Constify a lot more items.

[libsigrok.git] / src / analog.c

diff --git a/src/analog.c b/src/analog.c
index 4b7f15e69cd0c21b75946367fdd5dc1e8b8741c6..f26f7a5c2b931e0afa855cd0b106fa401ca7c3cf 100644 (file)
--- a/src/analog.c
+++ b/src/analog.c
@@ -45,7 +45,7 @@
 
 struct unit_mq_string {
        uint64_t value;
-       char *str;
+       const char *str;
 };
 
 /* Please use the same order as in enum sr_unit (libsigrok.h). */
@@ -151,14 +151,35 @@ SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog,
        return SR_OK;
 }
 
+/**
+ * Convert an analog datafeed payload to an array of floats.
+ *
+ * @param[in] analog The analog payload to convert. Must not be NULL.
+ *                   analog->data, analog->meaning, and analog->encoding
+ *                   must not be NULL.
+ * @param[out] outbuf Memory where to store the result. Must not be NULL.
+ *
+ * Sufficient memory for outbuf must have been pre-allocated by the caller,
+ * who is also responsible for freeing it when no longer needed.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR Unsupported encoding.
+ * @retval SR_ERR_ARG Invalid argument.
+ *
+ * @since 0.4.0
+ */
 SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
                float *outbuf)
 {
        float offset;
-       unsigned int b, i;
+       unsigned int b, i, count;
        gboolean bigendian;
-       unsigned int count = (analog->num_samples
-                       * g_slist_length(analog->meaning->channels));
+
+       if (!analog || !(analog->data) || !(analog->meaning)
+                       || !(analog->encoding) || !outbuf)
+               return SR_ERR_ARG;
+
+       count = analog->num_samples * g_slist_length(analog->meaning->channels);
 
 #ifdef WORDS_BIGENDIAN
        bigendian = TRUE;
@@ -199,49 +220,18 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
        return SR_OK;
 }
 
-/*
- * Convert a floating point value to a string, limited to the given
- * number of decimal digits.
- *
- * @param value The value to convert.
- * @param digits Number of digits after the decimal point to print.
- * @param result Pointer to store result.
- *
- * The string is allocated by the function and must be freed by the caller
- * after use by calling g_free().
- *
- * @retval SR_OK
- *
- * @since 0.4.0
- */
-SR_API int sr_analog_float_to_string(float value, unsigned int digits, char **result)
-{
-       unsigned int cnt, i;
-
-       /* This produces at least one too many digits */
-       *result = g_strdup_printf("%.*f", digits, value);
-       for (i = 0, cnt = 0; (*result)[i]; i++) {
-               if (isdigit((*result)[i++]))
-                       cnt++;
-               if (cnt == digits) {
-                       (*result)[i] = 0;
-                       break;
-               }
-       }
-
-       return SR_OK;
-}
-
-/*
+/**
  * Convert the unit/MQ/MQ flags in the analog struct to a string.
  *
- * @param analog Struct containing the unit, MQ and MQ flags.
- * @param result Pointer to store result.
+ * @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.
  *
  * The string is allocated by the function and must be freed by the caller
  * after use by calling g_free().
  *
- * @retval SR_OK
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Invalid argument.
  *
  * @since 0.4.0
  */
@@ -249,7 +239,12 @@ SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
                char **result)
 {
        int i;
-       GString *buf = g_string_new(NULL);
+       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) {
@@ -269,14 +264,20 @@ SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
        return SR_OK;
 }
 
-/*
+/**
  * Set sr_rational r to the given value.
  *
- * @param p Numerator
- * @param q Denominator
+ * @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;
 }