trace-graph: Make zooming in on task plots stay filled

Currently when you zoom into a task plot, when there are no events in
the viewable area, the line turns blank (as if it were just idle).

This patch keeps the plot with a bar even if no events are visible.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 84 insertions, 62 deletions

diff --git a/trace-plot-task.c b/trace-plot-task.c
index aac771e..f341493 100644
--- a/trace-plot-task.c
+++ b/trace-plot-task.c
@@ -329,13 +329,90 @@ static void task_plot_start(struct graph_info *ginfo, struct graph_plot *plot,
         task_info->display_wake_time = 0ULL;
 }
 
+static void update_last_record(struct graph_info *ginfo,
+                               struct task_plot_info *task_info,
+                               struct record *record)
+{
+        struct tracecmd_input *handle = ginfo->handle;
+        struct record *trecord, *t2record;
+        struct record *saved;
+        unsigned long long ts;
+        int sched_pid;
+        int pid;
+        int rec_pid;
+        int is_wakeup;
+        int is_sched;
+        int this_cpu;
+        int cpu;
+
+        pid = task_info->pid;
+
+        if (record) {
+                ts = record->ts;
+                this_cpu = record->cpu;
+        } else {
+                ts = ginfo->view_end_time;
+                this_cpu = -1;
+        }
+
+        for (cpu = 0; cpu < ginfo->cpus; cpu++) {
+
+                if (task_info->last_records[cpu])
+                        continue;
+
+                if (cpu == this_cpu) {
+                        static int once;
+
+                        trecord = tracecmd_read_prev(handle, record);
+                        /* Set cpu cursor back to what it was  */
+                        saved = tracecmd_read_data(handle, cpu);
+                        if (!once && saved->offset != record->offset) {
+                                once++;
+                                warning("failed to reset cursor!");
+                        }
+                        free_record(saved);
+                } else {
+                        static int once;
+
+                        saved = tracecmd_peek_data(handle, cpu);
+                        set_cpu_to_time(cpu, ginfo, ts);
+                        t2record = tracecmd_read_data(handle, cpu);
+                        trecord = tracecmd_read_prev(handle, t2record);
+                        free_record(t2record);
+                        /* reset cursor back to what it was */
+                        if (saved)
+                                tracecmd_set_cursor(handle, cpu, saved->offset);
+                        else {
+                                saved = tracecmd_read_data(handle, cpu);
+                                if (!once && saved) {
+                                        once++;
+                                        warning("failed to reset cursor to end!");
+                                }
+                        }
+                }
+                if (!trecord)
+                        continue;
+
+                if (record_matches_pid(ginfo, trecord, pid, &rec_pid,
+                                       &sched_pid, &is_sched, &is_wakeup) &&
+                    !is_wakeup &&
+                    (!is_sched || (is_sched && sched_pid == pid))) {
+                        task_info->last_records[cpu] = trecord;
+                        task_info->last_cpu = trecord->cpu;
+                        task_info->last_time = trecord->ts;
+                        break;
+                }
+
+                free_record(trecord);
+        }
+}
+
 static int task_plot_event(struct graph_info *ginfo,
                            struct graph_plot *plot,
                            struct record *record,
                            struct plot_info *info)
 {
         struct task_plot_info *task_info = plot->private;
-        struct tracecmd_input *handle = ginfo->handle;
         gboolean match;
         int sched_pid;
         int rec_pid;
@@ -347,10 +424,7 @@ static int task_plot_event(struct graph_info *ginfo,
         pid = task_info->pid;
 
         if (!record) {
-                for (cpu = 0; cpu < ginfo->cpus; cpu++) {
-                        free_record(task_info->last_records[cpu]);
-                        task_info->last_records[cpu] = NULL;
-                }
+                update_last_record(ginfo, task_info, record);
                 /* no more records, finish a box if one was started */
                 if (task_info->last_cpu >= 0) {
                         info->box = TRUE;
@@ -358,6 +432,10 @@ static int task_plot_event(struct graph_info *ginfo,
                         info->bend = ginfo->view_end_time;
                         info->bcolor = hash_cpu(task_info->last_cpu);
                 }
+                for (cpu = 0; cpu < ginfo->cpus; cpu++) {
+                        free_record(task_info->last_records[cpu]);
+                        task_info->last_records[cpu] = NULL;
+                }
                 return 0;
         }
 
@@ -385,63 +463,7 @@ static int task_plot_event(struct graph_info *ginfo,
                  * viewable range. Search to see if one exists, and if
                  * it is the record we want to match.
                  */
-                for (cpu = 0; cpu < ginfo->cpus; cpu++) {
-                        struct record *trecord, *t2record;
-                        struct record *saved;
-                        int this_cpu = record->cpu;
-                        int tsched_pid;
-                        int tpid;
-                        int tis_wakeup;
-                        int tis_sched;
-
-                        if (task_info->last_records[cpu])
-                                continue;
-
-                        if (cpu == this_cpu) {
-                                static int once;
-
-                                trecord = tracecmd_read_prev(handle, record);
-                                /* Set cpu cursor back to what it was  */
-                                saved = tracecmd_read_data(handle, cpu);
-                                if (!once && saved->offset != record->offset) {
-                                        once++;
-                                        warning("failed to reset cursor!");
-                                }
-                                free_record(saved);
-                        } else {
-                                static int once;
-
-                                saved = tracecmd_peek_data(handle, cpu);
-                                set_cpu_to_time(cpu, ginfo, record->ts);
-                                t2record = tracecmd_read_data(handle, cpu);
-                                trecord = tracecmd_read_prev(handle, t2record);
-                                free_record(t2record);
-                                /* reset cursor back to what it was */
-                                if (saved)
-                                        tracecmd_set_cursor(handle, cpu, saved->offset);
-                                else {
-                                        saved = tracecmd_read_data(handle, cpu);
-                                        if (!once && saved) {
-                                                once++;
-                                                warning("failed to reset cursor to end!");
-                                        }
-                                }
-                        }
-                        if (!trecord)
-                                continue;
-
-                        if (record_matches_pid(ginfo, trecord, pid, &tpid,
-                                               &tsched_pid, &tis_sched, &tis_wakeup) &&
-                            !tis_wakeup &&
-                            (!is_sched || (is_sched && sched_pid == pid))) {
-                                task_info->last_records[cpu] = trecord;
-                                task_info->last_cpu = trecord->cpu;
-                                task_info->last_time = trecord->ts;
-                                break;
-                        }
-
-                        free_record(trecord);
-                }
+                update_last_record(ginfo, task_info, record);
 
                 if (is_wakeup) {
                         /* Wake up but not task */