hash_upgrade.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: hash_upgrade.c,v 12.1 2005/06/16 20:22:54 bostic Exp $
 */

#include "db_config.h"

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <string.h>
#endif

#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc/hash.h"
#include "dbinc/db_upgrade.h"

/*
 * __ham_30_hashmeta --
 *      Upgrade the database from version 4/5 to version 6.
 *
 * PUBLIC: int __ham_30_hashmeta __P((DB *, char *, u_int8_t *));
 */
int
__ham_30_hashmeta(dbp, real_name, obuf)
        DB *dbp;
        char *real_name;
        u_int8_t *obuf;
{
        DB_ENV *dbenv;
        HASHHDR *oldmeta;
        HMETA30 newmeta;
        u_int32_t *o_spares, *n_spares;
        u_int32_t fillf, i, maxb, max_entry, nelem;
        int ret;

        dbenv = dbp->dbenv;
        memset(&newmeta, 0, sizeof(newmeta));

        oldmeta = (HASHHDR *)obuf;

        /*
         * The first 32 bytes are similar.  The only change is the version
         * and that we removed the ovfl_point and have the page type now.
         */

        newmeta.dbmeta.lsn = oldmeta->lsn;
        newmeta.dbmeta.pgno = oldmeta->pgno;
        newmeta.dbmeta.magic = oldmeta->magic;
        newmeta.dbmeta.version = 6;
        newmeta.dbmeta.pagesize = oldmeta->pagesize;
        newmeta.dbmeta.type = P_HASHMETA;

        /* Move flags */
        newmeta.dbmeta.flags = oldmeta->flags;

        /* Copy the free list, which has changed its name but works the same. */
        newmeta.dbmeta.free = oldmeta->last_freed;

        /* Copy: max_bucket, high_mask, low-mask, ffactor, nelem, h_charkey */
        newmeta.max_bucket = oldmeta->max_bucket;
        newmeta.high_mask = oldmeta->high_mask;
        newmeta.low_mask = oldmeta->low_mask;
        newmeta.ffactor = oldmeta->ffactor;
        newmeta.nelem = oldmeta->nelem;
        newmeta.h_charkey = oldmeta->h_charkey;

        /*
         * There was a bug in 2.X versions where the nelem could go negative.
         * In general, this is considered "bad."  If it does go negative
         * (that is, very large and positive), we'll die trying to dump and
         * load this database.  So, let's see if we can fix it here.
         */
        nelem = newmeta.nelem;
        fillf = newmeta.ffactor;
        maxb = newmeta.max_bucket;

        if ((fillf != 0 && fillf * maxb < 2 * nelem) ||
            (fillf == 0 && nelem > 0x8000000))
                newmeta.nelem = 0;

        /*
         * We now have to convert the spares array.  The old spares array
         * contained the total number of extra pages allocated prior to
         * the bucket that begins the next doubling.  The new spares array
         * contains the page number of the first bucket in the next doubling
         * MINUS the bucket number of that bucket.
         */
        o_spares = oldmeta->spares;
        n_spares = newmeta.spares;
        max_entry = __db_log2(maxb + 1);   /* highest spares entry in use */
        n_spares[0] = 1;
        for (i = 1; i < NCACHED && i <= max_entry; i++)
                n_spares[i] = 1 + o_spares[i - 1];

                                        /* Replace the unique ID. */
        if ((ret = __os_fileid(dbenv, real_name, 1, newmeta.dbmeta.uid)) != 0)
                return (ret);

        /* Overwrite the original. */
        memcpy(oldmeta, &newmeta, sizeof(newmeta));

        return (0);
}

/*
 * __ham_30_sizefix --
 *      Make sure that all hash pages belonging to the current
 *      hash doubling are within the bounds of the file.
 *
 * PUBLIC: int __ham_30_sizefix __P((DB *, DB_FH *, char *, u_int8_t *));
 */
int
__ham_30_sizefix(dbp, fhp, realname, metabuf)
        DB *dbp;
        DB_FH *fhp;
        char *realname;
        u_int8_t *metabuf;
{
        u_int8_t buf[DB_MAX_PGSIZE];
        DB_ENV *dbenv;
        HMETA30 *meta;
        db_pgno_t last_actual, last_desired;
        int ret;
        size_t nw;
        u_int32_t pagesize;

        dbenv = dbp->dbenv;
        memset(buf, 0, DB_MAX_PGSIZE);

        meta = (HMETA30 *)metabuf;
        pagesize = meta->dbmeta.pagesize;

