hash_rec.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2005
 *      Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1995, 1996
 *      Margo Seltzer.  All rights reserved.
 */
/*
 * Copyright (c) 1995, 1996
 *      The President and Fellows of Harvard University.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Margo Seltzer.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: hash_rec.c,v 12.7 2005/09/28 17:44:52 margo 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/db_shash.h"
#include "dbinc/btree.h"
#include "dbinc/hash.h"
#include "dbinc/log.h"
#include "dbinc/mp.h"

static int __ham_alloc_pages __P((DB *, __ham_groupalloc_args *, DB_LSN *));

/*
 * __ham_insdel_recover --
 *
 * PUBLIC: int __ham_insdel_recover
 * PUBLIC:     __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_insdel_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_insdel_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t flags, opcode;
        int cmp_n, cmp_p, ret, type;

        pagep = NULL;
        COMPQUIET(info, NULL);

        REC_PRINT(__ham_insdel_print);
        REC_INTRO(__ham_insdel_read, 1, 0);

        if ((ret = __memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
                if (DB_UNDO(op)) {
                        if (ret == DB_PAGE_NOTFOUND)
                                goto done;
                        else {
                                ret = __db_pgerr(file_dbp, argp->pgno, ret);
                                goto out;
                        }
                }
#ifdef HAVE_FTRUNCATE
                /* If the page is not here then it was later truncated. */
                if (!IS_ZERO_LSN(argp->pagelsn))
                        goto done;
#endif
                /*
                 * This page was created by a group allocation and
                 * the file may not have been extend yet.
                 * Create the page if necessary.
                 */
                if ((ret = __memp_fget(mpf,
                     &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0) {
                        ret = __db_pgerr(file_dbp, argp->pgno, ret);
                        goto out;
                }
        }

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->pagelsn);
        /*
         * Two possible things going on:
         * redo a delete/undo a put: delete the item from the page.
         * redo a put/undo a delete: add the item to the page.
         * If we are undoing a delete, then the information logged is the
         * entire entry off the page, not just the data of a dbt.  In
         * this case, we want to copy it back onto the page verbatim.
         * We do this by calling __putitem with the type H_OFFPAGE instead
         * of H_KEYDATA.
         */

        opcode = OPCODE_OF(argp->opcode);
        flags = 0;
        if ((opcode == DELPAIR && cmp_n == 0 && DB_UNDO(op)) ||
            (opcode == PUTPAIR && cmp_p == 0 && DB_REDO(op))) {
                /*
                 * Need to redo a PUT or undo a delete.  If we are undoing a
                 * delete, we've got to restore the item back to its original
                 * position.  That's a royal pain in the butt (because we do
                 * not store item lengths on the page), but there's no choice.
                 */
                if (opcode != DELPAIR ||
                    argp->ndx == (u_int32_t)NUM_ENT(pagep)) {
                        __ham_putitem(file_dbp, pagep, &argp->key,
                            DB_UNDO(op) || PAIR_ISKEYBIG(argp->opcode) ?
                            H_OFFPAGE : H_KEYDATA);

                        if (PAIR_ISDATADUP(argp->opcode))
                                type = H_DUPLICATE;
                        else if (DB_UNDO(op) || PAIR_ISDATABIG(argp->opcode))
                                type = H_OFFPAGE;
                        else
                                type = H_KEYDATA;
                        __ham_putitem(file_dbp, pagep, &argp->data, type);
                } else
                        __ham_reputpair(file_dbp, pagep,
                            argp->ndx, &argp->key, &argp->data);

                LSN(pagep) = DB_REDO(op) ? *lsnp : argp->pagelsn;
                flags = DB_MPOOL_DIRTY;

        } else if ((opcode == DELPAIR && cmp_p == 0 && DB_REDO(op)) ||
            (opcode == PUTPAIR && cmp_n == 0 && DB_UNDO(op))) {
                /* Need to undo a put or redo a delete. */
                __ham_dpair(file_dbp, pagep, argp->ndx);
                LSN(pagep) = DB_REDO(op) ? *lsnp : argp->pagelsn;
                flags = DB_MPOOL_DIRTY;
        }

        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

        /* Return the previous LSN. */
done:   *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (pagep != NULL)
                (void)__memp_fput(mpf, pagep, 0);
        REC_CLOSE;
}

/*
 * __ham_newpage_recover --
 *      This log message is used when we add/remove overflow pages.  This
 *      message takes care of the pointer chains, not the data on the pages.
 *
 * PUBLIC: int __ham_newpage_recover
 * PUBLIC:     __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_newpage_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_newpage_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t flags;
        int cmp_n, cmp_p, ret;

        pagep = NULL;
        COMPQUIET(info, NULL);

