factor. For lists
1478  * up to ~50 Quicksort is slightly faster; up to ~100 they are even.
1479  * Much faster than quicksort for lists longer than ~100. Insertion
1480  * sort is actually superior for lists <50.
1481  */
1482
1483 #define BUCKETS (1<<8)
1484 #define SMALL   50
1485
1486 void
1487 bdb_idl_sort( ID *ids, ID *tmp )
1488 {
1489         int count, soft_limit, phase = 0, size = ids[0];
1490         ID *idls[2];
1491         unsigned char *maxv = (unsigned char *)&ids[size];
1492
1493         if ( BDB_IDL_IS_RANGE( ids ))
1494                 return;
1495
1496         /* Use insertion sort for small lists */
1497         if ( size <= SMALL ) {
1498                 int i,j;
1499                 ID a;
1500
1501                 for (j=1;j<=size;j++) {
1502                         a = ids[j];
1503                         for (i=j-1;i>=1;i--) {
1504                                 if (ids[i] <= a) break;
1505                                 ids[i+1] = ids[i];
1506                         }
1507                         ids[i+1] = a;
1508                 }
1509                 return;
1510         }
1511
1512         tmp[0] = size;
1513         idls[0] = ids;
1514         idls[1] = tmp;
1515
1516 #if BYTE_ORDER == BIG_ENDIAN
1517     for (soft_limit = 0; !maxv[soft_limit]; soft_limit++);
1518 #else
1519     for (soft_limit = sizeof(ID)-1; !maxv[soft_limit]; soft_limit--);
1520 #endif
1521
1522         for (
1523 #if BYTE_ORDER == BIG_ENDIAN
1524         count = sizeof(ID)-1; count >= soft_limit; --count
1525 #else
1526         count = 0; count <= soft_limit; ++count
1527 #endif
1528         ) {
1529                 unsigned int num[BUCKETS], * np, n, sum;
1530                 int i;
1531         ID *sp, *source, *dest;
1532         unsigned char *bp, *source_start;
1533
1534                 source = idls[phase]+1;
1535                 dest = idls[phase^1]+1;
1536                 source_start =  ((unsigned char *) source) + count;
1537
1538         np = num;
1539         for ( i = BUCKETS; i > 0; --i ) *np++ = 0;
1540
1541                 /* count occurences of every byte value */
1542                 bp = source_start;
1543         for ( i = size; i > 0; --i, bp += sizeof(ID) )
1544                                 num[*bp]++;
1545
1546                 /* transform count into index by summing elements and storing
1547                  * into same array
1548                  */
1549         sum = 0;
1550         np = num;
1551         for ( i = BUCKETS; i > 0; --i ) {
1552                 n = *np;
1553                 *np++ = sum;
1554                 sum += n;
1555         }
1556
1557                 /* fill dest with the right values in the right place */
1558                 bp = source_start;
1559         sp = source;
1560         for ( i = size; i > 0; --i, bp += sizeof(ID) ) {
1561                 np = num + *bp;
1562                 dest[*np] = *sp++;
1563                 ++(*np);
1564         }
1565                 phase ^= 1;
1566         }
1567
1568         /* copy back from temp if needed */
1569         if ( phase ) {
1570                 ids++; tmp++;
1571                 for ( count = 0; count < size; ++count )
1572                         *ids++ = *tmp++;
1573         }
1574 }
1575 #endif  /* Quick vs Radix */
1576
1577 #endif  /* BDB_HIER */