1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 2013 Oracle and/or its affiliates. All rights reserved.
*
* $Id$
*/
#ifndef _DB_PAGE_H_
#define _DB_PAGE_H_
#if defined(__cplusplus)
extern "C" {
#endif
/*
* DB page formats.
*
* !!!
* This implementation requires that values within the following structures
* NOT be padded -- note, ANSI C permits random padding within structures.
* If your compiler pads randomly you can just forget ever making DB run on
* your system. In addition, no data type can require larger alignment than
* its own size, e.g., a 4-byte data element may not require 8-byte alignment.
*
* Note that key/data lengths are often stored in db_indx_t's -- this is
* not accidental, nor does it limit the key/data size. If the key/data
* item fits on a page, it's guaranteed to be small enough to fit into a
* db_indx_t, and storing it in one saves space.
*/
#define PGNO_INVALID 0 /* Invalid page number in any database. */
#define PGNO_BASE_MD 0 /* Base database: metadata page number. */
/* Page types. */
#define P_INVALID 0 /* Invalid page type. */
#define __P_DUPLICATE 1 /* Duplicate. DEPRECATED in 3.1 */
#define P_HASH_UNSORTED 2 /* Hash pages created pre 4.6. DEPRECATED */
#define P_IBTREE 3 /* Btree internal. */
#define P_IRECNO 4 /* Recno internal. */
#define P_LBTREE 5 /* Btree leaf. */
#define P_LRECNO 6 /* Recno leaf. */
#define P_OVERFLOW 7 /* Overflow. */
#define P_HASHMETA 8 /* Hash metadata page. */
#define P_BTREEMETA 9 /* Btree metadata page. */
#define P_QAMMETA 10 /* Queue metadata page. */
#define P_QAMDATA 11 /* Queue data page. */
#define P_LDUP 12 /* Off-page duplicate leaf. */
#define P_HASH 13 /* Sorted hash page. */
#define P_HEAPMETA 14 /* Heap metadata page. */
#define P_HEAP 15 /* Heap data page. */
#define P_IHEAP 16 /* Heap internal. */
#define P_PAGETYPE_MAX 17
/* Flag to __db_new */
#define P_DONTEXTEND 0x8000 /* Don't allocate if there are no free pages. */
/*
* When we create pages in mpool, we ask mpool to clear some number of bytes
* in the header. This number must be at least as big as the regular page
* headers and cover enough of the btree and hash meta-data pages to obliterate
* the page type.
*/
#define DB_PAGE_DB_LEN 32
#define DB_PAGE_QUEUE_LEN 0
/************************************************************************
GENERIC METADATA PAGE HEADER
*
* !!!
* The magic and version numbers have to be in the same place in all versions
* of the metadata page as the application may not have upgraded the database.
************************************************************************/
typedef struct _dbmeta33 {
DB_LSN lsn; /* 00-07: LSN. */
db_pgno_t pgno; /* 08-11: Current page number. */
u_int32_t magic; /* 12-15: Magic number. */
u_int32_t version; /* 16-19: Version. */
u_int32_t pagesize; /* 20-23: Pagesize. */
u_int8_t encrypt_alg; /* 24: Encryption algorithm. */
u_int8_t type; /* 25: Page type. */
#define DBMETA_CHKSUM 0x01
#define DBMETA_PART_RANGE 0x02
#define DBMETA_PART_CALLBACK 0x04
u_int8_t metaflags; /* 26: Meta-only flags */
u_int8_t unused1; /* 27: Unused. */
u_int32_t free; /* 28-31: Free list page number. */
db_pgno_t last_pgno; /* 32-35: Page number of last page in db. */
u_int32_t nparts; /* 36-39: Number of partitions. */
u_int32_t key_count; /* 40-43: Cached key count. */
u_int32_t record_count; /* 44-47: Cached record count. */
u_int32_t flags; /* 48-51: Flags: unique to each AM. */
/* 52-71: Unique file ID. */
u_int8_t uid[DB_FILE_ID_LEN];
} DBMETA33, DBMETA;
/************************************************************************
BTREE METADATA PAGE LAYOUT
************************************************************************/
typedef struct _btmeta33 {
#define BTM_DUP 0x001 /* Duplicates. */
#define BTM_RECNO 0x002 /* Recno tree. */
#define BTM_RECNUM 0x004 /* Btree: maintain record count. */
#define BTM_FIXEDLEN 0x008 /* Recno: fixed length records. */
#define BTM_RENUMBER 0x010 /* Recno: renumber on insert/delete. */
#define BTM_SUBDB 0x020 /* Subdatabases. */
#define BTM_DUPSORT 0x040 /* Duplicates are sorted. */
#define BTM_COMPRESS 0x080 /* Compressed. */
#define BTM_MASK 0x0ff
DBMETA dbmeta; /* 00-71: Generic meta-data header. */
u_int32_t unused1; /* 72-75: Unused space. */
u_int32_t minkey; /* 76-79: Btree: Minkey. */
u_int32_t re_len; /* 80-83: Recno: fixed-length record length. */
u_int32_t re_pad; /* 84-87: Recno: fixed-length record pad. */
u_int32_t root; /* 88-91: Root page. */
u_int32_t unused2[92]; /* 92-459: Unused space. */
u_int32_t crypto_magic; /* 460-463: Crypto magic number */
u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
/*
* Minimum page size is 512.
