snapshot: implement snapshot unit logic

1 files changed, 156 insertions, 5 deletions

diff --git a/snapshot.c b/snapshot.c
index 0039ca4610..1fc0ab8164 100644
--- a/snapshot.c
+++ b/snapshot.c
@@ -19,25 +19,176 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
+
 #include "unit.h"
 #include "snapshot.h"
+#include "unit-name.h"
+#include "dbus-snapshot.h"
+
+static const UnitActiveState state_translation_table[_SNAPSHOT_STATE_MAX] = {
+        [SNAPSHOT_DEAD] = UNIT_INACTIVE,
+        [SNAPSHOT_ACTIVE] = UNIT_ACTIVE
+};
+
+static const char* const state_string_table[_SNAPSHOT_STATE_MAX] = {
+        [SNAPSHOT_DEAD] = "dead",
+        [SNAPSHOT_ACTIVE] = "active"
+};
+
+static int snapshot_load(Unit *u) {
+        Iterator i;
+        Unit *other;
+        int r;
+
+        assert(u);
+
+        HASHMAP_FOREACH(other, u->meta.manager->units, i) {
 
-static void snapshot_done(Unit *u) {
+                if (UNIT_VTABLE(other)->no_snapshots)
+                        continue;
+
+                if ((r = unit_add_dependency(u, UNIT_REQUIRES, other)) < 0)
+                        return r;
+
+                if ((r = unit_add_dependency(u, UNIT_AFTER, other)) < 0)
+                        return r;
+        }
+
+        u->meta.load_state = UNIT_LOADED;
+
+        return 0;
+}
+
+static void snapshot_dump(Unit *u, FILE *f, const char *prefix) {
         Snapshot *s = SNAPSHOT(u);
 
         assert(s);
+        assert(f);
 
-        /* Nothing here for now */
+        fprintf(f,
+                "%sSnapshot State: %s\n"
+                "%sClean Up: %s\n",
+                prefix, state_string_table[s->state],
+                prefix, yes_no(s->cleanup));
+}
+
+static void snapshot_set_state(Snapshot *s, SnapshotState state) {
+        SnapshotState old_state;
+        assert(s);
+
+        old_state = s->state;
+        s->state = state;
+
+        if (state != old_state)
+                log_debug("%s changed %s → %s", UNIT(s)->meta.id, state_string_table[old_state], state_string_table[state]);
+
+        unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state]);
+}
+
+static int snapshot_start(Unit *u) {
+        Snapshot *s = SNAPSHOT(u);
+
+        assert(s);
+        assert(s->state == SNAPSHOT_DEAD);
+
+        snapshot_set_state(s, SNAPSHOT_ACTIVE);
+
+        if (s->cleanup)
+                unit_add_to_cleanup_queue(u);
+
+        return 0;
+}
+
+static int snapshot_stop(Unit *u) {
+        Snapshot *s = SNAPSHOT(u);
+
+        assert(s);
+        assert(s->state == SNAPSHOT_ACTIVE);
+
+        snapshot_set_state(s, SNAPSHOT_DEAD);
+        return 0;
 }
 
 static UnitActiveState snapshot_active_state(Unit *u) {
-        return SNAPSHOT(u)->state == SNAPSHOT_DEAD ? UNIT_INACTIVE : UNIT_ACTIVE;
+        assert(u);
+
+        return state_translation_table[SNAPSHOT(u)->state];
+}
+
+static const char *snapshot_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return state_string_table[SNAPSHOT(u)->state];
+}
+
+int snapshot_create(Manager *m, const char *name, bool cleanup, Snapshot **_s) {
+        Unit *u;
+        char *n = NULL;
+        int r;
+
+        assert(m);
+        assert(_s);
+
+        if (name) {
+                if (!unit_name_is_valid(name))
+                        return -EINVAL;
+
+                if (unit_name_to_type(name) != UNIT_SNAPSHOT)
+                        return -EINVAL;
+
+                if (manager_get_unit(m, name))
+                        return -EEXIST;
+
+        } else {
+
+                for (;;) {
+                        if (asprintf(&n, "snapshot-%u.snapshot", ++ m->n_snapshots) < 0)
+                                return -ENOMEM;
+
+                        if (!manager_get_unit(m, n))
+                                break;
+
+                        free(n);
+                }
+
+                name = n;
+        }
+
+        r = manager_load_unit(m, name, NULL, &u);
+        free(n);
+
+        if (r < 0)
+                return r;
+
+        SNAPSHOT(u)->cleanup = cleanup;
+        *_s = SNAPSHOT(u);
+
+        return 0;
+}
+
+void snapshot_remove(Snapshot *s) {
+        assert(s);
+
+        unit_add_to_cleanup_queue(UNIT(s));
 }
 
 const UnitVTable snapshot_vtable = {
         .suffix = ".snapshot",
 
-        .done = snapshot_done,
+        .no_alias = true,
+        .no_instances = true,
+        .no_snapshots = true,
+
+        .load = snapshot_load,
+
+        .dump = snapshot_dump,
+
+        .start = snapshot_start,
+        .stop = snapshot_stop,
+
+        .active_state = snapshot_active_state,
+        .sub_state_to_string = snapshot_sub_state_to_string,
 
-        .active_state = snapshot_active_state
+        .bus_message_handler = bus_snapshot_message_handler
 };