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hameg-hmo: simplify code by using new sr_rational_parse/_eq API functions

This commit is contained in:
Stefan Brüns 2016-04-23 00:27:35 +02:00 committed by Uwe Hermann
parent 17d5a11c69
commit a53acd7d46
1 changed files with 8 additions and 47 deletions
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55
src/hardware/hameg-hmo/protocol.c
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@ -343,14 +343,8 @@ static int scope_state_get_array_option(struct sr_scpi_dev_inst *scpi,
} }
/** /**
* This function takes a value of the form "2.000E-03", converts it to a * This function takes a value of the form "2.000E-03" and returns the index
* significand / factor pair and returns the index of an array where * of an array where a matching pair was found.
* a matching pair was found.
*
* It's a bit convoluted because of floating-point issues. The value "10.00E-09"
* is parsed by g_ascii_strtod() as 0.000000009999999939, for example.
* Therefore it's easier to break the number up into two strings and handle
* them separately.
* *
* @param value The string to be parsed. * @param value The string to be parsed.
* @param array The array of s/f pairs. * @param array The array of s/f pairs.
@ -362,48 +356,15 @@ static int scope_state_get_array_option(struct sr_scpi_dev_inst *scpi,
static int array_float_get(gchar *value, const uint64_t array[][2], static int array_float_get(gchar *value, const uint64_t array[][2],
int array_len, unsigned int *result) int array_len, unsigned int *result)
{ {
int i, e; struct sr_rational rval;
size_t pos; struct sr_rational aval;
uint64_t f;
float s;
unsigned int s_int;
gchar ss[10], es[10];
memset(ss, 0, sizeof(ss)); if (sr_parse_rational(value, &rval) != SR_OK)
memset(es, 0, sizeof(es));
/* Get index of the separating 'E' character and break up the string. */
pos = strcspn(value, "E");
strncpy(ss, value, pos);
strncpy(es, &(value[pos+1]), 3);
if (sr_atof_ascii(ss, &s) != SR_OK)
return SR_ERR;
if (sr_atoi(es, &e) != SR_OK)
return SR_ERR; return SR_ERR;
/* Transform e.g. 10^-03 to 1000 as the array stores the inverse. */ for (int i = 0; i < array_len; i++) {
f = pow(10, abs(e)); sr_rational_set(&aval, array[i][0], array[i][1]);
if (sr_rational_eq(&rval, &aval)) {
/*
* Adjust the significand/factor pair to make sure
* that f is a multiple of 1000.
*/
while ((int)fmod(log10(f), 3) > 0) {
s *= 10;
if (e < 0)
f *= 10;
else
f /= 10;
}
/* Truncate s to circumvent rounding errors. */
s_int = (unsigned int)s;
for (i = 0; i < array_len; i++) {
if ((s_int == array[i][0]) && (f == array[i][1])) {
*result = i; *result = i;
return SR_OK; return SR_OK;
} }