Kill struct edge_snapshot_data.

Just get the full snapshot list and take the last complete one instead.

diff --git a/dss.c b/dss.c
index df4a7ee3fc9b2f3f0b954b55acf9470321479e2c..0b6e77e3fd8850dd76f2d87dfb2a74abe67629a8 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -113,19 +113,6 @@ struct snapshot {
        unsigned interval;
 };
 
-/*
- * An edge snapshot is either the oldest one or the newest one.
- *
- * We need to find either of them occasionally: The create code
- * needs to know the newest snapshot because that is the one
- * used as the link destination dir. The pruning code needs to
- * find the oldest one in case disk space becomes low.
- */
-struct edge_snapshot_data {
-       int64_t now;
-       struct snapshot snap;
-};
-
 __printf_2_3 void dss_log(int ll, const char* fmt,...)
 {
        va_list argp;
@@ -300,6 +287,16 @@ struct snapshot_list {
 #define FOR_EACH_SNAPSHOT(s, i, sl) \
        for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
 
+#define FOR_EACH_SNAPSHOT_REVERSE(s, i, sl) \
+       for ((i) = (sl)->num_snapshots; (i) > 0 && ((s) = (sl)->snapshots[(i - 1)]); (i)--)
+
+static inline struct snapshot *oldest_snapshot(struct snapshot_list *sl)
+{
+       if (!sl->num_snapshots)
+               return NULL;
+       return sl->snapshots[0];
+}
+
 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
 
 static int compare_snapshots(const void *a, const void *b)
@@ -734,31 +731,23 @@ out:
        return ret;
 }
 
-int get_newest_complete(const char *dirname, void *private)
+__malloc char *name_of_newest_complete_snapshot(void)
 {
-       struct edge_snapshot_data *esd = private;
-       struct snapshot s;
-       int ret = is_snapshot(dirname, esd->now, &s);
+       struct snapshot_list sl;
+       struct snapshot *s;
+       int i;
+       char *name = NULL;
 
-       if (ret <= 0)
-               return 1;
-       if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
-               return 1;
-       if (s.creation_time < esd->snap.creation_time)
-               return 1;
-       free(esd->snap.name);
-       esd->snap = s;
-       return 1;
-}
+       get_snapshot_list(&sl);
 
-__malloc char *name_of_newest_complete_snapshot(void)
-{
-       struct edge_snapshot_data esd = {
-               .now = get_current_time(),
-               .snap = {.creation_time = -1}
-       };
-       for_each_subdir(get_newest_complete, &esd);
-       return esd.snap.name;
+       FOR_EACH_SNAPSHOT_REVERSE(s, i, &sl) {
+               if (s->flags != SS_COMPLETE) /* incomplete or being deleted */
+                       continue;
+               name = dss_strdup(s->name);
+               break;
+       }
+       free_snapshot_list(&sl);
+       return name;
 }
 
 void create_rsync_argv(char ***argv, int64_t *num)
@@ -932,39 +921,16 @@ out:
                DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
 }
 
-int get_oldest(const char *dirname, void *private)
+int remove_oldest_snapshot(struct snapshot_list *sl)
 {
-       struct edge_snapshot_data *esd = private;
-       struct snapshot s;
-       int ret = is_snapshot(dirname, esd->now, &s);
-
-       if (ret <= 0)
-               return 1;
-       if (s.creation_time > esd->snap.creation_time)
-               return 1;
-       free(esd->snap.name);
-       esd->snap = s;
-       return 1;
-}
+       struct snapshot *s = oldest_snapshot(sl);
 
-int remove_oldest_snapshot()
-{
-       int ret;
-       struct edge_snapshot_data esd = {
-               .now = get_current_time(),
-               .snap = {.creation_time = LLONG_MAX}
-       };
-       for_each_subdir(get_oldest, &esd);
-       if (!esd.snap.name) /* no snapshot found */
+       if (!s) /* no snapshot found */
                return 0;
-       DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
-       ret = 0;
-       if (esd.snap.creation_time == current_snapshot_creation_time)
-               goto out; /* do not remove the snapshot currently being created */
-       ret = remove_snapshot(&esd.snap);
-out:
-       free(esd.snap.name);
-       return ret;
+       DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
+       if (s->creation_time == current_snapshot_creation_time)
+               return 0; /* do not remove the snapshot currently being created */
+       return remove_snapshot(s);
 }
 
 /* TODO: Also consider number of inodes. */
@@ -1001,7 +967,7 @@ int try_to_free_disk_space(int low_disk_space)
        if (!low_disk_space)
                goto out;
        DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
-       ret = remove_oldest_snapshot();
+       ret = remove_oldest_snapshot(&sl);
        if (ret)
                goto out;
        DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");