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

   1 /* idl.c - ldap id list handling routines */
   2 /*
   3  * Copyright 1998-1999 The OpenLDAP Foundation, All Rights Reserved.
   4  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   5  */
   6
   7 #include "portable.h"
   8
   9 #include <stdio.h>
  10
  11 #include <ac/string.h>
  12 #include <ac/socket.h>
  13
  14 #include "ldap_defaults.h"
  15 #include "slap.h"
  16 #include "back-ldbm.h"
  17
  18 static ID_BLOCK* idl_dup( ID_BLOCK *idl );
  19
  20 /* Allocate an ID_BLOCK with room for nids ids */
  21 ID_BLOCK *
  22 idl_alloc( unsigned int nids )
  23 {
  24         ID_BLOCK        *new;
  25
  26         /* nmax + nids + space for the ids */
  27         new = (ID_BLOCK *) ch_calloc( (ID_BLOCK_IDS_OFFSET + nids), sizeof(ID) );
  28         ID_BLOCK_NMAX(new) = nids;
  29         ID_BLOCK_NIDS(new) = 0;
  30
  31         return( new );
  32 }
  33
  34
  35 /* Allocate an empty ALLIDS ID_BLOCK */
  36 ID_BLOCK        *
  37 idl_allids( Backend *be )
  38 {
  39         ID_BLOCK        *idl;
  40
  41         idl = idl_alloc( 0 );
  42         ID_BLOCK_NMAX(idl) = ID_BLOCK_ALLIDS_VALUE;
  43         ID_BLOCK_NIDS(idl) = next_id_get( be );
  44
  45         return( idl );
  46 }
  47
  48 /* Free an ID_BLOCK */
  49 void
  50 idl_free( ID_BLOCK *idl )
  51 {
  52         if ( idl == NULL ) {
  53                 Debug( LDAP_DEBUG_TRACE,
  54                         "idl_free: called with NULL pointer\n",
  55                         0, 0, 0 );
  56                 return;
  57         }
  58
  59         free( (char *) idl );
  60 }
  61
  62
  63 /* Fetch an single ID_BLOCK from the cache */
  64 static ID_BLOCK *
  65 idl_fetch_one(
  66     Backend             *be,
  67     DBCache     *db,
  68     Datum               key
  69 )
  70 {
  71         Datum   data;
  72         ID_BLOCK        *idl;
  73
  74         /* Debug( LDAP_DEBUG_TRACE, "=> idl_fetch_one\n", 0, 0, 0 ); */
  75
  76         data = ldbm_cache_fetch( db, key );
  77
  78         if( data.dptr == NULL ) {
  79                 return NULL;
  80         }
  81
  82         idl = idl_dup( (ID_BLOCK *) data.dptr);
  83         ldbm_datum_free( db->dbc_db, data );
  84
  85         return( idl );
  86 }
  87
  88
  89 /* Fetch a set of ID_BLOCKs from the cache
  90  *      if not INDIRECT
  91  *              if block return is an ALLIDS block,
  92  *                      return an new ALLIDS block
  93  *              otherwise
  94  *                      return block
  95  *      construct super block from all blocks referenced by INDIRECT block
  96  *      return super block
  97  */
  98 ID_BLOCK *
  99 idl_fetch(
 100     Backend             *be,
 101     DBCache     *db,
 102     Datum               key
 103 )
 104 {
 105         Datum   data;
 106         ID_BLOCK        *idl;
 107         ID_BLOCK        **tmp;
 108         char    *kstr;
 109         int     i, nids;
 110
 111         idl = idl_fetch_one( be, db, key );
 112
 113         if ( idl == NULL ) {
 114                 return NULL;
 115         }
 116
 117         if ( ID_BLOCK_ALLIDS(idl) ) {
 118                 /* all ids block */
 119                 /* make sure we have the current value of highest id */
 120                 idl_free( idl );
 121                 idl = idl_allids( be );
 122
 123                 return( idl );
 124         }
 125
 126         if ( ! ID_BLOCK_INDIRECT( idl ) ) {
 127                 /* regular block */
 128                 return( idl );
 129         }
 130
 131         /*
 132          * this is an indirect block which points to other blocks.
 133          * we need to read in all the blocks it points to and construct
 134          * a big id list containing all the ids, which we will return.
