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CBKEYLAS.C
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1989-08-31
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/* Copyright (c) 1989 Citadel */
/* All Rights Reserved */
/* #ident "cbkeylas.c 1.1 - 89/08/31" */
#include <blkio.h>
#include <btree.h>
#include <errno.h>
#include <lseq.h>
/* #include <stdlib.h> */
/* #include <string.h> */
#include "cbase_.h"
/*man---------------------------------------------------------------------------
NAME
cbkeylast - last cbase key
SYNOPSIS
#include <cbase.h>
int cbkeylast(cbp, field)
cbase_t *cbp;
int field;
DESCRIPTION
The cbkeylast function positions a key cursor for cbase cbp to the
last key. The record cursor of cbp is positioned to the record
associated with that key.
field is the field for which to set the key cursor.
cbkeylast will fail if one or more of the following is true:
[EINVAL] cbp is not a valid cbase pointer.
[EINVAL] field is less than 1 or greater than
the number of fields defined for cbp.
[CBELOCK] cbp is not locked.
[CBENKEY] field is not a key.
[CBENOPEN] cbp is not open.
[CBENREC] cbp is empty.
SEE ALSO
cbkeyfirst, cbkeynext, cbkeyprev, cbreccnt, cbreclast.
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 cbkeylast(cbp, field)
cbase_t * cbp;
int field;
{
int rs = 0;
void * buf = NULL;
cbrpos_t cbrpos = 0;
lspos_t lspos = 0;
errno = 0;
/* validate arguments */
if (!cb_valid(cbp)) {
errno = EINVAL;
return -1;
}
if ((field < 1) || (field > cbp->fldcnt)) {
errno = EINVAL;
return -1;
}
/* check if not open */
if (!(cbp->flags & CBOPEN)) {
errno = CBENOPEN;
return -1;
}
/* check if field not a key */
if (!(cbp->fields[field - 1].flags & CBFKEY)) {
errno = CBENKEY;
return -1;
}
/* check if not locked */
if (!(cbp->flags & CBLOCKS)) {
errno = CBELOCK;
return -1;
}
/* check if cbase empty */
if (lsreccnt(cbp->lsp) == 0) {
errno = CBENREC;
return -1;
}
/* set key cursor to last key */
rs = btlast(cbp->btp[field - 1]);
if (rs == -1) {
CBEPRINT;
return -1;
}
/* get record position */
if (btkeysize(cbp->btp[field - 1]) !=
(cbp->fields[field - 1].size + sizeof(lspos_t))) {
CBEPRINT;
errno = CBEPANIC;
return -1;
}
buf = calloc(1, btkeysize(cbp->btp[field - 1]));
if (buf == NULL) {
CBEPRINT;
errno = ENOMEM;
return -1;
}
rs = btgetk(cbp->btp[field - 1], buf);
if (rs == -1) {
CBEPRINT;
free(buf);
return -1;
}
memcpy((void *)&cbrpos, (void *)((char *)buf +
cbp->fields[field - 1].size), sizeof(cbrpos));
free(buf);
buf = NULL;
/* set record cursor */
lspos = cbrpos;
rs = lssetcur(cbp->lsp, &lspos);
if (rs == -1) {
CBEPRINT;
return -1;
}
errno = 0;
return 0;
}