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658 lines
24 KiB
C
658 lines
24 KiB
C
/*-
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* See the file LICENSE for redistribution information.
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*
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* Copyright (c) 1996-2004
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* Sleepycat Software. All rights reserved.
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*
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* $Id: db_page.h,v 11.63 2004/09/17 22:00:27 mjc Exp $
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*/
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#ifndef _DB_PAGE_H_
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#define _DB_PAGE_H_
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#if defined(__cplusplus)
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extern "C" {
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#endif
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/*
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* DB page formats.
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*
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* !!!
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* This implementation requires that values within the following structures
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* NOT be padded -- note, ANSI C permits random padding within structures.
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* If your compiler pads randomly you can just forget ever making DB run on
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* your system. In addition, no data type can require larger alignment than
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* its own size, e.g., a 4-byte data element may not require 8-byte alignment.
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*
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* Note that key/data lengths are often stored in db_indx_t's -- this is
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* not accidental, nor does it limit the key/data size. If the key/data
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* item fits on a page, it's guaranteed to be small enough to fit into a
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* db_indx_t, and storing it in one saves space.
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*/
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#define PGNO_INVALID 0 /* Invalid page number in any database. */
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#define PGNO_BASE_MD 0 /* Base database: metadata page number. */
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/* Page types. */
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#define P_INVALID 0 /* Invalid page type. */
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#define __P_DUPLICATE 1 /* Duplicate. DEPRECATED in 3.1 */
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#define P_HASH 2 /* Hash. */
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#define P_IBTREE 3 /* Btree internal. */
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#define P_IRECNO 4 /* Recno internal. */
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#define P_LBTREE 5 /* Btree leaf. */
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#define P_LRECNO 6 /* Recno leaf. */
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#define P_OVERFLOW 7 /* Overflow. */
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#define P_HASHMETA 8 /* Hash metadata page. */
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#define P_BTREEMETA 9 /* Btree metadata page. */
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#define P_QAMMETA 10 /* Queue metadata page. */
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#define P_QAMDATA 11 /* Queue data page. */
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#define P_LDUP 12 /* Off-page duplicate leaf. */
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#define P_PAGETYPE_MAX 13
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/*
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* When we create pages in mpool, we ask mpool to clear some number of bytes
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* in the header. This number must be at least as big as the regular page
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* headers and cover enough of the btree and hash meta-data pages to obliterate
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* the page type.
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*/
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#define DB_PAGE_DB_LEN 32
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#define DB_PAGE_QUEUE_LEN 0
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/************************************************************************
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GENERIC METADATA PAGE HEADER
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*
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* !!!
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* The magic and version numbers have to be in the same place in all versions
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* of the metadata page as the application may not have upgraded the database.
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************************************************************************/
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typedef struct _dbmeta33 {
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DB_LSN lsn; /* 00-07: LSN. */
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db_pgno_t pgno; /* 08-11: Current page number. */
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u_int32_t magic; /* 12-15: Magic number. */
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u_int32_t version; /* 16-19: Version. */
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u_int32_t pagesize; /* 20-23: Pagesize. */
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u_int8_t encrypt_alg; /* 24: Encryption algorithm. */
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u_int8_t type; /* 25: Page type. */
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#define DBMETA_CHKSUM 0x01
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u_int8_t metaflags; /* 26: Meta-only flags */
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u_int8_t unused1; /* 27: Unused. */
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u_int32_t free; /* 28-31: Free list page number. */
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db_pgno_t last_pgno; /* 32-35: Page number of last page in db. */
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u_int32_t unused3; /* 36-39: Unused. */
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u_int32_t key_count; /* 40-43: Cached key count. */
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u_int32_t record_count; /* 44-47: Cached record count. */
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u_int32_t flags; /* 48-51: Flags: unique to each AM. */
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/* 52-71: Unique file ID. */
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u_int8_t uid[DB_FILE_ID_LEN];
