[taskbar] truncate output at terminal size

Summary: This prevents the task bar from scrolling the terminal in case the lines are not wide enough. Instead it will truncate the display to the terminal size. Also display only the most useful info when there is not much room.

Reviewed By: jeremydubreil

Differential Revision: D8590580

fbshipit-source-id: e12d5c9

infer/src/base/TaskBar.ml

@@ -6,17 +6,29 @@
  *)
 
 open! IStd
+module F = Format
 module L = Logging
 
-(** arbitrary *)
-let progress_bar_total_size_default = 60
+(** {2 arbitrary constants } *)
+
+(** max size for the top bar of the multiline task bar *)
+let top_bar_size_default = 100
+
+(** do not attempt to draw the top bar of the multiline task bar unless it can be at least this big *)
+let min_acceptable_progress_bar = 10
+
+(** infer rulez *)
+let job_prefix = "⊢ "
+
+(** {2 Task bar} *)
 
 (** state of a multi-line task bar *)
 type multiline_info =
   { jobs: int  (** number of jobs running in parallel *)
-  ; statuses: string Array.t
+  ; jobs_statuses: string Array.t
         (** array of size [jobs] with a description of what the process is doing *)
-  ; start_times: Mtime.t Array.t  (** array of size [jobs] of start times for each process *)
+  ; jobs_start_times: Mtime.t Array.t  (** array of size [jobs] of start times for each process *)
+  ; start_time: Mtime_clock.counter  (** time since the creation of the task bar *)
   ; mutable tasks_done: int
   ; mutable tasks_total: int }
 
@@ -32,31 +44,53 @@ let rec pp_n c oc n =
     pp_n c oc (n - 1) )
 
 
-let progress_bar_total_size =
-  lazy
-    ( if Unix.(isatty stdin) then
-        let term_width, _ = ANSITerminal.size () in
-        min progress_bar_total_size_default term_width
-    else progress_bar_total_size_default )
-
-
-let draw_progress_bar ~total ~don =
-  let lazy progress_bar_total_size = progress_bar_total_size in
-  let bar_done_size = don * progress_bar_total_size / total in
+let draw_top_bar ~term_width ~total ~finished ~elapsed =
   let tasks_total_string = Int.to_string total in
   let bar_tasks_num_size = String.length tasks_total_string in
-  Printf.eprintf "%*d/%s [%a%a] %d%%\n" bar_tasks_num_size don tasks_total_string (pp_n '#')
+  let elapsed_string = F.asprintf "%a" Mtime.Span.pp elapsed in
+  (* format string for the full top bar, assuming there is enough room, and number of characters
+     taken by the portion of the top bar that is not the progress bar itself *)
+  let top_bar_fmt, size_around_progress_bar =
+    (* add pairs of a partial format string and its expected size *)
+    let ( ++ ) (f1, l1) (f2, l2) = (f1 ^^ f2, l1 + l2) in
+    let ( +++ ) (f1, l1) f2 = (f1 ^^ f2, l1 + (string_of_format f2 |> String.length)) in
+    ("%*d", bar_tasks_num_size (* finished *)) +++ "/" ++ ("%s", bar_tasks_num_size (* total *))
+    +++ " [" ++ ("%a%a", 0 (* progress bar *)) +++ "] "
+    ++ ("%d%%", 3 (* "xx%", even though sometimes it's just "x%" *)) +++ " "
+    ++ ( "%s"
+       , max (String.length elapsed_string) 9
+         (* leave some room for elapsed_string to avoid flicker. 9 characters is "XXhXXmXXs" so it
+            gives some reasonable margin. *)
+       )
+  in
+  let top_bar_size = min term_width top_bar_size_default in
+  let progress_bar_size = top_bar_size - size_around_progress_bar in
+  ( if progress_bar_size < min_acceptable_progress_bar then
+      let s = Printf.sprintf "%d/%s %s" finished tasks_total_string elapsed_string in
+      Out_channel.output_string stderr (String.prefix s term_width)
+  else
+    let bar_done_size = finished * progress_bar_size / total in
+    Printf.eprintf top_bar_fmt bar_tasks_num_size finished tasks_total_string (pp_n '#')
       bar_done_size (pp_n '.')
-    (progress_bar_total_size - bar_done_size)
-    (don * 100 / total)
+      (progress_bar_size - bar_done_size)
+      (finished * 100 / total)
+      elapsed_string ) ;
+  ANSITerminal.erase Eol ;
+  Out_channel.output_string stderr "\n"
 
