Store the calculated percentage as a double rather than an int, so the granular progress bar is still granular on wide displays.

docs/NEWS.md

@@ -3,6 +3,7 @@
  * *feature:* new **--bar-style** option to change the default bar style ([#15](https://codeberg.org/a-j-wood/pv/issues/15))
  * *feature:* new bar formats "**%{bar-plain}**", "**%{bar-block}**", "**%{bar-granular}**", "**%{bar-shaded}**" ([#15](https://codeberg.org/a-j-wood/pv/issues/15))
  * *feature:* allow decimal values such as "1.5G" with "**--size**", "**--rate-limit**", "**--buffer-size**", and "**error-skip-block**" ([#35](https://codeberg.org/a-j-wood/pv/issues/35))
+ * *cleanup:* track transfer percentage as a floating point value for better precision (and rounding)
  * *docs:* simplified the synopsis section of the manual
 
 ### 1.9.15 - 8 December 2024

src/include/pv-internal.h

@@ -310,7 +310,7 @@ struct pvstate_s {
 
 		off_t prev_transferred;		 /* total amount transferred when called last time */
 
-		int percentage;			 /* transfer percentage completion */
+		double percentage;		 /* transfer percentage completion */
 	} calc;
 
 	/********************

src/include/pv.h

@@ -86,11 +86,11 @@ extern unsigned int pv_getnum_count(const char *, bool);
 extern bool pv_getnum_check(const char *, pv_numtype);
 
 /*
- * Return an integer representing the first amount as a percentage of the
+ * Return a value representing the first amount as a percentage of the
  * second total, i.e. 100*amount/total.  If the second value, the total, is
  * zero or less, return 0.
  */
-extern int pv_percentage(off_t, const off_t);
+extern double pv_percentage(off_t, const off_t);
 
 /*
  * String handling wrappers.

src/pv/calc.c

@@ -164,8 +164,8 @@ void pv_calculate_transfer_rate(pvstate_t state, bool final)
 	}
 
 	/* Ensure the percentage is never negative or huge. */
-	if (state->calc.percentage < 0)
-		state->calc.percentage = 0;
-	if (state->calc.percentage > 100000)
-		state->calc.percentage = 100000;
+	if (state->calc.percentage < 0.0)
+		state->calc.percentage = 0.0;
+	if (state->calc.percentage > 100000.0)
+		state->calc.percentage = 100000.0;
 }

src/pv/display.c

@@ -515,7 +515,7 @@ static bool pv__format_numeric(pvstate_t state, pvdisplay_t display)
 	msg_percent[0] = '\0';
 	if (show_percentage) {
 		(void) pv_snprintf(msg_percent, sizeof(msg_percent),
-				   "%s%d", first_item ? "" : " ", state->calc.percentage);
+				   "%s%.0f", first_item ? "" : " ", state->calc.percentage);
 		first_item = false;
 	}
 

src/pv/format/bufferpercent.c

@@ -24,12 +24,12 @@ size_t pv_formatter_buffer_percent(pvformatter_args_t args)
 		return 0;
 
 	if (args->state->transfer.buffer_size > 0) {
-		int pct_used = pv_percentage((off_t)
-					     (args->state->transfer.read_position -
-					      args->state->transfer.write_position),
-					     (off_t)
-					     (args->state->transfer.buffer_size));
-		(void) pv_snprintf(content, sizeof(content), "{%3d%%}", pct_used);
+		double pct_used = pv_percentage((off_t)
+						(args->state->transfer.read_position -
+						 args->state->transfer.write_position),
+						(off_t)
+						(args->state->transfer.buffer_size));
+		(void) pv_snprintf(content, sizeof(content), "{%3.0f%%}", pct_used);
 	}
 #ifdef HAVE_SPLICE
 	if (args->state->transfer.splice_used)

src/pv/format/progressbar.c

@@ -132,8 +132,8 @@ static size_t pv_formatter_progress_knownsize(pvformatter_args_t args, char *buf
 	if (has_tip && filled_bar_width > 0)
 		filled_bar_width -= style->tip.width;
 
-	debug("width=%d bar_area_width=%d filled_bar_width=%d after_bar_width=%d", args->segment->width, bar_area_width,
-	      filled_bar_width, after_bar_width);
+	debug("percentage=%.2f width=%d bar_area_width=%d filled_bar_width=%d after_bar_width=%d", bar_percentage,
+	      args->segment->width, bar_area_width, filled_bar_width, after_bar_width);
 
 	buffer_offset = 0;
 

src/pv/number.c

@@ -285,16 +285,20 @@ bool pv_getnum_check(const char *str, pv_numtype type)
 
 
 /*
- * Return an integer representing "amount" as a percentage of "total", i.e.
+ * Return a value representing "amount" as a percentage of "total", i.e.
  * 100*amount/total.  If "total" is zero or less, return 0.
  */
-int pv_percentage(off_t amount, const off_t total)
+double pv_percentage(off_t amount, const off_t total)
 {
+	double amount_as_double;
+
 	if (total < 1)
-		return 0;
+		return 0.0;
 
-	amount *= 100;
-	amount /= total;
+	amount_as_double = (double) amount;
 
-	return (int) amount;
+	amount_as_double *= 100.0;
+	amount_as_double /= (double) total;
+
+	return amount_as_double;
 }

src/pv/state.c

@@ -80,7 +80,7 @@ void pv_state_reset(pvstate_t state)
 	state->calc.ratesquared_sum = 0.0;
 	state->calc.measurements_taken = 0;
 	state->calc.prev_transferred = 0;
-	state->calc.percentage = 0;
+	state->calc.percentage = 0.0;
 	state->calc.history_first = state->calc.history_last = 0;
 	if (NULL != state->calc.history) {
 		state->calc.history[0].elapsed_sec = 0.0;