curses: Add ability to reset statistics

Press 'r' in curses mode to reset a statistic counter to
start counting from 0 again. This does NOT reset the
counter from the source itself but merely emulates a
counter reset. If you restart bmon, the counter will be
back to its total value.

Signed-off-by: Thomas Graf <tgraf@suug.ch>

include/bmon/attr.h

@@ -42,6 +42,9 @@ struct rate
 	/* Value of r_current at last read */
 	uint64_t		r_prev;
 
+	/* Reset value to substract to emulate statistics reset */
+	uint64_t		r_reset;
+
 	/* Rate per second calculated every `rate_interval' */
 	float			r_rate;
 
@@ -49,6 +52,8 @@ struct rate
 	timestamp_t		r_last_calc;
 };
 
+extern uint64_t			rate_get_total(struct rate *);
+
 enum {
 	ATTR_TYPE_UNSPEC,
 	ATTR_TYPE_COUNTER,
@@ -134,5 +139,6 @@ extern struct attr *		attr_select_prev(void);
 extern struct attr *		attr_current(void);
 
 extern void			attr_start_collecting_history(struct attr *);
+extern void			attr_reset_counter(struct attr *a);
 
 #endif

src/attr.c

@@ -524,6 +524,11 @@ static float __calc_usage(double rate, uint64_t max)
 	return 100.0f / ((double) max / (rate * cfg_rate_interval));
 }
 
+uint64_t rate_get_total(struct rate *r)
+{
+	return r->r_total - r->r_reset;
+}
+
 void attr_calc_usage(struct attr *a, float *rx, float *tx,
 		     uint64_t rxmax, uint64_t txmax)
 {
@@ -626,6 +631,14 @@ void attr_notify_update(struct attr *a, timestamp_t *ts)
 	}
 }
 
+void attr_reset_counter(struct attr *a)
+{
+	if (a->a_def->ad_type == ATTR_TYPE_COUNTER) {
+		a->a_rx_rate.r_reset = a->a_rx_rate.r_total;
+		a->a_tx_rate.r_reset = a->a_tx_rate.r_total;
+	}
+}
+
 static void __exit attr_exit(void)
 {
 	struct attr_def *ad, *n;

src/out_ascii.c

@@ -101,10 +101,10 @@ static void print_attr_detail(struct element *e, struct attr *a, void *arg)
 	char *rx_u, *tx_u;
 	int rxprec, txprec;
 
-	double rx = unit_value2str(a->a_rx_rate.r_total,
+	double rx = unit_value2str(rate_get_total(&a->a_rx_rate),
 				   a->a_def->ad_unit,
 				   &rx_u, &rxprec);
-	double tx = unit_value2str(a->a_tx_rate.r_total,
+	double tx = unit_value2str(rate_get_total(&a->a_tx_rate),
 				   a->a_def->ad_unit,
 				   &tx_u, &txprec);
 

src/out_curses.c

@@ -241,10 +241,10 @@ static void draw_attr_detail(struct element *e, struct attr *a, void *arg)
 	int rxprec, txprec, ncol;
 	struct detail_arg *da = arg;
 
-	double rx = unit_value2str(a->a_rx_rate.r_total,
+	double rx = unit_value2str(rate_get_total(&a->a_rx_rate),
 				   a->a_def->ad_unit,
 				   &rx_u, &rxprec);
-	double tx = unit_value2str(a->a_tx_rate.r_total,
+	double tx = unit_value2str(rate_get_total(&a->a_tx_rate),
 				   a->a_def->ad_unit,
 				   &tx_u, &txprec);
 
@@ -392,6 +392,7 @@ static void draw_help(void)
 	mvaddnstr(y+15, x+3, "H             Start recording history data", -1);
 	mvaddnstr(y+16, x+3, "TAB           Switch time unit of graph", -1);
 	mvaddnstr(y+17, x+3, "<, >          Change number of graphs", -1);
+	mvaddnstr(y+18, x+3, "r             Reset counter of element", -1);
 
 	attroff(A_STANDOUT);
 
@@ -1079,6 +1080,16 @@ out:
 	refresh();
 }
 
+static void __reset_attr_counter(struct element *e, struct attr *a, void *arg)
+{
+	attr_reset_counter(a);
+}
+
+static void reset_counters(void)
+{
+	element_foreach_attr(current_element, __reset_attr_counter, NULL);
+}
+
 static int handle_input(int ch)
 {
 	switch (ch) 
@@ -1198,6 +1209,10 @@ static int handle_input(int ch)
 		case '\t':
 			history_select_next();
 			return 1;
+
+		case 'r':
+			reset_counters();
+			return 1;
 	}
 
 	return 0;

src/out_format.c

@@ -123,10 +123,10 @@ static char *get_token(struct element_group *g, struct element *e,
 			goto out;
 
 		if (!strncasecmp(type, "rx:", 3)) {
-			snprintf(buf, len, "%" PRIu64, a->a_rx_rate.r_total);
+			snprintf(buf, len, "%" PRIu64, rate_get_total(&a->a_rx_rate));
 			return buf;
 		} else if (!strncasecmp(type, "tx:", 3)) {
-			snprintf(buf, len, "%" PRIu64, a->a_tx_rate.r_total);
+			snprintf(buf, len, "%" PRIu64, rate_get_total(&a->a_tx_rate));
 			return buf;
 		} else if (!strncasecmp(type, "rxrate:", 7)) {
 			snprintf(buf, len, "%.2f", a->a_rx_rate.r_rate);