perf report: Display pregress bar on redirected pipe data

It's possible to save pipe output of perf record into a file.

  $ perf record -o- ... > pipe.data

And you can use the data same as the normal perf data.

  $ perf report -i pipe.data

In that case, perf tools will treat the input as a pipe, but it can get
the total size of the input.  This means it can show the progress bar
unlike the normal pipe input (which doesn't know the total size in
advance).

While at it, fix the string in __perf_session__process_dir_events().
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240627181916.1202110-1-namhyung@kernel.org

tools/perf/util/session.c

@@ -2050,6 +2050,7 @@ static int __perf_session__process_pipe_events(struct perf_session *session)
 {
 	struct ordered_events *oe = &session->ordered_events;
 	struct perf_tool *tool = session->tool;
+	struct ui_progress prog;
 	union perf_event *event;
 	uint32_t size, cur_size = 0;
 	void *buf = NULL;
@@ -2057,9 +2058,21 @@ static int __perf_session__process_pipe_events(struct perf_session *session)
 	u64 head;
 	ssize_t err;
 	void *p;
+	bool update_prog = false;
 
 	perf_tool__fill_defaults(tool);
 
+	/*
+	 * If it's from a file saving pipe data (by redirection), it would have
+	 * a file name other than "-".  Then we can get the total size and show
+	 * the progress.
+	 */
+	if (strcmp(session->data->path, "-") && session->data->file.size) {
+		ui_progress__init_size(&prog, session->data->file.size,
+				       "Processing events...");
+		update_prog = true;
+	}
+
 	head = 0;
 	cur_size = sizeof(union perf_event);
 
@@ -2131,6 +2144,9 @@ static int __perf_session__process_pipe_events(struct perf_session *session)
 	if (err)
 		goto out_err;
 
+	if (update_prog)
+		ui_progress__update(&prog, size);
+
 	if (!session_done())
 		goto more;
 done:
@@ -2144,6 +2160,8 @@ static int __perf_session__process_pipe_events(struct perf_session *session)
 	err = perf_session__flush_thread_stacks(session);
 out_err:
 	free(buf);
+	if (update_prog)
+		ui_progress__finish();
 	if (!tool->no_warn)
 		perf_session__warn_about_errors(session);
 	ordered_events__free(&session->ordered_events);
@@ -2523,7 +2541,7 @@ static int __perf_session__process_dir_events(struct perf_session *session)
 
 	perf_tool__fill_defaults(tool);
 
-	ui_progress__init_size(&prog, total_size, "Sorting events...");
+	ui_progress__init_size(&prog, total_size, "Processing events...");
 
 	nr_readers = 1;
 	for (i = 0; i < data->dir.nr; i++) {