/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998
 *      Sleepycat Software.  All rights reserved.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)db_rec.c      10.19 (Sleepycat) 9/27/98";
#endif /* not lint */

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

#include <string.h>
#endif

#include "db_int.h"
#include "shqueue.h"
#include "db_page.h"
#include "log.h"
#include "hash.h"
#include "btree.h"

/*
 * PUBLIC: int __db_addrem_recover
 * PUBLIC:    __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 *
 * This log message is generated whenever we add or remove a duplicate
 * to/from a duplicate page.  On recover, we just do the opposite.
 */
int
__db_addrem_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_addrem_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t change;
        int cmp_n, cmp_p, ret;

        REC_PRINT(__db_addrem_print);
        REC_INTRO(__db_addrem_read);

        if ((ret = memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
                if (!redo) {
                        /*
                         * We are undoing and the page doesn't exist.  That
                         * is equivalent to having a pagelsn of 0, so we
                         * would not have to undo anything.  In this case,
                         * don't bother creating a page.
                         */
                        goto done;
                } else
                        if ((ret = memp_fget(mpf,
                            &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0)
                                goto out;
        }

        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        change = 0;
        if ((cmp_p == 0 && redo && argp->opcode == DB_ADD_DUP) ||
            (cmp_n == 0 && !redo && argp->opcode == DB_REM_DUP)) {

                /* Need to redo an add, or undo a delete. */
                if ((ret = __db_pitem(dbc, pagep, argp->indx, argp->nbytes,
                    argp->hdr.size == 0 ? NULL : &argp->hdr,
                    argp->dbt.size == 0 ? NULL : &argp->dbt)) != 0)
                        goto out;

                change = DB_MPOOL_DIRTY;

        } else if ((cmp_n == 0 && !redo && argp->opcode == DB_ADD_DUP) ||
            (cmp_p == 0 && redo && argp->opcode == DB_REM_DUP)) {
                /* Need to undo an add, or redo a delete. */
                if ((ret = __db_ditem(dbc,
                    pagep, argp->indx, argp->nbytes)) != 0)
                        goto out;
                change = DB_MPOOL_DIRTY;
        }

        if (change)
                if (redo)
                        LSN(pagep) = *lsnp;
                else
                        LSN(pagep) = argp->pagelsn;

        if ((ret = memp_fput(mpf, pagep, change)) != 0)
                goto out;

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

out:    REC_CLOSE;
}

/*
 * PUBLIC: int __db_split_recover __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__db_split_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_split_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        int change, cmp_n, cmp_p, ret;

        REC_PRINT(__db_split_print);
        REC_INTRO(__db_split_read);

        if ((ret = memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0)
                if (!redo) {
                        /*
                         * We are undoing and the page doesn't exist.  That
                         * is equivalent to having a pagelsn of 0, so we
                         * would not have to undo anything.  In this case,
                         * don't bother creating a page.
                         */
                        goto done;
                } else
                        if ((ret = memp_fget(mpf,
                            &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0)
                                goto out;

        /*
         * 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 redo NEW messages
         * and only undo OLD messages.
         */

        change = 0;
        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        if (cmp_p == 0 && redo) {
                if (argp->opcode == DB_SPLITNEW) {
                        /* Need to redo the split described. */
                        memcpy(pagep,
                            argp->pageimage.data, argp->pageimage.size);
                }
                LSN(pagep) = *lsnp;
                change = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && !redo) {
                if (argp->opcode == DB_SPLITOLD) {
                        /* Put back the old image. */
                        memcpy(pagep,
                            argp->pageimage.data, argp->pageimage.size);
                }
                LSN(pagep) = argp->pagelsn;
                change = DB_MPOOL_DIRTY;
        }
        if ((ret = memp_fput(mpf, pagep, change)) != 0)
                goto out;

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

out:    REC_CLOSE;
}

/*
 * PUBLIC: int __db_big_recover __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__db_big_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_big_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t change;
        int cmp_n, cmp_p, ret;

