output/analog: Add option to restrict number of decimal digits printed.

This is a feature restricted to the new analog struct.

By default all the digits available in the encoding struct are printed.
The option "digits", when set to "spec", changes this to print the
number given in the spec struct.

src/output/analog.c

@@ -29,6 +29,12 @@
 struct context {
 	int num_enabled_channels;
 	GPtrArray *channellist;
+	int digits;
+};
+
+enum {
+	DIGITS_ALL,
+	DIGITS_SPEC,
 };
 
 static int init(struct sr_output *o, GHashTable *options)
@@ -36,17 +42,17 @@ static int init(struct sr_output *o, GHashTable *options)
 	struct context *ctx;
 	struct sr_channel *ch;
 	GSList *l;
-
+	const char *s;
-	(void)options;
 
 	if (!o || !o->sdi)
 		return SR_ERR_ARG;
 
-	if (!(ctx = g_try_malloc0(sizeof(struct context)))) {
+	o->priv = ctx = g_try_malloc0(sizeof(struct context));
-		sr_err("Output module context malloc failed.");
+	s = g_variant_get_string(g_hash_table_lookup(options, "digits"), NULL);
-		return SR_ERR_MALLOC;
+	if (!strcmp(s, "all"))
-	}
+		ctx->digits = DIGITS_ALL;
-	o->priv = ctx;
+	else
+		ctx->digits = DIGITS_SPEC;
 
 	/* Get the number of channels and their names. */
 	ctx->channellist = g_ptr_array_new();
@@ -227,17 +233,20 @@ static void fancyprint(int unit, int mqflags, float value, GString *out)
 static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
 		GString **out)
 {
+	struct context *ctx;
 	const struct sr_datafeed_analog *analog;
 	const struct sr_datafeed_analog2 *analog2;
 	struct sr_channel *ch;
 	GSList *l;
 	float *fdata;
 	unsigned int i;
-	int num_channels, c, ret, si;
+	int num_channels, c, ret, si, digits;
+	char number[32], suffix[32];
 
 	*out = NULL;
 	if (!o || !o->sdi)
 		return SR_ERR_ARG;
+	ctx = o->priv;
 
 	switch (packet->type) {
 	case SR_DF_FRAME_BEGIN:
@@ -267,13 +276,27 @@ static int receive(const struct sr_output *o, const struct sr_datafeed_packet *p
 		if ((ret = sr_analog_to_float(analog2, fdata)) != SR_OK)
 			return ret;
 		*out = g_string_sized_new(512);
+		if (analog2->encoding->is_digits_decimal) {
+			if (ctx->digits == DIGITS_ALL)
+				digits = analog2->encoding->digits;
+			else
+				digits = analog2->spec->spec_digits;
+		} else {
+			/* TODO we don't know how to print by number of bits yet. */
+			digits = 6;
+		}
+		sr_analog_unit_to_string(analog2, suffix, sizeof(suffix));
 		num_channels = g_slist_length(analog2->meaning->channels);
 		for (i = 0; i < analog2->num_samples; i++) {
 			for (l = analog2->meaning->channels, c = 0; l; l = l->next, c++) {
 				ch = l->data;
 				g_string_append_printf(*out, "%s: ", ch->name);
-				fancyprint(analog2->meaning->unit, analog2->meaning->mqflags,
+				sr_analog_float_to_string(fdata[i * num_channels + c],
-						fdata[i * num_channels + c], *out);
+						digits, number, sizeof(number));
+				g_string_append(*out, number);
+				g_string_append(*out, " ");
+				g_string_append(*out, suffix);
+				g_string_append(*out, "\n");
 			}
 		}
 		break;
@@ -297,11 +320,29 @@ static int cleanup(struct sr_output *o)
 	return SR_OK;
 }
 
+static struct sr_option options[] = {
+	{ "digits", "Digits", "Digits to show", NULL, NULL },
+	ALL_ZERO
+};
+
+static const struct sr_option *get_options(void)
+{
+	if (!options[0].def) {
+		options[0].def = g_variant_ref_sink(g_variant_new_string("all"));
+		options[0].values = g_slist_append(options[0].values,
+				g_variant_ref_sink(g_variant_new_string("all")));
+		options[0].values = g_slist_append(options[0].values,
+				g_variant_ref_sink(g_variant_new_string("spec")));
+	}
+
+	return options;
+}
+
 SR_PRIV struct sr_output_module output_analog = {
 	.id = "analog",
 	.name = "Analog",
 	.desc = "Analog data and types",
-	.options = NULL,
+	.options = get_options,
 	.init = init,
 	.receive = receive,
 	.cleanup = cleanup