X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fjournal%2Fjournal-file.c;h=9d8c9e686d3ec186e29d859a5a435afb85725d16;hp=a60a896c2f3ad7370f43abf8ba97514d0c9f20d2;hb=71fa6f006f92831c0c02e844b4c35e4b7197c6d6;hpb=7ea07dcddafe573c699fc48171b57b912897e7e2

diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index a60a896c2..9d8c9e686 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -58,18 +58,27 @@
  * size */
 #define DEFAULT_KEEP_FREE (1024ULL*1024ULL)                    /* 1 MB */
 
-static const char signature[] = { 'L', 'P', 'K', 'S', 'H', 'H', 'R', 'H' };
+/* n_data was the first entry we added after the initial file format design */
+#define HEADER_SIZE_MIN ALIGN64(offsetof(Header, n_data))
 
 #define ALIGN64(x) (((x) + 7ULL) & ~7ULL)
 
+#define JOURNAL_HEADER_CONTAINS(h, field) \
+        (le64toh((h)->header_size) >= offsetof(Header, field) + sizeof((h)->field))
+
+static const char signature[] = { 'L', 'P', 'K', 'S', 'H', 'H', 'R', 'H' };
+
 void journal_file_close(JournalFile *f) {
         int t;
 
         assert(f);
 
-        if (f->header && f->writable)
-                f->header->state = STATE_OFFLINE;
+        if (f->header) {
+                if (f->writable)
+                        f->header->state = STATE_OFFLINE;
 
+                munmap(f->header, PAGE_ALIGN(sizeof(Header)));
+        }
 
         for (t = 0; t < _WINDOW_MAX; t++)
                 if (f->windows[t].ptr)
@@ -96,7 +105,7 @@ static int journal_file_init_header(JournalFile *f, JournalFile *template) {
 
         zero(h);
         memcpy(h.signature, signature, 8);
-        h.arena_offset = htole64(ALIGN64(sizeof(h)));
+        h.header_size = htole64(ALIGN64(sizeof(h)));
 
         r = sd_id128_randomize(&h.file_id);
         if (r < 0)
@@ -104,7 +113,7 @@ static int journal_file_init_header(JournalFile *f, JournalFile *template) {
 
         if (template) {
                 h.seqnum_id = template->header->seqnum_id;
-                h.seqnum = template->header->seqnum;
+                h.tail_seqnum = template->header->tail_seqnum;
         } else
                 h.seqnum_id = h.file_id;
 
@@ -158,7 +167,11 @@ static int journal_file_verify_header(JournalFile *f) {
                 return -EPROTONOSUPPORT;
 #endif
 
-        if ((uint64_t) f->last_stat.st_size < (le64toh(f->header->arena_offset) + le64toh(f->header->arena_size)))
+        /* The first addition was n_data, so check that we are at least this large */
+        if (le64toh(f->header->header_size) < HEADER_SIZE_MIN)
+                return -EBADMSG;
+
+        if ((uint64_t) f->last_stat.st_size < (le64toh(f->header->header_size) + le64toh(f->header->arena_size)))
                 return -ENODATA;
 
         if (f->writable) {
@@ -175,12 +188,15 @@ static int journal_file_verify_header(JournalFile *f) {
 
                 state = f->header->state;
 
-                if (state == STATE_ONLINE)
-                        log_debug("Journal file %s is already online. Assuming unclean closing. Ignoring.", f->path);
-                else if (state == STATE_ARCHIVED)
+                if (state == STATE_ONLINE) {
+                        log_debug("Journal file %s is already online. Assuming unclean closing.", f->path);
+                        return -EBUSY;
+                } else if (state == STATE_ARCHIVED)
                         return -ESHUTDOWN;
-                else if (state != STATE_OFFLINE)
-                        log_debug("Journal file %s has unknown state %u. Ignoring.", f->path, state);
+                else if (state != STATE_OFFLINE) {
+                        log_debug("Journal file %s has unknown state %u.", f->path, state);
+                        return -EBUSY;
+                }
         }
 
         return 0;
@@ -188,6 +204,7 @@ static int journal_file_verify_header(JournalFile *f) {
 
 static int journal_file_allocate(JournalFile *f, uint64_t offset, uint64_t size) {
         uint64_t old_size, new_size;
+        int r;
 
         assert(f);
 
