[metrics] Add more unit related metrics

Author: YapingLi04

src/core/varlink-metrics.c

@@ -1,11 +1,29 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include "hashmap.h"
 #include "json-util.h"
 #include "manager.h"
+#include "list.h"
+#include "set.h"
 #include "sd-json.h"
 #include "sd-varlink.h"
+#include "unit-def.h"
 #include "varlink-metrics.h"
 
+static unsigned get_list_size(Manager *m, UnitType t);
+
+static unsigned get_list_size(Manager *m, UnitType t) {
+        unsigned count = 0;
+
+        assert(m);
+        // TODO: check t <= UNIT_SCOPE
+
+        LIST_FOREACH(units_by_type, _u, m->units_by_type[t])
+                count++;
+
+        return count;
+}
+
 int vl_method_list(sd_varlink *link, sd_json_variant *parameters, sd_varlink_method_flags_t flags, void *userdata) {
         Manager *m = ASSERT_PTR(userdata);
         int r;
@@ -22,5 +40,15 @@ int vl_method_list(sd_varlink *link, sd_json_variant *parameters, sd_varlink_met
                 SD_JSON_BUILD_PAIR_UNSIGNED("value", hashmap_size(m->units)),
                 SD_JSON_BUILD_PAIR("fields",
                         SD_JSON_BUILD_OBJECT(
-                                SD_JSON_BUILD_PAIR_STRING("state", "active"))));
+                                SD_JSON_BUILD_PAIR_STRING("state", "active"))),
+                SD_JSON_BUILD_PAIR_STRING("name", "units"),
+                SD_JSON_BUILD_PAIR_UNSIGNED("value", get_list_size(m, UNIT_SOCKET)),
+                SD_JSON_BUILD_PAIR("fields",
+                        SD_JSON_BUILD_OBJECT(
+                                SD_JSON_BUILD_PAIR_STRING("state", "automount"))),
+                SD_JSON_BUILD_PAIR_STRING("name", "units"),
+                SD_JSON_BUILD_PAIR_UNSIGNED("value", set_size(m->failed_units)),
+                SD_JSON_BUILD_PAIR("fields",
+                        SD_JSON_BUILD_OBJECT(
+                                SD_JSON_BUILD_PAIR_STRING("state", "failed"))));
 }