Initial import of the CDE 2.1.30 sources from the Open Group.
This commit is contained in:
Peter Howkins
397
cde/lib/tt/mini_isam/isfixrec.c
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397
cde/lib/tt/mini_isam/isfixrec.c
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/*%% (c) Copyright 1993, 1994 Hewlett-Packard Company */
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/*%% (c) Copyright 1993, 1994 International Business Machines Corp. */
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/*%% (c) Copyright 1993, 1994 Sun Microsystems, Inc. */
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/*%% (c) Copyright 1993, 1994 Novell, Inc. */
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/*%% $XConsortium: isfixrec.c /main/3 1995/10/23 11:39:42 rswiston $ */
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#ifndef lint
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static char sccsid[] = "@(#)isfixrec.c 1.5 89/07/17 Copyr 1988 Sun Micro";
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#endif
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/*
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* Copyright (c) 1988 by Sun Microsystems, Inc.
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*/
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/*
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* isfixrec.c
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*
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* Description:
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* Fixed length record access (FLRA) module.
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*/
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#include "isam_impl.h"
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/* Local functions */
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long _fl_getpos(); /* Get offset in .rec file */
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int _fl_deleted(); /* 0/1 returns 1 if record is deleted */
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static void remove_from_chain(); /* used by _flrec_wrrec() */
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/*
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* _flrec_write(fcb, record, recnum, reclen)
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*
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* Write a record.
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*
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* Input params:
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* FCB File Control Block
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* record record buffer
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* reclen record length (NOT USED)
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*
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* Output params:
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* recnum record number of the new record
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*
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* Returns 0 if record was written succesfully, or -1 if any error.
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*/
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/*ARGSUSED*/
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int
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_flrec_write(fcb, record, recnum, reclen)
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register Fcb *fcb;
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char *record;
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Recno *recnum;
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int reclen;
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{
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Recno recnum2;
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long rec_position;
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char delflag = FL_RECEXISTS;
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char recnobuf [RECNOSIZE];
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/*
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* Reuse a deleted record if one exits.
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* Otherwise, extend .rec file by a record.
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*/
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if (fcb->freerecno != NULL_RECNO) {
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recnum2 = fcb->freerecno;
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/*
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* Remove record from the chain of deleted records.
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*/
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rec_position = _fl_getpos(fcb, recnum2); /* Offset in .rec file */
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_cp_fromfile(fcb, fcb->datfd, recnobuf, rec_position + 1, RECNOSIZE);
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fcb->freerecno = ldrecno(recnobuf);
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}
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else {
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recnum2 = ++(fcb->lastrecno);
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/*
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* Extend .rec file size if necessary.
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*/
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while (_fl_getpos(fcb, recnum2 + 1) > fcb->datsize * ISPAGESIZE) {
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fcb->datsize = _extend_file(fcb, fcb->datfd, fcb->datsize);
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}
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rec_position = _fl_getpos(fcb, recnum2); /* Offset in .rec file */
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}
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/*
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* Copy record to the .at file. Mark record as undeleted.
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*/
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_cp_tofile(fcb, fcb->datfd, &delflag, rec_position, 1);
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_cp_tofile(fcb, fcb->datfd, record, rec_position + 1, fcb->minreclen);
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*recnum = recnum2;
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return (ISOK);
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}
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/*
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* _flrec_read(fcb, record, recnum, reclen)
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*
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* Read a record.
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*
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* Input params:
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* FCB File Control Block
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* recnum record number of the record
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* reclen filled with the record size for compatibilty with
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* variable length records
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*
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* Output params:
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* record record buffer is filled with data
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*
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* Returns 0 if record was read succesfully, or error code if any error.
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*/
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int
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_flrec_read(fcb, record, recnum, reclen)
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register Fcb *fcb;
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char *record;
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Recno recnum;
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int *reclen;
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{
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long rec_position;
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char delflag;
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/*
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* Check that recnum is within the range of existing record numbers.
