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

#include "config.h"

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1997\n\
	Sleepycat Software Inc.  All rights reserved.\n";
static const char sccsid[] = "@(#)db_apprec.c	10.15 (Sleepycat) 7/27/97";
#endif

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

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

#include "db_int.h"
#include "shqueue.h"
#include "db_page.h"
#include "db_dispatch.h"
#include "db_am.h"
#include "log.h"
#include "txn.h"
#include "common_ext.h"

/*
 * __db_apprec --
 *	Perform recovery.
 *
 * PUBLIC: int __db_apprec __P((DB_ENV *, int));
 */
int
__db_apprec(dbenv, flags)
	DB_ENV *dbenv;
	int flags;
{
	DBT data;
	DB_LOG *lp;
	DB_LSN ckp_lsn, first_lsn, lsn, tmp_lsn;
	time_t now;
	int first_flag, ret, tret;
	void *txninfo;

	ZERO_LSN(ckp_lsn);

	/* Initialize the transaction list. */
	if ((ret = __db_txnlist_init(&txninfo)) != 0)
		return (ret);

	/*
	 * Read forward through the log opening the appropriate files
	 * so that we can call recovery routines.  In general, we start
	 * at the last checkpoint prior to the last checkpointed LSN.
	 * For catastrophic recovery, we begin at the first LSN that
	 * appears in any log file (log figures this out for us when
	 * we pass it the DB_FIRST flag).
	 */
	lp = dbenv->lg_info;
	if (LF_ISSET(DB_RECOVER_FATAL))
		first_flag = DB_FIRST;
	else
		first_flag = __log_findckp(lp, &lsn) != 0 ? DB_FIRST : DB_SET;

	memset(&data, 0, sizeof(data));
	if ((ret = log_get(lp, &lsn, &data, first_flag)) != 0) {
		__db_err(dbenv, "Failure: unable to get log record");
		if (first_flag == DB_SET)
			__db_err(dbenv, "Retrieving LSN %lu %lu",
			    (u_long)lsn.file, (u_long)lsn.offset);
		else
			__db_err(dbenv, "Retrieving first LSN");
		goto err;
	}

	first_lsn = lsn;
	for (; ret == 0;
	    ret = log_get(dbenv->lg_info, &lsn, &data, DB_NEXT))
		if ((tret = __db_dispatch(lp,
		    &data, &lsn, TXN_OPENFILES, txninfo)) < 0) {
			ret = tret;
			goto msgerr;
		}

	for (ret = log_get(lp, &lsn, &data, DB_LAST);
	    ret == 0 && log_compare(&lsn, &first_lsn) > 0;
	    ret = log_get(lp,&lsn, &data, DB_PREV)) {
		tmp_lsn = lsn;
		tret =
		    __db_dispatch(lp, &data, &lsn, TXN_BACKWARD_ROLL, txninfo);
		if (IS_ZERO_LSN(ckp_lsn) && tret > 0)
			ckp_lsn = tmp_lsn;
		if (tret < 0) {
			ret = tret;
			goto msgerr;
		}
	}

	for (ret = log_get(lp, &lsn, &data, DB_NEXT);
	    ret == 0; ret = log_get(lp, &lsn, &data, DB_NEXT))
		if ((tret = __db_dispatch(lp,
		    &data, &lsn, TXN_FORWARD_ROLL, txninfo)) < 0) {
			ret = tret;
			goto msgerr;
		}

	/* Now close all the db files that are open. */
	__log_close_files(lp);

	/*
	 * Now set the maximum transaction id, set the last checkpoint lsn,
	 * and the current time.  Then take a checkpoint.
	 */
	(void)time(&now);

	dbenv->tx_info->region->last_txnid = ((__db_txnhead *)txninfo)->maxid;
	dbenv->tx_info->region->last_ckp = ckp_lsn;
	dbenv->tx_info->region->time_ckp = (u_int32_t) now;
	txn_checkpoint(dbenv->tx_info, 0, 0);

	if (dbenv->db_verbose) {
		__db_err(lp->dbenv, "Recovery complete at %s", ctime(&now));
		__db_err(lp->dbenv, "%s %lu %s [%lu][%lu]",
		    "Maximum transaction id",
		    (u_long)dbenv->tx_info->region->last_txnid,
		    "Recovery checkpoint",
		    (u_long)dbenv->tx_info->region->last_ckp.file,
		    (u_long)dbenv->tx_info->region->last_ckp.offset);
	}

	return (0);

msgerr:	__db_err(dbenv, "Recovery function for LSN %lu %lu failed",
	    (u_long)lsn.file, (u_long)lsn.offset);

err:	return (ret);
}