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, 0 insertions, 14 deletions

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 6cc1b1dced55..48c2cc9dae4f 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -131,20 +131,6 @@ typedef union event_union {
 	struct build_id_event		build_id;
 } event_t;
 
-struct events_stats {
-	u64 total;
-	u64 lost;
-};
-
-struct event_stat_id {
-	struct rb_node		rb_node;
-	struct rb_root		hists;
-	struct events_stats	stats;
-	u64			config;
-	u64			event_stream;
-	u32			type;
-};
-
 void event__print_totals(void);
 
 struct perf_session;