*/
} BTMETA33, BTMETA;
/************************************************************************
HASH METADATA PAGE LAYOUT
************************************************************************/
typedef struct _hashmeta33 {
#define DB_HASH_DUP 0x01 /* Duplicates. */
#define DB_HASH_SUBDB 0x02 /* Subdatabases. */
#define DB_HASH_DUPSORT 0x04 /* Duplicates are sorted. */
DBMETA dbmeta; /* 00-71: Generic meta-data page header. */
u_int32_t max_bucket; /* 72-75: ID of Maximum bucket in use */
u_int32_t high_mask; /* 76-79: Modulo mask into table */
u_int32_t low_mask; /* 80-83: Modulo mask into table lower half */
u_int32_t ffactor; /* 84-87: Fill factor */
u_int32_t nelem; /* 88-91: Number of keys in hash table */
u_int32_t h_charkey; /* 92-95: Value of hash(CHARKEY) */
#define NCACHED 32 /* number of spare points */
/* 96-223: Spare pages for overflow */
u_int32_t spares[NCACHED];
u_int32_t unused[59]; /* 224-459: Unused space */
u_int32_t crypto_magic; /* 460-463: Crypto magic number */
u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
/*
* Minimum page size is 512.
*/
} HMETA33, HMETA;
/************************************************************************
HEAP METADATA PAGE LAYOUT
*************************************************************************/
/*
* Heap Meta data page structure
*
*/
typedef struct _heapmeta {
DBMETA dbmeta; /* 00-71: Generic meta-data header. */
db_pgno_t curregion; /* 72-75: Current region pgno. */
u_int32_t nregions; /* 76-79: Number of regions. */
u_int32_t gbytes; /* 80-83: GBytes for fixed size heap. */
u_int32_t bytes; /* 84-87: Bytes for fixed size heap. */
u_int32_t region_size; /* 88-91: Max region size. */
u_int32_t unused2[92]; /* 92-459: Unused space.*/
u_int32_t crypto_magic; /* 460-463: Crypto magic number */
u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
/*
* Minimum page size is 512.
*/
} HEAPMETA;
/************************************************************************
QUEUE METADATA PAGE LAYOUT
************************************************************************/
/*
* QAM Meta data page structure
*
*/
typedef struct _qmeta33 {
DBMETA dbmeta; /* 00-71: Generic meta-data header. */
u_int32_t first_recno; /* 72-75: First not deleted record. */
u_int32_t cur_recno; /* 76-79: Next recno to be allocated. */
u_int32_t re_len; /* 80-83: Fixed-length record length. */
u_int32_t re_pad; /* 84-87: Fixed-length record pad. */
u_int32_t rec_page; /* 88-91: Records Per Page. */
u_int32_t page_ext; /* 92-95: Pages per extent */
u_int32_t unused[91]; /* 96-459: Unused space */
u_int32_t crypto_magic; /* 460-463: Crypto magic number */
u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
/*
* Minimum page size is 512.
*/
} QMETA33, QMETA;
/*
* DBMETASIZE is a constant used by __db_file_setup and DB->verify
* as a buffer which is guaranteed to be larger than any possible
* metadata page size and smaller than any disk sector.
*/
#define DBMETASIZE 512
/************************************************************************
BTREE/HASH MAIN PAGE LAYOUT
************************************************************************/
/*
* +-----------------------------------+
* | lsn | pgno | prev pgno |
* +-----------------------------------+
* | next pgno | entries | hf offset |
* +-----------------------------------+
* | level | type | chksum |
* +-----------------------------------+
* | iv | index | free --> |
* +-----------+-----------------------+
* | F R E E A R E A |
* +-----------------------------------+
* | <-- free | item |
* +-----------------------------------+
* | item | item | item |
* +-----------------------------------+
*
* sizeof(PAGE) == 26 bytes + possibly 20 bytes of checksum and possibly
* 16 bytes of IV (+ 2 bytes for alignment), and the following indices
* are guaranteed to be two-byte aligned. If we aren't doing crypto or
* checksumming the bytes are reclaimed for data storage.