 135          */
 136
 137         /* count the number of blocks & allocate space for pointers to them */
 138         for ( i = 0; !ID_BLOCK_NOID(idl, i); i++ )
 139                 ;       /* NULL */
 140         tmp = (ID_BLOCK **) ch_malloc( (i + 1) * sizeof(ID_BLOCK *) );
 141
 142         /* read in all the blocks */
 143         kstr = (char *) ch_malloc( key.dsize + CONT_SIZE );
 144         nids = 0;
 145         for ( i = 0; !ID_BLOCK_NOID(idl, i); i++ ) {
 146                 ldbm_datum_init( data );
 147
 148                 sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 149                         ID_BLOCK_ID(idl, i), key.dptr );
 150
 151                 data.dptr = kstr;
 152                 data.dsize = strlen( kstr ) + 1;
 153
 154                 if ( (tmp[i] = idl_fetch_one( be, db, data )) == NULL ) {
 155                         Debug( LDAP_DEBUG_ANY,
 156                             "idl_fetch of (%s) returns NULL\n", data.dptr, 0, 0 );
 157                         continue;
 158                 }
 159
 160                 nids += ID_BLOCK_NIDS(tmp[i]);
 161         }
 162         tmp[i] = NULL;
 163         free( kstr );
 164         idl_free( idl );
 165
 166         /* allocate space for the big block */
 167         idl = idl_alloc( nids );
 168         ID_BLOCK_NIDS(idl) = nids;
 169         nids = 0;
 170
 171         /* copy in all the ids from the component blocks */
 172         for ( i = 0; tmp[i] != NULL; i++ ) {
 173                 if ( tmp[i] == NULL ) {
 174                         continue;
 175                 }
 176
 177                 SAFEMEMCPY(
 178                         (char *) &ID_BLOCK_ID(idl, nids),
 179                         (char *) &ID_BLOCK_ID(tmp[i], 0),
 180                         ID_BLOCK_NIDS(tmp[i]) * sizeof(ID) );
 181                 nids += ID_BLOCK_NIDS(tmp[i]);
 182
 183                 idl_free( tmp[i] );
 184         }
 185         free( (char *) tmp );
 186
 187         Debug( LDAP_DEBUG_TRACE, "<= idl_fetch %ld ids (%ld max)\n",
 188                ID_BLOCK_NIDS(idl), ID_BLOCK_NMAX(idl), 0 );
 189         return( idl );
 190 }
 191
 192
 193 /* store a single block */
 194 static int
 195 idl_store(
 196     Backend             *be,
 197     DBCache     *db,
 198     Datum               key,
 199     ID_BLOCK            *idl
 200 )
 201 {
 202         int     rc, flags;
 203         Datum   data;
 204         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 205
 206         ldbm_datum_init( data );
 207
 208         /* Debug( LDAP_DEBUG_TRACE, "=> idl_store\n", 0, 0, 0 ); */
 209
 210         data.dptr = (char *) idl;
 211         data.dsize = (ID_BLOCK_IDS_OFFSET + ID_BLOCK_NMAX(idl)) * sizeof(ID);
 212
 213 #ifdef LDBM_DEBUG
 214         Statslog( LDAP_DEBUG_STATS, "<= idl_store(): rc=%d\n",
 215                 rc, 0, 0, 0, 0 );
 216 #endif
 217
 218         flags = LDBM_REPLACE;
 219         if( li->li_dbcachewsync ) flags |= LDBM_SYNC;
 220         rc = ldbm_cache_store( db, key, data, flags );
 221
 222         /* Debug( LDAP_DEBUG_TRACE, "<= idl_store %d\n", rc, 0, 0 ); */
 223         return( rc );
 224 }
 225
 226 /* split the block at id
 227  *      locate ID greater than or equal to id.
 228  */
 229 static void
 230 idl_split_block(
 231     ID_BLOCK    *b,
 232     ID          id,
 233     ID_BLOCK    **right,
 234     ID_BLOCK    **left
 235 )
 236 {
 237         unsigned int    nr, nl;
 238
 239         /* find where to split the block *//* XXX linear search XXX */
 240         for ( nr = 0; nr < ID_BLOCK_NIDS(b) && id > ID_BLOCK_ID(b, nr); nr++ )
 241                 ;       /* NULL */
 242
 243         nl = ID_BLOCK_NIDS(b) - nr;
 244
 245         *right = idl_alloc( nr == 0 ? 1 : nr );
 246         *left = idl_alloc( nl + (nr == 0 ? 0 : 1));
 247
 248         /*
 249          * everything before the id being inserted in the first block
 250          * unless there is nothing, in which case the id being inserted
 251          * goes there.
 252          */
 253         if ( nr == 0 ) {
 254                 ID_BLOCK_NIDS(*right) = 1;
 255                 ID_BLOCK_ID(*right, 0) = id;
 256         } else {
 257                 SAFEMEMCPY(
 258                         (char *) &ID_BLOCK_ID(*right, 0),
 259                         (char *) &ID_BLOCK_ID(b, 0),
 260                         nr * sizeof(ID) );
 261                 ID_BLOCK_NIDS(*right) = nr;
 262                 ID_BLOCK_ID(*left, 0) = id;
 263         }
 264
 265         /* the id being inserted & everything after in the second block */
 266         SAFEMEMCPY(
 267                 (char *) &ID_BLOCK_ID(*left, (nr == 0 ? 0 : 1)),
 268             (char *) &ID_BLOCK_ID(b, nr),
 269                 nl * sizeof(ID) );
 270         ID_BLOCK_NIDS(*left) = nl + (nr == 0 ? 0 : 1);
 271 }
 272
 273
 274 /*
 275  * idl_change_first - called when an indirect block's first key has
 276  * changed, meaning it needs to be stored under a new key, and the
 277  * header block pointing to it needs updating.
