suffix.c

////////////////////////////////////////////////////////////////////////
//
// Copyright 2014 PMC-Sierra, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////
//
//   Author: Logan Gunthorpe
//
//   Date:   Oct 23 2014
//
//   Description:
//     Functions for dealing with number suffixes
//
////////////////////////////////////////////////////////////////////////

#include "suffix.h"

#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <math.h>

static struct si_suffix {
	double magnitude;
	const char *suffix;
} si_suffixes[] = {
	{1e15, "P"},
	{1e12, "T"},
	{1e9, "G"},
	{1e6, "M"},
	{1e3, "k"},
	{1e0, ""},
	{1e-3, "m"},
	{1e-6, "u"},
	{1e-9, "n"},
	{1e-12, "p"},
	{1e-15, "f"},
	{0}
};

const char *suffix_si_get(double *value)
{
	struct si_suffix *s;

	for (s = si_suffixes; s->magnitude != 0; s++) {
		if (*value >= s->magnitude) {
			*value /= s->magnitude;
			return s->suffix;
		}
	}

	return "";
}

static struct binary_suffix {
	int shift;
	const char *suffix;
} binary_suffixes[] = {
	{50, "Pi"},
	{40, "Ti"},
	{30, "Gi"},
	{20, "Mi"},
	{10, "Ki"},
	{0, ""}
};

const char *suffix_binary_get(long long *value)
{
	struct binary_suffix *s;

	for (s = binary_suffixes; s->shift != 0; s++) {
		if (llabs(*value) >= (1LL << s->shift)) {
			*value =
			    (*value + (1LL << (s->shift - 1))) / (1LL << s->shift);
			return s->suffix;
		}
	}

	return "";
}

const char *suffix_dbinary_get(double *value)
{
	struct binary_suffix *s;

	for (s = binary_suffixes; s->shift != 0; s++) {
		if (fabs(*value) >= (1LL << s->shift)) {
			*value = *value / (1LL << s->shift);
			return s->suffix;
		}
	}

	return "";
}

uint64_t suffix_binary_parse(const char *value)
{
	char *suffix;
	errno = 0;
	uint64_t ret = strtoll(value, &suffix, 0);
	if (errno)
		return 0;

	struct binary_suffix *s;
	for (s = binary_suffixes; s->shift != 0; s++) {
		if (tolower(suffix[0]) == tolower(s->suffix[0])) {
			ret <<= s->shift;
			return ret;
		}
	}

	if (suffix[0] != '\0')
		errno = EINVAL;

	return ret;
}