        REC_PRINT(__db_big_print);
        REC_INTRO(__db_big_read);

        if ((ret = memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
                if (!redo) {
                        /*
                         * We are undoing and the page doesn't exist.  That
                         * is equivalent to having a pagelsn of 0, so we
                         * would not have to undo anything.  In this case,
                         * don't bother creating a page.
                         */
                        ret = 0;
                        goto ppage;
                } else
                        if ((ret = memp_fget(mpf,
                            &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0)
                                goto out;
        }

        /*
         * There are three pages we need to check.  The one on which we are
         * adding data, the previous one whose next_pointer may have
         * been updated, and the next one whose prev_pointer may have
         * been updated.
         */
        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->pagelsn);
        change = 0;
        if ((cmp_p == 0 && redo && argp->opcode == DB_ADD_BIG) ||
            (cmp_n == 0 && !redo && argp->opcode == DB_REM_BIG)) {
                /* We are either redo-ing an add, or undoing a delete. */
                P_INIT(pagep, file_dbp->pgsize, argp->pgno, argp->prev_pgno,
                        argp->next_pgno, 0, P_OVERFLOW);
                OV_LEN(pagep) = argp->dbt.size;
                OV_REF(pagep) = 1;
                memcpy((u_int8_t *)pagep + P_OVERHEAD, argp->dbt.data,
                    argp->dbt.size);
                PREV_PGNO(pagep) = argp->prev_pgno;
                change = DB_MPOOL_DIRTY;
        } else if ((cmp_n == 0 && !redo && argp->opcode == DB_ADD_BIG) ||
            (cmp_p == 0 && redo && argp->opcode == DB_REM_BIG)) {
                /*
                 * We are either undo-ing an add or redo-ing a delete.
                 * The page is about to be reclaimed in either case, so
                 * there really isn't anything to do here.
                 */
                change = DB_MPOOL_DIRTY;
        }
        if (change)
                LSN(pagep) = redo ? *lsnp : argp->pagelsn;

        if ((ret = memp_fput(mpf, pagep, change)) != 0)
                goto out;

        /* Now check the previous page. */
ppage:  if (argp->prev_pgno != PGNO_INVALID) {
                change = 0;
                if ((ret = memp_fget(mpf, &argp->prev_pgno, 0, &pagep)) != 0)
                        if (!redo) {
                                /*
                                 * We are undoing and the page doesn't exist.
                                 * That is equivalent to having a pagelsn of 0,
                                 * so we would not have to undo anything.  In
                                 * this case, don't bother creating a page.
                                 */
                                *lsnp = argp->prev_lsn;
                                ret = 0;
                                goto npage;
                        } else
                                if ((ret = memp_fget(mpf, &argp->prev_pgno,
                                    DB_MPOOL_CREATE, &pagep)) != 0)
                                        goto out;

                cmp_n = log_compare(lsnp, &LSN(pagep));
                cmp_p = log_compare(&LSN(pagep), &argp->prevlsn);

                if ((cmp_p == 0 && redo && argp->opcode == DB_ADD_BIG) ||
                    (cmp_n == 0 && !redo && argp->opcode == DB_REM_BIG)) {
                        /* Redo add, undo delete. */
                        NEXT_PGNO(pagep) = argp->pgno;
                        change = DB_MPOOL_DIRTY;
                } else if ((cmp_n == 0 &&
                    !redo && argp->opcode == DB_ADD_BIG) ||
                    (cmp_p == 0 && redo && argp->opcode == DB_REM_BIG)) {
                        /* Redo delete, undo add. */
                        NEXT_PGNO(pagep) = argp->next_pgno;
                        change = DB_MPOOL_DIRTY;
                }
                if (change)
                        LSN(pagep) = redo ? *lsnp : argp->prevlsn;
                if ((ret = memp_fput(mpf, pagep, change)) != 0)
                        goto out;
        }

