Move snapshot helpers to new file snap.[ch].

[dss.git] / snap.h

diff --git a/snap.h b/snap.h
new file mode 100644 (file)
index 0000000..1e9fc2b
--- /dev/null
+++ b/snap.h
@@ -0,0 +1,72 @@
+enum {
+       /** We are ready to take the next snapshot. */
+       SCS_READY,
+       /** The pre-creation hook has been started. */
+       SCS_PRE_HOOK_RUNNING,
+       /** The pre-creation hook exited successfully. */
+       SCS_PRE_HOOK_SUCCESS,
+       /** The rsync process is running. */
+       SCS_RSYNC_RUNNING,
+       /** The rsync process exited successfully. */
+       SCS_RSYNC_SUCCESS,
+       /** The post-create hook has been started- */
+       SCS_POST_HOOK_RUNNING,
+};
+
+/*
+ * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
+ * complete, being deleted: 1204565370-1204565371.being_deleted
+ * incomplete, not being deleted: 1204565370-incomplete
+ * incomplete, being deleted: 1204565370-incomplete.being_deleted
+ */
+enum snapshot_status_flags {
+       /** The rsync process terminated successfully. */
+       SS_COMPLETE = 1,
+       /** The rm process is running to remove this snapshot. */
+       SS_BEING_DELETED = 2,
+};
+
+struct snapshot {
+       char *name;
+       int64_t creation_time;
+       int64_t completion_time;
+       enum snapshot_status_flags flags;
+       unsigned interval;
+};
+
+struct snapshot_list {
+       int64_t now;
+       unsigned num_snapshots;
+       unsigned array_size;
+       struct snapshot **snapshots;
+       /**
+        * Array of size num_intervals + 1
+        *
+        * It contains the number of snapshots in each interval. interval_count[num_intervals]
+        * is the number of snapshots which belong to any interval greater than num_intervals.
+        */
+       unsigned *interval_count;
+};
+
+#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)--)
+
+
+unsigned desired_number_of_snapshots(int interval_num, int num_intervals);
+void get_snapshot_list(struct snapshot_list *sl, int unit_interval,
+               int num_intervals);
+void free_snapshot_list(struct snapshot_list *sl);
+__malloc char *incomplete_name(int64_t start);
+__malloc char *being_deleted_name(struct snapshot *s);
+int complete_name(int64_t start, int64_t end, char **result);
+__malloc char *name_of_newest_complete_snapshot(struct snapshot_list *sl);
+
+static inline struct snapshot *get_oldest_snapshot(struct snapshot_list *sl)
+{
+       if (!sl->num_snapshots)
+               return NULL;
+       return sl->snapshots[0];
+}