        REC_PRINT(__ham_newpage_print);
        REC_INTRO(__ham_newpage_read, 1, 0);

        REC_FGET(mpf, argp->new_pgno, &pagep, ppage);

        /*
         * There are potentially three pages we need to check: the one
         * that we created/deleted, the one before it and the one after
         * it.
         */

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->pagelsn);

        flags = 0;
        if ((cmp_p == 0 && DB_REDO(op) && argp->opcode == PUTOVFL) ||
            (cmp_n == 0 && DB_UNDO(op) && argp->opcode == DELOVFL)) {
                /* Redo a create new page or undo a delete new page. */
                P_INIT(pagep, file_dbp->pgsize, argp->new_pgno,
                    argp->prev_pgno, argp->next_pgno, 0, P_HASH);
                flags = DB_MPOOL_DIRTY;
        } else if ((cmp_p == 0 && DB_REDO(op) && argp->opcode == DELOVFL) ||
            (cmp_n == 0 && DB_UNDO(op) && argp->opcode == PUTOVFL)) {
                /*
                 * Redo a delete or undo a create new page.  All we
                 * really need to do is change the LSN.
                 */
                flags = DB_MPOOL_DIRTY;
        }

        if (flags)
                LSN(pagep) = DB_REDO(op) ? *lsnp : argp->pagelsn;

        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

        /* Now do the prev page. */
ppage:  if (argp->prev_pgno != PGNO_INVALID) {
                REC_FGET(mpf, argp->prev_pgno, &pagep, npage);

                cmp_n = log_compare(lsnp, &LSN(pagep));
                cmp_p = log_compare(&LSN(pagep), &argp->prevlsn);
                CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->prevlsn);
                flags = 0;

                if ((cmp_p == 0 && DB_REDO(op) && argp->opcode == PUTOVFL) ||
                    (cmp_n == 0 && DB_UNDO(op) && argp->opcode == DELOVFL)) {
                        /* Redo a create new page or undo a delete new page. */
                        pagep->next_pgno = argp->new_pgno;
                        flags = DB_MPOOL_DIRTY;
                } else if ((cmp_p == 0 &&
                    DB_REDO(op) && argp->opcode == DELOVFL) ||
                    (cmp_n == 0 && DB_UNDO(op) && argp->opcode == PUTOVFL)) {
                        /* Redo a delete or undo a create new page. */
                        pagep->next_pgno = argp->next_pgno;
                        flags = DB_MPOOL_DIRTY;
                }

                if (flags)
                        LSN(pagep) = DB_REDO(op) ? *lsnp : argp->prevlsn;

                if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                        goto out;
                pagep = NULL;
        }

        /* Now time to do the next page */
npage:  if (argp->next_pgno != PGNO_INVALID) {
                REC_FGET(mpf, argp->next_pgno, &pagep, done);

                cmp_n = log_compare(lsnp, &LSN(pagep));
                cmp_p = log_compare(&LSN(pagep), &argp->nextlsn);
                CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->nextlsn);
                flags = 0;

                if ((cmp_p == 0 && DB_REDO(op) && argp->opcode == PUTOVFL) ||
                    (cmp_n == 0 && DB_UNDO(op) && argp->opcode == DELOVFL)) {
                        /* Redo a create new page or undo a delete new page. */
                        pagep->prev_pgno = argp->new_pgno;
                        flags = DB_MPOOL_DIRTY;
                } else if ((cmp_p == 0 &&
                    DB_REDO(op) && argp->opcode == DELOVFL) ||
                    (cmp_n == 0 && DB_UNDO(op) && argp->opcode == PUTOVFL)) {
                        /* Redo a delete or undo a create new page. */
                        pagep->prev_pgno = argp->prev_pgno;
                        flags = DB_MPOOL_DIRTY;
                }

                if (flags)
                        LSN(pagep) = DB_REDO(op) ? *lsnp : argp->nextlsn;

                if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                        goto out;
                pagep = NULL;
        }
done:   *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (pagep != NULL)
                (void)__memp_fput(mpf, pagep, 0);
        REC_CLOSE;
}