*
* For hash and btree leaf pages, index items are paired, e.g., inp[0] is the
* key for inp[1]'s data. All other types of pages only contain single items.
*/
typedef struct __pg_chksum {
u_int8_t unused[2]; /* 26-27: For alignment */
u_int8_t chksum[4]; /* 28-31: Checksum */
} PG_CHKSUM;
typedef struct __pg_crypto {
u_int8_t unused[2]; /* 26-27: For alignment */
u_int8_t chksum[DB_MAC_KEY]; /* 28-47: Checksum */
u_int8_t iv[DB_IV_BYTES]; /* 48-63: IV */
/* !!!
* Must be 16-byte aligned for crypto
*/
} PG_CRYPTO;
/*
* With most compilers sizeof(PG_CRYPTO) == 38. However some ABIs
* require it to be padded to 40 bytes. The padding must be excluded
* from our size calculations due to the 16-byte alignment requirement
* for crypto.
*
* A similar problem applies to PG_CHKSUM, but it's too late to change
* that.
*/
#define SIZEOF_PG_CRYPTO 38
typedef struct _db_page {
DB_LSN lsn; /* 00-07: Log sequence number. */
db_pgno_t pgno; /* 08-11: Current page number. */
db_pgno_t prev_pgno; /* 12-15: Previous page number. */
db_pgno_t next_pgno; /* 16-19: Next page number. */
db_indx_t entries; /* 20-21: Number of items on the page. */
db_indx_t hf_offset; /* 22-23: High free byte page offset. */
/*
* The btree levels are numbered from the leaf to the root, starting
* with 1, so the leaf is level 1, its parent is level 2, and so on.
* We maintain this level on all btree pages, but the only place that
* we actually need it is on the root page. It would not be difficult
* to hide the byte on the root page once it becomes an internal page,
* so we could get this byte back if we needed it for something else.
*/
#define LEAFLEVEL 1
#define MAXBTREELEVEL 255
u_int8_t level; /* 24: Btree tree level. */
u_int8_t type; /* 25: Page type. */
} PAGE;
/*
* With many compilers sizeof(PAGE) == 28, while SIZEOF_PAGE == 26.
* We add in other things directly after the page header and need
* the SIZEOF_PAGE. When giving the sizeof(), many compilers will
* pad it out to the next 4-byte boundary.
*/
#define SIZEOF_PAGE 26
/*
* !!!
* DB_AM_ENCRYPT always implies DB_AM_CHKSUM so that must come first.
*/
#define P_INP(dbp, pg) \
((db_indx_t *)((u_int8_t *)(pg) + SIZEOF_PAGE + \
(F_ISSET((dbp), DB_AM_ENCRYPT) ? SIZEOF_PG_CRYPTO : \
(F_ISSET((dbp), DB_AM_CHKSUM) ? sizeof(PG_CHKSUM) : 0))))
#define P_IV(dbp, pg) \
(F_ISSET((dbp), DB_AM_ENCRYPT) ? ((u_int8_t *)(pg) + \
SIZEOF_PAGE + SSZA(PG_CRYPTO, iv)) \
: NULL)
#define P_CHKSUM(dbp, pg) \
(F_ISSET((dbp), DB_AM_ENCRYPT) ? ((u_int8_t *)(pg) + \
SIZEOF_PAGE + SSZA(PG_CRYPTO, chksum)) : \
(F_ISSET((dbp), DB_AM_CHKSUM) ? ((u_int8_t *)(pg) + \
SIZEOF_PAGE + SSZA(PG_CHKSUM, chksum)) \
: NULL))
/* PAGE element macros. */
#define LSN(p) (((PAGE *)p)->lsn)
#define PGNO(p) (((PAGE *)p)->pgno)
#define PREV_PGNO(p) (((PAGE *)p)->prev_pgno)
#define NEXT_PGNO(p) (((PAGE *)p)->next_pgno)
#define NUM_ENT(p) (((PAGE *)p)->entries)
#define HOFFSET(p) (((PAGE *)p)->hf_offset)
#define LEVEL(p) (((PAGE *)p)->level)
#define TYPE(p) (((PAGE *)p)->type)
/************************************************************************
HEAP PAGE LAYOUT
************************************************************************/
#define HEAPPG_NORMAL 26
#define HEAPPG_CHKSUM 48
#define HEAPPG_SEC 64
/*
* +0-----------2------------4-----------6-----------7+
* | lsn |
* +-------------------------+------------------------+
* | pgno | unused0 |
* +-------------+-----------+-----------+------------+
* | high_indx | free_indx | entries | hf offset |
* +-------+-----+-----------+-----------+------------+
* |unused2|type | unused3 | ...chksum... |
* +-------+-----+-----------+------------------------+
* | ...iv... | offset table / free space map |
* +-------------+------------------------------------+
* |free-> F R E E A R E A |
* +--------------------------------------------------+
* | <-- free | item |
* +-------------------------+------------------------+
* | item | item |
* +-------------------------+------------------------+
*
* The page layout of both heap internal and data pages. If not using
* crypto, iv will be overwritten with data. If not using checksumming,
* unused3 and chksum will also be overwritten with data and data will start at
* 26. Note that this layout lets us re-use a lot of the PAGE element macros
* defined above.