 278  */
 279 static int
 280 idl_change_first(
 281     Backend             *be,
 282     DBCache     *db,
 283     Datum               hkey,           /* header block key     */
 284     ID_BLOCK            *h,             /* header block         */
 285     int                 pos,            /* pos in h to update   */
 286     Datum               bkey,           /* data block key       */
 287     ID_BLOCK            *b              /* data block           */
 288 )
 289 {
 290         int     rc;
 291
 292         /* Debug( LDAP_DEBUG_TRACE, "=> idl_change_first\n", 0, 0, 0 ); */
 293
 294         /* delete old key block */
 295         if ( (rc = ldbm_cache_delete( db, bkey )) != 0 ) {
 296                 Debug( LDAP_DEBUG_ANY,
 297                     "ldbm_delete of (%s) returns %d\n", bkey.dptr, rc,
 298                     0 );
 299                 return( rc );
 300         }
 301
 302         /* write block with new key */
 303         sprintf( bkey.dptr, "%c%ld%s", CONT_PREFIX,
 304                 ID_BLOCK_ID(b, 0), hkey.dptr );
 305
 306         bkey.dsize = strlen( bkey.dptr ) + 1;
 307         if ( (rc = idl_store( be, db, bkey, b )) != 0 ) {
 308                 Debug( LDAP_DEBUG_ANY,
 309                     "idl_store of (%s) returns %d\n", bkey.dptr, rc, 0 );
 310                 return( rc );
 311         }
 312
 313         /* update + write indirect header block */
 314         ID_BLOCK_ID(h, pos) = ID_BLOCK_ID(b, 0);
 315         if ( (rc = idl_store( be, db, hkey, h )) != 0 ) {
 316                 Debug( LDAP_DEBUG_ANY,
 317                     "idl_store of (%s) returns %d\n", hkey.dptr, rc, 0 );
 318                 return( rc );
 319         }
 320
 321         return( 0 );
 322 }
 323
 324
 325 int
 326 idl_insert_key(
 327     Backend             *be,
 328     DBCache     *db,
 329     Datum               key,
 330     ID                  id
 331 )
 332 {
 333         int     i, j, first, rc;
 334         ID_BLOCK        *idl, *tmp, *tmp2, *tmp3;
 335         char    *kstr;
 336         Datum   k2;
 337
 338         ldbm_datum_init( k2 );
 339
 340         if ( (idl = idl_fetch_one( be, db, key )) == NULL ) {
 341 #ifdef LDBM_DEBUG
 342                 Statslog( LDAP_DEBUG_STATS, "=> idl_insert_key(): no key yet\n",
 343                         0, 0, 0, 0, 0 );
 344 #endif
 345
 346                 idl = idl_alloc( 1 );
 347                 ID_BLOCK_ID(idl, ID_BLOCK_NIDS(idl)++) = id;
 348                 rc = idl_store( be, db, key, idl );
 349
 350                 idl_free( idl );
 351                 return( rc );
 352         }
 353
 354         if ( ID_BLOCK_ALLIDS( idl ) ) {
 355                 /* ALLIDS */
 356                 idl_free( idl );
 357                 return 0;
 358         }
 359
 360         if ( ! ID_BLOCK_INDIRECT( idl ) ) {
 361                 /* regular block */
 362                 switch ( idl_insert( &idl, id, db->dbc_maxids ) ) {
 363                 case 0:         /* id inserted - store the updated block */
 364                 case 1:
 365                         rc = idl_store( be, db, key, idl );
 366                         break;
 367
 368                 case 2:         /* id already there - nothing to do */
 369                         rc = 0;
 370                         break;
 371
 372                 case 3:         /* id not inserted - block must be split */
 373                         /* check threshold for marking this an all-id block */
 374                         if ( db->dbc_maxindirect < 2 ) {
 375                                 idl_free( idl );
 376                                 idl = idl_allids( be );
 377                                 rc = idl_store( be, db, key, idl );
 378                                 break;
 379                         }
 380
 381                         idl_split_block( idl, id, &tmp, &tmp2 );
 382                         idl_free( idl );
 383
 384                         /* create the header indirect block */
 385                         idl = idl_alloc( 3 );
 386                         ID_BLOCK_NMAX(idl) = 3;
 387                         ID_BLOCK_NIDS(idl) = ID_BLOCK_INDIRECT_VALUE;
 388                         ID_BLOCK_ID(idl, 0) = ID_BLOCK_ID(tmp, 0);
 389                         ID_BLOCK_ID(idl, 1) = ID_BLOCK_ID(tmp2, 0);
 390                         ID_BLOCK_ID(idl, 2) = NOID;
 391
 392                         /* store it */
 393                         rc = idl_store( be, db, key, idl );
 394
 395                         /* store the first id block */
 396                         kstr = (char *) ch_malloc( key.dsize + CONT_SIZE );
 397                         sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 398                                 ID_BLOCK_ID(tmp, 0), key.dptr );
 399
 400                         k2.dptr = kstr;
 401                         k2.dsize = strlen( kstr ) + 1;
 402                         rc = idl_store( be, db, k2, tmp );
 403
 404                         /* store the second id block */
 405                         sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 406                                 ID_BLOCK_ID(tmp2, 0), key.dptr );
 407                         k2.dptr = kstr;
 408                         k2.dsize = strlen( kstr ) + 1;
 409                         rc = idl_store( be, db, k2, tmp2 );
 410
 411                         free( kstr );
 412                         idl_free( tmp );
 413                         idl_free( tmp2 );
 414                         break;
 415                 }
 416
 417                 idl_free( idl );
 418                 return( rc );
 419         }
 420
 421         /*
 422          * this is an indirect block which points to other blocks.
