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cdesktop/cde/lib/DtSearch/raima/reclast.c

129 lines
4.4 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* $XConsortium: reclast.c /main/2 1996/05/09 04:14:30 drk $ */
/*
* COMPONENT_NAME: austext
*
* FUNCTIONS: d_reclast
*
* ORIGINS: 157
*
* OBJECT CODE ONLY SOURCE MATERIALS
*/
/*-----------------------------------------------------------------------
reclast.c - find last record occurrence in database
reclast is used to setup a scan of a database by database number
backwards, and is complementary to recfrst.
AUTHOR: R.S. Carlson
DATE: 06-Jul-88
PROJECT: db_VISTA 3.10
Copyright (C) 1988 by Raima Corporation
-----------------------------------------------------------------------*/
/* ********************** EDIT HISTORY *******************************
SCR DATE INI DESCRIPTION
----- --------- --- -----------------------------------------------------
351 06-Jul-88 RSC new function added to runtime
04-Aug-88 RTK MULTI_TASK changes
09-Aug-88 RSC rno-- needs to be outside ifndef SINGLE_USER
18-Aug-88 RSC moved rn_type/dba to separate table
*/
/* ********************** INCLUDE FILES ****************************** */
#include <stdio.h>
#include "vista.h"
#include "dbtype.h"
/* ********************** GLOBAL VARIABLE DECLARATIONS *************** */
/* ********************** GLOBAL FUNCTION DECLARATIONS *************** */
/* ********************** EXTERNAL VARIABLE DECLARATIONS ************* */
/* ********************** EXTERNAL FUNCTION DECLARATIONS ************* */
/* ********************** LOCAL VARIABLE DECLARATIONS **************** */
/* ********************** LOCAL FUNCTION DECLARATIONS **************** */
/* ======================================================================
d_reclast - find last record occurrence in database
*/
int d_reclast(
int rec, /* record # to find last occurrence of */
int dbn /* optional database number */
)
{
/*
RETURNS: db_status. Sets current record to last record, if found.
ASSUMES: nothing.
*/
DB_ADDR dba; /* current database addr we're scanning */
FILE_NO ftype; /* file desc for file holding rec */
F_ADDR last; /* last slot in file */
char *recptr; /* record from database */
RECORD_ENTRY *rec_ptr; /* RECORD ENTRY for this record */
INT rectype; /* record type from record */
F_ADDR rno; /* current slot we're scanning */
DB_ENTER(DB_ID TASK_ID LOCK_SET(RECORD_IO));
/* validate and convert record number */
if ( nrec_check(rec, &rec, (RECORD_ENTRY * *)&rec_ptr) != S_OKAY)
RETURN( db_status );
/* get the last record # for this file */
ftype = NUM2EXT(rec_ptr->rt_file, ft_offset);
if ( (last = dio_pznext(rec_ptr->rt_file)) <= 0 )
RETURN( db_status );
/* start at the end, working backwards, find a matching record */
rno = last - 1;
do {
if ( rno < 1)
RETURN ( db_status = S_NOTFOUND );
/* create the database address, and read this record */
dba = ((FILEMASK & ftype) << FILESHIFT) | (ADDRMASK & rno);
dio_read(dba, (char * *)&recptr, NOPGHOLD);
if ( db_status != S_OKAY )
RETURN( db_status );
/* See if this record is of the type we're looking for */
bytecpy(&rectype, recptr, sizeof(INT));
rno--;
} while ( (int)rectype != rec );
/* when we get here, we know a match was found */
curr_rec = dba; /* set current record */
RN_REF(rn_type) = rectype; /* setup for future recprev,recnext */
RN_REF(rn_dba) = dba;
RETURN( db_status = S_OKAY );
}
/* vpp -nOS2 -dUNIX -nBSD -nVANILLA_BSD -nVMS -nMEMLOCK -nWINDOWS -nFAR_ALLOC -f/usr/users/master/config/nonwin reclast.c */