        /* Now check the next page.  Can only be set on a delete. */
npage:  if (argp->next_pgno != PGNO_INVALID) {
                change = 0;
                if ((ret = memp_fget(mpf, &argp->next_pgno, 0, &pagep)) != 0)
                        if (!redo) {
                                /*
                                 * We are undoing and the page doesn't exist.
                                 * That is equivalent to having a pagelsn of 0,
                                 * so we would not have to undo anything.  In
                                 * this case, don't bother creating a page.
                                 */
                                goto done;
                        } else
                                if ((ret = memp_fget(mpf, &argp->next_pgno,
                                    DB_MPOOL_CREATE, &pagep)) != 0)
                                        goto out;

                cmp_n = log_compare(lsnp, &LSN(pagep));
                cmp_p = log_compare(&LSN(pagep), &argp->nextlsn);
                if (cmp_p == 0 && redo) {
                        PREV_PGNO(pagep) = PGNO_INVALID;
                        change = DB_MPOOL_DIRTY;
                } else if (cmp_n == 0 && !redo) {
                        PREV_PGNO(pagep) = argp->pgno;
                        change = DB_MPOOL_DIRTY;
                }
                if (change)
                        LSN(pagep) = redo ? *lsnp : argp->nextlsn;
                if ((ret = memp_fput(mpf, pagep, change)) != 0)
                        goto out;
        }

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

out:    REC_CLOSE;
}

/*
 * __db_ovref_recover --
 *      Recovery function for __db_ovref().
 *
 * PUBLIC: int __db_ovref_recover __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__db_ovref_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_ovref_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        int modified, ret;

        REC_PRINT(__db_ovref_print);
        REC_INTRO(__db_ovref_read);

        if ((ret = memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
                (void)__db_pgerr(file_dbp, argp->pgno);
                goto out;
        }

        modified = 0;
        if (log_compare(&LSN(pagep), &argp->lsn) == 0 && redo) {
                /* Need to redo update described. */
                OV_REF(pagep) += argp->adjust;

                pagep->lsn = *lsnp;
                modified = 1;
        } else if (log_compare(lsnp, &LSN(pagep)) == 0 && !redo) {
                /* Need to undo update described. */
                OV_REF(pagep) -= argp->adjust;

                pagep->lsn = argp->lsn;
                modified = 1;
        }
        if ((ret = memp_fput(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
                goto out;

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

out:    REC_CLOSE;
}

/*
 * __db_relink_recover --
 *      Recovery function for relink.
 *
 * PUBLIC: int __db_relink_recover
 * PUBLIC:   __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__db_relink_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_relink_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        int cmp_n, cmp_p, modified, ret;

        REC_PRINT(__db_relink_print);
        REC_INTRO(__db_relink_read);

        /*
         * There are up to three pages we need to check -- the page, and the
         * previous and next pages, if they existed.  For a page add operation,
         * the current page is the result of a split and is being recovered
         * elsewhere, so all we need do is recover the next page.
         */
        if ((ret = memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
                if (redo) {
                        (void)__db_pgerr(file_dbp, argp->pgno);
                        goto out;
                }
                goto next;
        }
        if (argp->opcode == DB_ADD_PAGE)
                goto next;

        modified = 0;
        if (log_compare(&LSN(pagep), &argp->lsn) == 0 && redo) {
                /* Redo the relink. */
                pagep->lsn = *lsnp;
                modified = 1;
        } else if (log_compare(lsnp, &LSN(pagep)) == 0 && !redo) {
                /* Undo the relink. */
                pagep->next_pgno = argp->next;
                pagep->prev_pgno = argp->prev;

                pagep->lsn = argp->lsn;
                modified = 1;
        }
        if ((ret = memp_fput(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
                goto out;

next:   if ((ret = memp_fget(mpf, &argp->next, 0, &pagep)) != 0) {
                if (redo) {
                        (void)__db_pgerr(file_dbp, argp->next);
                        goto out;
                }
                goto prev;
        }
        modified = 0;
        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->lsn_next);
        if ((argp->opcode == DB_REM_PAGE && cmp_p == 0 && redo) ||
            (argp->opcode == DB_ADD_PAGE && cmp_n == 0 && !redo)) {
                /* Redo the remove or undo the add. */
                pagep->prev_pgno = argp->prev;

