+ if (input_unitsize == sizeof(uint8_t) && input_signed) {
+ int8_t (*reader)(const uint8_t **p);
+ reader = read_i8_inc;
+ while (count--) {
+ value = reader(&data8);
+ value *= scale;
+ value += offset;
+ *outbuf++ = value;
+ }
+ return SR_OK;
+ }
+ if (input_unitsize == sizeof(uint8_t)) {
+ uint8_t (*reader)(const uint8_t **p);
+ reader = read_u8_inc;
+ while (count--) {
+ value = reader(&data8);
+ value *= scale;
+ value += offset;
+ *outbuf++ = value;
+ }
+ return SR_OK;
+ }
+ if (input_unitsize == sizeof(uint16_t) && input_signed) {
+ int16_t (*reader)(const uint8_t **p);
+ if (input_bigendian)
+ reader = read_i16be_inc;
+ else
+ reader = read_i16le_inc;
+ while (count--) {
+ value = reader(&data8);
+ value *= scale;
+ value += offset;
+ *outbuf++ = value;
+ }
+ return SR_OK;
+ }
+ if (input_unitsize == sizeof(uint16_t)) {
+ uint16_t (*reader)(const uint8_t **p);
+ if (input_bigendian)
+ reader = read_u16be_inc;
+ else
+ reader = read_u16le_inc;
+ while (count--) {
+ value = reader(&data8);
+ value *= scale;
+ value += offset;
+ *outbuf++ = value;
+ }
+ return SR_OK;
+ }
+ if (input_unitsize == sizeof(uint32_t) && input_signed) {
+ int32_t (*reader)(const uint8_t **p);
+ if (input_bigendian)
+ reader = read_i32be_inc;
+ else
+ reader = read_i32le_inc;
+ while (count--) {
+ value = reader(&data8);
+ value *= scale;
+ value += offset;
+ *outbuf++ = value;
+ }
+ return SR_OK;
+ }
+ if (input_unitsize == sizeof(uint32_t)) {
+ uint32_t (*reader)(const uint8_t **p);
+ if (input_bigendian)
+ reader = read_u32be_inc;
+ else
+ reader = read_u32le_inc;
+ while (count--) {
+ value = reader(&data8);
+ value *= scale;
+ value += offset;
+ *outbuf++ = value;
+ }
+ return SR_OK;
+ }
+ snprintf(type_text, sizeof(type_text), "%c%zu%s",
+ input_float ? 'f' : input_signed ? 'i' : 'u',
+ input_unitsize * 8, input_bigendian ? "be" : "le");
+ sr_err("Unsupported type for analog-to-float conversion: %s.",
+ type_text);
+ return SR_ERR;
+}
+
+/**
+ * Scale a float value to the appropriate SI prefix.
+ *
+ * @param[in,out] value The float value to convert to appropriate SI prefix.
+ * @param[in,out] digits The number of significant decimal digits in value.
+ *
+ * @return The SI prefix to which value was scaled, as a printable string.
+ *
+ * @since 0.5.0
+ */
+SR_API const char *sr_analog_si_prefix(float *value, int *digits)
+{
+/** @cond PRIVATE */
+#define NEG_PREFIX_COUNT 5 /* number of prefixes below unity */
+#define POS_PREFIX_COUNT (int)(ARRAY_SIZE(prefixes) - NEG_PREFIX_COUNT - 1)
+/** @endcond */
+ static const char *prefixes[] = { "f", "p", "n", "ยต", "m", "", "k", "M", "G", "T" };
+
+ if (!value || !digits || isnan(*value))
+ return prefixes[NEG_PREFIX_COUNT];
+
+ float logval = log10f(fabsf(*value));
+ int prefix = (logval / 3) - (logval < 1);
+
+ if (prefix < -NEG_PREFIX_COUNT)
+ prefix = -NEG_PREFIX_COUNT;
+ if (3 * prefix < -*digits)
+ prefix = (-*digits + 2 * (*digits < 0)) / 3;
+ if (prefix > POS_PREFIX_COUNT)
+ prefix = POS_PREFIX_COUNT;
+
+ *value *= powf(10, -3 * prefix);
+ *digits += 3 * prefix;
+
+ return prefixes[prefix + NEG_PREFIX_COUNT];
+}
+
+/**
+ * Check if a unit "accepts" an SI prefix.
+ *
+ * E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or
+ * SR_UNIT_PERCENTAGE are not.
+ *
+ * @param[in] unit The unit to check for SI prefix "friendliness".
+ *
+ * @return TRUE if the unit "accept" an SI prefix.
+ *
+ * @since 0.5.0
+ */
+SR_API gboolean sr_analog_si_prefix_friendly(enum sr_unit unit)
+{
+ static const enum sr_unit prefix_friendly_units[] = {
+ SR_UNIT_VOLT,
+ SR_UNIT_AMPERE,
+ SR_UNIT_OHM,
+ SR_UNIT_FARAD,
+ SR_UNIT_KELVIN,
+ SR_UNIT_HERTZ,
+ SR_UNIT_SECOND,
+ SR_UNIT_SIEMENS,
+ SR_UNIT_VOLT_AMPERE,
+ SR_UNIT_WATT,
+ SR_UNIT_WATT_HOUR,
+ SR_UNIT_METER_SECOND,
+ SR_UNIT_HENRY,
+ SR_UNIT_GRAM
+ };
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(prefix_friendly_units); i++)
+ if (unit == prefix_friendly_units[i])
+ return TRUE;
+
+ return FALSE;
+}
+
+/**
+ * Convert the unit/MQ/MQ flags in the analog struct to a string.