*/
typedef struct _heappg {
DB_LSN lsn; /* 00-07: Log sequence number. */
db_pgno_t pgno; /* 08-11: Current page number. */
u_int32_t high_pgno; /* 12-15: Highest page in region. */
u_int16_t high_indx; /* 16-17: Highest index in the offset table. */
db_indx_t free_indx; /* 18-19: First available index. */
db_indx_t entries; /* 20-21: Number of items on the page. */
db_indx_t hf_offset; /* 22-23: High free byte page offset. */
u_int8_t unused2[1]; /* 24: Unused. */
u_int8_t type; /* 25: Page type. */
u_int8_t unused3[2]; /* 26-27: Never used, just checksum alignment. */
u_int8_t chksum[DB_MAC_KEY]; /* 28-47: Checksum */
u_int8_t iv[DB_IV_BYTES]; /* 48-63: IV */
} HEAPPG;
/* Define first possible data page for heap, 0 is metapage, 1 is region page */
#define FIRST_HEAP_RPAGE 1
#define FIRST_HEAP_DPAGE 2
typedef struct __heaphdr {
#define HEAP_RECSPLIT 0x01 /* Heap data record is split */
#define HEAP_RECFIRST 0x02 /* First piece of a split record */
#define HEAP_RECLAST 0x04 /* Last piece of a split record */
u_int8_t flags; /* 00: Flags describing record. */
u_int8_t unused; /* 01: Padding. */
u_int16_t size; /* 02-03: The size of the stored data piece. */
} HEAPHDR;
typedef struct __heaphdrsplt {
HEAPHDR std_hdr; /* 00-03: The standard data header */
u_int32_t tsize; /* 04-07: Total record size, 1st piece only */
db_pgno_t nextpg; /* 08-11: RID.pgno of the next record piece */
db_indx_t nextindx; /* 12-13: RID.indx of the next record piece */
u_int16_t unused; /* 14-15: Padding. */
} HEAPSPLITHDR;
#define HEAP_HDRSIZE(hdr) \
(F_ISSET((hdr), HEAP_RECSPLIT) ? sizeof(HEAPSPLITHDR) : sizeof(HEAPHDR))
#define HEAPPG_SZ(dbp) \
(F_ISSET((dbp), DB_AM_ENCRYPT) ? HEAPPG_SEC : \
F_ISSET((dbp), DB_AM_CHKSUM) ? HEAPPG_CHKSUM : HEAPPG_NORMAL)
/* Each byte in the bitmap describes 4 pages (2 bits per page.) */
#define HEAP_REGION_COUNT(dbp, size) (((size) - HEAPPG_SZ(dbp)) * 4)
#define HEAP_DEFAULT_REGION_MAX(dbp) \
(HEAP_REGION_COUNT(dbp, (u_int32_t)8 * 1024))
#define HEAP_REGION_SIZE(dbp) (((HEAP*) (dbp)->heap_internal)->region_size)
/* Figure out which region a given page belongs to. */
#define HEAP_REGION_PGNO(dbp, p) \
((((p) - 1) / (HEAP_REGION_SIZE(dbp) + 1)) * \
(HEAP_REGION_SIZE(dbp) + 1) + 1)
/* Translate a region pgno to region number */
#define HEAP_REGION_NUM(dbp, pgno) \
((((pgno) - 1) / (HEAP_REGION_SIZE((dbp)) + 1)) + 1)
/*
* Given an internal heap page and page number relative to that page, return the
* bits from map describing free space on the nth page. Each byte in the map
* describes 4 pages. Point at the correct byte and mask the correct 2 bits.