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*/
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if (recnum < 1 || recnum > fcb->lastrecno)
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return (EENDFILE);
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rec_position = _fl_getpos(fcb, recnum); /* Offset in .rec file */
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/*
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* Check that the record is not marked as deleted.
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*/
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_cp_fromfile(fcb, fcb->datfd, &delflag, rec_position, 1);
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if (delflag == FL_RECDELETED) {
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return (ENOREC);
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}
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/*
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* Copy record from the .at file.
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*/
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_cp_fromfile(fcb, fcb->datfd, record, rec_position + 1, fcb->minreclen);
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*reclen = fcb->minreclen;
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return (ISOK);
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}
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/*
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* pos = _fl_getpos(fcb, recnum)
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*
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* Calculate the position of record in .rec file.
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*/
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long
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_fl_getpos(fcb, recnum)
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Fcb *fcb;
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Recno recnum;
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{
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return ((long)(ISCNTLSIZE + (fcb->minreclen + 1) * (recnum -1)));
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}
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/*
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* _flrec_rewrite(fcb, record, recnum, reclen)
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*
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* Rewrite a record.
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*
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* Input params:
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* FCB File Control Block
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* recnum record number of the record
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* record new record
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* int reclen (NOT USED)
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*
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* Returns 0 if record was rewritten succesfully, or error code if any error.
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*/
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/*ARGSUSED*/
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int
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_flrec_rewrite(fcb, record, recnum, reclen)
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register Fcb *fcb;
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char *record;
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Recno recnum;
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int reclen;
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{
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long rec_position;
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char delflag;
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/*
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* Check that recnum is within the range of existing record numbers.
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*/
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if (recnum < 1 || recnum > fcb->lastrecno)
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return (EENDFILE);
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rec_position = _fl_getpos(fcb, recnum); /* Offset in .rec file */
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/*
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* Check that the record is not marked as deleted.
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*/
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_cp_fromfile(fcb, fcb->datfd, &delflag, rec_position, 1);
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if (delflag == FL_RECDELETED) {
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return (ENOREC);
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}
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/*
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* Copy new record to the .rec file.
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*/
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_cp_tofile(fcb, fcb->datfd, record, rec_position + 1, fcb->minreclen);
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return (ISOK);
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}
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/*
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* _flrec_delete(fcb, recnum)
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*
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* Rewrite a record.
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*
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* Input params:
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* FCB File Control Block
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* recnum record number of the record
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*
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* Returns 0 if record was rewritten succesfully, or error code if any error.
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*/
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int
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_flrec_delete(fcb, recnum)
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register Fcb *fcb;
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Recno recnum;
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{
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long rec_position;
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char delflag;
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char recnobuf [RECNOSIZE];
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/*
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* Check that recnum is within the range of existing record numbers.
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*/
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if (recnum < 1 || recnum > fcb->lastrecno)
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return (EENDFILE);
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rec_position = _fl_getpos(fcb, recnum); /* Offset in .rec file */
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/*
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* Check that the record is not marked as deleted.
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*/
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_cp_fromfile(fcb, fcb->datfd, &delflag, rec_position, 1);
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if (delflag == FL_RECDELETED) {
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return (ENOREC);
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}
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/*
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* Set the delete flag to FL_RECDELETED.
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*/
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delflag = FL_RECDELETED;
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_cp_tofile(fcb, fcb->datfd, &delflag, rec_position, 1);
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/*
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* Insert record into chain of deleted records.
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*/
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strecno(fcb->freerecno, recnobuf);
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_cp_tofile(fcb, fcb->datfd, recnobuf, rec_position + 1, RECNOSIZE);
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fcb->freerecno = recnum;
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return (ISOK);
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}
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/*
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* _flrec_wrrec(fcb, record, recnum, reclen)
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*
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* Write a record by record number.
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*
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* Input params:
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* FCB File Control Block
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* recnum record number of the record
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* record record buffer
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* int reclen (NOT USED)
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*
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* Returns 0 if record was written succesfully, or error code if any error.
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*
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* Note that _flrec_wrrec() commits updates and syncs the FCB to avoid
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* buffer pool overflow.
