1 files changed, 67 insertions, 4 deletions

diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index adf16bb7571a..81101be51044 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -59,8 +59,29 @@ static bool key_equal(const void *key1, const void *key2,
 	return !strcmp((const char *)key1, (const char *)key2);
 }
 
-/* Caller must make sure id is allocated */
-int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
+struct hashmap *ids__new(void)
+{
+	return hashmap__new(key_hash, key_equal, NULL);
+}
+
+void ids__free(struct hashmap *ids)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	if (ids == NULL)
+		return;
+
+	hashmap__for_each_entry(ids, cur, bkt) {
+		free((char *)cur->key);
+		free(cur->value);
+	}
+
+	hashmap__free(ids);
+}
+
+int ids__insert(struct hashmap *ids, const char *id,
+		struct expr_id *parent)
 {
 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
 	char *old_key = NULL;
@@ -70,10 +91,10 @@ int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
 	if (!data_ptr)
 		return -ENOMEM;
 
-	data_ptr->parent = ctx->parent;
+	data_ptr->parent = parent;
 	data_ptr->kind = EXPR_ID_DATA__PARENT;
 
-	ret = hashmap__set(ctx->ids, id, data_ptr,
+	ret = hashmap__set(ids, id, data_ptr,
 			   (const void **)&old_key, (void **)&old_data);
 	if (ret)
 		free(data_ptr);
@@ -82,6 +103,48 @@ int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
 	return ret;
 }
 
+struct hashmap *ids__union(struct hashmap *ids1, struct hashmap *ids2)
+{
+	size_t bkt;
+	struct hashmap_entry *cur;
+	int ret;
+	struct expr_id_data *old_data = NULL;
+	char *old_key = NULL;
+
+	if (!ids1)
+		return ids2;
+
+	if (!ids2)
+		return ids1;
+
+	if (hashmap__size(ids1) <  hashmap__size(ids2)) {
+		struct hashmap *tmp = ids1;
+
+		ids1 = ids2;
+		ids2 = tmp;
+	}
+	hashmap__for_each_entry(ids2, cur, bkt) {
+		ret = hashmap__set(ids1, cur->key, cur->value,
+				(const void **)&old_key, (void **)&old_data);
+		free(old_key);
+		free(old_data);
+
+		if (ret) {
+			hashmap__free(ids1);
+			hashmap__free(ids2);
+			return NULL;
+		}
+	}
+	hashmap__free(ids2);
+	return ids1;
+}
+
+/* Caller must make sure id is allocated */
+int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
+{
+	return ids__insert(ctx->ids, id, ctx->parent);
+}
+
 /* Caller must make sure id is allocated */
 int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
 {