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} DBMETA33, DBMETA;
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/************************************************************************
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BTREE METADATA PAGE LAYOUT
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************************************************************************/
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typedef struct _btmeta33 {
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#define BTM_DUP 0x001 /* Duplicates. */
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#define BTM_RECNO 0x002 /* Recno tree. */
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#define BTM_RECNUM 0x004 /* Btree: maintain record count. */
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#define BTM_FIXEDLEN 0x008 /* Recno: fixed length records. */
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#define BTM_RENUMBER 0x010 /* Recno: renumber on insert/delete. */
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#define BTM_SUBDB 0x020 /* Subdatabases. */
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#define BTM_DUPSORT 0x040 /* Duplicates are sorted. */
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#define BTM_MASK 0x07f
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DBMETA dbmeta; /* 00-71: Generic meta-data header. */
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u_int32_t maxkey; /* 72-75: Btree: Maxkey. */
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u_int32_t minkey; /* 76-79: Btree: Minkey. */
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u_int32_t re_len; /* 80-83: Recno: fixed-length record length. */
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u_int32_t re_pad; /* 84-87: Recno: fixed-length record pad. */
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u_int32_t root; /* 88-91: Root page. */
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u_int32_t unused[92]; /* 92-459: Unused space */
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u_int32_t crypto_magic; /* 460-463: Crypto magic number */
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u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
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u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
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u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
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/*
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* Minimum page size is 512.
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*/
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} BTMETA33, BTMETA;
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/************************************************************************
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HASH METADATA PAGE LAYOUT
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************************************************************************/
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typedef struct _hashmeta33 {
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#define DB_HASH_DUP 0x01 /* Duplicates. */
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#define DB_HASH_SUBDB 0x02 /* Subdatabases. */
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#define DB_HASH_DUPSORT 0x04 /* Duplicates are sorted. */
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DBMETA dbmeta; /* 00-71: Generic meta-data page header. */
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u_int32_t max_bucket; /* 72-75: ID of Maximum bucket in use */
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u_int32_t high_mask; /* 76-79: Modulo mask into table */
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u_int32_t low_mask; /* 80-83: Modulo mask into table lower half */
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u_int32_t ffactor; /* 84-87: Fill factor */
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u_int32_t nelem; /* 88-91: Number of keys in hash table */
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u_int32_t h_charkey; /* 92-95: Value of hash(CHARKEY) */
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#define NCACHED 32 /* number of spare points */
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/* 96-223: Spare pages for overflow */
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u_int32_t spares[NCACHED];
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u_int32_t unused[59]; /* 224-459: Unused space */
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u_int32_t crypto_magic; /* 460-463: Crypto magic number */
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u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
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u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
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u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
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/*
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* Minimum page size is 512.
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*/
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} HMETA33, HMETA;
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/************************************************************************
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QUEUE METADATA PAGE LAYOUT
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************************************************************************/
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/*
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* QAM Meta data page structure
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*
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*/
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typedef struct _qmeta33 {
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DBMETA dbmeta; /* 00-71: Generic meta-data header. */
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u_int32_t first_recno; /* 72-75: First not deleted record. */
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u_int32_t cur_recno; /* 76-79: Next recno to be allocated. */
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u_int32_t re_len; /* 80-83: Fixed-length record length. */
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u_int32_t re_pad; /* 84-87: Fixed-length record pad. */
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u_int32_t rec_page; /* 88-91: Records Per Page. */
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u_int32_t page_ext; /* 92-95: Pages per extent */
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u_int32_t unused[91]; /* 96-459: Unused space */
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u_int32_t crypto_magic; /* 460-463: Crypto magic number */
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u_int32_t trash[3]; /* 464-475: Trash space - Do not use */
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u_int8_t iv[DB_IV_BYTES]; /* 476-495: Crypto IV */
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u_int8_t chksum[DB_MAC_KEY]; /* 496-511: Page chksum */
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/*
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* Minimum page size is 512.
