strutil.c

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/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * 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 St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <config.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

/** @cond PRIVATE */
#define LOG_PREFIX "strutil"
/** @endcond */

/**
 * @file
 *
 * Helper functions for handling or converting libsigrok-related strings.
 */

/**
 * @defgroup grp_strutil String utilities
 *
 * Helper functions for handling or converting libsigrok-related strings.
 *
 * @{
 */

/**
 * @private
 *
 * Convert a string representation of a numeric value (base 10) to a long integer. The
 * conversion is strict and will fail if the complete string does not represent
 * a valid long integer. The function sets errno according to the details of the
 * failure.
 *
 * @param str The string representation to convert.
 * @param ret Pointer to long where the result of the conversion will be stored.
 *
 * @retval SR_OK Conversion successful.
 * @retval SR_ERR Failure.
 */
SR_PRIV int sr_atol(const char *str, long *ret)
{
        long tmp;
        char *endptr = NULL;

        errno = 0;
        tmp = strtol(str, &endptr, 10);

        if (!endptr || *endptr || errno) {
                if (!errno)
                        errno = EINVAL;
                return SR_ERR;
        }

        *ret = tmp;
        return SR_OK;
}

/**
 * @private
 *
 * Convert a string representation of a numeric value (base 10) to an integer. The
 * conversion is strict and will fail if the complete string does not represent
 * a valid integer. The function sets errno according to the details of the
 * failure.
 *
 * @param str The string representation to convert.
 * @param ret Pointer to int where the result of the conversion will be stored.
 *
 * @retval SR_OK Conversion successful.
 * @retval SR_ERR Failure.
 */
SR_PRIV int sr_atoi(const char *str, int *ret)
{
        long tmp;

        if (sr_atol(str, &tmp) != SR_OK)
                return SR_ERR;

        if ((int) tmp != tmp) {
                errno = ERANGE;
                return SR_ERR;
        }

        *ret = (int) tmp;
        return SR_OK;
}

/**
 * @private
 *
 * Convert a string representation of a numeric value to a double. The
 * conversion is strict and will fail if the complete string does not represent
 * a valid double. The function sets errno according to the details of the
 * failure.
 *
 * @param str The string representation to convert.
 * @param ret Pointer to double where the result of the conversion will be stored.
 *
 * @retval SR_OK Conversion successful.
 * @retval SR_ERR Failure.
 */
SR_PRIV int sr_atod(const char *str, double *ret)
{
        double tmp;
        char *endptr = NULL;

        errno = 0;
        tmp = strtof(str, &endptr);

        if (!endptr || *endptr || errno) {
                if (!errno)
                        errno = EINVAL;
                return SR_ERR;
        }

        *ret = tmp;
        return SR_OK;
}

/**
 * @private
 *
 * Convert a string representation of a numeric value to a float. The
 * conversion is strict and will fail if the complete string does not represent
 * a valid float. The function sets errno according to the details of the
 * failure.
 *
 * @param str The string representation to convert.
 * @param ret Pointer to float where the result of the conversion will be stored.
 *
 * @retval SR_OK Conversion successful.
 * @retval SR_ERR Failure.
 */
SR_PRIV int sr_atof(const char *str, float *ret)
{
        double tmp;

        if (sr_atod(str, &tmp) != SR_OK)
                return SR_ERR;

        if ((float) tmp != tmp) {
                errno = ERANGE;
                return SR_ERR;
        }

        *ret = (float) tmp;
        return SR_OK;
}

/**
 * @private
 *
 * Convert a string representation of a numeric value to a float. The
 * conversion is strict and will fail if the complete string does not represent
 * a valid float. The function sets errno according to the details of the
 * failure. This version ignores the locale.
 *
 * @param str The string representation to convert.
 * @param ret Pointer to float where the result of the conversion will be stored.
 *
 * @retval SR_OK Conversion successful.
 * @retval SR_ERR Failure.
 */
SR_PRIV int sr_atof_ascii(const char *str, float *ret)
{
        double tmp;
        char *endptr = NULL;

        errno = 0;
        tmp = g_ascii_strtod(str, &endptr);

        if (!endptr || *endptr || errno) {
                if (!errno)
                        errno = EINVAL;
                return SR_ERR;
        }

        /* FIXME This fails unexpectedly. Some other method to safel downcast
         * needs to be found. Checking against FLT_MAX doesn't work as well. */
        /*
        if ((float) tmp != tmp) {
                errno = ERANGE;
                sr_dbg("ERANGEEEE %e != %e", (float) tmp, tmp);
                return SR_ERR;
        }
        */