/*
 * __ham_replace_recover --
 *      This log message refers to partial puts that are local to a single
 *      page.  You can think of them as special cases of the more general
 *      insdel log message.
 *
 * PUBLIC: int __ham_replace_recover
 * PUBLIC:    __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_replace_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_replace_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        DBT dbt;
        PAGE *pagep;
        u_int32_t flags;
        u_int32_t change;
        int cmp_n, cmp_p, is_plus, ret;
        u_int8_t *hk;

        pagep = NULL;
        COMPQUIET(info, NULL);

        REC_PRINT(__ham_replace_print);
        REC_INTRO(__ham_replace_read, 1, 0);

        REC_FGET(mpf, argp->pgno, &pagep, done);

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->pagelsn);

        memset(&dbt, 0, sizeof(dbt));
        flags = 0;

        /*
         * Before we know the direction of the transformation we will
         * determine the size differential; then once we know if we are
         * redoing or undoing, we'll adjust the sign (is_plus) appropriately.
         */
        if (argp->newitem.size > argp->olditem.size) {
                change = argp->newitem.size - argp->olditem.size;
                is_plus = 1;
        } else {
                change = argp->olditem.size - argp->newitem.size;
                is_plus = 0;
        }
        if (cmp_p == 0 && DB_REDO(op)) {
                /* Reapply the change as specified. */
                dbt.data = argp->newitem.data;
                dbt.size = argp->newitem.size;
                LSN(pagep) = *lsnp;
                /*
                 * The is_plus flag is set properly to reflect
                 * newitem.size - olditem.size.
                 */
                flags = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
                /* Undo the already applied change. */
                dbt.data = argp->olditem.data;
                dbt.size = argp->olditem.size;
                /*
                 * Invert is_plus to reflect sign of
                 * olditem.size - newitem.size.
                 */
                is_plus = !is_plus;
                LSN(pagep) = argp->pagelsn;
                flags = DB_MPOOL_DIRTY;
        }

        if (flags) {
                __ham_onpage_replace(file_dbp, pagep,
                    argp->ndx, argp->off, change, is_plus, &dbt);
                if (argp->makedup) {
                        hk = P_ENTRY(file_dbp, pagep, argp->ndx);
                        if (DB_REDO(op))
                                HPAGE_PTYPE(hk) = H_DUPLICATE;
                        else
                                HPAGE_PTYPE(hk) = H_KEYDATA;
                }
        }

        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

done:   *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (pagep != NULL)
                (void)__memp_fput(mpf, pagep, 0);
        REC_CLOSE;
}

/*
 * __ham_splitdata_recover --
 *
 * PUBLIC: int __ham_splitdata_recover
 * PUBLIC:    __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_splitdata_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_splitdata_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t flags;
        int cmp_n, cmp_p, ret;

        pagep = NULL;
        COMPQUIET(info, NULL);

        REC_PRINT(__ham_splitdata_print);
        REC_INTRO(__ham_splitdata_read, 1, 0);

        if ((ret = __memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
                if (DB_UNDO(op)) {
                        if (ret == DB_PAGE_NOTFOUND)
                                goto done;
                        else {
                                ret = __db_pgerr(file_dbp, argp->pgno, ret);
                                goto out;
                        }
                }
#ifdef HAVE_FTRUNCATE
                /* If the page is not here then it was later truncated. */
                if (!IS_ZERO_LSN(argp->pagelsn))
                        goto done;
#endif
                /*
                 * This page was created by a group allocation and
                 * the file may not have been extend yet.
                 * Create the page if necessary.
                 */
                if ((ret = __memp_fget(mpf,
                     &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0) {
                        ret = __db_pgerr(file_dbp, argp->pgno, ret);
                        goto out;
                }
        }

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->pagelsn);

        /*
         * There are two types of log messages here, one for the old page
         * and one for the new pages created.  The original image in the
         * SPLITOLD record is used for undo.  The image in the SPLITNEW
         * is used for redo.  We should never have a case where there is
         * a redo operation and the SPLITOLD record is on disk, but not
         * the SPLITNEW record.  Therefore, we only have work to do when
         * redo NEW messages and undo OLD messages, but we have to update
         * LSNs in both cases.
         */
        flags = 0;
        if (cmp_p == 0 && DB_REDO(op)) {
                if (argp->opcode == SPLITNEW)
                        /* Need to redo the split described. */
                        memcpy(pagep, argp->pageimage.data,
                            argp->pageimage.size);
                LSN(pagep) = *lsnp;
                flags = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
                if (argp->opcode == SPLITOLD) {
                        /* Put back the old image. */
                        memcpy(pagep, argp->pageimage.data,
                            argp->pageimage.size);
                } else
                        P_INIT(pagep, file_dbp->pgsize, argp->pgno,
                            PGNO_INVALID, PGNO_INVALID, 0, P_HASH);
                LSN(pagep) = argp->pagelsn;
                flags = DB_MPOOL_DIRTY;
        }
        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

done:   *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (pagep != NULL)
                (void)__memp_fput(mpf, pagep, 0);
        REC_CLOSE;
}

