core: Filter by unit name behind the D-Bus, instead on the client side (#3142)

This commit improves systemd performance on the systems which have
thousands of units.

2 files changed, 11 insertions, 2 deletions

diff --git a/src/shared/install.c b/src/shared/install.c
index b74ff6de22..931d3e2907 100644
--- a/src/shared/install.c
+++ b/src/shared/install.c
@@ -2653,7 +2653,9 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(UnitFileList*, unit_file_list_free_one);
 int unit_file_get_list(
                 UnitFileScope scope,
                 const char *root_dir,
-                Hashmap *h) {
+                Hashmap *h,
+                char **states,
+                char **patterns) {
 
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         char **i;
@@ -2685,6 +2687,9 @@ int unit_file_get_list(
                         if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
                                 continue;
 
+                        if (!strv_fnmatch_or_empty(patterns, de->d_name, FNM_NOESCAPE))
+                                continue;
+
                         if (hashmap_get(h, de->d_name))
                                 continue;
 
@@ -2705,6 +2710,10 @@ int unit_file_get_list(
                         if (r < 0)
                                 f->state = UNIT_FILE_BAD;
 
+                        if (!strv_isempty(states) &&
+                            !strv_contains(states, unit_file_state_to_string(f->state)))
+                                continue;
+
                         r = hashmap_put(h, basename(f->path), f);
                         if (r < 0)
                                 return r;
diff --git a/src/shared/install.h b/src/shared/install.h
index 4133faffa2..4ffc5a21f2 100644
--- a/src/shared/install.h
+++ b/src/shared/install.h
@@ -232,7 +232,7 @@ int unit_file_add_dependency(
 int unit_file_get_state(UnitFileScope scope, const char *root_dir, const char *filename, UnitFileState *ret);
 int unit_file_exists(UnitFileScope scope, const LookupPaths *paths, const char *name);
 
-int unit_file_get_list(UnitFileScope scope, const char *root_dir, Hashmap *h);
+int unit_file_get_list(UnitFileScope scope, const char *root_dir, Hashmap *h, char **states, char **patterns);
 Hashmap* unit_file_list_free(Hashmap *h);
 
 int unit_file_changes_add(UnitFileChange **changes, unsigned *n_changes, UnitFileChangeType type, const char *path, const char *source);