 
-let draw_job_status ~draw_time t ~status ~t0 =
-  ANSITerminal.(prerr_string [Bold; magenta]) "⊢ " ;
-  ( if draw_time then
+let draw_job_status ~term_width ~draw_time t ~status ~t0 =
+  let length = ref 0 in
+  let job_prefix_size = String.length job_prefix in
+  if term_width > job_prefix_size then (
+    ANSITerminal.(prerr_string [Bold; magenta]) job_prefix ;
+    length := !length + job_prefix_size ) ;
+  let time_width = 4 + (* actually drawing the time *) 3 (* "[] " *) in
+  if draw_time && term_width > time_width + job_prefix_size then (
     let time_running = Mtime.span t0 t |> Mtime.Span.to_s in
-      Printf.eprintf "[%4.1fs] " time_running ) ;
-  Out_channel.output_string stderr status ;
+    Printf.eprintf "[%4.1fs] " time_running ;
+    length := !length + time_width ) ;
+  String.prefix status (term_width - !length) |> Out_channel.output_string stderr ;
   ANSITerminal.erase Eol ;
   Out_channel.output_string stderr "\n"
 
@@ -64,17 +98,19 @@ let draw_job_status ~draw_time t ~status ~t0 =
 let refresh_multiline task_bar =
   ANSITerminal.move_bol () ;
   let should_draw_progress_bar = task_bar.tasks_total > 0 && task_bar.tasks_done >= 0 in
+  let term_width, _ = ANSITerminal.size () in
   if should_draw_progress_bar then
-    draw_progress_bar ~total:task_bar.tasks_total ~don:task_bar.tasks_done ;
-  let t = Mtime_clock.now () in
+    draw_top_bar ~term_width ~total:task_bar.tasks_total ~finished:task_bar.tasks_done
+      ~elapsed:(Mtime_clock.count task_bar.start_time) ;
   let draw_time =
     (* When there is only 1 job we are careful not to spawn processes needlessly, thus there is no
        one to refresh the task bar while the analysis is running and the time displayed will always
        be 0. Avoid confusion by not displaying the time in that case. *)
     task_bar.jobs > 1
   in
-  Array.iter2_exn task_bar.statuses task_bar.start_times ~f:(fun status t0 ->
-      draw_job_status ~draw_time t ~status ~t0 ) ;
+  let now = Mtime_clock.now () in
+  Array.iter2_exn task_bar.jobs_statuses task_bar.jobs_start_times ~f:(fun status t0 ->
+      draw_job_status ~term_width ~draw_time now ~status ~t0 ) ;
   let lines_printed =
     let progress_bar = if should_draw_progress_bar then 1 else 0 in
     task_bar.jobs + progress_bar
@@ -90,8 +126,9 @@ let create_multiline ~jobs =
     let t0 = Mtime_clock.now () in
     let task_bar =
       { jobs
-      ; statuses= Array.create ~len:jobs "idle"
-      ; start_times= Array.create ~len:jobs t0
+      ; jobs_statuses= Array.create ~len:jobs "idle"
+      ; jobs_start_times= Array.create ~len:jobs t0
+      ; start_time= Mtime_clock.counter ()
       ; tasks_done= 0
       ; tasks_total= 0 }
     in
@@ -102,8 +139,8 @@ let create_multiline ~jobs =
 let create_dummy () = Dummy
 
 let update_status_multiline task_bar ~slot:job t0 status =
-  (task_bar.statuses).(job) <- status ;
-  (task_bar.start_times).(job) <- t0 ;
+  (task_bar.jobs_statuses).(job) <- status ;
+  (task_bar.jobs_start_times).(job) <- t0 ;
   ()