source: rtems/cpukit/librpc/src/xdr/xdr_sizeof.c @ e5fc1df

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 * 
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 * 
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 * 
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 * 
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 * 
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */
/*
 * xdr_sizeof.c
 *
 * Copyright 1990 Sun Microsystems, Inc.
 *
 * General purpose routine to see how much space something will use
 * when serialized using XDR.
 */

#include <rpc/types.h>
#include <rpc/xdr.h>
#include <sys/types.h>
#include <stdlib.h>

/* ARGSUSED */
static bool_t
x_putlong(xdrs, longp)
        XDR *xdrs;
        long *longp;
{
        xdrs->x_handy += BYTES_PER_XDR_UNIT;
        return (TRUE);
}

/* ARGSUSED */
static bool_t
x_putbytes(xdrs, bp, len)
        XDR *xdrs;
        char  *bp;
        int len;
{
        xdrs->x_handy += len;
        return (TRUE);
}

static u_int
x_getpostn(xdrs)
        XDR *xdrs;
{
        return (xdrs->x_handy);
}

/* ARGSUSED */
static bool_t
x_setpostn(xdrs, pos)
        XDR *xdrs;
        u_int pos;
{
        /* This is not allowed */
        return (FALSE);
}

static int32_t *
x_inline(xdrs, len)
        XDR *xdrs;
        long len;
{
        if (len == 0) {
                return (NULL);
        }
        if (xdrs->x_op != XDR_ENCODE) {
                return (NULL);
        }
        if (len < (long) xdrs->x_base) {
                /* x_private was already allocated */
                xdrs->x_handy += len;
                return ((int32_t *) xdrs->x_private);
        } else {
                /* Free the earlier space and allocate new area */
                if (xdrs->x_private)
                        free(xdrs->x_private);
                if ((xdrs->x_private = (caddr_t) malloc(len)) == NULL) {
                        xdrs->x_base = 0;
                        return (NULL);
                }
                xdrs->x_base = (caddr_t) len;
                xdrs->x_handy += len;
                return ((int32_t *) xdrs->x_private);
        }
}

static int
harmless()
{
        /* Always return FALSE/NULL, as the case may be */
        return (0);
}

static void
x_destroy(xdrs)
        XDR *xdrs;
{
        xdrs->x_handy = 0;
        xdrs->x_base = 0;
        if (xdrs->x_private) {
                free(xdrs->x_private);
                xdrs->x_private = NULL;
        }
        return;
}

unsigned long
xdr_sizeof(func, data)
        xdrproc_t func;
        void *data;
{
        XDR x;
        struct xdr_ops ops;
        bool_t stat;
        /* to stop ANSI-C compiler from complaining */
        typedef  bool_t (* dummyfunc1)(XDR *, long *);
        typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);

        ops.x_putlong = x_putlong;
        ops.x_putbytes = x_putbytes;
        ops.x_inline = x_inline;
        ops.x_getpostn = x_getpostn;
        ops.x_setpostn = x_setpostn;
        ops.x_destroy = x_destroy;

        /* the other harmless ones */
        ops.x_getlong =  (dummyfunc1) harmless;
        ops.x_getbytes = (dummyfunc2) harmless;

        x.x_op = XDR_ENCODE;
        x.x_ops = &ops;
        x.x_handy = 0;
        x.x_private = (caddr_t) NULL;
        x.x_base = (caddr_t) 0;

        stat = func(&x, data);
        if (x.x_private)
                free(x.x_private);
        return (stat == TRUE ? (unsigned) x.x_handy: 0);
}