+ *
+ * The string is allocated by the function and must be freed by the caller
+ * after use by calling g_free().
+ *
+ * @param[in] analog Struct containing the unit, MQ and MQ flags.
+ * Must not be NULL. analog->meaning must not be NULL.
+ * @param[out] result Pointer to store result. Must not be NULL.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Invalid argument.
+ *
+ * @since 0.4.0
+ */
+SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
+ char **result)
+{
+ int i;
+ GString *buf;
+
+ if (!analog || !(analog->meaning) || !result)
+ return SR_ERR_ARG;
+
+ buf = g_string_new(NULL);
+
+ for (i = 0; unit_strings[i].value; i++) {
+ if (analog->meaning->unit == unit_strings[i].value) {
+ g_string_assign(buf, unit_strings[i].str);
+ break;
+ }
+ }
+
+ /* More than one MQ flag may apply. */
+ for (i = 0; mq_strings[i].value; i++)
+ if (analog->meaning->mqflags & mq_strings[i].value)
+ g_string_append(buf, mq_strings[i].str);
+
+ *result = buf->str;
+ g_string_free(buf, FALSE);
+
+ return SR_OK;
+}
+
+/**
+ * Set sr_rational r to the given value.
+ *
+ * @param[out] r Rational number struct to set. Must not be NULL.
+ * @param[in] p Numerator.
+ * @param[in] q Denominator.
+ *
+ * @since 0.4.0
+ */
+SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q)
+{
+ if (!r)
+ return;
+
+ r->p = p;
+ r->q = q;
+}
+
+#ifndef HAVE___INT128_T
+struct sr_int128_t {
+ int64_t high;
+ uint64_t low;
+};
+
+struct sr_uint128_t {
+ uint64_t high;
+ uint64_t low;
+};
+
+static void mult_int64(struct sr_int128_t *res, const int64_t a,
+ const int64_t b)
+{
+ uint64_t t1, t2, t3, t4;
+
+ t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
+ t2 = (UINT32_MAX & a) * (b >> 32);
+ t3 = (a >> 32) * (UINT32_MAX & b);
+ t4 = (a >> 32) * (b >> 32);
+
+ res->low = t1 + (t2 << 32) + (t3 << 32);
+ res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
+ res->high >>= 32;
+ res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
+}
+
+static void mult_uint64(struct sr_uint128_t *res, const uint64_t a,
+ const uint64_t b)
+{
+ uint64_t t1, t2, t3, t4;
+
+ // (x1 + x2) * (y1 + y2) = x1*y1 + x1*y2 + x2*y1 + x2*y2
+ t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
+ t2 = (UINT32_MAX & a) * (b >> 32);
+ t3 = (a >> 32) * (UINT32_MAX & b);
+ t4 = (a >> 32) * (b >> 32);
+
+ res->low = t1 + (t2 << 32) + (t3 << 32);
+ res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
+ res->high >>= 32;
+ res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
+}
+#endif
+
+/**
+ * Compare two sr_rational for equality.
+ *
+ * The values are compared for numerical equality, i.e. 2/10 == 1/5.
+ *
+ * @param[in] a First value.
+ * @param[in] b Second value.
+ *
+ * @retval 1 if both values are equal.
+ * @retval 0 Otherwise.
+ *
+ * @since 0.5.0
+ */
+SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b)
+{
+#ifdef HAVE___INT128_T
+ __int128_t m1, m2;
+
+ /* p1/q1 = p2/q2 <=> p1*q2 = p2*q1 */
+ m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q);
+ m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q);
+
+ return (m1 == m2);
+
+#else
+ struct sr_int128_t m1, m2;
+
+ mult_int64(&m1, a->q, b->p);
+ mult_int64(&m2, a->p, b->q);
+
+ return (m1.high == m2.high) && (m1.low == m2.low);
+#endif
+}
+
+/**
+ * Multiply two sr_rational.
+ *
+ * The resulting nominator/denominator are reduced if the result would not fit
+ * otherwise. If the resulting nominator/denominator are relatively prime,
+ * this may not be possible.
+ *
+ * It is safe to use the same variable for result and input values.
+ *
+ * @param[in] a First value.
+ * @param[in] b Second value.
+ * @param[out] res Result.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Resulting value too large.
+ *
+ * @since 0.5.0
+ */
+SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a,
+ const struct sr_rational *b)
+{
+#ifdef HAVE___INT128_T
+ __int128_t p;
+ __uint128_t q;
+
+ p = (__int128_t)(a->p) * (__int128_t)(b->p);
+ q = (__uint128_t)(a->q) * (__uint128_t)(b->q);
+
+ if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) {
+ while (!((p & 1) || (q & 1))) {
+ p /= 2;
+ q /= 2;