 423          * we need to read in the block into which the id should be
 424          * inserted, then insert the id and store the block.  we might
 425          * have to split the block if it is full, which means we also
 426          * need to write a new "header" block.
 427          */
 428
 429         /* select the block to try inserting into *//* XXX linear search XXX */
 430         for ( i = 0; !ID_BLOCK_NOID(idl, i) && id > ID_BLOCK_ID(idl, i); i++ )
 431                 ;       /* NULL */
 432         if ( i != 0 ) {
 433                 i--;
 434                 first = 0;
 435         } else {
 436                 first = 1;
 437         }
 438
 439         /* get the block */
 440         kstr = (char *) ch_malloc( key.dsize + CONT_SIZE );
 441         sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 442                 ID_BLOCK_ID(idl, i), key.dptr );
 443         k2.dptr = kstr;
 444         k2.dsize = strlen( kstr ) + 1;
 445         if ( (tmp = idl_fetch_one( be, db, k2 )) == NULL ) {
 446                 Debug( LDAP_DEBUG_ANY, "nonexistent continuation block (%s)\n",
 447                     k2.dptr, 0, 0 );
 448                 free( kstr );
 449                 idl_free( idl );
 450                 return( -1 );
 451         }
 452
 453         /* insert the id */
 454         switch ( idl_insert( &tmp, id, db->dbc_maxids ) ) {
 455         case 0:         /* id inserted ok */
 456                 if ( (rc = idl_store( be, db, k2, tmp )) != 0 ) {
 457                         Debug( LDAP_DEBUG_ANY,
 458                             "idl_store of (%s) returns %d\n", k2.dptr, rc, 0 );
 459                 }
 460                 break;
 461
 462         case 1:         /* id inserted - first id in block has changed */
 463                 /*
 464                  * key for this block has changed, so we have to
 465                  * write the block under the new key, delete the
 466                  * old key block + update and write the indirect
 467                  * header block.
 468                  */
 469
 470                 rc = idl_change_first( be, db, key, idl, i, k2, tmp );
 471                 break;
 472
 473         case 2:         /* id not inserted - already there */
 474                 break;
 475
 476         case 3:         /* id not inserted - block is full */
 477                 /*
 478                  * first, see if it will fit in the next block,
 479                  * without splitting, unless we're trying to insert
 480                  * into the beginning of the first block.
 481                  */
 482
 483                 /* is there a next block? */
 484                 if ( !first && !ID_BLOCK_NOID(idl, i + 1) ) {
 485                         /* read it in */
 486                         sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 487                                 ID_BLOCK_ID(idl, i + 1), key.dptr );
 488                         k2.dptr = kstr;
 489                         k2.dsize = strlen( kstr ) + 1;
 490                         if ( (tmp2 = idl_fetch_one( be, db, k2 )) == NULL ) {
 491                                 Debug( LDAP_DEBUG_ANY,
 492                                     "idl_fetch_one (%s) returns NULL\n",
 493                                     k2.dptr, 0, 0 );
 494                                 break;
 495                         }
 496
 497                         switch ( (rc = idl_insert( &tmp2, id,
 498                             db->dbc_maxids )) ) {
 499                         case 1:         /* id inserted first in block */
 500                                 rc = idl_change_first( be, db, key, idl,
 501                                     i + 1, k2, tmp2 );
 502                                 /* FALL */
 503
 504                         case 2:         /* id already there - how? */
 505                         case 0:         /* id inserted */
 506                                 if ( rc == 2 ) {
 507                                         Debug( LDAP_DEBUG_ANY,
 508                                             "id %ld already in next block\n",
 509                                             id, 0, 0 );
 510                                 }
 511                                 free( kstr );
 512                                 idl_free( tmp );
 513                                 idl_free( tmp2 );
 514                                 idl_free( idl );
 515                                 return( 0 );
 516
 517                         case 3:         /* split the original block */
 518                                 break;
 519                         }
 520                         idl_free( tmp2 );
 521                 }
 522
 523                 /*
 524                  * must split the block, write both new blocks + update
 525                  * and write the indirect header block.