        *ret = (float) tmp;
        return SR_OK;
}

/**
 * Convert a numeric value value to its "natural" string representation
 * in SI units.
 *
 * E.g. a value of 3000000, with units set to "W", would be converted
 * to "3 MW", 20000 to "20 kW", 31500 would become "31.5 kW".
 *
 * @param x The value to convert.
 * @param unit The unit to append to the string, or NULL if the string
 *             has no units.
 *
 * @return A newly allocated string representation of the samplerate value,
 *         or NULL upon errors. The caller is responsible to g_free() the
 *         memory.
 *
 * @since 0.2.0
 */
SR_API char *sr_si_string_u64(uint64_t x, const char *unit)
{
        uint8_t i;
        uint64_t quot, divisor[] = {
                SR_HZ(1), SR_KHZ(1), SR_MHZ(1), SR_GHZ(1),
                SR_GHZ(1000), SR_GHZ(1000 * 1000), SR_GHZ(1000 * 1000 * 1000),
        };
        const char *p, prefix[] = "\0kMGTPE";
        char fmt[16], fract[20] = "", *f;

        if (!unit)
                unit = "";

        for (i = 0; (quot = x / divisor[i]) >= 1000; i++);

        if (i) {
                sprintf(fmt, ".%%0%d"PRIu64, i * 3);
                f = fract + sprintf(fract, fmt, x % divisor[i]) - 1;

                while (f >= fract && strchr("0.", *f))
                        *f-- = 0;
        }

        p = prefix + i;

        return g_strdup_printf("%" PRIu64 "%s %.1s%s", quot, fract, p, unit);
}

/**
 * Convert a numeric samplerate value to its "natural" string representation.
 *
 * E.g. a value of 3000000 would be converted to "3 MHz", 20000 to "20 kHz",
 * 31500 would become "31.5 kHz".
 *
 * @param samplerate The samplerate in Hz.
 *
 * @return A newly allocated string representation of the samplerate value,
 *         or NULL upon errors. The caller is responsible to g_free() the
 *         memory.
 *
 * @since 0.1.0
 */
SR_API char *sr_samplerate_string(uint64_t samplerate)
{
        return sr_si_string_u64(samplerate, "Hz");
}

/**
 * Convert a numeric frequency value to the "natural" string representation
 * of its period.
 *
 * E.g. a value of 3000000 would be converted to "3 us", 20000 to "50 ms".
 *
 * @param frequency The frequency in Hz.
 *
 * @return A newly allocated string representation of the frequency value,
 *         or NULL upon errors. The caller is responsible to g_free() the
 *         memory.
 *
 * @since 0.1.0
 */
SR_API char *sr_period_string(uint64_t frequency)
{
        char *o;
        int r;

        /* Allocate enough for a uint64_t as string + " ms". */
        o = g_malloc0(30 + 1);

        if (frequency >= SR_GHZ(1))
                r = snprintf(o, 30, "%" PRIu64 " ns", frequency / 1000000000);
        else if (frequency >= SR_MHZ(1))
                r = snprintf(o, 30, "%" PRIu64 " us", frequency / 1000000);
        else if (frequency >= SR_KHZ(1))
                r = snprintf(o, 30, "%" PRIu64 " ms", frequency / 1000);
        else
                r = snprintf(o, 30, "%" PRIu64 " s", frequency);

        if (r < 0) {
                /* Something went wrong... */
                g_free(o);
                return NULL;
        }

        return o;
}

/**
 * Convert a numeric voltage value to the "natural" string representation
 * of its voltage value. The voltage is specified as a rational number's
 * numerator and denominator.
 *
 * E.g. a value of 300000 would be converted to "300mV", 2 to "2V".
 *
 * @param v_p The voltage numerator.
 * @param v_q The voltage denominator.
 *
 * @return A newly allocated string representation of the voltage value,
 *         or NULL upon errors. The caller is responsible to g_free() the
 *         memory.
 *
 * @since 0.2.0
 */
SR_API char *sr_voltage_string(uint64_t v_p, uint64_t v_q)
{
        int r;
        char *o;

        o = g_malloc0(30 + 1);

        if (v_q == 1000)
                r = snprintf(o, 30, "%" PRIu64 "mV", v_p);
        else if (v_q == 1)
                r = snprintf(o, 30, "%" PRIu64 "V", v_p);
        else
                r = snprintf(o, 30, "%gV", (float)v_p / (float)v_q);

        if (r < 0) {
                /* Something went wrong... */
                g_free(o);
                return NULL;
        }

        return o;
}

/**
 * Convert a "natural" string representation of a size value to uint64_t.
 *
 * E.g. a value of "3k" or "3 K" would be converted to 3000, a value
 * of "15M" would be converted to 15000000.
 *
 * Value representations other than decimal (such as hex or octal) are not
 * supported. Only 'k' (kilo), 'm' (mega), 'g' (giga) suffixes are supported.
 * Spaces (but not other whitespace) between value and suffix are allowed.
 *
 * @param sizestring A string containing a (decimal) size value.
 * @param size Pointer to uint64_t which will contain the string's size value.
 *
 * @return SR_OK upon success, SR_ERR upon errors.
 *
 * @since 0.1.0
 */
SR_API int sr_parse_sizestring(const char *sizestring, uint64_t *size)
{
        int multiplier, done;
        double frac_part;
        char *s;

