perf metric: Add utilities to work on ids map.

Add utilities to new/free an ids hashmap, as well as to union. Add
testing of the union. Unioning hashmaps will be used when parsing the
metric, if a value is known then the hashmap is unnecessary, otherwise
we need to union together all the event ids to compute their values for
reporting.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210923074616.674826-9-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index de109c2ab917..4ed186bd1f13 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -30,9 +30,19 @@ struct expr_scanner_ctx {
 	int runtime;
 };
 
+struct hashmap *ids__new(void);
+void ids__free(struct hashmap *ids);
+int ids__insert(struct hashmap *ids, const char *id, struct expr_id *parent);
+/*
+ * Union two sets of ids (hashmaps) and construct a third, freeing ids1 and
+ * ids2.
+ */
+struct hashmap *ids__union(struct hashmap *ids1, struct hashmap *ids2);
+
 struct expr_parse_ctx *expr__ctx_new(void);
 void expr__ctx_clear(struct expr_parse_ctx *ctx);
 void expr__ctx_free(struct expr_parse_ctx *ctx);
+
 void expr__del_id(struct expr_parse_ctx *ctx, const char *id);
 int expr__add_id(struct expr_parse_ctx *ctx, const char *id);
 int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val);
@@ -41,8 +51,10 @@ int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
 		 struct expr_id_data **data);
 int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
 		     struct expr_id_data **datap);
+
 int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
 		const char *expr, int runtime);
+
 int expr__find_ids(const char *expr, const char *one,
 		struct expr_parse_ctx *ids, int runtime);