*/
#define HEAP_SPACE(dbp, pg, n) \
(HEAP_SPACEMAP((dbp), (pg))[(n) / 4] >> (2 * ((n) % 4)) & 3)
#define HEAP_SETSPACE(dbp, pg, n, b) do { \
HEAP_SPACEMAP((dbp), (pg))[(n) / 4] &= ~(3 << (2 * ((n) % 4))); \
HEAP_SPACEMAP((dbp), (pg))[(n) / 4] |= ((b & 3) << (2 * ((n) % 4))); \
} while (0)
/* Return the bitmap describing free space on heap data pages. */
#define HEAP_SPACEMAP(dbp, pg) ((u_int8_t *)P_INP((dbp), (pg)))
/* Return the offset table for a heap data page. */
#define HEAP_OFFSETTBL(dbp, pg) P_INP((dbp), (pg))
/*
* Calculate the % of a page a given size occupies and translate that to the
* corresponding bitmap value.
*/
#define HEAP_CALCSPACEBITS(dbp, sz, space) do { \
(space) = 100 * (sz) / (dbp)->pgsize; \
if ((space) <= HEAP_PG_FULL_PCT) \
(space) = HEAP_PG_FULL; \
else if ((space) <= HEAP_PG_GT66_PCT) \
(space) = HEAP_PG_GT66; \
else if ((space) <= HEAP_PG_GT33_PCT) \
(space) = HEAP_PG_GT33; \
else \
(space) = HEAP_PG_LT33; \
} while (0)
/* Return the amount of free space on a heap data page. */
#define HEAP_FREESPACE(dbp, p) \
(HOFFSET(p) - HEAPPG_SZ(dbp) - \
(NUM_ENT(p) == 0 ? 0 : ((HEAP_HIGHINDX(p) + 1) * sizeof(db_indx_t))))
/* The maximum amount of data that can fit on an empty heap data page. */
#define HEAP_MAXDATASIZE(dbp) \
((dbp)->pgsize - HEAPPG_SZ(dbp) - sizeof(db_indx_t))
#define HEAP_FREEINDX(p) (((HEAPPG *)p)->free_indx)
#define HEAP_HIGHINDX(p) (((HEAPPG *)p)->high_indx)
/* True if we have a page that deals with heap */
#define HEAPTYPE(h) \
(TYPE(h) == P_HEAPMETA || TYPE(h) == P_HEAP || TYPE(h) == P_IHEAP)
/************************************************************************
QUEUE MAIN PAGE LAYOUT
************************************************************************/
/*
* Sizes of page below. Used to reclaim space if not doing
* crypto or checksumming. If you change the QPAGE below you
* MUST adjust this too.
*/
#define QPAGE_NORMAL 28
#define QPAGE_CHKSUM 48
#define QPAGE_SEC 64
typedef struct _qpage {
DB_LSN lsn; /* 00-07: Log sequence number. */
db_pgno_t pgno; /* 08-11: Current page number. */
u_int32_t unused0[3]; /* 12-23: Unused. */
u_int8_t unused1[1]; /* 24: Unused. */
u_int8_t type; /* 25: Page type. */
u_int8_t unused2[2]; /* 26-27: Unused. */
u_int8_t chksum[DB_MAC_KEY]; /* 28-47: Checksum */
u_int8_t iv[DB_IV_BYTES]; /* 48-63: IV */
} QPAGE;
#define QPAGE_SZ(dbp) \
(F_ISSET((dbp), DB_AM_ENCRYPT) ? QPAGE_SEC : \
F_ISSET((dbp), DB_AM_CHKSUM) ? QPAGE_CHKSUM : QPAGE_NORMAL)
/*
* !!!
* The next_pgno and prev_pgno fields are not maintained for btree and recno
* internal pages. Doing so only provides a minor performance improvement,
* it's hard to do when deleting internal pages, and it increases the chance
* of deadlock during deletes and splits because we have to re-link pages at
* more than the leaf level.
*
* !!!
* The btree/recno access method needs db_recno_t bytes of space on the root
* page to specify how many records are stored in the tree. (The alternative
* is to store the number of records in the meta-data page, which will create
* a second hot spot in trees being actively modified, or recalculate it from
* the BINTERNAL fields on each access.) Overload the PREV_PGNO field.
*/
#define RE_NREC(p) \
((TYPE(p) == P_IBTREE || TYPE(p) == P_IRECNO) ? PREV_PGNO(p) : \
(db_pgno_t)(TYPE(p) == P_LBTREE ? NUM_ENT(p) / 2 : NUM_ENT(p)))
#define RE_NREC_ADJ(p, adj) \
PREV_PGNO(p) += adj;
#define RE_NREC_SET(p, num) \
PREV_PGNO(p) = (num);
/*
* Initialize a page.
*
* !!!
* Don't modify the page's LSN, code depends on it being unchanged after a
* P_INIT call.