/*
 * __ham_copypage_recover --
 *      Recovery function for copypage.
 *
 * PUBLIC: int __ham_copypage_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_copypage_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_copypage_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t flags;
        int cmp_n, cmp_p, ret;

        pagep = NULL;
        COMPQUIET(info, NULL);

        REC_PRINT(__ham_copypage_print);
        REC_INTRO(__ham_copypage_read, 1, 0);

        flags = 0;

        /* This is the bucket page. */
        REC_FGET(mpf, argp->pgno, &pagep, donext);

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->pagelsn);

        if (cmp_p == 0 && DB_REDO(op)) {
                /* Need to redo update described. */
                memcpy(pagep, argp->page.data, argp->page.size);
                PGNO(pagep) = argp->pgno;
                PREV_PGNO(pagep) = PGNO_INVALID;
                LSN(pagep) = *lsnp;
                flags = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
                /* Need to undo update described. */
                P_INIT(pagep, file_dbp->pgsize, argp->pgno, PGNO_INVALID,
                    argp->next_pgno, 0, P_HASH);
                LSN(pagep) = argp->pagelsn;
                flags = DB_MPOOL_DIRTY;
        }
        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

donext: /* Now fix up the "next" page. */
        REC_FGET(mpf, argp->next_pgno, &pagep, do_nn);

        /* For REDO just update the LSN. For UNDO copy page back. */
        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->nextlsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->nextlsn);
        flags = 0;
        if (cmp_p == 0 && DB_REDO(op)) {
                LSN(pagep) = *lsnp;
                flags = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
                /* Need to undo update described. */
                memcpy(pagep, argp->page.data, argp->page.size);
                flags = DB_MPOOL_DIRTY;
        }
        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

        /* Now fix up the next's next page. */
do_nn:  if (argp->nnext_pgno == PGNO_INVALID)
                goto done;

        REC_FGET(mpf, argp->nnext_pgno, &pagep, done);

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->nnextlsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->nnextlsn);

        flags = 0;
        if (cmp_p == 0 && DB_REDO(op)) {
                /* Need to redo update described. */
                PREV_PGNO(pagep) = argp->pgno;
                LSN(pagep) = *lsnp;
                flags = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
                /* Need to undo update described. */
                PREV_PGNO(pagep) = argp->next_pgno;
                LSN(pagep) = argp->nnextlsn;
                flags = DB_MPOOL_DIRTY;
        }
        if ((ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;
        pagep = NULL;

done:   *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (pagep != NULL)
                (void)__memp_fput(mpf, pagep, 0);
        REC_CLOSE;
}

/*
 * __ham_metagroup_recover --
 *      Recovery function for metagroup.
 *
 * PUBLIC: int __ham_metagroup_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_metagroup_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_metagroup_args *argp;
        HASH_CURSOR *hcp;
        DB *file_dbp;
        DBMETA *mmeta;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        db_pgno_t pgno;
        u_int32_t flags, mmeta_flags;
        int cmp_n, cmp_p, did_alloc, did_recover, groupgrow, ret;

        COMPQUIET(info, NULL);
        mmeta_flags = 0;
        did_alloc = 0;
        mmeta = NULL;
        REC_PRINT(__ham_metagroup_print);
        REC_INTRO(__ham_metagroup_read, 1, 1);

        /*
         * This logs the virtual create of pages pgno to pgno + bucket
         * If HAVE_FTRUNCATE is not supported the mpool page-allocation is not
         * transaction protected, we can never undo it.  Even in an abort,
         * we have to allocate these pages to the hash table if they
         * were actually created.  In particular, during disaster
         * recovery the metapage may be before this point if we
         * are rolling backward.  If the file has not been extended
         * then the metapage could not have been updated.
         * The log record contains:
         * bucket: old maximum bucket
         * pgno: page number of the new bucket.
         * We round up on log calculations, so we can figure out if we are
         * about to double the hash table if argp->bucket+1 is a power of 2.
         * If it is, then we are allocating an entire doubling of pages,
         * otherwise, we are simply allocated one new page.
         */
        groupgrow =
            (u_int32_t)(1 << __db_log2(argp->bucket + 1)) == argp->bucket + 1;
        pgno = argp->pgno;
        if (argp->newalloc)
                pgno += argp->bucket;

        flags = 0;
        pagep = NULL;
#ifndef HAVE_FTRUNCATE
        flags = DB_MPOOL_CREATE;
#endif
        ret = __memp_fget(mpf, &pgno, flags, &pagep);