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*/
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/*ARGSUSED*/
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int
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_flrec_wrrec(fcb, record, recnum, reclen)
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register Fcb *fcb;
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char *record;
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Recno recnum;
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int reclen;
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{
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long rec_position;
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char delflag;
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Recno recnum2;
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char recnumbuf [RECNOSIZE];
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/*
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* Check that recnum is not negative.
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*/
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if (recnum < 1)
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return (EBADARG);
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rec_position = _fl_getpos(fcb, recnum); /* Offset in .rec file */
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if (recnum > fcb->lastrecno) {
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/*
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* If the recnum is bigger than the highest record number in the .rec
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* file, extend the .rec file.
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*/
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while (_fl_getpos(fcb, recnum + 1) > fcb->datsize * ISPAGESIZE) {
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fcb->datsize = _extend_file(fcb, fcb->datfd, fcb->datsize);
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/* Sync the updates to avoid buffer pool overflow. */
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_isdisk_commit();
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_isdisk_sync();
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(void)_isfcb_cntlpg_w2(fcb);
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}
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/*
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* Mark all records in the range <fcb->lastrecno+1, recnum> as
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* deleted.
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*/
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delflag = FL_RECDELETED;
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for (recnum2 = fcb->lastrecno + 1; recnum2 <= recnum; recnum2++) {
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_cp_tofile(fcb, fcb->datfd, &delflag, _fl_getpos(fcb, recnum2), 1);
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strecno(fcb->freerecno, recnumbuf);
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_cp_tofile(fcb, fcb->datfd, recnumbuf,
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_fl_getpos(fcb, recnum2) + 1, RECNOSIZE);
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fcb->freerecno = recnum2;
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/* Sync the updates to avoid buffer pool overflow. */
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_isdisk_commit();
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_isdisk_sync();
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fcb->lastrecno = recnum;
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(void)_isfcb_cntlpg_w2(fcb);
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}
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/*
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* Note that the disk structures are in a consistent state now,
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* the .rec was extended by a few records marked as 'deleted'.
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* This is important for subsequent rollbacks.
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*/
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}
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/*
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* If recnum specifies a record that has existed, check whether it
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* has been deleted. _flrec_wrrec() does not override existing record.
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*/
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_cp_fromfile(fcb, fcb->datfd, &delflag, rec_position, 1);
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if (delflag == FL_RECEXISTS) {
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return (EDUPL);
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}
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/*
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* Remove the record from the chain of deleted records.
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*/
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remove_from_chain(fcb, recnum);
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/*
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* Copy new record to the .rec file.
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*/
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delflag = FL_RECEXISTS;
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_cp_tofile(fcb, fcb->datfd, &delflag, rec_position, 1);
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_cp_tofile(fcb, fcb->datfd, record, rec_position + 1, fcb->minreclen);
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return (ISOK);
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}
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/*
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* remvoe_from_chain(fcb, recnum)
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*
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* Remove record from the chain of deleted records.
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*/
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static void
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remove_from_chain(fcb, recnum)
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Fcb *fcb;
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Recno recnum;
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{
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char recnobuf1 [RECNOSIZE] , recnobuf2 [RECNOSIZE];
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long pos1, pos2;
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Recno recnum2;
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pos1 = _fl_getpos(fcb, recnum);
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_cp_fromfile(fcb, fcb->datfd, recnobuf1, pos1 + 1, RECNOSIZE);
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if (fcb->freerecno == recnum) {
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fcb->freerecno = ldrecno(recnobuf1);
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}
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else {
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recnum2 = fcb->freerecno;
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do {
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pos2 = _fl_getpos(fcb, recnum2);
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_cp_fromfile(fcb, fcb->datfd, recnobuf2, pos2 + 1, RECNOSIZE);
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recnum2 = ldrecno(recnobuf2);
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} while (recnum2 != recnum && recnum2 != NULL_RECNO);
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_cp_tofile(fcb, fcb->datfd, recnobuf1, pos2 + 1, RECNOSIZE);
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}
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}
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