[PATCH 09/18] perf metric: Collect referenced metrics in struct metric_ref_node

[Jiri Olsa <jolsa@kernel.org>]

Collecting referenced metrics in struct metric_ref_node object,
so we can process them later on.

The change will parse nested metric names out of expression and
'resolve' them.

All referenced metrics are dissolved into one context, meaning all
nested metrics events and added to the parent context.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/metricgroup.c | 147 ++++++++++++++++++++++++++++++----
 1 file changed, 132 insertions(+), 15 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index f0b0a053bfd2..9923eef1e2d4 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -102,12 +102,20 @@ void metricgroup__rblist_exit(struct rblist *metric_events)
 	rblist__exit(metric_events);
 }
 
+struct metric_ref_node {
+	const char *metric_name;
+	const char *metric_expr;
+	struct list_head list;
+};
+
 struct egroup {
 	struct list_head nd;
 	struct expr_parse_ctx pctx;
 	const char *metric_name;
 	const char *metric_expr;
 	const char *metric_unit;
+	struct list_head refs;
+	int refs_cnt;
 	int runtime;
 	bool has_constraint;
 };
@@ -574,27 +582,66 @@ int __weak arch_get_runtimeparam(void)
 static int __add_metric(struct list_head *group_list,
 			struct pmu_event *pe,
 			bool metric_no_group,
-			int runtime)
+			int runtime,
+		        struct egroup **egp)
 {
+	struct metric_ref_node *ref;
 	struct egroup *eg;
 
-	eg = malloc(sizeof(*eg));
-	if (!eg)
-		return -ENOMEM;
+	if (*egp == NULL) {
+		/*
+		 * We got in here for the master group,
+		 * allocate it and put it on the list.
+		 */
+		eg = malloc(sizeof(*eg));
+		if (!eg)
+			return -ENOMEM;
+
+		expr__ctx_init(&eg->pctx);
+		eg->metric_name = pe->metric_name;
+		eg->metric_expr = pe->metric_expr;
+		eg->metric_unit = pe->unit;
+		eg->runtime = runtime;
+		eg->has_constraint = metric_no_group || metricgroup__has_constraint(pe);
+		INIT_LIST_HEAD(&eg->refs);
+		eg->refs_cnt = 0;
+		*egp = eg;
+	} else {
+		/*
+		 * We got here for the referenced metric, via the
+		 * recursive metricgroup__add_metric call, add
+		 * it to the master group.
+		 */
+		eg = *egp;
+
+		ref = malloc(sizeof(*ref));
+		if (!ref)
+			return -ENOMEM;
 
-	expr__ctx_init(&eg->pctx);
-	eg->metric_name = pe->metric_name;
-	eg->metric_expr = pe->metric_expr;
-	eg->metric_unit = pe->unit;
-	eg->runtime = runtime;
-	eg->has_constraint = metric_no_group || metricgroup__has_constraint(pe);
+		ref->metric_name = pe->metric_name;
+		ref->metric_expr = pe->metric_expr;
+		list_add(&ref->list, &eg->refs);
+		eg->refs_cnt++;
+		eg->has_constraint |= metricgroup__has_constraint(pe);
+	}
 
+	/*
+	 * For both the master and referenced metrics, we parse
+	 * all the metric's IDs and add it to the parent context.
+	 */
 	if (expr__find_other(pe->metric_expr, NULL, &eg->pctx, runtime) < 0) {
 		expr__ctx_clear(&eg->pctx);
 		free(eg);
 		return -EINVAL;
 	}
 
+	/*
+	 * We add new group only in the 'master' call,
+	 * so bail out for referenced metric case.
+	 */
+	if (eg->refs_cnt)
+		return 0;
+
 	if (list_empty(group_list))
 		list_add(&eg->nd, group_list);
 	else {
@@ -636,14 +683,63 @@ static struct pmu_event *find_metric(const char *metric, struct pmu_events_map *
 
 static int add_metric(struct list_head *group_list,
 		      struct pmu_event *pe,
-		      bool metric_no_group)
+		      bool metric_no_group,
+		      struct egroup **egp);
+
+static int resolve_metric(struct egroup *eg,
+			  bool metric_no_group,
+			  struct list_head *group_list,
+			  struct pmu_events_map *map)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+	bool all;
+	int ret;
+
+	/*
+	 * Iterate all the parsed IDs and if there's metric,
+	 * add it to the context.
+	 */
+	do {
+		all = true;
+		hashmap__for_each_entry((&eg->pctx.ids), cur, bkt) {
+			struct pmu_event *pe;
+
+			pe = find_metric(cur->key, map);
+			if (!pe)
+				continue;
+
+			all = false;
+			/* The metric key itself needs to go out.. */
+			expr__del_id(&eg->pctx, cur->key);
+
+			/* ... and it gets resolved to the parent context. */
+			ret = add_metric(group_list, pe, metric_no_group, &eg);
+			if (ret)
+				return ret;
+
+			/*
+			 * We added new metric to hashmap, so we need
+			 * to break the iteration and start over.
+			 */
+			break;
+		}
+	} while (!all);
+
+	return 0;
+}
+
+static int add_metric(struct list_head *group_list,
+		      struct pmu_event *pe,
+		      bool metric_no_group,
+		      struct egroup **egp)
 {
 	int ret = 0;
 
 	pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
 
 	if (!strstr(pe->metric_expr, "?")) {
-		ret = __add_metric(group_list, pe, metric_no_group, 1);
+		ret = __add_metric(group_list, pe, metric_no_group, 1, egp);
 	} else {
 		int j, count;
 
@@ -655,7 +751,7 @@ static int add_metric(struct list_head *group_list,
 		 */
 
 		for (j = 0; j < count && !ret; j++) {
-			ret = __add_metric(group_list, pe, metric_no_group, j);
+			ret = __add_metric(group_list, pe, metric_no_group, j, egp);
 		}
 	}
 
@@ -666,16 +762,26 @@ static int metricgroup__add_metric(const char *metric, bool metric_no_group,
 				   struct strbuf *events,
 				   struct list_head *group_list,
 				   struct pmu_events_map *map)
+
 {
+	struct egroup *eg = NULL;
 	struct pmu_event *pe;
-	struct egroup *eg;
 	int ret;
 
 	pe = find_metric(metric, map);
 	if (!pe)
 		return -EINVAL;
 
-	ret = add_metric(group_list, pe, metric_no_group);
+	ret = add_metric(group_list, pe, metric_no_group, &eg);
+	if (ret)
+		return ret;
+
+	/*
+	 * Process any possible referenced metrics
+	 * included in the expression.
+	 */
+	ret = resolve_metric(eg, metric_no_group,
+			     group_list, map);
 	if (ret)
 		return ret;
 
@@ -727,11 +833,22 @@ static int metricgroup__add_metric_list(const char *list, bool metric_no_group,
 	return ret;
 }
 
+static void egroup__free_refs(struct egroup *egroup)
+{
+	struct metric_ref_node *ref, *tmp;
+
+	list_for_each_entry_safe(ref, tmp, &egroup->refs, list) {
+		list_del(&ref->list);
+		free(ref);
+	}
+}
+
 static void metricgroup__free_egroups(struct list_head *group_list)
 {
 	struct egroup *eg, *egtmp;
 
 	list_for_each_entry_safe (eg, egtmp, group_list, nd) {
+		egroup__free_refs(eg);
 		expr__ctx_clear(&eg->pctx);
 		list_del_init(&eg->nd);
 		free(eg);
-- 
2.25.4