#ifdef HAVE_FTRUNCATE
        /* If we are undoing, then we don't want to create the page. */
        if (ret != 0 && DB_REDO(op))
                ret = __memp_fget(mpf, &pgno, DB_MPOOL_CREATE, &pagep);
        else if (ret == DB_PAGE_NOTFOUND)
                goto do_meta;
#endif
        if (ret != 0) {
                if (ret != ENOSPC)
                        goto out;
                pgno = 0;
                goto do_meta;
        }

        /*
         * When we get here then either we did not grow the file
         * (groupgrow == 0) or we did grow the file and the allocation
         * of those new pages succeeded.
         */
        did_alloc = groupgrow;

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(pagep), &argp->pagelsn);

        flags = 0;
        if (cmp_p == 0 && DB_REDO(op)) {
                pagep->lsn = *lsnp;
                flags = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
#ifdef HAVE_FTRUNCATE
                /* If this record allocated the pages give them back. */
                if (argp->newalloc) {
                        if (pagep != NULL && (ret =
                             __memp_fput(mpf, pagep, DB_MPOOL_DISCARD)) != 0)
                                goto out;
                        pagep = NULL;
                        if ((ret = __memp_ftruncate(mpf, argp->pgno, 0)) != 0)
                                goto out;
                } else
#endif
                {
                        /*
                         * Otherwise just roll the page back to its
                         * previous state.
                         */
                        pagep->lsn = argp->pagelsn;
                        flags = DB_MPOOL_DIRTY;
                }
        }
        if (pagep != NULL && (ret = __memp_fput(mpf, pagep, flags)) != 0)
                goto out;

do_meta:
        /* Now we have to update the meta-data page. */
        hcp = (HASH_CURSOR *)dbc->internal;
        if ((ret = __ham_get_meta(dbc)) != 0)
                goto out;
        cmp_n = log_compare(lsnp, &hcp->hdr->dbmeta.lsn);
        cmp_p = log_compare(&hcp->hdr->dbmeta.lsn, &argp->metalsn);
        CHECK_LSN(dbenv, op, cmp_p, &hcp->hdr->dbmeta.lsn, &argp->metalsn);
        did_recover = 0;
        if (cmp_p == 0 && DB_REDO(op)) {
                /* Redo the actual updating of bucket counts. */
                ++hcp->hdr->max_bucket;
                if (groupgrow) {
                        hcp->hdr->low_mask = hcp->hdr->high_mask;
                        hcp->hdr->high_mask =
                            (argp->bucket + 1) | hcp->hdr->low_mask;
                }
                hcp->hdr->dbmeta.lsn = *lsnp;
                did_recover = 1;
        } else if (cmp_n == 0 && DB_UNDO(op)) {
                /* Undo the actual updating of bucket counts. */
                hcp->hdr->max_bucket = argp->bucket;
                if (groupgrow) {
                        hcp->hdr->high_mask = argp->bucket;
                        hcp->hdr->low_mask = hcp->hdr->high_mask >> 1;
                }
                hcp->hdr->dbmeta.lsn = argp->metalsn;
                did_recover = 1;
        }

        /*
         * Now we need to fix up the spares array.  Each entry in the
         * spares array indicates the beginning page number for the
         * indicated doubling.  We need to fill this in whenever the
         * spares array is invalid, if we never reclaim pages then
         * we have to allocate the pages to the spares array in both
         * the redo and undo cases.
         */
        if (did_alloc &&
#ifdef HAVE_FTRUNCATE
            !DB_UNDO(op) &&
#endif
            hcp->hdr->spares[__db_log2(argp->bucket + 1) + 1] == PGNO_INVALID) {
                hcp->hdr->spares[__db_log2(argp->bucket + 1) + 1] =
                    (argp->pgno - argp->bucket) - 1;
                did_recover = 1;
        }
#ifdef HAVE_FTRUNCATE
        if (cmp_n == 0 && groupgrow && DB_UNDO(op)) {
                hcp->hdr->spares[
                    __db_log2(argp->bucket + 1) + 1] = PGNO_INVALID;
                did_recover = 1;
        }
#endif

