pybootchartgui/draw.py: skip empty CPU and disk usage charts

The only real change is the addition of two if checks that skips the
corresponding drawing code when there is no data.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

1 files changed, 50 insertions, 48 deletions

diff --git a/scripts/pybootchartgui/pybootchartgui/draw.py b/scripts/pybootchartgui/pybootchartgui/draw.py
index bddd8048c9..ec5dd333a1 100644
--- a/scripts/pybootchartgui/pybootchartgui/draw.py
+++ b/scripts/pybootchartgui/pybootchartgui/draw.py
@@ -344,56 +344,58 @@ def render_charts(ctx, options, clip, trace, curr_y, w, h, sec_w):
 	proc_tree = options.proc_tree(trace)
 
 	# render bar legend
-	ctx.set_font_size(LEGEND_FONT_SIZE)
-
-	draw_legend_box(ctx, "CPU (user+sys)", CPU_COLOR, off_x, curr_y+20, leg_s)
-	draw_legend_box(ctx, "I/O (wait)", IO_COLOR, off_x + 120, curr_y+20, leg_s)
-
-	# render I/O wait
-	chart_rect = (off_x, curr_y+30, w, bar_h)
-	if clip_visible (clip, chart_rect):
-		draw_box_ticks (ctx, chart_rect, sec_w)
-		draw_annotations (ctx, proc_tree, trace.times, chart_rect)
-		draw_chart (ctx, IO_COLOR, True, chart_rect, \
-			    [(sample.time, sample.user + sample.sys + sample.io) for sample in trace.cpu_stats], \
-			    proc_tree, None)
-		# render CPU load
-		draw_chart (ctx, CPU_COLOR, True, chart_rect, \
-			    [(sample.time, sample.user + sample.sys) for sample in trace.cpu_stats], \
-			    proc_tree, None)
-
-	curr_y = curr_y + 30 + bar_h
+	if trace.cpu_stats:
+		ctx.set_font_size(LEGEND_FONT_SIZE)
+
+		draw_legend_box(ctx, "CPU (user+sys)", CPU_COLOR, off_x, curr_y+20, leg_s)
+		draw_legend_box(ctx, "I/O (wait)", IO_COLOR, off_x + 120, curr_y+20, leg_s)
+
+		# render I/O wait
+		chart_rect = (off_x, curr_y+30, w, bar_h)
+		if clip_visible (clip, chart_rect):
+			draw_box_ticks (ctx, chart_rect, sec_w)
+			draw_annotations (ctx, proc_tree, trace.times, chart_rect)
+			draw_chart (ctx, IO_COLOR, True, chart_rect, \
+				    [(sample.time, sample.user + sample.sys + sample.io) for sample in trace.cpu_stats], \
+				    proc_tree, None)
+			# render CPU load
+			draw_chart (ctx, CPU_COLOR, True, chart_rect, \
+				    [(sample.time, sample.user + sample.sys) for sample in trace.cpu_stats], \
+				    proc_tree, None)
+
+		curr_y = curr_y + 30 + bar_h
 
 	# render second chart
-	draw_legend_line(ctx, "Disk throughput", DISK_TPUT_COLOR, off_x, curr_y+20, leg_s)
-	draw_legend_box(ctx, "Disk utilization", IO_COLOR, off_x + 120, curr_y+20, leg_s)
-
-        # render I/O utilization
-	chart_rect = (off_x, curr_y+30, w, bar_h)
-	if clip_visible (clip, chart_rect):
-		draw_box_ticks (ctx, chart_rect, sec_w)
-		draw_annotations (ctx, proc_tree, trace.times, chart_rect)
-		draw_chart (ctx, IO_COLOR, True, chart_rect, \
-			    [(sample.time, sample.util) for sample in trace.disk_stats], \
-			    proc_tree, None)
-
-	# render disk throughput
-	max_sample = max (trace.disk_stats, key = lambda s: s.tput)
-	if clip_visible (clip, chart_rect):
-		draw_chart (ctx, DISK_TPUT_COLOR, False, chart_rect, \
-			    [(sample.time, sample.tput) for sample in trace.disk_stats], \
-			    proc_tree, None)
-
-	pos_x = off_x + ((max_sample.time - proc_tree.start_time) * w / proc_tree.duration)
-
-	shift_x, shift_y = -20, 20
-	if (pos_x < off_x + 245):
-		shift_x, shift_y = 5, 40
-
-	label = "%dMB/s" % round ((max_sample.tput) / 1024.0)
-	draw_text (ctx, label, DISK_TPUT_COLOR, pos_x + shift_x, curr_y + shift_y)
-
-	curr_y = curr_y + 30 + bar_h
+	if trace.disk_stats:
+		draw_legend_line(ctx, "Disk throughput", DISK_TPUT_COLOR, off_x, curr_y+20, leg_s)
+		draw_legend_box(ctx, "Disk utilization", IO_COLOR, off_x + 120, curr_y+20, leg_s)
+
+		# render I/O utilization
+		chart_rect = (off_x, curr_y+30, w, bar_h)
+		if clip_visible (clip, chart_rect):
+			draw_box_ticks (ctx, chart_rect, sec_w)
+			draw_annotations (ctx, proc_tree, trace.times, chart_rect)
+			draw_chart (ctx, IO_COLOR, True, chart_rect, \
+				    [(sample.time, sample.util) for sample in trace.disk_stats], \
+				    proc_tree, None)
+
+		# render disk throughput
+		max_sample = max (trace.disk_stats, key = lambda s: s.tput)
+		if clip_visible (clip, chart_rect):
+			draw_chart (ctx, DISK_TPUT_COLOR, False, chart_rect, \
+				    [(sample.time, sample.tput) for sample in trace.disk_stats], \
+				    proc_tree, None)
+
+		pos_x = off_x + ((max_sample.time - proc_tree.start_time) * w / proc_tree.duration)
+
+		shift_x, shift_y = -20, 20
+		if (pos_x < off_x + 245):
+			shift_x, shift_y = 5, 40
+
+		label = "%dMB/s" % round ((max_sample.tput) / 1024.0)
+		draw_text (ctx, label, DISK_TPUT_COLOR, pos_x + shift_x, curr_y + shift_y)
+
+		curr_y = curr_y + 30 + bar_h
 
 	# render mem usage
 	chart_rect = (off_x, curr_y+30, w, meminfo_bar_h)