lsputrf.cpp

CBASE v1.01 采用Borland公司TC++编写的数据库管理源程序库

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

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

/* ansi headers */
#include <errno.h>
/*#include <stddef.h>*/
/*#include <string.h>*/

/* library headers */
#include <blkio.h>

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

/*man---------------------------------------------------------------------------
NAME
     lsputrf - put field to current lseq record

SYNOPSIS
     #include <lseq.h>

     int lsputrf(lsp, offset, buf, bufsize)
     lseq_t *lsp;
     size_t offset;
     const void *buf;
     size_t bufsize;

DESCRIPTION
     The lsputrf function writes the contents of buf into a field in
     the current record in lseq lsp.  The field begins offset
     characters from the beginning of the record and is bufsize
     characters long.  buf must point to a storage area at least
     bufsize characters long.

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

     [EINVAL]       lsp is not a valid lseq pointer.
     [EINVAL]       buf is the NULL pointer.
     [EINVAL]       bufsize is 0.
     [LSEBOUND]     offset + bufsize extends beyond the end
                    of the record.
     [LSELOCK]      lsp is not write locked.
     [LSENOPEN]     lsp is not open.
     [LSENREC]      The cursor is null.

SEE ALSO
     lscursor, lsgetrf, lsputr.

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 lsputrf(lseq_t *lsp,size_t offset, const void *buf, size_t bufsize)
{
	/* validate arguments */
	if (!ls_valid(lsp) || buf == NULL || bufsize < 1) {
		errno = EINVAL;
		return -1;
	}

	/* check if not open */
	if (!(lsp->flags & LSOPEN)) {
		errno = EINVAL;
		return -1;
	}

	/* check if not write locked */
	if (!(lsp->flags & LSWRLCK)) {
		errno = LSELOCK;
		return -1;
	}

	/* check if over record boundary */
	if (offset + bufsize > lsp->lshdr.recsize) {
		errno = LSEBOUND;
		return -1;
	}

	/* check if cursor is null */
	if (lsp->clspos == NIL) {
		errno = LSENREC;
		return -1;
	}

	/* copy field to current record */
	memcpy(((char *)lsp->clsrp->recbuf + offset), buf, bufsize);

	/* write field */
	if (ls_rcputf(lsp, lsp->clspos, offset, buf, bufsize) == -1) {
		LSEPRINT;
		return -1;
	}

	errno = 0;
	return 0;
}