        /*
         * Finally, we need to potentially fix up the last_pgno field
         * in the master meta-data page (which may or may not be the
         * same as the hash header page).
         */
        if (argp->mmpgno != argp->mpgno) {
                if ((ret = __memp_fget(mpf, &argp->mmpgno, 0, &mmeta)) != 0)
                        goto out;
                mmeta_flags = 0;
                cmp_n = log_compare(lsnp, &mmeta->lsn);
                cmp_p = log_compare(&mmeta->lsn, &argp->mmetalsn);
                if (cmp_p == 0 && DB_REDO(op))
                        mmeta->lsn = *lsnp;
                else if (cmp_n == 0 && DB_UNDO(op))
                        mmeta->lsn = argp->mmetalsn;
        } else
                mmeta = (DBMETA *)hcp->hdr;

#ifdef HAVE_FTRUNCATE
        if (cmp_n == 0 && DB_UNDO(op))
                mmeta->last_pgno = argp->last_pgno;
        else if (DB_REDO(op))
#endif
        if (mmeta->last_pgno < pgno)
                mmeta->last_pgno = pgno;
        mmeta_flags = DB_MPOOL_DIRTY;

        if (argp->mmpgno != argp->mpgno &&
            (ret = __memp_fput(mpf, mmeta, mmeta_flags)) != 0)
                goto out;
        mmeta = NULL;

        if (did_recover)
                F_SET(hcp, H_DIRTY);

done:   *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (mmeta != NULL)
                (void)__memp_fput(mpf, mmeta, 0);
        if (dbc != NULL)
                (void)__ham_release_meta(dbc);
        if (ret == ENOENT && op == DB_TXN_BACKWARD_ALLOC)
                ret = 0;

        REC_CLOSE;
}

/*
 * __ham_groupalloc_recover --
 *      Recover the batch creation of a set of pages for a new database.
 *
 * PUBLIC: int __ham_groupalloc_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_groupalloc_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_groupalloc_args *argp;
        DBMETA *mmeta;
        DB_MPOOLFILE *mpf;
        DB *file_dbp;
        DBC *dbc;
        PAGE *pagep;
        db_pgno_t pgno;
        int cmp_n, cmp_p, modified, ret;

        mmeta = NULL;
        modified = 0;
        REC_PRINT(__ham_groupalloc_print);
        REC_INTRO(__ham_groupalloc_read, 0, 0);

        pgno = PGNO_BASE_MD;
        if ((ret = __memp_fget(mpf, &pgno, 0, &mmeta)) != 0) {
                if (DB_REDO(op)) {
                        ret = __db_pgerr(file_dbp, pgno, ret);
                        goto out;
                } else
                        goto done;
        }

        cmp_n = log_compare(lsnp, &LSN(mmeta));
        cmp_p = log_compare(&LSN(mmeta), &argp->meta_lsn);
        CHECK_LSN(dbenv, op, cmp_p, &LSN(mmeta), &argp->meta_lsn);

        /*
         * Basically, we used mpool to allocate a chunk of pages.
         * We need to either add those to a free list (in the undo
         * case) or initialize them (in the redo case).
         *
         * If we are redoing and this is a hash subdatabase, it's possible
         * that the pages were never allocated, so we'd better check for
         * that and handle it here.
         */
        pgno = argp->start_pgno + argp->num - 1;
        if (DB_REDO(op)) {
                if ((ret = __ham_alloc_pages(file_dbp, argp, lsnp)) != 0)
                        goto out;
                if (cmp_p == 0) {
                        LSN(mmeta) = *lsnp;
                        modified = 1;
                }
        } else if (DB_UNDO(op)) {
                /*
                 * Fetch the last page and determine if it is in
                 * the post allocation state.
                 */
                pagep = NULL;
                if ((ret = __memp_fget(mpf, &pgno, 0, &pagep)) == 0) {
                        if (log_compare(&pagep->lsn, lsnp) != 0) {
                                if ((ret = __memp_fput(mpf,
                                     pagep, DB_MPOOL_DISCARD)) != 0)
                                        goto out;
                                pagep = NULL;
                        }
                } else if (ret != DB_PAGE_NOTFOUND)
                        goto out;
#ifdef HAVE_FTRUNCATE
                COMPQUIET(info, NULL);
                /*
                 * If the last page was allocated then truncate back
                 * to the first page.
                 */
                if (pagep != NULL) {
                        if ((ret =
                            __memp_fput(mpf, pagep, DB_MPOOL_DISCARD)) != 0)
                                goto out;
                        if ((ret =
                             __memp_ftruncate(mpf, argp->start_pgno, 0)) != 0)
                                goto out;
                }