@@ -196,12 +213,12 @@ static int journal_file_allocate(JournalFile *f, uint64_t offset, uint64_t size)
          * ourselves */
 
         old_size =
-                le64toh(f->header->arena_offset) +
+                le64toh(f->header->header_size) +
                 le64toh(f->header->arena_size);
 
         new_size = PAGE_ALIGN(offset + size);
-        if (new_size < le64toh(f->header->arena_offset))
-                new_size = le64toh(f->header->arena_offset);
+        if (new_size < le64toh(f->header->header_size))
+                new_size = le64toh(f->header->header_size);
 
         if (new_size <= old_size)
                 return 0;
@@ -232,13 +249,14 @@ static int journal_file_allocate(JournalFile *f, uint64_t offset, uint64_t size)
         /* Note that the glibc fallocate() fallback is very
            inefficient, hence we try to minimize the allocation area
            as we can. */
-        if (posix_fallocate(f->fd, old_size, new_size - old_size) < 0)
-                return -errno;
+        r = posix_fallocate(f->fd, old_size, new_size - old_size);
+        if (r != 0)
+                return -r;
 
         if (fstat(f->fd, &f->last_stat) < 0)
                 return -errno;
 
-        f->header->arena_size = htole64(new_size - le64toh(f->header->arena_offset));
+        f->header->arena_size = htole64(new_size - le64toh(f->header->header_size));
 
         return 0;
 }
@@ -418,7 +436,7 @@ static uint64_t journal_file_seqnum(JournalFile *f, uint64_t *seqnum) {
 
         assert(f);
 
-        r = le64toh(f->header->seqnum) + 1;
+        r = le64toh(f->header->tail_seqnum) + 1;
 
         if (seqnum) {
                 /* If an external seqnum counter was passed, we update
@@ -431,10 +449,10 @@ static uint64_t journal_file_seqnum(JournalFile *f, uint64_t *seqnum) {
                 *seqnum = r;
         }
 
-        f->header->seqnum = htole64(r);
+        f->header->tail_seqnum = htole64(r);
 
-        if (f->header->first_seqnum == 0)
-                f->header->first_seqnum = htole64(r);
+        if (f->header->head_seqnum == 0)
+                f->header->head_seqnum = htole64(r);
 
         return r;
 }
@@ -452,7 +470,7 @@ static int journal_file_append_object(JournalFile *f, int type, uint64_t size, O
 
         p = le64toh(f->header->tail_object_offset);
         if (p == 0)
-                p = le64toh(f->header->arena_offset);
+                p = le64toh(f->header->header_size);
         else {
                 r = journal_file_move_to_object(f, -1, p, &tail);
                 if (r < 0)
@@ -588,7 +606,7 @@ static int journal_file_link_data(JournalFile *f, Object *o, uint64_t offset, ui
         o->data.n_entries = 0;
 
         h = hash % (le64toh(f->header->data_hash_table_size) / sizeof(HashItem));
-        p = le64toh(f->data_hash_table[h].head_hash_offset);
+        p = le64toh(f->data_hash_table[h].tail_hash_offset);
         if (p == 0) {
                 /* Only entry in the hash table is easy */
                 f->data_hash_table[h].head_hash_offset = htole64(offset);
@@ -605,6 +623,9 @@ static int journal_file_link_data(JournalFile *f, Object *o, uint64_t offset, ui
 
         f->data_hash_table[h].tail_hash_offset = htole64(offset);
 
+        if (JOURNAL_HEADER_CONTAINS(f->header, n_data))
+                f->header->n_data = htole64(le64toh(f->header->n_data) + 1);
+
         return 0;
 }
 
@@ -1203,8 +1224,15 @@ static int generic_array_bisect(JournalFile *f,
                         }
                 }
 
