perf ui progress: Add ui specific init function

Adding ui specific init function allowing to setup the progress bar
width based on current screen scales.

Adding TUI init function to get more grained update of the progress bar.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170908120510.22515-4-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/progress.c

@@ -34,6 +34,8 @@ void ui_progress__init(struct ui_progress *p, u64 total, const char *title)
 	p->total = total;
 	p->title = title;
 
+	if (ui_progress__ops->init)
+		ui_progress__ops->init(p);
 }
 
 void ui_progress__finish(void)

tools/perf/ui/progress.h

@@ -14,6 +14,7 @@ void ui_progress__init(struct ui_progress *p, u64 total, const char *title);
 void ui_progress__update(struct ui_progress *p, u64 adv);
 
 struct ui_progress_ops {
+	void (*init)(struct ui_progress *p);
 	void (*update)(struct ui_progress *p);
 	void (*finish)(void);
 };

tools/perf/ui/tui/progress.c

@@ -5,6 +5,11 @@
 #include "tui.h"
 #include "../browser.h"
 
+static void __tui_progress__init(struct ui_progress *p)
+{
+	p->next = p->step = p->total / (SLtt_Screen_Cols - 2) ?: 1;
+}
+
 static void tui_progress__update(struct ui_progress *p)
 {
 	int bar, y;
@@ -49,8 +54,8 @@ static void tui_progress__finish(void)
 	pthread_mutex_unlock(&ui__lock);
 }
 
-static struct ui_progress_ops tui_progress__ops =
-{
+static struct ui_progress_ops tui_progress__ops = {
+	.init   = __tui_progress__init,
 	.update = tui_progress__update,
 	.finish = tui_progress__finish,
 };