 526                  */
 527
 528                 /* count how many indirect blocks *//* XXX linear count XXX */
 529                 for ( j = 0; !ID_BLOCK_NOID(idl, j); j++ )
 530                         ;       /* NULL */
 531
 532                 /* check it against all-id thresholed */
 533                 if ( j + 1 > db->dbc_maxindirect ) {
 534                         /*
 535                          * we've passed the all-id threshold, meaning
 536                          * that this set of blocks should be replaced
 537                          * by a single "all-id" block.  our job: delete
 538                          * all the indirect blocks, and replace the header
 539                          * block by an all-id block.
 540                          */
 541
 542                         /* delete all indirect blocks */
 543                         for ( j = 0; !ID_BLOCK_NOID(idl, j); j++ ) {
 544                                 sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 545                                         ID_BLOCK_ID(idl, j), key.dptr );
 546                                 k2.dptr = kstr;
 547                                 k2.dsize = strlen( kstr ) + 1;
 548
 549                                 rc = ldbm_cache_delete( db, k2 );
 550                         }
 551
 552                         /* store allid block in place of header block */
 553                         idl_free( idl );
 554                         idl = idl_allids( be );
 555                         rc = idl_store( be, db, key, idl );
 556
 557                         free( kstr );
 558                         idl_free( idl );
 559                         idl_free( tmp );
 560                         return( rc );
 561                 }
 562
 563                 idl_split_block( tmp, id, &tmp2, &tmp3 );
 564                 idl_free( tmp );
 565
 566                 /* create a new updated indirect header block */
 567                 tmp = idl_alloc( ID_BLOCK_NMAX(idl) + 1 );
 568                 ID_BLOCK_NIDS(tmp) = ID_BLOCK_INDIRECT_VALUE;
 569                 /* everything up to the split block */
 570                 SAFEMEMCPY(
 571                         (char *) &ID_BLOCK_ID(tmp, 0),
 572                         (char *) &ID_BLOCK_ID(idl, 0),
 573                     i * sizeof(ID) );
 574                 /* the two new blocks */
 575                 ID_BLOCK_ID(tmp, i) = ID_BLOCK_ID(tmp2, 0);
 576                 ID_BLOCK_ID(tmp, i + 1) = ID_BLOCK_ID(tmp3, 0);
 577                 /* everything after the split block */
 578                 SAFEMEMCPY(
 579                         (char *) &ID_BLOCK_ID(tmp, i + 2),
 580                         (char *) &ID_BLOCK_ID(idl, i + 1),
 581                         (ID_BLOCK_NMAX(idl) - i - 1) * sizeof(ID) );
 582
 583                 /* store the header block */
 584                 rc = idl_store( be, db, key, tmp );
 585
 586                 /* store the first id block */
 587                 sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 588                         ID_BLOCK_ID(tmp2, 0), key.dptr );
 589                 k2.dptr = kstr;
 590                 k2.dsize = strlen( kstr ) + 1;
 591                 rc = idl_store( be, db, k2, tmp2 );
 592
 593                 /* store the second id block */
 594                 sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 595                         ID_BLOCK_ID(tmp3, 0), key.dptr );
 596                 k2.dptr = kstr;
 597                 k2.dsize = strlen( kstr ) + 1;
 598                 rc = idl_store( be, db, k2, tmp3 );
 599
 600                 idl_free( tmp2 );
 601                 idl_free( tmp3 );
 602                 break;
 603         }
 604
 605         free( kstr );
 606         idl_free( tmp );
 607         idl_free( idl );
 608         return( rc );
 609 }
 610
 611
 612 /*
 613  * idl_insert - insert an id into an id list.