-                if (k > n)
+                if (k > n) {
+                        if (direction == DIRECTION_UP) {
+                                i = n;
+                                subtract_one = true;
+                                goto found;
+                        }
+
                         return 0;
+                }
 
                 last_p = lp;
 
@@ -1237,7 +1265,7 @@ found:
                 *offset = p;
 
         if (idx)
-                *idx = t + i - (subtract_one ? 1 : 0);
+                *idx = t + i + (subtract_one ? -1 : 0);
 
         return 1;
 }
@@ -1254,6 +1282,8 @@ static int generic_array_bisect_plus_one(JournalFile *f,
                                          uint64_t *idx) {
 
         int r;
+        bool step_back = false;
+        Object *o;
 
         assert(f);
         assert(test_object);
@@ -1266,34 +1296,81 @@ static int generic_array_bisect_plus_one(JournalFile *f,
         r = test_object(f, extra, needle);
         if (r < 0)
                 return r;
-        else if (r == TEST_FOUND) {
-                Object *o;
 
-                r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, &o);
-                if (r < 0)
-                        return r;
+        if (r == TEST_FOUND)
+                r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT;
 
-                if (ret)
-                        *ret = o;
+        /* if we are looking with DIRECTION_UP then we need to first
+           see if in the actual array there is a matching entry, and
+           return the last one of that. But if there isn't any we need
+           to return this one. Hence remember this, and return it
+           below. */
+        if (r == TEST_LEFT)
+                step_back = direction == DIRECTION_UP;
 
-                if (offset)
-                        *offset = extra;
-
-                if (idx)
-                        *idx = 0;
-
-                return 1;
-        } else if (r == TEST_RIGHT)
-                return 0;
+        if (r == TEST_RIGHT) {
+                if (direction == DIRECTION_DOWN)
+                        goto found;
+                else
+                        return 0;
+        }
 
         r = generic_array_bisect(f, first, n-1, needle, test_object, direction, ret, offset, idx);
 
-        if (r > 0)
+        if (r == 0 && step_back)
+                goto found;
+
+        if (r > 0 && idx)
                 (*idx) ++;
 
         return r;
+
+found:
+        r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, &o);
+        if (r < 0)
+                return r;
+
+        if (ret)
+                *ret = o;
+
+        if (offset)
+                *offset = extra;
+
+        if (idx)
+                *idx = 0;
+
+        return 1;
 }
 
+static int test_object_offset(JournalFile *f, uint64_t p, uint64_t needle) {
+        assert(f);
+        assert(p > 0);
+
+        if (p == needle)
+                return TEST_FOUND;
+        else if (p < needle)
+                return TEST_LEFT;
+        else
+                return TEST_RIGHT;
+}
+
+int journal_file_move_to_entry_by_offset(
+                JournalFile *f,
+                uint64_t p,
+                direction_t direction,
+                Object **ret,
+                uint64_t *offset) {
+
+        return generic_array_bisect(f,
+                                    le64toh(f->header->entry_array_offset),
+                                    le64toh(f->header->n_entries),
+                                    p,
+                                    test_object_offset,
+                                    direction,
+                                    ret, offset, NULL);
+}
+
+
 static int test_object_seqnum(JournalFile *f, uint64_t p, uint64_t needle) {
         Object *o;
         int r;
@@ -1391,16 +1468,17 @@ int journal_file_move_to_entry_by_monotonic(
                 Object **ret,
                 uint64_t *offset) {
 
-        char t[8+32+1] = "_BOOT_ID=";
+        char t[9+32+1] = "_BOOT_ID=";
         Object *o;
         int r;
 
-        sd_id128_to_string(boot_id, t + 8);
+        assert(f);
 
+        sd_id128_to_string(boot_id, t + 9);
         r = journal_file_find_data_object(f, t, strlen(t), &o, NULL);
         if (r < 0)
                 return r;
-        else if (r == 0)
+        if (r == 0)
                 return -ENOENT;
 
         return generic_array_bisect_plus_one(f,
@@ -1413,18 +1491,6 @@ int journal_file_move_to_entry_by_monotonic(
                                              ret, offset, NULL);
 }
 
