/*
 * Copyright (C) 1994-2021 Altair Engineering, Inc.
 * For more information, contact Altair at www.altair.com.
 *
 * This file is part of both the OpenPBS software ("OpenPBS")
 * and the PBS Professional ("PBS Pro") software.
 *
 * Open Source License Information:
 *
 * OpenPBS is free software. You can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * OpenPBS is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Commercial License Information:
 *
 * PBS Pro is commercially licensed software that shares a common core with
 * the OpenPBS software.  For a copy of the commercial license terms and
 * conditions, go to: (http://www.pbspro.com/agreement.html) or contact the
 * Altair Legal Department.
 *
 * Altair's dual-license business model allows companies, individuals, and
 * organizations to create proprietary derivative works of OpenPBS and
 * distribute them - whether embedded or bundled with other software -
 * under a commercial license agreement.
 *
 * Use of Altair's trademarks, including but not limited to "PBS™",
 * "OpenPBS®", "PBS Professional®", and "PBS Pro™" and Altair's logos is
 * subject to Altair's trademark licensing policies.
 */

/**
 * @file	disrf.c
 *
 * @par Synopsis:
 * 	float disrf(int stream, int *retval)
 *
 *	Gets a Data-is-Strings floating point number from <stream> and converts
 *	it into a float and returns it.  The number from <stream> consists of
 *	two consecutive signed integers.  The first is the coefficient, with its
 *	implied decimal point at the low-order end.  The second is the exponent
 *	as a power of 10.
 *
 *	*<retval> gets DIS_SUCCESS if everything works well.  It gets an error
 *	code otherwise.  In case of an error, the <stream> character pointer is
 *	reset, making it possible to retry with some other conversion strategy.
 *
 *	By fiat of the author, neither loss of significance nor underflow are
 *	errors.
 */

#include <pbs_config.h> /* the master config generated by configure */

#include <assert.h>
#include <math.h>
#include <stddef.h>

#include "dis.h"
#include "dis_.h"
#undef disrf

/**
 * @brief
 *	-Gets a Data-is-Strings floating point number from <stream> and converts
 *      it into a double and returns it.  The number from <stream> consists of
 *      two consecutive signed integers.  The first is the coefficient, with its
 *      implied decimal point at the low-order end.  The second is the exponent
 *      as a power of 10.
 *
 * @return	int
 * @retval	DIS_success/error status
 *
 */
static int
disrd_(int stream, unsigned count, unsigned *ndigs, unsigned *nskips, double *dval, int recursv)
{
	int c;
	int negate;
	unsigned unum;
	char *cp;

	if (++recursv > DIS_RECURSIVE_LIMIT)
		return (DIS_PROTO);

	/* dis_umaxd would be initialized by prior call to dis_init_tables */
	switch (c = dis_getc(stream)) {
		case '-':
		case '+':
			negate = c == '-';
			*nskips = count > FLT_DIG ? count - FLT_DIG : 0;
			count -= *nskips;
			*ndigs = count;
			*dval = 0.0;
			do {
				if ((c = dis_getc(stream)) < '0' || c > '9') {
					if (c < 0)
						return (DIS_EOD);
					return (DIS_NONDIGIT);
				}
				*dval = *dval * 10.0 + (double) (c - '0');
			} while (--count);
			if ((count = *nskips) > 0) {
				count--;
				switch (dis_getc(stream)) {
					case '5':
						if (count == 0)
							break;
					case '6':
					case '7':
					case '8':
					case '9':
						*dval += 1.0;
					case '0':
					case '1':
					case '2':
					case '3':
					case '4':
						if (count > 0 &&
						    disr_skip(stream, (size_t) count) < 0)
							return (DIS_EOD);
						break;
					default:
						return (DIS_NONDIGIT);
				}
			}
			*dval = negate ? -(*dval) : (*dval);
			return (DIS_SUCCESS);
		case '0':
			return (DIS_LEADZRO);
		case '1':
		case '2':
		case '3':
		case '4':
		case '5':
		case '6':
		case '7':
		case '8':
		case '9':
			unum = c - '0';
			if (count > 1) {
				if (count > dis_umaxd)
					break;
				if (dis_gets(stream, dis_buffer + 1, count - 1) !=
				    count - 1)
					return (DIS_EOD);
				cp = dis_buffer;
				if (count == dis_umaxd) {
					*cp = c;
					if (memcmp(dis_buffer, dis_umax, dis_umaxd) > 0)
						break;
				}
				while (--count) {
					if ((c = *++cp) < '0' || c > '9')
						return (DIS_NONDIGIT);
					unum = unum * 10 + (unsigned) (c - '0');
				}
			}
			return (disrd_(stream, unum, ndigs, nskips, dval, recursv));
		case -1:
			return (DIS_EOD);
		case -2:
			return (DIS_EOF);
		default:
			return (DIS_NONDIGIT);
	}
	*dval = HUGE_VAL;
	return (DIS_OVERFLOW);
}

/**
 * @brief
 *      Gets a Data-is-Strings floating point number from <stream> and converts
 *      it into a float which it returns.  The number from <stream> consists of
 *      two consecutive signed integers.  The first is the coefficient, with its
 *      implied decimal point at the low-order end.  The second is the exponent
 *      as a power of 10.
 *
 * @param[in] stream - socket descriptor
 * @param[out] retval - success/error code
 *
 * @return      double
 * @retval      double value    success
 * @retval      0.0             error
 *
 */

float
disrf(int stream, int *retval)
{
	int expon;
	unsigned uexpon;
	int locret;
	int negate;
	/* following were static vars, so initializing them to defaults */
	unsigned ndigs = 0; /* 3 vars now stack variables for threads */
	unsigned nskips = 0;
	double dval = 0.0;

	assert(retval != NULL);
	assert(stream >= 0);

	dval = 0.0;
	if ((locret = disrd_(stream, 1, &ndigs, &nskips, &dval, 0)) == DIS_SUCCESS) {
		locret = disrsi_(stream, &negate, &uexpon, 1, 0);
		if (locret == DIS_SUCCESS) {
			expon = negate ? nskips - uexpon : nskips + uexpon;
			if (expon + (int) ndigs > FLT_MAX_10_EXP) {
				if (expon + (int) ndigs > FLT_MAX_10_EXP + 1) {
					dval = dval < 0.0 ? -HUGE_VAL : HUGE_VAL;
					locret = DIS_OVERFLOW;
				} else {
					dval *= disp10d_(expon - 1);
					if (dval > FLT_MAX / 10.0) {
						dval = dval < 0.0 ? -HUGE_VAL : HUGE_VAL;
						locret = DIS_OVERFLOW;
					} else
						dval *= 10.0;
				}
			} else {
				if (expon < DBL_MIN_10_EXP) {
					dval *= disp10d_(expon + (int) ndigs);
					dval /= disp10d_((int) ndigs);
				} else
					dval *= disp10d_(expon);
			}
		}
	}
	*retval = locret;
	return (dval);
}