*/
#define P_INIT(pg, pg_size, n, pg_prev, pg_next, btl, pg_type) do { \
PGNO(pg) = (n); \
PREV_PGNO(pg) = (pg_prev); \
NEXT_PGNO(pg) = (pg_next); \
NUM_ENT(pg) = (0); \
HOFFSET(pg) = (db_indx_t)(pg_size); \
LEVEL(pg) = (btl); \
TYPE(pg) = (pg_type); \
} while (0)
/* Page header length (offset to first index). */
#define P_OVERHEAD(dbp) P_TO_UINT16(P_INP(dbp, 0))
/* First free byte. */
#define LOFFSET(dbp, pg) \
(P_OVERHEAD(dbp) + NUM_ENT(pg) * sizeof(db_indx_t))
/* Free space on a regular page. */
#define P_FREESPACE(dbp, pg) (HOFFSET(pg) - LOFFSET(dbp, pg))
/* Get a pointer to the bytes at a specific index. */
#define P_ENTRY(dbp, pg, indx) ((u_int8_t *)pg + P_INP(dbp, pg)[indx])
/************************************************************************
OVERFLOW PAGE LAYOUT
************************************************************************/
/*
* Overflow items are referenced by HOFFPAGE and BOVERFLOW structures, which
* store a page number (the first page of the overflow item) and a length
* (the total length of the overflow item). The overflow item consists of
* some number of overflow pages, linked by the next_pgno field of the page.
* A next_pgno field of PGNO_INVALID flags the end of the overflow item.
*
* Overflow page overloads:
* The amount of overflow data stored on each page is stored in the
* hf_offset field.
*
* Before 4.3 the implementation reference counted overflow items as it
* once was possible for them to be promoted onto btree internal pages.
* The reference count is stored in the entries field.
*/
#define OV_LEN(p) (((PAGE *)p)->hf_offset)
#define OV_REF(p) (((PAGE *)p)->entries)
/* Maximum number of bytes that you can put on an overflow page. */
#define P_MAXSPACE(dbp, psize) ((psize) - P_OVERHEAD(dbp))
/* Free space on an overflow page. */
#define P_OVFLSPACE(dbp, psize, pg) (P_MAXSPACE(dbp, psize) - HOFFSET(pg))
/************************************************************************
HASH PAGE LAYOUT
************************************************************************/
/* Each index references a group of bytes on the page. */
#define H_KEYDATA 1 /* Key/data item. */
#define H_DUPLICATE 2 /* Duplicate key/data item. */
#define H_OFFPAGE 3 /* Overflow key/data item. */
#define H_OFFDUP 4 /* Overflow page of duplicates. */
/*
* !!!
* Items on hash pages are (potentially) unaligned, so we can never cast the
* (page + offset) pointer to an HKEYDATA, HOFFPAGE or HOFFDUP structure, as
* we do with B+tree on-page structures. Because we frequently want the type
* field, it requires no alignment, and it's in the same location in all three
* structures, there's a pair of macros.
*/
#define HPAGE_PTYPE(p) (*(u_int8_t *)p)
#define HPAGE_TYPE(dbp, pg, indx) (*P_ENTRY(dbp, pg, indx))
/*
* The first and second types are H_KEYDATA and H_DUPLICATE, represented
* by the HKEYDATA structure:
*
* +-----------------------------------+
* | type | key/data ... |
* +-----------------------------------+
*
* For duplicates, the data field encodes duplicate elements in the data
* field:
*
* +---------------------------------------------------------------+
* | type | len1 | element1 | len1 | len2 | element2 | len2 |
* +---------------------------------------------------------------+
*
* Thus, by keeping track of the offset in the element, we can do both
* backward and forward traversal.
*/
typedef struct _hkeydata {
u_int8_t type; /* 00: Page type. */
u_int8_t data[1]; /* Variable length key/data item. */
} HKEYDATA;
#define HKEYDATA_DATA(p) (((u_int8_t *)p) + SSZA(HKEYDATA, data))
/*
* The length of any HKEYDATA item. Note that indx is an element index,
* not a PAIR index.
*/
#define LEN_HITEM(dbp, pg, pgsize, indx) \
(((indx) == 0 ? (pgsize) : \
(P_INP(dbp, pg)[(indx) - 1])) - (P_INP(dbp, pg)[indx]))
#define LEN_HKEYDATA(dbp, pg, psize, indx) \
(db_indx_t)(LEN_HITEM(dbp, pg, psize, indx) - HKEYDATA_SIZE(0))
/*
* Page space required to add a new HKEYDATA item to the page, with and
* without the index value.