-static int test_object_offset(JournalFile *f, uint64_t p, uint64_t needle) {
-        assert(f);
-        assert(p > 0);
-
-        if (p == needle)
-                return TEST_FOUND;
-        else if (p < needle)
-                return TEST_LEFT;
-        else
-                return TEST_RIGHT;
-}
-
 int journal_file_next_entry(
                 JournalFile *f,
                 Object *o, uint64_t p,
@@ -1589,6 +1655,119 @@ int journal_file_next_entry_for_data(
                                           ret, offset);
 }
 
+int journal_file_move_to_entry_by_offset_for_data(
+                JournalFile *f,
+                uint64_t data_offset,
+                uint64_t p,
+                direction_t direction,
+                Object **ret, uint64_t *offset) {
+
+        int r;
+        Object *d;
+
+        assert(f);
+
+        r = journal_file_move_to_object(f, OBJECT_DATA, data_offset, &d);
+        if (r < 0)
+                return r;
+
+        return generic_array_bisect_plus_one(f,
+                                             le64toh(d->data.entry_offset),
+                                             le64toh(d->data.entry_array_offset),
+                                             le64toh(d->data.n_entries),
+                                             p,
+                                             test_object_offset,
+                                             direction,
+                                             ret, offset, NULL);
+}
+
+int journal_file_move_to_entry_by_monotonic_for_data(
+                JournalFile *f,
+                uint64_t data_offset,
+                sd_id128_t boot_id,
+                uint64_t monotonic,
+                direction_t direction,
+                Object **ret, uint64_t *offset) {
+
+        char t[9+32+1] = "_BOOT_ID=";
+        Object *o, *d;
+        int r;
+        uint64_t b, z;
+
+        assert(f);
+
+        /* First, seek by time */
+        sd_id128_to_string(boot_id, t + 9);
+        r = journal_file_find_data_object(f, t, strlen(t), &o, &b);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ENOENT;
+
+        r = generic_array_bisect_plus_one(f,
+                                          le64toh(o->data.entry_offset),
+                                          le64toh(o->data.entry_array_offset),
+                                          le64toh(o->data.n_entries),
+                                          monotonic,
+                                          test_object_monotonic,
+                                          direction,
+                                          NULL, &z, NULL);
+        if (r <= 0)
+                return r;
+
+        /* And now, continue seeking until we find an entry that
+         * exists in both bisection arrays */
+
+        for (;;) {
+                Object *qo;
+                uint64_t p, q;
+
+                r = journal_file_move_to_object(f, OBJECT_DATA, data_offset, &d);
+                if (r < 0)
+                        return r;
+
+                r = generic_array_bisect_plus_one(f,
+                                                  le64toh(d->data.entry_offset),
+                                                  le64toh(d->data.entry_array_offset),
+                                                  le64toh(d->data.n_entries),
+                                                  z,
+                                                  test_object_offset,
+                                                  direction,
+                                                  NULL, &p, NULL);
+                if (r <= 0)
+                        return r;
+
+                r = journal_file_move_to_object(f, OBJECT_DATA, b, &o);
+                if (r < 0)
+                        return r;
+
+                r = generic_array_bisect_plus_one(f,
+                                                  le64toh(o->data.entry_offset),
+                                                  le64toh(o->data.entry_array_offset),
+                                                  le64toh(o->data.n_entries),
+                                                  p,
+                                                  test_object_offset,
+                                                  direction,
+                                                  &qo, &q, NULL);
+
+                if (r <= 0)
+                        return r;
+
+                if (p == q) {
+                        if (ret)
+                                *ret = qo;
+                        if (offset)
+                                *offset = q;
+
+                        return 1;
+                }
+
+                z = q;
+        }
+
+        return 0;
+}
+
 int journal_file_move_to_entry_by_seqnum_for_data(
                 JournalFile *f,
                 uint64_t data_offset,
@@ -1599,8 +1778,10 @@ int journal_file_move_to_entry_by_seqnum_for_data(
         Object *d;
         int r;
 