 614  *
 615  *      returns
 616  *              0       id inserted
 617  *              1       id inserted, first id in block has changed
 618  *              2       id not inserted, already there
 619  *              3       id not inserted, block must be split
 620  */
 621 int
 622 idl_insert( ID_BLOCK **idl, ID id, unsigned int maxids )
 623 {
 624         unsigned int    i;
 625
 626         if ( ID_BLOCK_ALLIDS( *idl ) ) {
 627                 return( 2 );    /* already there */
 628         }
 629
 630         /* is it already there? *//* XXX linear search XXX */
 631         for ( i = 0; i < ID_BLOCK_NIDS(*idl) && id > ID_BLOCK_ID(*idl, i); i++ ) {
 632                 ;       /* NULL */
 633         }
 634         if ( i < ID_BLOCK_NIDS(*idl) && ID_BLOCK_ID(*idl, i) == id ) {
 635                 return( 2 );    /* already there */
 636         }
 637
 638         /* do we need to make room for it? */
 639         if ( ID_BLOCK_NIDS(*idl) == ID_BLOCK_NMAX(*idl) ) {
 640                 /* make room or indicate block needs splitting */
 641                 if ( ID_BLOCK_NMAX(*idl) >= maxids ) {
 642                         return( 3 );    /* block needs splitting */
 643                 }
 644
 645                 ID_BLOCK_NMAX(*idl) *= 2;
 646                 if ( ID_BLOCK_NMAX(*idl) > maxids ) {
 647                         ID_BLOCK_NMAX(*idl) = maxids;
 648                 }
 649                 *idl = (ID_BLOCK *) ch_realloc( (char *) *idl,
 650                     (ID_BLOCK_NMAX(*idl) + ID_BLOCK_IDS_OFFSET) * sizeof(ID) );
 651         }
 652
 653         /* make a slot for the new id */
 654         SAFEMEMCPY( &ID_BLOCK_ID(*idl, i), &ID_BLOCK_ID(*idl, i+1),
 655                 ID_BLOCK_NIDS(*idl) - i );
 656
 657         ID_BLOCK_ID(*idl, i) = id;
 658         ID_BLOCK_NIDS(*idl)++;
 659         (void) memset(
 660                 (char *) &ID_BLOCK_ID((*idl), ID_BLOCK_NIDS(*idl)),
 661                 '\0',
 662             (ID_BLOCK_NMAX(*idl) - ID_BLOCK_NIDS(*idl)) * sizeof(ID) );
 663
 664         return( i == 0 ? 1 : 0 );       /* inserted - first id changed or not */
 665 }
 666
 667
 668 int
 669 idl_delete_key (
 670         Backend         *be,
 671         DBCache  *db,
 672         Datum           key,
 673         ID              id
 674 )
 675 {
 676         Datum  data;
 677         ID_BLOCK *idl, *tmp;
 678         unsigned i;
 679         int j, nids;
 680         char    *kstr;
 681
 682         if ( (idl = idl_fetch_one( be, db, key ) ) == NULL )
 683         {
 684                 /* It wasn't found.  Hmm... */
 685                 return -1;
 686         }
 687
 688         if ( ID_BLOCK_ALLIDS( idl ) ) {
 689                 idl_free( idl );
 690                 return 0;
 691         }
 692
 693         if ( ! ID_BLOCK_INDIRECT( idl ) ) {
 694                 for ( i=0; i < ID_BLOCK_NIDS(idl); i++ ) {
 695                         if ( ID_BLOCK_ID(idl, i) == id ) {
 696                                 if( --ID_BLOCK_NIDS(idl) == 0 ) {
 697                                         ldbm_cache_delete( db, key );
 698
 699                                 } else {
 700                                         SAFEMEMCPY (
 701                                                 &ID_BLOCK_ID(idl, i),
 702                                                 &ID_BLOCK_ID(idl, i+1),
 703                                                 (ID_BLOCK_NIDS(idl)-i) * sizeof(ID) );
 704
 705                                         ID_BLOCK_ID(idl, ID_BLOCK_NIDS(idl)) = NOID;
 706
 707                                         idl_store( be, db, key, idl );
 708                                 }
 709
 710                                 idl_free( idl );
 711                                 return 0;
 712                         }
 713                         /*  We didn't find the ID.  Hmmm... */
 714                 }
 715                 idl_free( idl );
 716                 return -1;
 717         }
 718
 719         /* We have to go through an indirect block and find the ID
 720            in the list of IDL's
 721            */
 722         for ( nids = 0; !ID_BLOCK_NOID(idl, nids); nids++ )
 723                 ;       /* NULL */
 724         kstr = (char *) ch_malloc( key.dsize + CONT_SIZE );
 725
 726         for ( j = 0; !ID_BLOCK_NOID(idl, j); j++ )
 727         {
 728                 ldbm_datum_init( data );
 729                 sprintf( kstr, "%c%ld%s", CONT_PREFIX,
 730                         ID_BLOCK_ID(idl, j), key.dptr );
 731                 data.dptr = kstr;
 732                 data.dsize = strlen( kstr ) + 1;
 733
 734                 if ( (tmp = idl_fetch_one( be, db, data )) == NULL ) {
 735                         Debug( LDAP_DEBUG_ANY,
 736                             "idl_fetch of (%s) returns NULL\n", data.dptr, 0, 0 );
 737                         continue;
 738                 }
 739                 /*
 740                    Now try to find the ID in tmp
 741                 */
 742                 for ( i=0; i < ID_BLOCK_NIDS(tmp); i++ )
