db_verify.h

Go to the documentation of this file.

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1999, 2000
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: db__verify_8h-source.html,v 1.1 2008/06/08 10:18:23 sebdiaz Exp $
 */

#ifndef _DB_VERIFY_H
#define _DB_VERIFY_H_

/*
 * Structures and macros for the storage and retrieval of all information
 * needed for inter-page verification of a database.
 */

/*
 * EPRINT is the macro for error printing.  Takes as an arg the arg set
 * for DB->err.
 */
#define EPRINT(x)                                                       \
        do {                                                            \
                if (!LF_ISSET(DB_SALVAGE))                              \
                        CDB___db_err x;                                 \
        } while (0)

#define TYPE_ERR_PRINT(dbp, func, pgno, type)                           \
    EPRINT(((dbp), "%s called on nonsensical page %lu of type %lu",     \
        (func), (u_long)(pgno), (u_long)(type)));

/* Is x a power of two?  (Tests true for zero, which doesn't matter here.) */
#define POWER_OF_TWO(x) (((x) & ((x) - 1)) == 0)

#define IS_VALID_PAGESIZE(x)                                            \
        (POWER_OF_TWO(x) && (x) >= DB_MIN_PGSIZE && ((x) <= DB_MAX_PGSIZE))

/*
 * Note that 0 is, in general, a valid pgno, despite equalling PGNO_INVALID;
 * we have to test it separately where it's not appropriate.
 */
#define IS_VALID_PGNO(x)        ((x) <= vdp->last_pgno)

/*
 * Flags understood by the btree structure checks (esp. CDB___bam_vrfy_subtree).
 * These share the same space as the global flags to CDB___db_verify, and must not
 * dip below 0x00010000.
 */
#define ST_DUPOK        0x00010000
#define ST_DUPSORT      0x00020000
#define ST_IS_RECNO     0x00040000
#define ST_OVFL_LEAF    0x00080000      /* Overflow reffed from leaf page. */
#define ST_RECNUM       0x00100000
#define ST_RELEN        0x00200000
#define ST_TOPLEVEL     0x00400000      /* subtree == entire tree */

/*
 * Flags understood by CDB___bam_salvage and CDB___db_salvage.  These need not share
 * the same space with the CDB___bam_vrfy_subtree flags, but must share with
 * CDB___db_verify.
 */
#define SA_HASDUPS      0x00010000
#define SA_MARKDATAPGS  0x00020000
#define SA_PRINTHEADER  0x00040000
#define SA_SKIPFIRSTKEY 0x00080000

/*
 * VRFY_DBINFO is the fundamental structure;  it either represents the database
 * of subdatabases, or the sole database if there are no subdatabases.
 */
struct __vrfy_dbinfo {
        /* Info about this database in particular. */
        DBTYPE          type;

        /* List of subdatabase meta pages, if any. */
        LIST_HEAD(__subdbs, __vrfy_childinfo) subdbs;

        /* File-global info--stores VRFY_PAGEINFOs for each page. */
        DB *pgdbp;

        /* Child database--stores VRFY_CHILDINFOs of each page. */
        DB *cdbp;

        /* Page info structures currently in use. */
        LIST_HEAD(__activepips, __vrfy_pageinfo) activepips;

        /*
         * DB we use to keep track of which pages are linked somehow
         * during verification.  0 is the default, "unseen";  1 is seen.
         */
        DB *pgset;

        /*
         * This is a database we use during salvaging to keep track of which
         * overflow and dup pages we need to come back to at the end and print
         * with key "UNKNOWN".  Pages which print with a good key get set
         * to SALVAGE_IGNORE;  others get set, as appropriate, to SALVAGE_LDUP,
         * SALVAGE_LRECNODUP, SALVAGE_OVERFLOW for normal db overflow pages,
         * and SALVAGE_BTREE, SALVAGE_LRECNO, and SALVAGE_HASH for subdb
         * pages.
         */
#define SALVAGE_INVALID         0
#define SALVAGE_IGNORE          1
#define SALVAGE_LDUP            2
#define SALVAGE_LRECNODUP       3
#define SALVAGE_OVERFLOW        4
#define SALVAGE_LBTREE          5
#define SALVAGE_HASH            6
#define SALVAGE_LRECNO          7
        DB *salvage_pages;

        db_pgno_t       last_pgno;

        /* Queue needs these to verify data pages in the first pass. */
        u_int32_t       re_len;
        u_int32_t       rec_page;

#define SALVAGE_PRINTHEADER     0x01
#define SALVAGE_PRINTFOOTER     0x02
        u_int32_t       flags;
}; /* VRFY_DBINFO */

/*
 * The amount of state information we need per-page is small enough that
 * it's not worth the trouble to define separate structures for each
 * possible type of page, and since we're doing verification with these we
 * have to be open to the possibility that page N will be of a completely
 * unexpected type anyway.  So we define one structure here with all the
 * info we need for inter-page verification.
 */
struct __vrfy_pageinfo {
        u_int8_t        type;
        u_int8_t        bt_level;
        u_int8_t        unused1;
        u_int8_t        unused2;
        db_pgno_t       pgno;
        db_pgno_t       prev_pgno;
        db_pgno_t       next_pgno;

        /* meta pages */
        db_pgno_t       root;
        db_pgno_t       free;           /* Free list head. */

        db_indx_t       entries;        /* Actual number of entries. */
        u_int16_t       unused;
        db_recno_t      rec_cnt;        /* Record count. */
        u_int32_t       re_len;         /* Record length. */
        u_int32_t       bt_minkey;
        u_int32_t       bt_maxkey;
        u_int32_t       h_ffactor;
        u_int32_t       h_nelem;

        /* overflow pages */
        /*
         * Note that refcount is the refcount for an overflow page; pi_refcount
         * is this structure's own refcount!
         */
        u_int32_t       refcount;
        u_int32_t       olen;

#define VRFY_DUPS_UNSORTED      0x0001  /* Have to flag the negative! */
#define VRFY_HAS_DUPS           0x0002
#define VRFY_HAS_DUPSORT        0x0004  /* Has the flag set. */
#define VRFY_HAS_SUBDBS         0x0008
#define VRFY_HAS_RECNUMS        0x0010
#define VRFY_INCOMPLETE         0x0020  /* Meta or item order checks incomp. */
#define VRFY_IS_ALLZEROES       0x0040  /* Hash page we haven't touched? */
#define VRFY_IS_FIXEDLEN        0x0080
#define VRFY_IS_RECNO           0x0100
#define VRFY_IS_RRECNO          0x0200
#define VRFY_OVFL_LEAFSEEN      0x0400
        u_int32_t       flags;

        LIST_ENTRY(__vrfy_pageinfo) links;
        u_int32_t       pi_refcount;
}; /* VRFY_PAGEINFO */

struct __vrfy_childinfo {
        db_pgno_t       pgno;

#define V_DUPLICATE     1               /* off-page dup metadata */
#define V_OVERFLOW      2               /* overflow page */
#define V_RECNO         3               /* btree internal or leaf page */
        u_int32_t       type;
        db_recno_t      nrecs;          /* record count on a btree subtree */
        u_int32_t       tlen;           /* ovfl. item total size */

        LIST_ENTRY(__vrfy_childinfo) links;
}; /* VRFY_CHILDINFO */

#endif /* _DB_VERIFY_H_ */

---