*/
#define HKEYDATA_SIZE(len) \
((len) + SSZA(HKEYDATA, data))
#define HKEYDATA_PSIZE(len) \
(HKEYDATA_SIZE(len) + sizeof(db_indx_t))
/* Put a HKEYDATA item at the location referenced by a page entry. */
#define PUT_HKEYDATA(pe, kd, len, etype) { \
((HKEYDATA *)(pe))->type = etype; \
memcpy((u_int8_t *)(pe) + sizeof(u_int8_t), kd, len); \
}
/*
* Macros the describe the page layout in terms of key-data pairs.
*/
#define H_NUMPAIRS(pg) (NUM_ENT(pg) / 2)
#define H_KEYINDEX(indx) (indx)
#define H_DATAINDEX(indx) ((indx) + 1)
#define H_PAIRKEY(dbp, pg, indx) P_ENTRY(dbp, pg, H_KEYINDEX(indx))
#define H_PAIRDATA(dbp, pg, indx) P_ENTRY(dbp, pg, H_DATAINDEX(indx))
#define H_PAIRSIZE(dbp, pg, psize, indx) \
(LEN_HITEM(dbp, pg, psize, H_KEYINDEX(indx)) + \
LEN_HITEM(dbp, pg, psize, H_DATAINDEX(indx)))
#define LEN_HDATA(dbp, p, psize, indx) \
LEN_HKEYDATA(dbp, p, psize, H_DATAINDEX(indx))
#define LEN_HKEY(dbp, p, psize, indx) \
LEN_HKEYDATA(dbp, p, psize, H_KEYINDEX(indx))
/*
* The third type is the H_OFFPAGE, represented by the HOFFPAGE structure:
*/
typedef struct _hoffpage {
u_int8_t type; /* 00: Page type and delete flag. */
u_int8_t unused[3]; /* 01-03: Padding, unused. */
db_pgno_t pgno; /* 04-07: Offpage page number. */
u_int32_t tlen; /* 08-11: Total length of item. */
} HOFFPAGE;
#define HOFFPAGE_PGNO(p) (((u_int8_t *)p) + SSZ(HOFFPAGE, pgno))
#define HOFFPAGE_TLEN(p) (((u_int8_t *)p) + SSZ(HOFFPAGE, tlen))
/*
* Page space required to add a new HOFFPAGE item to the page, with and
* without the index value.
*/
#define HOFFPAGE_SIZE (sizeof(HOFFPAGE))
#define HOFFPAGE_PSIZE (HOFFPAGE_SIZE + sizeof(db_indx_t))
/*
* The fourth type is H_OFFDUP represented by the HOFFDUP structure:
*/
typedef struct _hoffdup {
u_int8_t type; /* 00: Page type and delete flag. */
u_int8_t unused[3]; /* 01-03: Padding, unused. */
db_pgno_t pgno; /* 04-07: Offpage page number. */
} HOFFDUP;
#define HOFFDUP_PGNO(p) (((u_int8_t *)p) + SSZ(HOFFDUP, pgno))
/*
* Page space required to add a new HOFFDUP item to the page, with and
* without the index value.
*/
#define HOFFDUP_SIZE (sizeof(HOFFDUP))
/************************************************************************
BTREE PAGE LAYOUT
************************************************************************/
/* Each index references a group of bytes on the page. */
#define B_KEYDATA 1 /* Key/data item. */
#define B_DUPLICATE 2 /* Duplicate key/data item. */
#define B_OVERFLOW 3 /* Overflow key/data item. */
/*
* We have to store a deleted entry flag in the page. The reason is complex,
* but the simple version is that we can't delete on-page items referenced by
* a cursor -- the return order of subsequent insertions might be wrong. The
* delete flag is an overload of the top bit of the type byte.
*/
#define B_DELETE (0x80)
#define B_DCLR(t) (t) &= ~B_DELETE
#define B_DSET(t) (t) |= B_DELETE
#define B_DISSET(t) ((t) & B_DELETE)
#define B_TYPE(t) ((t) & ~B_DELETE)
#define B_TSET(t, type) ((t) = B_TYPE(type))
#define B_TSET_DELETED(t, type) ((t) = (type) | B_DELETE)
/*
* The first type is B_KEYDATA, represented by the BKEYDATA structure:
*/
typedef struct _bkeydata {
db_indx_t len; /* 00-01: Key/data item length. */
u_int8_t type; /* 02: Page type AND DELETE FLAG. */
u_int8_t data[1]; /* Variable length key/data item. */
} BKEYDATA;
/* Get a BKEYDATA item for a specific index. */
#define GET_BKEYDATA(dbp, pg, indx) \
((BKEYDATA *)P_ENTRY(dbp, pg, indx))
/*
* Page space required to add a new BKEYDATA item to the page, with and
* without the index value. The (u_int16_t) cast avoids warnings: DB_ALIGN
* casts to uintmax_t, the cast converts it to a small integral type so we
* don't get complaints when we assign the final result to an integral type
* smaller than uintmax_t.