 743                 {
 744                         if ( ID_BLOCK_ID(tmp, i) == id )
 745                         {
 746                                 SAFEMEMCPY(
 747                                         &ID_BLOCK_ID(tmp, i),
 748                                         &ID_BLOCK_ID(tmp, i+1),
 749                                         (ID_BLOCK_NIDS(tmp)-(i+1)) * sizeof(ID));
 750                                 ID_BLOCK_ID(tmp, ID_BLOCK_NIDS(tmp)-1 ) = NOID;
 751                                 ID_BLOCK_NIDS(tmp)--;
 752
 753                                 if ( ID_BLOCK_NIDS(tmp) ) {
 754                                         idl_store ( be, db, data, tmp );
 755
 756                                 } else {
 757                                         ldbm_cache_delete( db, data );
 758                                         SAFEMEMCPY(
 759                                                 &ID_BLOCK_ID(idl, j),
 760                                                 &ID_BLOCK_ID(idl, j+1),
 761                                                 (nids-(j+1)) * sizeof(ID));
 762                                         ID_BLOCK_ID(idl, nids-1) = NOID;
 763                                         nids--;
 764                                         if ( ! nids )
 765                                                 ldbm_cache_delete( db, key );
 766                                         else
 767                                                 idl_store( be, db, key, idl );
 768                                 }
 769                                 idl_free( tmp );
 770                                 free( kstr );
 771                                 idl_free( idl );
 772                                 return 0;
 773                         }
 774                 }
 775                 idl_free( tmp );
 776         }
 777         free( kstr );
 778         idl_free( idl );
 779         return -1;
 780 }
 781
 782
 783 /* return a duplicate of a single ID_BLOCK */
 784 static ID_BLOCK *
 785 idl_dup( ID_BLOCK *idl )
 786 {
 787         ID_BLOCK        *new;
 788
 789         if ( idl == NULL ) {
 790                 return( NULL );
 791         }
 792
 793         new = idl_alloc( ID_BLOCK_NMAX(idl) );
 794
 795         SAFEMEMCPY(
 796                 (char *) new,
 797                 (char *) idl,
 798                 (ID_BLOCK_NMAX(idl) + ID_BLOCK_IDS_OFFSET) * sizeof(ID) );
 799
 800         return( new );
 801 }
 802
 803
 804 /* return the smaller ID_BLOCK */
 805 static ID_BLOCK *
 806 idl_min( ID_BLOCK *a, ID_BLOCK *b )
 807 {
 808         return( ID_BLOCK_NIDS(a) > ID_BLOCK_NIDS(b) ? b : a );
 809 }
 810
 811
 812 /*
 813  * idl_intersection - return a intersection b
 814  */
 815 ID_BLOCK *
 816 idl_intersection(
 817     Backend     *be,
 818     ID_BLOCK    *a,
 819     ID_BLOCK    *b
 820 )
 821 {
 822         unsigned int    ai, bi, ni;
 823         ID_BLOCK                *n;
 824
 825         if ( a == NULL || b == NULL ) {
 826                 return( NULL );
 827         }
 828         if ( ID_BLOCK_ALLIDS( a ) ) {
 829                 return( idl_dup( b ) );
 830         }
 831         if ( ID_BLOCK_ALLIDS( b ) ) {
 832                 return( idl_dup( a ) );
 833         }
 834
 835         n = idl_dup( idl_min( a, b ) );
 836
 837         for ( ni = 0, ai = 0, bi = 0; ai < ID_BLOCK_NIDS(a); ai++ ) {
 838                 for ( ;
 839                         bi < ID_BLOCK_NIDS(b) && ID_BLOCK_ID(b, bi) < ID_BLOCK_ID(a, ai);
 840                         bi++ )
 841                 {
 842                         ;       /* NULL */
 843                 }
 844
 845                 if ( bi == ID_BLOCK_NIDS(b) ) {
 846                         break;
 847                 }
 848
 849                 if ( ID_BLOCK_ID(b, bi) == ID_BLOCK_ID(a, ai) ) {
 850                         ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(a, ai);
 851                 }
 852         }
 853
 854         if ( ni == 0 ) {
 855                 idl_free( n );
 856                 return( NULL );
 857         }
 858         ID_BLOCK_NIDS(n) = ni;
 859
 860         return( n );
 861 }
 862
 863
 864 /*
 865  * idl_union - return a union b
 866  */
 867 ID_BLOCK *
 868 idl_union(
 869     Backend     *be,
 870     ID_BLOCK    *a,
 871     ID_BLOCK    *b
 872 )
 873 {
 874         unsigned int    ai, bi, ni;
 875         ID_BLOCK                *n;
 876
 877         if ( a == NULL ) {
 878                 return( idl_dup( b ) );
 879         }
 880         if ( b == NULL ) {
 881                 return( idl_dup( a ) );
 882         }
 883         if ( ID_BLOCK_ALLIDS( a ) || ID_BLOCK_ALLIDS( b ) ) {
 884                 return( idl_allids( be ) );
 885         }
 886
 887         if ( ID_BLOCK_NIDS(b) < ID_BLOCK_NIDS(a) ) {
 888                 n = a;
 889                 a = b;
 890                 b = n;
 891         }
 892
 893         n = idl_alloc( ID_BLOCK_NIDS(a) + ID_BLOCK_NIDS(b) );
 894
 895         for ( ni = 0, ai = 0, bi = 0;