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*/
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} QMETA33, QMETA;
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/*
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* DBMETASIZE is a constant used by __db_file_setup and DB->verify
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* as a buffer which is guaranteed to be larger than any possible
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* metadata page size and smaller than any disk sector.
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*/
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#define DBMETASIZE 512
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/************************************************************************
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BTREE/HASH MAIN PAGE LAYOUT
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************************************************************************/
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/*
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* +-----------------------------------+
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* | lsn | pgno | prev pgno |
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* +-----------------------------------+
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* | next pgno | entries | hf offset |
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* +-----------------------------------+
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* | level | type | chksum |
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* +-----------------------------------+
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* | iv | index | free --> |
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* +-----------+-----------------------+
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* | F R E E A R E A |
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* +-----------------------------------+
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* | <-- free | item |
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* +-----------------------------------+
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* | item | item | item |
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* +-----------------------------------+
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*
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* sizeof(PAGE) == 26 bytes + possibly 20 bytes of checksum and possibly
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* 16 bytes of IV (+ 2 bytes for alignment), and the following indices
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* are guaranteed to be two-byte aligned. If we aren't doing crypto or
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* checksumming the bytes are reclaimed for data storage.
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*
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* For hash and btree leaf pages, index items are paired, e.g., inp[0] is the
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* key for inp[1]'s data. All other types of pages only contain single items.
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*/
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typedef struct __pg_chksum {
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u_int8_t unused[2]; /* 26-27: For alignment */
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u_int8_t chksum[4]; /* 28-31: Checksum */
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} PG_CHKSUM;
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typedef struct __pg_crypto {
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u_int8_t unused[2]; /* 26-27: For alignment */
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u_int8_t chksum[DB_MAC_KEY]; /* 28-47: Checksum */
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u_int8_t iv[DB_IV_BYTES]; /* 48-63: IV */
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/* !!!
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* Must be 16-byte aligned for crypto
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*/
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} PG_CRYPTO;
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typedef struct _db_page {
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DB_LSN lsn; /* 00-07: Log sequence number. */
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db_pgno_t pgno; /* 08-11: Current page number. */
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db_pgno_t prev_pgno; /* 12-15: Previous page number. */
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db_pgno_t next_pgno; /* 16-19: Next page number. */
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db_indx_t entries; /* 20-21: Number of items on the page. */
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db_indx_t hf_offset; /* 22-23: High free byte page offset. */
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/*
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* The btree levels are numbered from the leaf to the root, starting
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* with 1, so the leaf is level 1, its parent is level 2, and so on.
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* We maintain this level on all btree pages, but the only place that
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* we actually need it is on the root page. It would not be difficult
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* to hide the byte on the root page once it becomes an internal page,
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* so we could get this byte back if we needed it for something else.
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*/
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#define LEAFLEVEL 1
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#define MAXBTREELEVEL 255
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u_int8_t level; /* 24: Btree tree level. */
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u_int8_t type; /* 25: Page type. */
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} PAGE;
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/*
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* With many compilers sizeof(PAGE) == 28, while SIZEOF_PAGE == 26.
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* We add in other things directly after the page header and need
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* the SIZEOF_PAGE. When giving the sizeof(), many compilers will
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* pad it out to the next 4-byte boundary.
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*/
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#define SIZEOF_PAGE 26
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/*
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* !!!
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* DB_AM_ENCRYPT always implies DB_AM_CHKSUM so that must come first.