                /*
                 * If we are rolling back the metapage, then make
                 * sure it reflects the the correct last_pgno.
                 */
                if (cmp_n == 0) {
                        mmeta->last_pgno = argp->last_pgno;
                        modified = 1;
                }
                pgno = 0;
#else
                /*
                 * Reset the last page back to its preallocation state.
                 */
                if (pagep != NULL) {
                        if (log_compare(&pagep->lsn, lsnp) == 0)
                                ZERO_LSN(pagep->lsn);

                        if ((ret =
                            __memp_fput(mpf, pagep, DB_MPOOL_DIRTY)) != 0)
                                goto out;
                }
                /*
                 * Put the pages into the limbo list and free them later.
                 */
                if ((ret = __db_add_limbo(dbenv,
                    info, argp->fileid, argp->start_pgno, argp->num)) != 0)
                        goto out;
#endif
                if (cmp_n == 0) {
                        LSN(mmeta) = argp->meta_lsn;
                        modified = 1;
                }
        }

        /*
         * In both REDO and UNDO, we have grown the file and need to make
         * sure that last_pgno is correct.  If we HAVE_FTRUNCATE pgno
         * will only be valid on REDO.
         */
        if (pgno > mmeta->last_pgno) {
                mmeta->last_pgno = pgno;
                modified = 1;
        }

done:   if (ret == 0)
                *lsnp = argp->prev_lsn;
        ret = 0;

out:    if (mmeta != NULL)
                (void)__memp_fput(mpf, mmeta, modified ? DB_MPOOL_DIRTY : 0);

        if (ret == ENOENT && op == DB_TXN_BACKWARD_ALLOC)
                ret = 0;
        REC_CLOSE;
}

/*
 * __ham_alloc_pages --
 *
 * Called during redo of a file create.  We create new pages in the file
 * using the MPOOL_NEW_GROUP flag.  We then log the meta-data page with a
 * __crdel_metasub message.  If we manage to crash without the newly written
 * pages getting to disk (I'm not sure this can happen anywhere except our
 * test suite?!), then we need to go through a recreate the final pages.
 * Hash normally has holes in its files and handles them appropriately.
 */
static int
__ham_alloc_pages(dbp, argp, lsnp)
        DB *dbp;
        __ham_groupalloc_args *argp;
        DB_LSN *lsnp;
{
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        db_pgno_t pgno;
        int ret;

        mpf = dbp->mpf;

        /* Read the last page of the allocation. */
        pgno = argp->start_pgno + argp->num - 1;

        /* If the page exists, and it has been initialized, then we're done. */
        if ((ret = __memp_fget(mpf, &pgno, 0, &pagep)) == 0) {
                if (NUM_ENT(pagep) == 0 && IS_ZERO_LSN(pagep->lsn))
                        goto reinit_page;
                if ((ret = __memp_fput(mpf, pagep, 0)) != 0)
                        return (ret);
                return (0);
        }

        /* Had to create the page. */
        if ((ret = __memp_fget(mpf, &pgno, DB_MPOOL_CREATE, &pagep)) != 0)
                return (__db_pgerr(dbp, pgno, ret));

reinit_page:
        /* Initialize the newly allocated page. */
        P_INIT(pagep, dbp->pgsize, pgno, PGNO_INVALID, PGNO_INVALID, 0, P_HASH);
        pagep->lsn = *lsnp;

        if ((ret = __memp_fput(mpf, pagep, DB_MPOOL_DIRTY)) != 0)
                return (ret);

        return (0);
}

/*
 * __ham_curadj_recover --
 *      Undo cursor adjustments if a subtransaction fails.
 *
 * PUBLIC: int __ham_curadj_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_curadj_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_curadj_args *argp;
        DB_MPOOLFILE *mpf;
        DB *file_dbp;
        DBC *dbc;
        int ret;
        HASH_CURSOR *hcp;

        COMPQUIET(info, NULL);
        REC_PRINT(__ham_curadj_print);
        REC_INTRO(__ham_curadj_read, 0, 1);

        if (op != DB_TXN_ABORT)
                goto done;