        *size = strtoull(sizestring, &s, 10);
        multiplier = 0;
        frac_part = 0;
        done = FALSE;
        while (s && *s && multiplier == 0 && !done) {
                switch (*s) {
                case ' ':
                        break;
                case '.':
                        frac_part = g_ascii_strtod(s, &s);
                        break;
                case 'k':
                case 'K':
                        multiplier = SR_KHZ(1);
                        break;
                case 'm':
                case 'M':
                        multiplier = SR_MHZ(1);
                        break;
                case 'g':
                case 'G':
                        multiplier = SR_GHZ(1);
                        break;
                default:
                        done = TRUE;
                        s--;
                }
                s++;
        }
        if (multiplier > 0) {
                *size *= multiplier;
                *size += frac_part * multiplier;
        } else
                *size += frac_part;

        if (s && *s && g_ascii_strcasecmp(s, "Hz"))
                return SR_ERR;

        return SR_OK;
}

/**
 * Convert a "natural" string representation of a time value to an
 * uint64_t value in milliseconds.
 *
 * E.g. a value of "3s" or "3 s" would be converted to 3000, a value
 * of "15ms" would be converted to 15.
 *
 * Value representations other than decimal (such as hex or octal) are not
 * supported. Only lower-case "s" and "ms" time suffixes are supported.
 * Spaces (but not other whitespace) between value and suffix are allowed.
 *
 * @param timestring A string containing a (decimal) time value.
 * @return The string's time value as uint64_t, in milliseconds.
 *
 * @todo Add support for "m" (minutes) and others.
 * @todo Add support for picoseconds?
 * @todo Allow both lower-case and upper-case? If no, document it.
 *
 * @since 0.1.0
 */
SR_API uint64_t sr_parse_timestring(const char *timestring)
{
        uint64_t time_msec;
        char *s;

        /* TODO: Error handling, logging. */

        time_msec = strtoull(timestring, &s, 10);
        if (time_msec == 0 && s == timestring)
                return 0;

        if (s && *s) {
                while (*s == ' ')
                        s++;
                if (!strcmp(s, "s"))
                        time_msec *= 1000;
                else if (!strcmp(s, "ms"))
                        ; /* redundant */
                else
                        return 0;
        }

        return time_msec;
}

/** @since 0.1.0 */
SR_API gboolean sr_parse_boolstring(const char *boolstr)
{
        if (!boolstr)
                return FALSE;

        if (!g_ascii_strncasecmp(boolstr, "true", 4) ||
            !g_ascii_strncasecmp(boolstr, "yes", 3) ||
            !g_ascii_strncasecmp(boolstr, "on", 2) ||
            !g_ascii_strncasecmp(boolstr, "1", 1))
                return TRUE;

        return FALSE;
}

/** @since 0.2.0 */
SR_API int sr_parse_period(const char *periodstr, uint64_t *p, uint64_t *q)
{
        char *s;

        *p = strtoull(periodstr, &s, 10);
        if (*p == 0 && s == periodstr)
                /* No digits found. */
                return SR_ERR_ARG;

        if (s && *s) {
                while (*s == ' ')
                        s++;
                if (!strcmp(s, "fs"))
                        *q = 1000000000000000ULL;
                else if (!strcmp(s, "ps"))
                        *q = 1000000000000ULL;
                else if (!strcmp(s, "ns"))
                        *q = 1000000000ULL;
                else if (!strcmp(s, "us"))
                        *q = 1000000;
                else if (!strcmp(s, "ms"))
                        *q = 1000;
                else if (!strcmp(s, "s"))
                        *q = 1;
                else
                        /* Must have a time suffix. */
                        return SR_ERR_ARG;
        }

        return SR_OK;
}

/** @since 0.2.0 */
SR_API int sr_parse_voltage(const char *voltstr, uint64_t *p, uint64_t *q)
{
        char *s;

        *p = strtoull(voltstr, &s, 10);
        if (*p == 0 && s == voltstr)
                /* No digits found. */
                return SR_ERR_ARG;

        if (s && *s) {
                while (*s == ' ')
                        s++;
                if (!g_ascii_strcasecmp(s, "mv"))
                        *q = 1000L;
                else if (!g_ascii_strcasecmp(s, "v"))
                        *q = 1;
                else
                        /* Must have a base suffix. */
                        return SR_ERR_ARG;
        }

        return SR_OK;
}

/** @} */