output/csv: Support getting samplerate from meta packets.

output/csv.c

@@ -30,8 +30,8 @@
 struct context {
 	unsigned int num_enabled_channels;
 	uint64_t samplerate;
-	GString *header;
 	char separator;
+	gboolean header_done;
 	int *channel_index;
 };
 
@@ -52,18 +52,14 @@ static int init(struct sr_output *o)
 	struct context *ctx;
 	struct sr_channel *ch;
 	GSList *l;
-	GVariant *gvar;
+	int i;
-	int num_channels, i, j;
-	time_t t;
 
-	if (!o)
+	if (!o || !o->sdi)
-		return SR_ERR_ARG;
-
-	if (!o->sdi)
 		return SR_ERR_ARG;
 
 	ctx = g_malloc0(sizeof(struct context));
 	o->internal = ctx;
+	ctx->separator = ',';
 
 	/* Get the number of channels, and the unitsize. */
 	for (l = o->sdi->channels; l; l = l->next) {
@@ -76,51 +72,78 @@ static int init(struct sr_output *o)
 	}
 	ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
 
-	num_channels = g_slist_length(o->sdi->channels);
+	/* Once more to map the enabled channels. */
-
+	for (i = 0, l = o->sdi->channels; l; l = l->next) {
-	if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
-			&gvar) == SR_OK) {
-		ctx->samplerate = g_variant_get_uint64(gvar);
-		g_variant_unref(gvar);
-	} else
-		ctx->samplerate = 0;
-
-	ctx->separator = ',';
-	ctx->header = g_string_sized_new(512);
-
-	t = time(NULL);
-
-	/* Some metadata */
-	g_string_append_printf(ctx->header, "; CSV, generated by %s on %s",
-			       PACKAGE_STRING, ctime(&t));
-	g_string_append_printf(ctx->header, "; Samplerate: %"PRIu64"\n",
-			       ctx->samplerate);
-
-	/* Columns / channels */
-	g_string_append_printf(ctx->header, "; Channels (%d/%d):",
-			       ctx->num_enabled_channels, num_channels);
-	for (i = 0, j = 0, l = o->sdi->channels; l; l = l->next, i++) {
 		ch = l->data;
 		if (ch->type != SR_CHANNEL_LOGIC)
 			continue;
 		if (!ch->enabled)
 			continue;
-		g_string_append_printf(ctx->header, " %s,", ch->name);
+		ctx->channel_index[i++] = ch->index;
-		/* Remember the enabled channel's index while we're at it. */
+	}
-		ctx->channel_index[j++] = i;
+
+	return SR_OK;
+}
+
+static GString *gen_header(struct sr_output *o)
+{
+	struct context *ctx;
+	struct sr_channel *ch;
+	GVariant *gvar;
+	GString *header;
+	GSList *l;
+	time_t t;
+	int num_channels, i;
+	char *samplerate_s;
+
+	ctx = o->internal;
+	header = g_string_sized_new(512);
+
+	/* Some metadata */
+	t = time(NULL);
+	g_string_append_printf(header, "; CSV, generated by %s on %s",
+			PACKAGE_STRING, ctime(&t));
+
+	/* Columns / channels */
+	num_channels = g_slist_length(o->sdi->channels);
+	g_string_append_printf(header, "; Channels (%d/%d):",
+			ctx->num_enabled_channels, num_channels);
+	for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
+		ch = l->data;
+		if (ch->type != SR_CHANNEL_LOGIC)
+			continue;
+		if (!ch->enabled)
+			continue;
+		g_string_append_printf(header, " %s,", ch->name);
 	}
 	if (o->sdi->channels)
 		/* Drop last separator. */
-		g_string_truncate(ctx->header, ctx->header->len - 1);
+		g_string_truncate(header, header->len - 1);
-	g_string_append_printf(ctx->header, "\n");
+	g_string_append_printf(header, "\n");
 
-	return SR_OK;
+	if (ctx->samplerate == 0) {
+		if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
+				&gvar) == SR_OK) {
+			ctx->samplerate = g_variant_get_uint64(gvar);
+			g_variant_unref(gvar);
+		}
+	}
+	if (ctx->samplerate != 0) {
+		samplerate_s = sr_samplerate_string(ctx->samplerate);
+		g_string_append_printf(header, "; Samplerate: %s\n", samplerate_s);
+		g_free(samplerate_s);
+	}
+
+	return header;
 }
 
 static int receive(struct sr_output *o, const struct sr_datafeed_packet *packet,
 		GString **out)
 {
+	const struct sr_datafeed_meta *meta;
 	const struct sr_datafeed_logic *logic;
+	const struct sr_config *src;
+	GSList *l;
 	struct context *ctx;
 	int idx;
 	uint64_t i, j;
@@ -133,15 +156,20 @@ static int receive(struct sr_output *o, const struct sr_datafeed_packet *packet,
 		return SR_ERR_ARG;
 
 	switch (packet->type) {
+	case SR_DF_META:
+		meta = packet->payload;
+		for (l = meta->config; l; l = l->next) {
+			src = l->data;
+			if (src->key != SR_CONF_SAMPLERATE)
+				continue;
+			ctx->samplerate = g_variant_get_uint64(src->data);
+		}
+		break;
 	case SR_DF_LOGIC:
 		logic = packet->payload;
-		if (ctx->header) {
+		if (!ctx->header_done) {
-			/*
+			*out = gen_header(o);
-			 * First data packet: prime the output with the
+			ctx->header_done = TRUE;
-			 * previously prepared header.
-			 */
-			*out = ctx->header;
-			ctx->header = NULL;
 		} else {
 			*out = g_string_sized_new(512);
 		}
@@ -175,8 +203,6 @@ static int cleanup(struct sr_output *o)
 
 	if (o->internal) {
 		ctx = o->internal;
-		if (ctx->header)
-			g_string_free(ctx->header, TRUE);
 		g_free(ctx->channel_index);
 		g_free(o->internal);
 		o->internal = NULL;