/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1999
 *	Sleepycat Software.  All rights reserved.
 */

#include "db_config.h"

#ifndef lint
static const char sccsid[] = "@(#)qam_open.c	11.12 (Sleepycat) 10/25/99";
#endif /* not lint */

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

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

#include "db_int.h"
#include "db_page.h"
#include "db_shash.h"
#include "db_swap.h"
#include "db_am.h"
#include "lock.h"
#include "qam.h"

/*
 * CDB___qam_open
 *
 * PUBLIC: int CDB___qam_open __P((DB *, const char *, db_pgno_t));
 */
int
CDB___qam_open(dbp, name, base_pgno)
	DB *dbp;
	const char *name;
	db_pgno_t base_pgno;
{
	QUEUE *t;
	DBC *dbc;
	DB_LOCK metalock;
	DB_LSN orig_lsn;
	QMETA *qmeta;
	int ret, t_ret;

	ret = 0;
	t = dbp->q_internal;

	/* Initialize the remaining fields/methods of the DB. */
	dbp->del = CDB___qam_delete;
	dbp->put = CDB___qam_put;
	dbp->stat = CDB___qam_stat;

	metalock.off = LOCK_INVALID;

	/* Get a cursor. */
	if ((ret = dbp->cursor(dbp, NULL, &dbc, 0)) != 0)
		return (ret);

	/* Get, and optionally create the metadata page. */
	if ((ret =
	    CDB___db_lget(dbc, 0, base_pgno, DB_LOCK_WRITE, 0, &metalock)) != 0)
		goto err;
	if ((ret = CDB_memp_fget(
	    dbp->mpf, &base_pgno, DB_MPOOL_CREATE, (PAGE **)&qmeta)) != 0)
		goto err;

	/*
	 * If the magic number is correct, we're not creating the tree.
	 * Correct any fields that may not be right.  Note, all of the
	 * local flags were set by DB->open.
	 */
	if (qmeta->dbmeta.magic == DB_QAMMAGIC) {
		t->re_pad = qmeta->re_pad;
		t->re_len = qmeta->re_len;
		t->rec_page = qmeta->rec_page;

		(void)CDB_memp_fput(dbp->mpf, (PAGE *)qmeta, 0);
		goto done;
	}

	/* Initialize the tree structure metadata information. */
	orig_lsn = qmeta->dbmeta.lsn;
	memset(qmeta, 0, sizeof(QMETA));
	ZERO_LSN(qmeta->dbmeta.lsn);
	qmeta->dbmeta.pgno = base_pgno;
	qmeta->dbmeta.magic = DB_QAMMAGIC;
	qmeta->dbmeta.version = DB_QAMVERSION;
	qmeta->dbmeta.pagesize = dbp->pgsize;
	qmeta->dbmeta.type = P_QAMMETA;
	qmeta->re_pad = t->re_pad;
	qmeta->start = 1;
	qmeta->re_len = t->re_len;
	qmeta->rec_page = CALC_QAM_RECNO_PER_PAGE(dbp);
	t->rec_page = qmeta->rec_page;
	memcpy(qmeta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN);

	/* Verify that we can fit at least one record per page. */
	if (QAM_RECNO_PER_PAGE(dbp) < 1) {
		CDB___db_err(dbp->dbenv,
		    "Record size of %d too large for page size of %d",
		    t->re_len, dbp->pgsize);
		(void)CDB_memp_fput(dbp->mpf, (PAGE *)qmeta, 0);
		ret = EINVAL;
		goto err;
	}

	if ((ret = CDB___db_log_page(dbp,
	    name, &orig_lsn, base_pgno, (PAGE *)qmeta)) != 0)
		goto err;

	/* Release the metadata page. */
	if ((ret = CDB_memp_fput(dbp->mpf, (PAGE *)qmeta, DB_MPOOL_DIRTY)) != 0)
		goto err;
	DB_TEST_RECOVERY(dbp, DB_TEST_POSTLOG, ret, name);

	/*
	 * Flush the metadata page to disk.
	 *
	 * !!!
	 * It's not useful to return not-yet-flushed here -- convert it to
	 * an error.
	 */
	if ((ret = CDB_memp_fsync(dbp->mpf)) == DB_INCOMPLETE)
		ret = EINVAL;
	DB_TEST_RECOVERY(dbp, DB_TEST_POSTSYNC, ret, name);

done:	t->q_meta = base_pgno;
	t->q_root = base_pgno + 1;

err:
DB_TEST_RECOVERY_LABEL
	/* Don't hold the meta page long term. */
	if (metalock.off != LOCK_INVALID)
		(void)__LPUT(dbc, metalock);

	if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
		ret = t_ret;

	return (ret);
}

/*
 * CDB___qam_metachk --
 *
 * PUBLIC: int CDB___qam_metachk __P((DB *, const char *, QMETA *));
 */
int
CDB___qam_metachk(dbp, name, qmeta)
	DB *dbp;
	const char *name;
	QMETA *qmeta;
{
	DB_ENV *dbenv;
	u_int32_t vers;
	int ret;

	dbenv = dbp->dbenv;

	/*
	 * At this point, all we know is that the magic number is for a Queue.
	 * Check the version, the database may be out of date.
	 */
	vers = qmeta->dbmeta.version;
	if (F_ISSET(dbp, DB_AM_SWAP))
		M_32_SWAP(vers);
	switch (vers) {
	case 1:
		break;
	default:
		CDB___db_err(dbenv,
		    "%s: unsupported qam version: %lu", name, (u_long)vers);
		return (EINVAL);
	}

	/* Swap the page if we need to. */
	if (F_ISSET(dbp, DB_AM_SWAP) && (ret = CDB___qam_mswap((PAGE *)qmeta)) != 0)
		return (ret);

	/* Check the type. */
	if (dbp->type != DB_QUEUE && dbp->type != DB_UNKNOWN)
		return (EINVAL);
	dbp->type = DB_QUEUE;
	DB_ILLEGAL_METHOD(dbp, DB_OK_QUEUE);

	/* Set the page size. */
	dbp->pgsize = qmeta->dbmeta.pagesize;
	F_CLR(dbp, DB_AM_PGDEF);

	/* Copy the file's ID. */
	memcpy(dbp->fileid, qmeta->dbmeta.uid, DB_FILE_ID_LEN);

	return (0);
}