/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998
 *      Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1995, 1996
 *      The President and Fellows of Harvard University.  All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)log_rec.c     10.26 (Sleepycat) 10/21/98";
#endif /* not lint */

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

#include <errno.h>
#include <string.h>
#endif

#include "db_int.h"
#include "shqueue.h"
#include "log.h"
#include "db_dispatch.h"
#include "common_ext.h"

static int __log_do_open __P((DB_LOG *,
    u_int8_t *, char *, DBTYPE, u_int32_t));
static int __log_lid_to_fname __P((DB_LOG *, u_int32_t, FNAME **));
static int __log_open_file __P((DB_LOG *, __log_register_args *));

/*
 * PUBLIC: int __log_register_recover
 * PUBLIC:     __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
 */
int
__log_register_recover(logp, dbtp, lsnp, redo, info)
        DB_LOG *logp;
        DBT *dbtp;
        DB_LSN *lsnp;
        int redo;
        void *info;
{
        DB_ENTRY *dbe;
        __log_register_args *argp;
        int ret;

#ifdef DEBUG_RECOVER
        __log_register_print(logp, dbtp, lsnp, redo, info);
#endif
        COMPQUIET(info, NULL);
        COMPQUIET(lsnp, NULL);

        F_SET(logp, DBC_RECOVER);

        if ((ret = __log_register_read(dbtp->data, &argp)) != 0)
                goto out;

        if ((argp->opcode == LOG_CHECKPOINT && redo == TXN_OPENFILES) ||
            (argp->opcode == LOG_OPEN &&
            (redo == TXN_REDO || redo == TXN_OPENFILES ||
             redo == TXN_FORWARD_ROLL)) ||
            (argp->opcode == LOG_CLOSE &&
            (redo == TXN_UNDO || redo == TXN_BACKWARD_ROLL))) {
                /*
                 * If we are redoing an open or undoing a close, then we need
                 * to open a file.
                 */
                ret = __log_open_file(logp, argp);
                if (ret == ENOENT) {
                        if (redo == TXN_OPENFILES)
                                __db_err(logp->dbenv, "warning: %s: %s",
                                    argp->name.data, strerror(ENOENT));
                        ret = 0;
                }
        } else if (argp->opcode != LOG_CHECKPOINT &&
            argp->opcode != LOG_CLOSE) {
                /*
                 * If we are undoing an open, then we need to close the file.
                 * Note that we do *not* close the file if we are redoing a
                 * close, because we do not log the reference counts on log
                 * files and we may have had the file open multiple times,
                 * and therefore, this close should just dec a reference
                 * count.  However, since we only do one open during a
                 * checkpoint, this will inadvertently close the file.
                 *
                 * If the file is deleted, then we can just ignore this close.
                 * Otherwise, we should usually have a valid dbp we should
                 * close or whose reference count should be decremented.
                 * However, if we shut down without closing a file, we
                 * may, in fact, not have the file open, and that's OK.
                 */
                LOCK_LOGTHREAD(logp);
                if (argp->id < logp->dbentry_cnt) {
                        dbe = &logp->dbentry[argp->id];
                        if (dbe->dbp != NULL && --dbe->refcount == 0) {
                                ret = dbe->dbp->close(dbe->dbp, 0);
                                if (dbe->name != NULL) {
                                        __os_freestr(dbe->name);
                                        dbe->name = NULL;
                                }
                                (void)__log_rem_logid(logp, argp->id);
                        }
                }
                UNLOCK_LOGTHREAD(logp);
        } else if (argp->opcode == LOG_CHECKPOINT && redo == TXN_UNDO &&
            (argp->id >= logp->dbentry_cnt ||
            (!logp->dbentry[argp->id].deleted &&
            logp->dbentry[argp->id].dbp == NULL))) {
                /*
                 * It's a checkpoint and we are rolling backward.  It
                 * is possible that the system was shut down and thus
                 * ended with a stable checkpoint; this file was never
                 * closed and has therefore not been reopened yet.  If
                 * so, we need to try to open it.
                 */
                ret = __log_open_file(logp, argp);
                if (ret == ENOENT) {
                        __db_err(logp->dbenv, "warning: %s: %s",
                            argp->name.data, strerror(ENOENT));
                        ret = 0;
                }
        }

out:    F_CLR(logp, DBC_RECOVER);
        if (argp != NULL)
                __os_free(argp, 0);
        return (ret);
}

