journal: expose and make use of cutoff times of journal

This helps explaining when the log output of "systemctl status" is
incomplete because the logs got rotated since the service was started.

1 files changed, 72 insertions, 0 deletions

diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index 9cec140f58..73420d9c1b 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -183,6 +183,7 @@ static int journal_file_verify_header(JournalFile *f) {
 
                 if (state == STATE_ONLINE)
                         log_debug("Journal file %s is already online. Assuming unclean closing. Ignoring.", f->path);
+                        /* FIXME: immediately rotate */
                 else if (state == STATE_ARCHIVED)
                         return -ESHUTDOWN;
                 else if (state != STATE_OFFLINE)
@@ -2284,3 +2285,74 @@ void journal_default_metrics(JournalMetrics *m, int fd) {
                  format_bytes(c, sizeof(c), m->min_size),
                  format_bytes(d, sizeof(d), m->keep_free));
 }
+
+int journal_file_get_cutoff_realtime_usec(JournalFile *f, usec_t *from, usec_t *to) {
+        Object *o;
+        int r;
+
+        assert(f);
+        assert(from || to);
+
+        if (from) {
+                r = journal_file_next_entry(f, NULL, 0, DIRECTION_DOWN, &o, NULL);
+                if (r <= 0)
+                        return r;
+
+                *from = le64toh(o->entry.realtime);
+        }
+
+        if (to) {
+                r = journal_file_next_entry(f, NULL, 0, DIRECTION_UP, &o, NULL);
+                if (r <= 0)
+                        return r;
+
+                *to = le64toh(o->entry.realtime);
+        }
+
+        return 1;
+}
+
+int journal_file_get_cutoff_monotonic_usec(JournalFile *f, sd_id128_t boot_id, usec_t *from, usec_t *to) {
+        char t[9+32+1] = "_BOOT_ID=";
+        Object *o;
+        uint64_t p;
+        int r;
+
+        assert(f);
+        assert(from || to);
+
+        sd_id128_to_string(boot_id, t + 9);
+
+        r = journal_file_find_data_object(f, t, strlen(t), &o, &p);
+        if (r <= 0)
+                return r;
+
+        if (le64toh(o->data.n_entries) <= 0)
+                return 0;
+
+        if (from) {
+                r = journal_file_move_to_object(f, OBJECT_ENTRY, le64toh(o->data.entry_offset), &o);
+                if (r < 0)
+                        return r;
+
+                *from = le64toh(o->entry.monotonic);
+        }
+
+        if (to) {
+                r = journal_file_move_to_object(f, OBJECT_DATA, p, &o);
+                if (r < 0)
+                        return r;
+
+                r = generic_array_get_plus_one(f,
+                                               le64toh(o->data.entry_offset),
+                                               le64toh(o->data.entry_array_offset),
+                                               le64toh(o->data.n_entries)-1,
+                                               &o, NULL);
+                if (r <= 0)
+                        return r;
+
+                *to = le64toh(o->entry.monotonic);
+        }
+
+        return 1;
+}