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*/
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#define P_INP(dbp, pg) \
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((db_indx_t *)((u_int8_t *)(pg) + SIZEOF_PAGE + \
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(F_ISSET((dbp), DB_AM_ENCRYPT) ? sizeof(PG_CRYPTO) : \
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(F_ISSET((dbp), DB_AM_CHKSUM) ? sizeof(PG_CHKSUM) : 0))))
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#define P_IV(dbp, pg) \
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(F_ISSET((dbp), DB_AM_ENCRYPT) ? ((u_int8_t *)(pg) + \
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SIZEOF_PAGE + SSZA(PG_CRYPTO, iv)) \
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: NULL)
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#define P_CHKSUM(dbp, pg) \
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(F_ISSET((dbp), DB_AM_ENCRYPT) ? ((u_int8_t *)(pg) + \
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SIZEOF_PAGE + SSZA(PG_CRYPTO, chksum)) : \
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(F_ISSET((dbp), DB_AM_CHKSUM) ? ((u_int8_t *)(pg) + \
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SIZEOF_PAGE + SSZA(PG_CHKSUM, chksum)) \
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: NULL))
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/* PAGE element macros. */
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#define LSN(p) (((PAGE *)p)->lsn)
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#define PGNO(p) (((PAGE *)p)->pgno)
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#define PREV_PGNO(p) (((PAGE *)p)->prev_pgno)
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#define NEXT_PGNO(p) (((PAGE *)p)->next_pgno)
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#define NUM_ENT(p) (((PAGE *)p)->entries)
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#define HOFFSET(p) (((PAGE *)p)->hf_offset)
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#define LEVEL(p) (((PAGE *)p)->level)
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#define TYPE(p) (((PAGE *)p)->type)
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/************************************************************************
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QUEUE MAIN PAGE LAYOUT
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************************************************************************/
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/*
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* Sizes of page below. Used to reclaim space if not doing
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* crypto or checksumming. If you change the QPAGE below you
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* MUST adjust this too.
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*/
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#define QPAGE_NORMAL 28
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#define QPAGE_CHKSUM 48
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#define QPAGE_SEC 64
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typedef struct _qpage {
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DB_LSN lsn; /* 00-07: Log sequence number. */
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db_pgno_t pgno; /* 08-11: Current page number. */
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u_int32_t unused0[3]; /* 12-23: Unused. */
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u_int8_t unused1[1]; /* 24: Unused. */
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u_int8_t type; /* 25: Page type. */
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u_int8_t unused2[2]; /* 26-27: Unused. */
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u_int8_t chksum[DB_MAC_KEY]; /* 28-47: Checksum */
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u_int8_t iv[DB_IV_BYTES]; /* 48-63: IV */
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} QPAGE;
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#define QPAGE_SZ(dbp) \
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(F_ISSET((dbp), DB_AM_ENCRYPT) ? QPAGE_SEC : \
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F_ISSET((dbp), DB_AM_CHKSUM) ? QPAGE_CHKSUM : QPAGE_NORMAL)
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/*
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* !!!
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* The next_pgno and prev_pgno fields are not maintained for btree and recno
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* internal pages. Doing so only provides a minor performance improvement,
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* it's hard to do when deleting internal pages, and it increases the chance
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* of deadlock during deletes and splits because we have to re-link pages at
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* more than the leaf level.
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*
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* !!!
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* The btree/recno access method needs db_recno_t bytes of space on the root
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* page to specify how many records are stored in the tree. (The alternative
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* is to store the number of records in the meta-data page, which will create
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* a second hot spot in trees being actively modified, or recalculate it from
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* the BINTERNAL fields on each access.) Overload the PREV_PGNO field.
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*/
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#define RE_NREC(p) \
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((TYPE(p) == P_IBTREE || TYPE(p) == P_IRECNO) ? PREV_PGNO(p) : \
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(db_pgno_t)(TYPE(p) == P_LBTREE ? NUM_ENT(p) / 2 : NUM_ENT(p)))
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#define RE_NREC_ADJ(p, adj) \
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PREV_PGNO(p) += adj;
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#define RE_NREC_SET(p, num) \
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PREV_PGNO(p) = (num);
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/*
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* Initialize a page.
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*
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* !!!
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* Don't modify the page's LSN, code depends on it being unchanged after a
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* P_INIT call.