/* Hand coded routines. */

/*
 * Called during log_register recovery.  Make sure that we have an
 * entry in the dbentry table for this ndx.
 * Returns 0 on success, non-zero on error.
 */
static int
__log_open_file(lp, argp)
        DB_LOG *lp;
        __log_register_args *argp;
{
        DB_ENTRY *dbe;

        if (argp->name.size == 0)
                return(0);

        /*
         * Because of reference counting, we cannot automatically close files
         * during recovery, so when we're opening, we have to check that the
         * name we are opening is what we expect.  If it's not, then we close
         * the old file and open the new one.
         */
        LOCK_LOGTHREAD(lp);
        if (argp->id < lp->dbentry_cnt)
                dbe = &lp->dbentry[argp->id];
        else
                dbe = NULL;

        if (dbe != NULL && (dbe->deleted == 1 || dbe->dbp != NULL) &&
            dbe->name != NULL && argp->name.data != NULL &&
            strncmp(argp->name.data, dbe->name, argp->name.size) == 0) {

                dbe->refcount++;
                UNLOCK_LOGTHREAD(lp);
                return (0);
        }
        UNLOCK_LOGTHREAD(lp);

        if (dbe != NULL && dbe->dbp != NULL) {
                (void)dbe->dbp->close(dbe->dbp, 0);
                if (dbe->name != NULL)
                        __os_freestr(dbe->name);
                dbe->name = NULL;
                (void)__log_rem_logid(lp, argp->id);
        }


        return (__log_do_open(lp,
            argp->uid.data, argp->name.data, argp->ftype, argp->id));
}

/*
 * __log_do_open --
 *      Open files referenced in the log.  This is the part of the open that
 * is not protected by the thread mutex.
 */

static int
__log_do_open(lp, uid, name, ftype, ndx)
        DB_LOG *lp;
        u_int8_t *uid;
        char *name;
        DBTYPE ftype;
        u_int32_t ndx;
{
        DB *dbp;
        int ret;

        dbp = NULL;
        if ((ret = db_open(name, ftype, 0, 0, lp->dbenv, NULL, &dbp)) == 0) {
                /*
                 * Verify that we are opening the same file that we were
                 * referring to when we wrote this log record.
                 */
                if (memcmp(uid, dbp->fileid, DB_FILE_ID_LEN) != 0) {
                        (void)dbp->close(dbp, 0);
                        dbp = NULL;
                        ret = ENOENT;
                }
        }

        if (ret == 0 || ret == ENOENT)
                (void)__log_add_logid(lp, dbp, name, ndx);

        return (ret);
}

/*
 * __log_add_logid --
 *      Adds a DB entry to the log's DB entry table.
 *
 * PUBLIC: int __log_add_logid __P((DB_LOG *, DB *, const char *, u_int32_t));
 */
int
__log_add_logid(logp, dbp, name, ndx)
        DB_LOG *logp;
        DB *dbp;
        const char *name;
        u_int32_t ndx;
{
        u_int32_t i;
        int ret;

        ret = 0;

        LOCK_LOGTHREAD(logp);

        /*
         * Check if we need to grow the table.  Note, ndx is 0-based (the
         * index into the DB entry table) an dbentry_cnt is 1-based, the
         * number of available slots.
         */
        if (logp->dbentry_cnt <= ndx) {
                if ((ret = __os_realloc(&logp->dbentry,
                    (ndx + DB_GROW_SIZE) * sizeof(DB_ENTRY))) != 0)
                        goto err;

                /* Initialize the new entries. */
                for (i = logp->dbentry_cnt; i < ndx + DB_GROW_SIZE; i++) {
                        logp->dbentry[i].dbp = NULL;
                        logp->dbentry[i].deleted = 0;
                        logp->dbentry[i].name = NULL;
                }

                logp->dbentry_cnt = i;
        }

        /* Make space for the name and copy it in. */
        if (name != NULL) {
                if ((ret = __os_malloc(strlen(name) + 1,
                    NULL, &logp->dbentry[ndx].name)) != 0)
                        goto err;
                strcpy(logp->dbentry[ndx].name, name);
        }

        if (logp->dbentry[ndx].deleted == 0 && logp->dbentry[ndx].dbp == NULL) {
                logp->dbentry[ndx].dbp = dbp;
                logp->dbentry[ndx].refcount = 1;
                logp->dbentry[ndx].deleted = dbp == NULL;
        } else
                logp->dbentry[ndx].refcount++;