+        assert(f);
+
         r = journal_file_move_to_object(f, OBJECT_DATA, data_offset, &d);
-        if (r <= 0)
+        if (r < 0)
                 return r;
 
         return generic_array_bisect_plus_one(f,
@@ -1623,8 +1804,10 @@ int journal_file_move_to_entry_by_realtime_for_data(
         Object *d;
         int r;
 
+        assert(f);
+
         r = journal_file_move_to_object(f, OBJECT_DATA, data_offset, &d);
-        if (r <= 0)
+        if (r < 0)
                 return r;
 
         return generic_array_bisect_plus_one(f,
@@ -1638,29 +1821,15 @@ int journal_file_move_to_entry_by_realtime_for_data(
 }
 
 void journal_file_dump(JournalFile *f) {
-        char a[33], b[33], c[33];
         Object *o;
         int r;
         uint64_t p;
 
         assert(f);
 
-        printf("File Path: %s\n"
-               "File ID: %s\n"
-               "Machine ID: %s\n"
-               "Boot ID: %s\n"
-               "Arena size: %llu\n"
-               "Objects: %lu\n"
-               "Entries: %lu\n",
-               f->path,
-               sd_id128_to_string(f->header->file_id, a),
-               sd_id128_to_string(f->header->machine_id, b),
-               sd_id128_to_string(f->header->boot_id, c),
-               (unsigned long long) le64toh(f->header->arena_size),
-               (unsigned long) le64toh(f->header->n_objects),
-               (unsigned long) le64toh(f->header->n_entries));
+        journal_file_print_header(f);
 
-        p = le64toh(f->header->arena_offset);
+        p = le64toh(f->header->header_size);
         while (p != 0) {
                 r = journal_file_move_to_object(f, -1, p, &o);
                 if (r < 0)
@@ -1694,6 +1863,10 @@ void journal_file_dump(JournalFile *f) {
                 case OBJECT_ENTRY_ARRAY:
                         printf("Type: OBJECT_ENTRY_ARRAY\n");
                         break;
+
+                case OBJECT_SIGNATURE:
+                        printf("Type: OBJECT_SIGNATURE\n");
+                        break;
                 }
 
                 if (o->object.flags & OBJECT_COMPRESSED)
@@ -1710,6 +1883,58 @@ fail:
         log_error("File corrupt");
 }
 
+void journal_file_print_header(JournalFile *f) {
+        char a[33], b[33], c[33];
+        char x[FORMAT_TIMESTAMP_MAX], y[FORMAT_TIMESTAMP_MAX];
+
+        assert(f);
+
+        printf("File Path: %s\n"
+               "File ID: %s\n"
+               "Machine ID: %s\n"
+               "Boot ID: %s\n"
+               "Sequential Number ID: %s\n"
+               "Header size: %llu\n"
+               "Arena size: %llu\n"
+               "Data Hash Table Size: %llu\n"
+               "Field Hash Table Size: %llu\n"
+               "Objects: %llu\n"
+               "Entry Objects: %llu\n"
+               "Rotate Suggested: %s\n"
+               "Head Sequential Number: %llu\n"
+               "Tail Sequential Number: %llu\n"
+               "Head Realtime Timestamp: %s\n"
+               "Tail Realtime Timestamp: %s\n",
+               f->path,
+               sd_id128_to_string(f->header->file_id, a),
+               sd_id128_to_string(f->header->machine_id, b),
+               sd_id128_to_string(f->header->boot_id, c),
+               sd_id128_to_string(f->header->seqnum_id, c),
+               (unsigned long long) le64toh(f->header->header_size),
+               (unsigned long long) le64toh(f->header->arena_size),
+               (unsigned long long) le64toh(f->header->data_hash_table_size) / sizeof(HashItem),
+               (unsigned long long) le64toh(f->header->field_hash_table_size) / sizeof(HashItem),
+               (unsigned long long) le64toh(f->header->n_objects),
+               (unsigned long long) le64toh(f->header->n_entries),
+               yes_no(journal_file_rotate_suggested(f)),
+               (unsigned long long) le64toh(f->header->head_seqnum),
+               (unsigned long long) le64toh(f->header->tail_seqnum),
+               format_timestamp(x, sizeof(x), le64toh(f->header->head_entry_realtime)),
+               format_timestamp(y, sizeof(y), le64toh(f->header->tail_entry_realtime)));
+
+        if (JOURNAL_HEADER_CONTAINS(f->header, n_data))
+                printf("Data Objects: %llu\n"
+                       "Data Hash Table Fill: %.1f%%\n",
+                       (unsigned long long) le64toh(f->header->n_data),
+                       100.0 * (double) le64toh(f->header->n_data) / ((double) (le64toh(f->header->data_hash_table_size) / sizeof(HashItem))));
+
+        if (JOURNAL_HEADER_CONTAINS(f->header, n_fields))
+                printf("Field Objects: %llu\n"
+                       "Field Hash Table Fill: %.1f%%\n",
+                       (unsigned long long) le64toh(f->header->n_fields),
+                       100.0 * (double) le64toh(f->header->n_fields) / ((double) (le64toh(f->header->field_hash_table_size) / sizeof(HashItem))));
+}
+
 int journal_file_open(
                 const char *fname,
                 int flags,
@@ -1775,7 +2000,7 @@ int journal_file_open(
                 }
         }
 
