Improve next_snapshot_is_due().

[dss.git] / dss.c

diff --git a/dss.c b/dss.c
index f82664faf32bcbe8392cf33f9e61ee0254a1b41b..04fe30c4bb7798ae8a049b9eb46638b278ea3927 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -151,19 +151,16 @@ static void dss_get_snapshot_list(struct snapshot_list *sl)
        get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
 }
 
-static int next_snapshot_is_due(void)
+static int64_t compute_next_snapshot_time(void)
 {
        int64_t x = 0, now = get_current_time(), unit_interval
-               = 24 * 3600 * conf.unit_interval_arg;
+               = 24 * 3600 * conf.unit_interval_arg, ret;
        unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
                num_complete_snapshots = 0;
-       int i, ret;
+       int i;
        struct snapshot *s = NULL;
        struct snapshot_list sl;
 
-       if (next_snapshot_time > now)
-               return 0;
-       assert(snapshot_creation_status == HS_READY);
        current_snapshot_creation_time = 0;
        dss_get_snapshot_list(&sl);
        FOR_EACH_SNAPSHOT(s, i, &sl) {
@@ -174,29 +171,51 @@ static int next_snapshot_is_due(void)
        }
        assert(x >= 0);
 
-       next_snapshot_time = now;
+       ret = now;
        if (num_complete_snapshots == 0)
                goto out;
        x /= num_complete_snapshots; /* avg time to create one snapshot */
        if (unit_interval < x * wanted) /* oops, no sleep at all */
                goto out;
-       next_snapshot_time = s->completion_time + unit_interval / wanted - x;
+       ret = s->completion_time + unit_interval / wanted - x;
 out:
        free_snapshot_list(&sl);
-       ret = next_snapshot_time <= now;
-       if (ret == 0)
-               DSS_DEBUG_LOG("next snapshot due in %lu seconds\n",
-                       next_snapshot_time - now);
-       else
-               DSS_DEBUG_LOG("next snapshot: now\n");
        return ret;
 }
 
+static inline void invalidate_next_snapshot_time(void)
+{
+       next_snapshot_time = 0;
+}
+
+static inline int next_snapshot_time_is_valid(void)
+{
+       return next_snapshot_time != 0;
+}
+
+static int next_snapshot_is_due(void)
+{
+       int64_t now = get_current_time();
+
+       assert(snapshot_creation_status == HS_READY);
+       if (!next_snapshot_time_is_valid())
+               next_snapshot_time = compute_next_snapshot_time();
+       if (next_snapshot_time <= now) {
+               DSS_DEBUG_LOG("next snapshot: now\n");
+               return 1;
+       }
+       DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
+               next_snapshot_time - now);
+       return 0;
+}
+
 static int pre_create_hook(void)
 {
        int ret, fds[3] = {0, 0, 0};
 
        assert(snapshot_creation_status == HS_READY);
+       /* make sure that the next snapshot time will be recomputed */
+       invalidate_next_snapshot_time();
        if (!conf.pre_create_hook_given) {
                snapshot_creation_status = HS_PRE_SUCCESS;
                return 0;
@@ -887,6 +906,7 @@ static int handle_sighup(void)
        ret = parse_config_file(1);
        if (ret < 0)
                return ret;
+       invalidate_next_snapshot_time();
        return change_to_dest_dir();
 }