                pagep->lsn = *lsnp;
                modified = 1;
        } else if ((argp->opcode == DB_REM_PAGE && cmp_n == 0 && !redo) ||
            (argp->opcode == DB_ADD_PAGE && cmp_p == 0 && redo)) {
                /* Undo the remove or redo the add. */
                pagep->prev_pgno = argp->pgno;

                pagep->lsn = argp->lsn_next;
                modified = 1;
        }
        if ((ret = memp_fput(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
                goto out;
        if (argp->opcode == DB_ADD_PAGE)
                goto done;

prev:   if ((ret = memp_fget(mpf, &argp->prev, 0, &pagep)) != 0) {
                if (redo) {
                        (void)__db_pgerr(file_dbp, argp->prev);
                        goto out;
                }
                goto done;
        }
        modified = 0;
        if (log_compare(&LSN(pagep), &argp->lsn_prev) == 0 && redo) {
                /* Redo the relink. */
                pagep->next_pgno = argp->next;

                pagep->lsn = *lsnp;
                modified = 1;
        } else if (log_compare(lsnp, &LSN(pagep)) == 0 && !redo) {
                /* Undo the relink. */
                pagep->next_pgno = argp->pgno;

                pagep->lsn = argp->lsn_prev;
                modified = 1;
        }
        if ((ret = memp_fput(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
                goto out;

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

out:    REC_CLOSE;
}

/*
 * PUBLIC: int __db_addpage_recover
 * PUBLIC:    __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__db_addpage_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_addpage_args *argp;
        DB *file_dbp;
        DBC *dbc;
        DB_MPOOLFILE *mpf;
        PAGE *pagep;
        u_int32_t change;
        int cmp_n, cmp_p, ret;

        REC_PRINT(__db_addpage_print);
        REC_INTRO(__db_addpage_read);

        /*
         * We need to check two pages: the old one and the new one onto
         * which we're going to add duplicates.  Do the old one first.
         */
        if ((ret = memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0)
                goto out;

        change = 0;
        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->lsn);
        if (cmp_p == 0 && redo) {
                NEXT_PGNO(pagep) = argp->nextpgno;

                LSN(pagep) = *lsnp;
                change = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && !redo) {
                NEXT_PGNO(pagep) = PGNO_INVALID;

                LSN(pagep) = argp->lsn;
                change = DB_MPOOL_DIRTY;
        }
        if ((ret = memp_fput(mpf, pagep, change)) != 0)
                goto out;

        if ((ret = memp_fget(mpf, &argp->nextpgno, 0, &pagep)) != 0)
                if (!redo) {
                        /*
                         * We are undoing and the page doesn't exist.  That
                         * is equivalent to having a pagelsn of 0, so we
                         * would not have to undo anything.  In this case,
                         * don't bother creating a page.
                         */
                        goto done;
                } else
                        if ((ret = memp_fget(mpf,
                            &argp->nextpgno, DB_MPOOL_CREATE, &pagep)) != 0)
                                goto out;

        change = 0;
        cmp_n = log_compare(lsnp, &LSN(pagep));
        cmp_p = log_compare(&LSN(pagep), &argp->nextlsn);
        if (cmp_p == 0 && redo) {
                PREV_PGNO(pagep) = argp->pgno;

                LSN(pagep) = *lsnp;
                change = DB_MPOOL_DIRTY;
        } else if (cmp_n == 0 && !redo) {
                PREV_PGNO(pagep) = PGNO_INVALID;

                LSN(pagep) = argp->nextlsn;
                change = DB_MPOOL_DIRTY;
        }
        if ((ret = memp_fput(mpf, pagep, change)) != 0)
                goto out;

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

out:    REC_CLOSE;
}

/*
 * __db_debug_recover --
 *      Recovery function for debug.
 *
 * PUBLIC: int __db_debug_recover __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__db_debug_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        __db_debug_args *argp;
        int ret;

        COMPQUIET(redo, 0);
        COMPQUIET(logp, NULL);

        REC_PRINT(__db_debug_print);
        REC_NOOP_INTRO(__db_debug_read);

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

        REC_NOOP_CLOSE;
}