-        if (f->last_stat.st_size < (off_t) sizeof(Header)) {
+        if (f->last_stat.st_size < (off_t) HEADER_SIZE_MIN) {
                 r = -EIO;
                 goto fail;
         }
@@ -1857,7 +2082,7 @@ int journal_file_rotate(JournalFile **f) {
         sd_id128_to_string(old_file->header->seqnum_id, p + l - 8 + 1);
         snprintf(p + l - 8 + 1 + 32, 1 + 16 + 1 + 16 + 8 + 1,
                  "-%016llx-%016llx.journal",
-                 (unsigned long long) le64toh((*f)->header->seqnum),
+                 (unsigned long long) le64toh((*f)->header->tail_seqnum),
                  (unsigned long long) le64toh((*f)->header->tail_entry_realtime));
 
         r = rename(old_file->path, p);
@@ -2137,9 +2362,6 @@ int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint6
             ts.monotonic < le64toh(to->header->tail_entry_monotonic))
                 return -EINVAL;
 
-        if (ts.realtime < le64toh(to->header->tail_entry_realtime))
-                return -EINVAL;
-
         n = journal_file_entry_n_items(o);
         items = alloca(sizeof(EntryItem) * n);
 
@@ -2272,3 +2494,94 @@ 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) {
+        assert(f);
+        assert(from || to);
+
+        if (from) {
+                if (f->header->head_entry_realtime == 0)
+                        return -ENOENT;
+
+                *from = le64toh(f->header->head_entry_realtime);
+        }
+
+        if (to) {
+                if (f->header->tail_entry_realtime == 0)
+                        return -ENOENT;
+
+                *to = le64toh(f->header->tail_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;
+}
+
+bool journal_file_rotate_suggested(JournalFile *f) {
+        assert(f);
+
+        /* If we gained new header fields we gained new features,
+         * hence suggest a rotation */
+        if (le64toh(f->header->header_size) < sizeof(Header))
+                return true;
+
+        /* Let's check if the hash tables grew over a certain fill
+         * level (75%, borrowing this value from Java's hash table
+         * implementation), and if so suggest a rotation. To calculate
+         * the fill level we need the n_data field, which only exists
+         * in newer versions. */
+
+        if (JOURNAL_HEADER_CONTAINS(f->header, n_data))
+                if (le64toh(f->header->n_data) * 4ULL > (le64toh(f->header->data_hash_table_size) / sizeof(HashItem)) * 3ULL)
+                        return true;
+
+        if (JOURNAL_HEADER_CONTAINS(f->header, n_fields))
+                if (le64toh(f->header->n_fields) * 4ULL > (le64toh(f->header->field_hash_table_size) / sizeof(HashItem)) * 3ULL)
+                        return true;
+
+        return false;
+}