perf hists browser: Add support for showing columns header

Open up space to show a one-line header text whenever 'H' is pressed,
hide it on another key press.

Follow up patch will format this line from the set of headers used.

Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-m894d6qk30h3qofw4k8neq4q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 40 insertions, 2 deletions

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index ef7abf896f5a..2be71bf17b71 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -26,6 +26,7 @@ struct hist_browser {
         struct map_symbol   *selection;
         int                  print_seq;
         bool                 show_dso;
+        bool                 show_headers;
         float                min_pcnt;
         u64                  nr_non_filtered_entries;
         u64                  nr_callchain_rows;
@@ -56,6 +57,21 @@ static u32 hist_browser__nr_entries(struct hist_browser *hb)
         return nr_entries + hb->nr_callchain_rows;
 }
 
+static void hist_browser__update_rows(struct hist_browser *hb)
+{
+        struct ui_browser *browser = &hb->b;
+        u16 header_offset = hb->show_headers ? 1 : 0, index_row;
+
+        browser->rows = browser->height - header_offset;
+        /*
+         * Verify if we were at the last line and that line isn't
+         * visibe because we now show the header line(s).
+         */
+        index_row = browser->index - browser->top_idx;
+        if (index_row >= browser->rows)
+                browser->index -= index_row - browser->rows + 1;
+}
+
 static void hist_browser__refresh_dimensions(struct ui_browser *browser)
 {
         struct hist_browser *hb = container_of(browser, struct hist_browser, b);
@@ -69,11 +85,14 @@ static void hist_browser__refresh_dimensions(struct ui_browser *browser)
          *        changeset.
          */
         ui_browser__refresh_dimensions(browser);
+        hist_browser__update_rows(hb);
 }
 
 static void hist_browser__gotorc(struct hist_browser *browser, int row, int column)
 {
-        ui_browser__gotorc(&browser->b, row, column);
+        u16 header_offset = browser->show_headers ? 1 : 0;
+
+        ui_browser__gotorc(&browser->b, row + header_offset, column);
 }
 
 static void hist_browser__reset(struct hist_browser *browser)
@@ -421,6 +440,10 @@ static int hist_browser__run(struct hist_browser *browser,
                         /* Expand the whole world. */
                         hist_browser__set_folding(browser, true);
                         break;
+                case 'H':
+                        browser->show_headers = !browser->show_headers;
+                        hist_browser__update_rows(browser);
+                        break;
                 case K_ENTER:
                         if (hist_browser__toggle_fold(browser))
                                 break;
@@ -799,6 +822,13 @@ static int hist_browser__show_entry(struct hist_browser *browser,
         return printed;
 }
 
+static void hist_browser__show_headers(struct hist_browser *browser)
+{
+        ui_browser__gotorc(&browser->b, 0, 0);
+        ui_browser__set_color(&browser->b, HE_COLORSET_ROOT);
+        slsmg_write_nstring(" ", browser->b.width + 1);
+}
+
 static void ui_browser__hists_init_top(struct ui_browser *browser)
 {
         if (browser->top == NULL) {
@@ -812,9 +842,15 @@ static void ui_browser__hists_init_top(struct ui_browser *browser)
 static unsigned int hist_browser__refresh(struct ui_browser *browser)
 {
         unsigned row = 0;
+        u16 header_offset = 0;
         struct rb_node *nd;
         struct hist_browser *hb = container_of(browser, struct hist_browser, b);
 
+        if (hb->show_headers) {
+                hist_browser__show_headers(hb);
+                header_offset = 1;
+        }
+
         ui_browser__hists_init_top(browser);
 
         for (nd = browser->top; nd; nd = rb_next(nd)) {
@@ -833,7 +869,7 @@ static unsigned int hist_browser__refresh(struct ui_browser *browser)
                         break;
         }
 
-        return row;
+        return row + header_offset;
 }
 
 static struct rb_node *hists__filter_entries(struct rb_node *nd,
@@ -1205,6 +1241,7 @@ static struct hist_browser *hist_browser__new(struct hists *hists)
                 browser->b.refresh_dimensions = hist_browser__refresh_dimensions;
                 browser->b.seek = ui_browser__hists_seek;
                 browser->b.use_navkeypressed = true;
+                browser->show_headers = false;
         }
 
         return browser;
@@ -1434,6 +1471,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
         "d             Zoom into current DSO\n"                         \
         "E             Expand all callchains\n"                         \
         "F             Toggle percentage of filtered entries\n"         \
+        "H             Display column headers\n"                        \
 
         /* help messages are sorted by lexical order of the hotkey */
         const char report_help[] = HIST_BROWSER_HELP_COMMON