        /*
         * Get the last page number.  To do this, we'll need dbp->pgsize
         * to be set right, so slam it into place.
         */
        dbp->pgsize = pagesize;
        if ((ret = __db_lastpgno(dbp, realname, fhp, &last_actual)) != 0)
                return (ret);

        /*
         * The last bucket in the doubling is equal to high_mask;  calculate
         * the page number that implies.
         */
        last_desired = BS_TO_PAGE(meta->high_mask, meta->spares);

        /*
         * If last_desired > last_actual, we need to grow the file.  Write
         * a zeroed page where last_desired would go.
         */
        if (last_desired > last_actual) {
                if ((ret = __os_seek(dbenv,
                    fhp, pagesize, last_desired, 0, 0, DB_OS_SEEK_SET)) != 0)
                        return (ret);
                if ((ret = __os_write(dbenv, fhp, buf, pagesize, &nw)) != 0)
                        return (ret);
        }

        return (0);
}

/*
 * __ham_31_hashmeta --
 *      Upgrade the database from version 6 to version 7.
 *
 * PUBLIC: int __ham_31_hashmeta
 * PUBLIC:      __P((DB *, char *, u_int32_t, DB_FH *, PAGE *, int *));
 */
int
__ham_31_hashmeta(dbp, real_name, flags, fhp, h, dirtyp)
        DB *dbp;
        char *real_name;
        u_int32_t flags;
        DB_FH *fhp;
        PAGE *h;
        int *dirtyp;
{
        HMETA31 *newmeta;
        HMETA30 *oldmeta;

        COMPQUIET(dbp, NULL);
        COMPQUIET(real_name, NULL);
        COMPQUIET(fhp, NULL);

        newmeta = (HMETA31 *)h;
        oldmeta = (HMETA30 *)h;

        /*
         * Copy the fields down the page.
         * The fields may overlap so start at the bottom and use memmove().
         */
        memmove(newmeta->spares, oldmeta->spares, sizeof(oldmeta->spares));
        newmeta->h_charkey = oldmeta->h_charkey;
        newmeta->nelem = oldmeta->nelem;
        newmeta->ffactor = oldmeta->ffactor;
        newmeta->low_mask = oldmeta->low_mask;
        newmeta->high_mask = oldmeta->high_mask;
        newmeta->max_bucket = oldmeta->max_bucket;
        memmove(newmeta->dbmeta.uid,
            oldmeta->dbmeta.uid, sizeof(oldmeta->dbmeta.uid));
        newmeta->dbmeta.flags = oldmeta->dbmeta.flags;
        newmeta->dbmeta.record_count = 0;
        newmeta->dbmeta.key_count = 0;
        ZERO_LSN(newmeta->dbmeta.unused3);

        /* Update the version. */
        newmeta->dbmeta.version = 7;

        /* Upgrade the flags. */
        if (LF_ISSET(DB_DUPSORT))
                F_SET(&newmeta->dbmeta, DB_HASH_DUPSORT);

        *dirtyp = 1;
        return (0);
}

/*
 * __ham_31_hash --
 *      Upgrade the database hash leaf pages.
 *
 * PUBLIC: int __ham_31_hash
 * PUBLIC:      __P((DB *, char *, u_int32_t, DB_FH *, PAGE *, int *));
 */
int
__ham_31_hash(dbp, real_name, flags, fhp, h, dirtyp)
        DB *dbp;
        char *real_name;
        u_int32_t flags;
        DB_FH *fhp;
        PAGE *h;
        int *dirtyp;
{
        HKEYDATA *hk;
        db_pgno_t pgno, tpgno;
        db_indx_t indx;
        int ret;

        COMPQUIET(flags, 0);

        ret = 0;
        for (indx = 0; indx < NUM_ENT(h); indx += 2) {
                hk = (HKEYDATA *)H_PAIRDATA(dbp, h, indx);
                if (HPAGE_PTYPE(hk) == H_OFFDUP) {
                        memcpy(&pgno, HOFFDUP_PGNO(hk), sizeof(db_pgno_t));
                        tpgno = pgno;
                        if ((ret = __db_31_offdup(dbp, real_name, fhp,
                            LF_ISSET(DB_DUPSORT) ? 1 : 0, &tpgno)) != 0)
                                break;
                        if (pgno != tpgno) {
                                *dirtyp = 1;
                                memcpy(HOFFDUP_PGNO(hk),
                                    &tpgno, sizeof(db_pgno_t));
                        }
                }
        }

        return (ret);
}

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