/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Olson.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)bt_close.c	5.1 (Berkeley) 09/04/91";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <errno.h>
#include <db.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "btree.h"

static int bt_meta __P((BTREE *));

/*
 * BT_CLOSE -- Close a btree.
 *
 * Parameters:
 *	dbp:	pointer to access method
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS
 */
int
__bt_close(dbp)
	DB *dbp;
{
	BTREE *t;
	int fd;

	t = dbp->internal;

	/*
	 * Delete any already deleted record that we've been saving
	 * because the cursor pointed to it.
	 */
	if (ISSET(t, BTF_DELCRSR) && __bt_crsrdel(t, &t->bt_bcursor))
		return (RET_ERROR);

	if (__bt_sync(dbp) == RET_ERROR)
		return (RET_ERROR);

	if (mpool_close(t->bt_mp) == RET_ERROR)
		return (RET_ERROR);

	if (t->bt_stack)
		free(t->bt_stack);
	if (t->bt_kbuf)
		free(t->bt_kbuf);
	if (t->bt_dbuf)
		free(t->bt_dbuf);

	fd = t->bt_fd;
	free(t);
	free(dbp);
	return (close(fd) ? RET_ERROR : RET_SUCCESS);
}

/*
 * BT_SYNC -- sync the btree to disk.
 *
 * Parameters:
 *	dbp:	pointer to access method
 *
 * Returns:
 *	RET_SUCCESS, RET_ERROR.
 *
 * XXX
 * Currently don't handle a key marked for deletion when the tree is synced.
 * Should copy the page and write it out instead of the real page.
 */
int
__bt_sync(dbp)
	const DB *dbp;
{
	BTREE *t;
	int status;

	t = dbp->internal;

	if (ISSET(t, BTF_INMEM))
		return (RET_SUCCESS);

	if (ISSET(t, BTF_RDONLY)) {
		errno = EPERM;
		return (RET_ERROR);
	}

	if (ISSET(t, BTF_METADIRTY) && bt_meta(t) == RET_ERROR)
		return (RET_ERROR);

	if ((status = mpool_sync(t->bt_mp)) == RET_SUCCESS) {
		UNSET(t, BTF_MODIFIED);
		return (RET_SUCCESS);
	}
	return (status);
}

/*
 * BT_META -- write the tree meta data to disk.
 *
 * Parameters:
 *	t:	tree
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS
 */
static int
bt_meta(t)
	BTREE *t;
{
	BTMETA m;
	void *p;

	if ((p = mpool_get(t->bt_mp, P_META, 0)) == NULL)
		return (RET_ERROR);

	/* Fill in meta structure -- lorder MUST be host-independent. */
	m.m_magic = BTREEMAGIC;
	m.m_version = BTREEVERSION;
	m.m_psize = t->bt_psize;
	m.m_free = 0;		/* XXX */
	m.m_nrecs = t->bt_nrecs;
	m.m_flags = t->bt_flags & SAVEMETA;
	m.m_lorder = (u_long)htonl((long)t->bt_lorder);

	if (t->bt_lorder != BYTE_ORDER) {
		BLSWAP(m.m_magic);
		BLSWAP(m.m_version);
		BLSWAP(m.m_psize);
		BLSWAP(m.m_free);
		BLSWAP(m.m_nrecs);
		BLSWAP(m.m_flags);
	}

	bcopy(&m, p, sizeof(BTMETA));
	mpool_put(t->bt_mp, p, MPOOL_DIRTY);
	return (RET_SUCCESS);
}