err:    UNLOCK_LOGTHREAD(logp);
        return (ret);
}


/*
 * __db_fileid_to_db --
 *      Return the DB corresponding to the specified fileid.
 *
 * PUBLIC: int __db_fileid_to_db __P((DB_LOG *, DB **, u_int32_t));
 */
int
__db_fileid_to_db(logp, dbpp, ndx)
        DB_LOG *logp;
        DB **dbpp;
        u_int32_t ndx;
{
        int ret;
        char *name;
        FNAME *fname;

        ret = 0;
        LOCK_LOGTHREAD(logp);

        /*
         * Under XA, a process different than the one issuing DB
         * operations may abort a transaction.  In this case,
         * recovery routines are run by a process that does not
         * necessarily have the file open.  In this case, we must
         * open the file explicitly.
         */
        if (ndx >= logp->dbentry_cnt ||
            (!logp->dbentry[ndx].deleted && logp->dbentry[ndx].dbp == NULL)) {
                if (__log_lid_to_fname(logp, ndx, &fname) != 0) {
                        /* Couldn't find entry; this is a fatal error. */
                        ret = EINVAL;
                        goto err;
                }
                name = R_ADDR(logp, fname->name_off);
                /*
                 * __log_do_open is called without protection of the
                 * log thread lock.
                 */
                UNLOCK_LOGTHREAD(logp);
                /*
                 * At this point, we are not holding the thread lock, so
                 * exit directly instead of going through the exit code
                 * at the bottom.  If the __log_do_open succeeded, then
                 * we don't need to do any of the remaining error checking
                 * at the end of this routine.
                 */
                if ((ret = __log_do_open(logp,
                    fname->ufid, name, fname->s_type, ndx)) != 0)
                        return (ret);
                *dbpp = logp->dbentry[ndx].dbp;
                return (0);
        }

        /*
         * Return DB_DELETED if the file has been deleted
         * (it's not an error).
         */
        if (logp->dbentry[ndx].deleted) {
                ret = DB_DELETED;
                goto err;
        }

        /*
         * Otherwise return 0, but if we don't have a corresponding DB,
         * it's an error.
         */
        if ((*dbpp = logp->dbentry[ndx].dbp) == NULL)
                ret = ENOENT;

err:    UNLOCK_LOGTHREAD(logp);
        return (ret);
}

/*
 * Close files that were opened by the recovery daemon.
 *
 * PUBLIC: void __log_close_files __P((DB_LOG *));
 */
void
__log_close_files(logp)
        DB_LOG *logp;
{
        u_int32_t i;

        LOCK_LOGTHREAD(logp);
        for (i = 0; i < logp->dbentry_cnt; i++)
                if (logp->dbentry[i].dbp) {
                        logp->dbentry[i].dbp->close(logp->dbentry[i].dbp, 0);
                        logp->dbentry[i].dbp = NULL;
                        logp->dbentry[i].deleted = 0;
                }
        F_CLR(logp, DBC_RECOVER);
        UNLOCK_LOGTHREAD(logp);
}

/*
 * PUBLIC: void __log_rem_logid __P((DB_LOG *, u_int32_t));
 */
void
__log_rem_logid(logp, ndx)
        DB_LOG *logp;
        u_int32_t ndx;
{
        LOCK_LOGTHREAD(logp);
        if (--logp->dbentry[ndx].refcount == 0) {
                logp->dbentry[ndx].dbp = NULL;
                logp->dbentry[ndx].deleted = 0;
        }
        UNLOCK_LOGTHREAD(logp);
}

/*
 * __log_lid_to_fname --
 *      Traverse the shared-memory region looking for the entry that
 * matches the passed log fileid.  Returns 0 on success; -1 on error.
 */
static int
__log_lid_to_fname(dblp, lid, fnamep)
        DB_LOG *dblp;
        u_int32_t lid;
        FNAME **fnamep;
{
        FNAME *fnp;

        for (fnp = SH_TAILQ_FIRST(&dblp->lp->fq, __fname);
            fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) {
                if (fnp->ref == 0)      /* Entry not in use. */
                        continue;
                if (fnp->id == lid) {
                        *fnamep = fnp;
                        return (0);
                }
        }
        return (-1);
}