btclose.cpp

来自「CBASE v1.01 采用Borland公司TC++编写的数据库管理源程序库」· C++ 代码 · 共 76 行

/*	Copyright (c) 1989 Citadel	*/
/*	   All Rights Reserved    	*/

/* #ident	"@(#)btclose.c	1.4 - 90/06/20" */

#include <blkio.h>
#include <errno.h>
/*#include <string.h>*/

/* local headers */
#include "btree_.h"

/*man---------------------------------------------------------------------------
NAME
     btclose - close btree

SYNOPSIS
     #include <btree.h>

     int btclose(btp)
     btree_t *btp;

DESCRIPTION
     The btclose function causes any buffered data for the named btree
     to be written out, the file unlocked, and the btree to be closed.

     btclose will fail if one or more of the following is true:

     [EINVAL]       btp is not a valid btree pointer.
     [BTENOPEN]     btp is not open.

SEE ALSO
     btcreate, btlock, btopen, btsync.

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Otherwise,
     a value of -1 is returned, and errno set to indicate the error.

------------------------------------------------------------------------------*/
int btclose(btree_t *btp)
{
	/* validate arguments */
	if (!bt_valid(btp)) {
		errno = EINVAL;
		return -1;
	}

	/* check if not open */
	if (!(btp->flags & BTOPEN)) {
		errno = BTENOPEN;
		return -1;
	}

	/* synchronize file with buffers and unlock file */
	if (btlock(btp, BT_UNLCK) == -1) {
		BTEPRINT;
		return -1;
	}

	/* free memory allocated for btree */
	bt_free(btp);

	/* close btree file */
	if (bclose(btp->bp) == -1) {
		BTEPRINT;
		return -1;
	}

	/* scrub slot in btb table then free it */
	memset(btp, 0, sizeof(*btb));
	btp->flags = 0;

	errno = 0;
	return 0;
}