*/
#define BKEYDATA_SIZE(len) \
(u_int16_t)DB_ALIGN((len) + SSZA(BKEYDATA, data), sizeof(u_int32_t))
#define BKEYDATA_PSIZE(len) \
(BKEYDATA_SIZE(len) + sizeof(db_indx_t))
/*
* The second and third types are B_DUPLICATE and B_OVERFLOW, represented
* by the BOVERFLOW structure.
*/
typedef struct _boverflow {
db_indx_t unused1; /* 00-01: Padding, unused. */
u_int8_t type; /* 02: Page type AND DELETE FLAG. */
u_int8_t unused2; /* 03: Padding, unused. */
db_pgno_t pgno; /* 04-07: Next page number. */
u_int32_t tlen; /* 08-11: Total length of item. */
} BOVERFLOW;
/* Get a BOVERFLOW item for a specific index. */
#define GET_BOVERFLOW(dbp, pg, indx) \
((BOVERFLOW *)P_ENTRY(dbp, pg, indx))
/*
* Page space required to add a new BOVERFLOW item to the page, with and
* without the index value.
*/
#define BOVERFLOW_SIZE \
((u_int16_t)DB_ALIGN(sizeof(BOVERFLOW), sizeof(u_int32_t)))
#define BOVERFLOW_PSIZE \
(BOVERFLOW_SIZE + sizeof(db_indx_t))
#define BITEM_SIZE(bk) \
(B_TYPE((bk)->type) != B_KEYDATA ? BOVERFLOW_SIZE : \
BKEYDATA_SIZE((bk)->len))
#define BITEM_PSIZE(bk) \
(B_TYPE((bk)->type) != B_KEYDATA ? BOVERFLOW_PSIZE : \
BKEYDATA_PSIZE((bk)->len))
/*
* Btree leaf and hash page layouts group indices in sets of two, one for the
* key and one for the data. Everything else does it in sets of one to save
* space. Use the following macros so that it's real obvious what's going on.
*/
#define O_INDX 1
#define P_INDX 2
/************************************************************************
BTREE INTERNAL PAGE LAYOUT
************************************************************************/
/*
* Btree internal entry.
*/
typedef struct _binternal {
db_indx_t len; /* 00-01: Key/data item length. */
u_int8_t type; /* 02: Page type AND DELETE FLAG. */
u_int8_t unused; /* 03: Padding, unused. */
db_pgno_t pgno; /* 04-07: Page number of referenced page. */
db_recno_t nrecs; /* 08-11: Subtree record count. */
u_int8_t data[1]; /* Variable length key item. */
} BINTERNAL;
/* Get a BINTERNAL item for a specific index. */
#define GET_BINTERNAL(dbp, pg, indx) \
((BINTERNAL *)P_ENTRY(dbp, pg, indx))
/*
* Page space required to add a new BINTERNAL item to the page, with and
* without the index value.
*/
#define BINTERNAL_SIZE(len) \
(u_int16_t)DB_ALIGN((len) + SSZA(BINTERNAL, data), sizeof(u_int32_t))
#define BINTERNAL_PSIZE(len) \
(BINTERNAL_SIZE(len) + sizeof(db_indx_t))
/************************************************************************
RECNO INTERNAL PAGE LAYOUT
************************************************************************/
/*
* The recno internal entry.
*/
typedef struct _rinternal {
db_pgno_t pgno; /* 00-03: Page number of referenced page. */
db_recno_t nrecs; /* 04-07: Subtree record count. */
} RINTERNAL;
/* Get a RINTERNAL item for a specific index. */
#define GET_RINTERNAL(dbp, pg, indx) \
((RINTERNAL *)P_ENTRY(dbp, pg, indx))
/*
* Page space required to add a new RINTERNAL item to the page, with and
* without the index value.
*/
#define RINTERNAL_SIZE \
(u_int16_t)DB_ALIGN(sizeof(RINTERNAL), sizeof(u_int32_t))
#define RINTERNAL_PSIZE \
(RINTERNAL_SIZE + sizeof(db_indx_t))
typedef struct __pglist {
db_pgno_t pgno, next_pgno;
DB_LSN lsn;
} db_pglist_t;
#if defined(__cplusplus)
}
#endif
#endif /* !_DB_PAGE_H_ */
|