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*/
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#define P_INIT(pg, pg_size, n, pg_prev, pg_next, btl, pg_type) do { \
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PGNO(pg) = (n); \
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PREV_PGNO(pg) = (pg_prev); \
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NEXT_PGNO(pg) = (pg_next); \
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NUM_ENT(pg) = (0); \
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HOFFSET(pg) = (db_indx_t)(pg_size); \
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LEVEL(pg) = (btl); \
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TYPE(pg) = (pg_type); \
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} while (0)
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/* Page header length (offset to first index). */
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#define P_OVERHEAD(dbp) P_TO_UINT16(P_INP(dbp, 0))
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/* First free byte. */
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#define LOFFSET(dbp, pg) \
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(P_OVERHEAD(dbp) + NUM_ENT(pg) * sizeof(db_indx_t))
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/* Free space on a regular page. */
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#define P_FREESPACE(dbp, pg) (HOFFSET(pg) - LOFFSET(dbp, pg))
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/* Get a pointer to the bytes at a specific index. */
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#define P_ENTRY(dbp, pg, indx) ((u_int8_t *)pg + P_INP(dbp, pg)[indx])
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/************************************************************************
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OVERFLOW PAGE LAYOUT
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************************************************************************/
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/*
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* Overflow items are referenced by HOFFPAGE and BOVERFLOW structures, which
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* store a page number (the first page of the overflow item) and a length
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* (the total length of the overflow item). The overflow item consists of
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* some number of overflow pages, linked by the next_pgno field of the page.
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* A next_pgno field of PGNO_INVALID flags the end of the overflow item.
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*
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* Overflow page overloads:
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* The amount of overflow data stored on each page is stored in the
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* hf_offset field.
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*
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* The implementation reference counts overflow items as it's possible
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* for them to be promoted onto btree internal pages. The reference
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* count is stored in the entries field.
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*/
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#define OV_LEN(p) (((PAGE *)p)->hf_offset)
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#define OV_REF(p) (((PAGE *)p)->entries)
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/* Maximum number of bytes that you can put on an overflow page. */
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#define P_MAXSPACE(dbp, psize) ((psize) - P_OVERHEAD(dbp))
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/* Free space on an overflow page. */
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#define P_OVFLSPACE(dbp, psize, pg) (P_MAXSPACE(dbp, psize) - HOFFSET(pg))
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/************************************************************************
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HASH PAGE LAYOUT
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************************************************************************/
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/* Each index references a group of bytes on the page. */
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#define H_KEYDATA 1 /* Key/data item. */
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#define H_DUPLICATE 2 /* Duplicate key/data item. */
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#define H_OFFPAGE 3 /* Overflow key/data item. */
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#define H_OFFDUP 4 /* Overflow page of duplicates. */
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/*
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* !!!
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* Items on hash pages are (potentially) unaligned, so we can never cast the
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* (page + offset) pointer to an HKEYDATA, HOFFPAGE or HOFFDUP structure, as
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* we do with B+tree on-page structures. Because we frequently want the type
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* field, it requires no alignment, and it's in the same location in all three
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* structures, there's a pair of macros.
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*/
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#define HPAGE_PTYPE(p) (*(u_int8_t *)p)
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#define HPAGE_TYPE(dbp, pg, indx) (*P_ENTRY(dbp, pg, indx))
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/*
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* The first and second types are H_KEYDATA and H_DUPLICATE, represented
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* by the HKEYDATA structure:
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*
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* +-----------------------------------+
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* | type | key/data ... |
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* +-----------------------------------+
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*
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* For duplicates, the data field encodes duplicate elements in the data
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* field:
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*
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* +---------------------------------------------------------------+
|
|
* | type | len1 | element1 | len1 | len2 | element2 | len2 |
|
|
* +---------------------------------------------------------------+
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|
*
|
|
* 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, type) { \
|
|
((HKEYDATA *)pe)->type = type; \
|
|
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, deleted) { \
|
|
(t) = (type); \
|
|
if (deleted) \
|
|
B_DSET(t); \
|
|
}
|
|
|
|
/*
|
|
* 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))
|
|
|
|
/*
|
|
* 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))
|
|
|
|
#if defined(__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif /* !_DB_PAGE_H_ */
|