        /*
         * Undo the adjustment by reinitializing the the cursor to look like
         * the one that was used to do the adjustment, then we invert the
         * add so that undo the adjustment.
         */
        hcp = (HASH_CURSOR *)dbc->internal;
        hcp->pgno = argp->pgno;
        hcp->indx = argp->indx;
        hcp->dup_off = argp->dup_off;
        hcp->order = argp->order;
        if (!argp->add)
                F_SET(hcp, H_DELETED);
        (void)__ham_c_update(dbc, argp->len, !argp->add, argp->is_dup);

done:   *lsnp = argp->prev_lsn;
out:    REC_CLOSE;
}

/*
 * __ham_chgpg_recover --
 *      Undo cursor adjustments if a subtransaction fails.
 *
 * PUBLIC: int __ham_chgpg_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__ham_chgpg_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __ham_chgpg_args *argp;
        BTREE_CURSOR *opdcp;
        DB_MPOOLFILE *mpf;
        DB *file_dbp, *ldbp;
        DBC *dbc;
        int ret;
        DBC *cp;
        HASH_CURSOR *lcp;
        u_int32_t order, indx;

        COMPQUIET(info, NULL);
        REC_PRINT(__ham_chgpg_print);
        REC_INTRO(__ham_chgpg_read, 0, 0);

        if (op != DB_TXN_ABORT)
                goto done;

        /* Overloaded fields for DB_HAM_DEL*PG */
        indx = argp->old_indx;
        order = argp->new_indx;

        MUTEX_LOCK(dbenv, dbenv->mtx_dblist);
        for (ldbp = __dblist_get(dbenv, file_dbp->adj_fileid);
            ldbp != NULL && ldbp->adj_fileid == file_dbp->adj_fileid;
            ldbp = LIST_NEXT(ldbp, dblistlinks)) {
                MUTEX_LOCK(dbenv, file_dbp->mutex);

                for (cp = TAILQ_FIRST(&ldbp->active_queue); cp != NULL;
                    cp = TAILQ_NEXT(cp, links)) {
                        lcp = (HASH_CURSOR *)cp->internal;

                        switch (argp->mode) {
                        case DB_HAM_DELFIRSTPG:
                                if (lcp->pgno != argp->new_pgno)
                                        break;
                                if (lcp->indx != indx ||
                                    !F_ISSET(lcp, H_DELETED) ||
                                    lcp->order >= order) {
                                        lcp->pgno = argp->old_pgno;
                                        if (lcp->indx == indx)
                                                lcp->order -= order;
                                }
                                break;
                        case DB_HAM_DELMIDPG:
                        case DB_HAM_DELLASTPG:
                                if (lcp->pgno == argp->new_pgno &&
                                    lcp->indx == indx &&
                                    F_ISSET(lcp, H_DELETED) &&
                                    lcp->order >= order) {
                                        lcp->pgno = argp->old_pgno;
                                        lcp->order -= order;
                                        lcp->indx = 0;
                                }
                                break;
                        case DB_HAM_CHGPG:
                                /*
                                 * If we're doing a CHGPG, we're undoing
                                 * the move of a non-deleted item to a
                                 * new page.  Any cursors with the deleted
                                 * flag set do not belong to this item;
                                 * don't touch them.
                                 */
                                if (F_ISSET(lcp, H_DELETED))
                                        break;
                                /* FALLTHROUGH */
                        case DB_HAM_SPLIT:
                                if (lcp->pgno == argp->new_pgno &&
                                    lcp->indx == argp->new_indx) {
                                        lcp->indx = argp->old_indx;
                                        lcp->pgno = argp->old_pgno;
                                }
                                break;
                        case DB_HAM_DUP:
                                if (lcp->opd == NULL)
                                        break;
                                opdcp = (BTREE_CURSOR *)lcp->opd->internal;
                                if (opdcp->pgno != argp->new_pgno ||
                                    opdcp->indx != argp->new_indx)
                                        break;

                                if (F_ISSET(opdcp, C_DELETED))
                                        F_SET(lcp, H_DELETED);
                                /*
                                 * We can't close a cursor while we have the
                                 * dbp mutex locked, since c_close reacquires
                                 * it.  It should be safe to drop the mutex
                                 * here, though, since newly opened cursors
                                 * are put only at the end of the tailq and
                                 * the cursor we're adjusting can't be closed
                                 * under us.
                                 */
                                MUTEX_UNLOCK(dbenv, file_dbp->mutex);
                                if ((ret = __db_c_close(lcp->opd)) != 0)
                                        goto out;
                                MUTEX_LOCK(dbenv, file_dbp->mutex);
                                lcp->opd = NULL;
                                break;
                        }
                }
                MUTEX_UNLOCK(dbenv, file_dbp->mutex);
        }
        MUTEX_UNLOCK(dbenv, dbenv->mtx_dblist);

done:   *lsnp = argp->prev_lsn;
out:    REC_CLOSE;
}

---