 896                 ai < ID_BLOCK_NIDS(a) && bi < ID_BLOCK_NIDS(b);
 897                 )
 898         {
 899                 if ( ID_BLOCK_ID(a, ai) < ID_BLOCK_ID(b, bi) ) {
 900                         ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(a, ai++);
 901
 902                 } else if ( ID_BLOCK_ID(b, bi) < ID_BLOCK_ID(a, ai) ) {
 903                         ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(b, bi++);
 904
 905                 } else {
 906                         ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(a, ai);
 907                         ai++, bi++;
 908                 }
 909         }
 910
 911         for ( ; ai < ID_BLOCK_NIDS(a); ai++ ) {
 912                 ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(a, ai);
 913         }
 914         for ( ; bi < ID_BLOCK_NIDS(b); bi++ ) {
 915                 ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(b, bi);
 916         }
 917         ID_BLOCK_NIDS(n) = ni;
 918
 919         return( n );
 920 }
 921
 922
 923 /*
 924  * idl_notin - return a intersection ~b (or a minus b)
 925  */
 926 ID_BLOCK *
 927 idl_notin(
 928     Backend     *be,
 929     ID_BLOCK    *a,
 930     ID_BLOCK    *b
 931 )
 932 {
 933         unsigned int    ni, ai, bi;
 934         ID_BLOCK                *n;
 935
 936         if ( a == NULL ) {
 937                 return( NULL );
 938         }
 939         if ( b == NULL || ID_BLOCK_ALLIDS( b )) {
 940                 return( idl_dup( a ) );
 941         }
 942
 943         if ( ID_BLOCK_ALLIDS( a ) ) {
 944                 n = idl_alloc( SLAPD_LDBM_MIN_MAXIDS );
 945                 ni = 0;
 946
 947                 for ( ai = 1, bi = 0;
 948                         ai < ID_BLOCK_NIDS(a) && ni < ID_BLOCK_NMAX(n) && bi < ID_BLOCK_NMAX(b);
 949                         ai++ )
 950                 {
 951                         if ( ID_BLOCK_ID(b, bi) == ai ) {
 952                                 bi++;
 953                         } else {
 954                                 ID_BLOCK_ID(n, ni++) = ai;
 955                         }
 956                 }
 957
 958                 for ( ; ai < ID_BLOCK_NIDS(a) && ni < ID_BLOCK_NMAX(n); ai++ ) {
 959                         ID_BLOCK_ID(n, ni++) = ai;
 960                 }
 961
 962                 if ( ni == ID_BLOCK_NMAX(n) ) {
 963                         idl_free( n );
 964                         return( idl_allids( be ) );
 965                 } else {
 966                         ID_BLOCK_NIDS(n) = ni;
 967                         return( n );
 968                 }
 969         }
 970
 971         n = idl_dup( a );
 972
 973         ni = 0;
 974         for ( ai = 0, bi = 0; ai < ID_BLOCK_NIDS(a); ai++ ) {
 975                 for ( ;
 976                         bi < ID_BLOCK_NIDS(b) && ID_BLOCK_ID(b, bi) < ID_BLOCK_ID(a, ai);
 977                     bi++ )
 978                 {
 979                         ;       /* NULL */
 980                 }
 981
 982                 if ( bi == ID_BLOCK_NIDS(b) ) {
 983                         break;
 984                 }
 985
 986                 if ( ID_BLOCK_ID(b, bi) != ID_BLOCK_ID(a, ai) ) {
 987                         ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(a, ai);
 988                 }
 989         }
 990
 991         for ( ; ai < ID_BLOCK_NIDS(a); ai++ ) {
 992                 ID_BLOCK_ID(n, ni++) = ID_BLOCK_ID(a, ai);
 993         }
 994         ID_BLOCK_NIDS(n) = ni;
 995
 996         return( n );
 997 }
 998
 999 /*      return the first ID in the block
1000  *      if ALLIDS block
1001  *              NIDS > 1 return 1
1002  *              otherwise return NOID
1003  *      otherwise return first ID
1004  *
1005  *      cursor is set to 1
1006  */
1007 ID
1008 idl_firstid( ID_BLOCK *idl, ID *cursor )
1009 {
1010         *cursor = 1;
1011
1012         if ( idl == NULL || ID_BLOCK_NIDS(idl) == 0 ) {
1013                 return( NOID );
1014         }
1015
1016         if ( ID_BLOCK_ALLIDS( idl ) ) {
1017                 return( ID_BLOCK_NIDS(idl) > 1 ? 1 : NOID );
1018         }
1019
1020         return( ID_BLOCK_ID(idl, 0) );
1021 }
1022
1023 /*      return next ID
1024  *      if ALLIDS block, cursor is id.
1025  *              increment id
1026  *              if id < NIDS return id
1027  *              otherwise NOID.
1028  *      otherwise cursor is index into block
1029  *              if index < nids
1030  *                      return id at index then increment
1031  */
1032 ID
1033 idl_nextid( ID_BLOCK *idl, ID *cursor )
1034 {
1035         if ( ID_BLOCK_ALLIDS( idl ) ) {
1036                 if( ++(*cursor) < ID_BLOCK_NIDS(idl) ) {
1037                         return *cursor;
1038                 } else {
1039                         return NOID;
1040                 }
1041         }
1042
1043         if ( *cursor < ID_BLOCK_NIDS(idl) ) {
1044                 return( ID_BLOCK_ID(idl, (*cursor)++) );
1045         }
1046
1047         return( NOID );
1048 }