perf hist: Introduce hists class and move lots of methods to it

In cbbc79a we introduced support for multiple events by introducing a
new "event_stat_id" struct and then made several perf_session methods
receive a point to it instead of a pointer to perf_session, and kept the
event_stats and hists rb_tree in perf_session.

While working on the new newt based browser, I realised that it would be
better to introduce a new class, "hists" (short for "histograms"),
renaming the "event_stat_id" struct and the perf_session methods that
were really "hists" methods, as they manipulate only struct hists
members, not touching anything in the other perf_session members.

Other optimizations, such as calculating the maximum lenght of a symbol
name present in an hists instance will be possible as we add them,
avoiding a re-traversal just for finding that information.

The rationale for the name "hists" to replace "event_stat_id" is that we
may have multiple sets of hists for the same event_stat id, as, for
instance, the 'perf diff' tool has, so event stat id is not what
characterizes what this struct and the functions that manipulate it do.

Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 35 insertions, 36 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 642a6d8eb5dc..53077fd973f0 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -44,16 +44,17 @@ static char		*pretty_printing_style = default_pretty_printing_style;
 
 static char             callchain_default_opt[] = "fractal,0.5";
 
-static struct event_stat_id *get_stats(struct perf_session *self,
-                                       u64 event_stream, u32 type, u64 config)
+static struct hists *perf_session__hists_findnew(struct perf_session *self,
+                                                 u64 event_stream, u32 type,
+                                                 u64 config)
 {
-        struct rb_node **p = &self->stats_by_id.rb_node;
+        struct rb_node **p = &self->hists_tree.rb_node;
         struct rb_node *parent = NULL;
-        struct event_stat_id *iter, *new;
+        struct hists *iter, *new;
 
         while (*p != NULL) {
                 parent = *p;
-                iter = rb_entry(parent, struct event_stat_id, rb_node);
+                iter = rb_entry(parent, struct hists, rb_node);
                 if (iter->config == config)
                         return iter;
 
@@ -64,15 +65,15 @@ static struct event_stat_id *get_stats(struct perf_session *self,
                         p = &(*p)->rb_left;
         }
 
-        new = malloc(sizeof(struct event_stat_id));
+        new = malloc(sizeof(struct hists));
         if (new == NULL)
                 return NULL;
-        memset(new, 0, sizeof(struct event_stat_id));
+        memset(new, 0, sizeof(struct hists));
         new->event_stream = event_stream;
         new->config = config;
         new->type = type;
         rb_link_node(&new->rb_node, parent, p);
-        rb_insert_color(&new->rb_node, &self->stats_by_id);
+        rb_insert_color(&new->rb_node, &self->hists_tree);
         return new;
 }
 
@@ -84,7 +85,7 @@ static int perf_session__add_hist_entry(struct perf_session *self,
         struct symbol *parent = NULL;
         int err = -ENOMEM;
         struct hist_entry *he;
-        struct event_stat_id *stats;
+        struct hists *hists;
         struct perf_event_attr *attr;
 
         if ((sort__has_parent || symbol_conf.use_callchain) && data->callchain) {
@@ -96,13 +97,12 @@ static int perf_session__add_hist_entry(struct perf_session *self,
 
         attr = perf_header__find_attr(data->id, &self->header);
         if (attr)
-                stats = get_stats(self, data->id, attr->type, attr->config);
+                hists = perf_session__hists_findnew(self, data->id, attr->type, attr->config);
         else
-                stats = get_stats(self, data->id, 0, 0);
-        if (stats == NULL)
+                hists = perf_session__hists_findnew(self, data->id, 0, 0);
+        if (hists == NULL)
                 goto out_free_syms;
-        he = __perf_session__add_hist_entry(&stats->hists, al, parent,
-                                            data->period);
+        he = __hists__add_entry(hists, al, parent, data->period);
         if (he == NULL)
                 goto out_free_syms;
         err = 0;
@@ -117,18 +117,19 @@ static int add_event_total(struct perf_session *session,
                            struct sample_data *data,
                            struct perf_event_attr *attr)
 {
-        struct event_stat_id *stats;
+        struct hists *hists;
 
         if (attr)
-                stats = get_stats(session, data->id, attr->type, attr->config);
+                hists = perf_session__hists_findnew(session, data->id,
+                                                    attr->type, attr->config);
         else
-                stats = get_stats(session, data->id, 0, 0);
+                hists = perf_session__hists_findnew(session, data->id, 0, 0);
 
-        if (!stats)
+        if (!hists)
                 return -ENOMEM;
 
-        stats->stats.total += data->period;
-        session->events_stats.total += data->period;
+        hists->stats.total += data->period;
+        session->hists.stats.total += data->period;
         return 0;
 }
 
@@ -292,35 +293,33 @@ static int __cmd_report(void)
         if (verbose > 2)
                 perf_session__fprintf_dsos(session, stdout);
 
-        next = rb_first(&session->stats_by_id);
+        next = rb_first(&session->hists_tree);
         while (next) {
-                struct event_stat_id *stats;
+                struct hists *hists;
                 u64 nr_hists;
 
-                stats = rb_entry(next, struct event_stat_id, rb_node);
-                perf_session__collapse_resort(&stats->hists);
-                nr_hists = perf_session__output_resort(&stats->hists,
-                                                       stats->stats.total);
+                hists = rb_entry(next, struct hists, rb_node);
+                hists__collapse_resort(hists);
+                nr_hists = hists__output_resort(hists);
                 if (use_browser)
-                        perf_session__browse_hists(&stats->hists, nr_hists,
-                                                   stats->stats.total, help,
+                        perf_session__browse_hists(&hists->entries, nr_hists,
+                                                   hists->stats.total, help,
                                                    input_name);
                 else {
-                        if (rb_first(&session->stats_by_id) ==
-                            rb_last(&session->stats_by_id))
+                        if (rb_first(&session->hists.entries) ==
+                            rb_last(&session->hists.entries))
                                 fprintf(stdout, "# Samples: %Ld\n#\n",
-                                        stats->stats.total);
+                                        hists->stats.total);
                         else
                                 fprintf(stdout, "# Samples: %Ld %s\n#\n",
-                                        stats->stats.total,
-                                        __event_name(stats->type, stats->config));
+                                        hists->stats.total,
+                                        __event_name(hists->type, hists->config));
 
-                        perf_session__fprintf_hists(&stats->hists, NULL, false, stdout,
-                                            stats->stats.total);
+                        hists__fprintf(hists, NULL, false, stdout);
                         fprintf(stdout, "\n\n");
                 }
 
-                next = rb_next(&stats->rb_node);
+                next = rb_next(&hists->rb_node);
         }
 
         if (!use_browser && sort_order == default_sort_order &&