virtual: Log a debug message why backend mailbox has changed

diff --git a/src/plugins/virtual/virtual-sync.c b/src/plugins/virtual/virtual-sync.c
index 9b0340d588bad852a112f0a5ad3d9bca50effcfe..f46e6201dc3d9cfe76405472a5727728bc769ee8 100644 (file)
--- a/src/plugins/virtual/virtual-sync.c
+++ b/src/plugins/virtual/virtual-sync.c
@@ -1210,6 +1210,37 @@ static int virtual_sync_backend_box_sync(struct virtual_sync_context *ctx,
        return 0;
 }
 
+static bool
+virtual_bbox_mailbox_equals(struct virtual_backend_box *bbox,
+                           const struct mailbox_status *status,
+                           struct mailbox_metadata *metadata,
+                           const char **reason_r)
+{
+       if (!guid_128_equals(bbox->sync_guid, metadata->guid)) {
+               *reason_r = t_strdup_printf("GUID changed: %s -> %s",
+                                           guid_128_to_string(bbox->sync_guid),
+                                           guid_128_to_string(metadata->guid));
+               return FALSE;
+       }
+       if (bbox->sync_uid_validity != status->uidvalidity) {
+               *reason_r = t_strdup_printf("UIDVALIDITY changed: %u -> %u",
+                       bbox->sync_uid_validity, status->uidvalidity);
+               return FALSE;
+       }
+       if (bbox->sync_next_uid != status->uidnext) {
+               *reason_r = t_strdup_printf("UIDNEXT changed: %u -> %u",
+                       bbox->sync_next_uid, status->uidnext);
+               return FALSE;
+       }
+       if (bbox->sync_highest_modseq != status->highest_modseq) {
+               *reason_r = t_strdup_printf("HIGHESTMODSEQ changed: "
+                       "%"PRIu64" -> %"PRIu64,
+                       bbox->sync_highest_modseq, status->highest_modseq);
+               return FALSE;
+       }
+       return TRUE;
+}
+
 static void virtual_sync_backend_ext_header(struct virtual_sync_context *ctx,
                                            struct virtual_backend_box *bbox)
 {
@@ -1222,6 +1253,7 @@ static void virtual_sync_backend_ext_header(struct virtual_sync_context *ctx,
        unsigned int mailbox_offset, ext2_offset;
        uint64_t wanted_ondisk_highest_modseq;
        struct mailbox_metadata metadata;
+       const char *reason;
 
        mailbox_get_open_status(bbox->box, STATUS_UIDVALIDITY |
                                STATUS_HIGHESTMODSEQ, &status);
@@ -1234,10 +1266,7 @@ static void virtual_sync_backend_ext_header(struct virtual_sync_context *ctx,
                                 &metadata) < 0)
                i_unreached();
 
-       if (bbox->sync_uid_validity == status.uidvalidity &&
-           bbox->sync_next_uid == status.uidnext &&
-           bbox->sync_highest_modseq == status.highest_modseq &&
-           guid_128_equals(bbox->sync_guid, metadata.guid) &&
+       if (virtual_bbox_mailbox_equals(bbox, &status, &metadata, &reason) &&
            bbox->ondisk_highest_modseq == wanted_ondisk_highest_modseq)
                return;
 
@@ -1318,6 +1347,7 @@ static int virtual_sync_backend_box(struct virtual_sync_context *ctx,
 {
        enum mailbox_sync_flags sync_flags;
        struct mailbox_status status;
+       const char *reason;
        int ret;
 
        if (bbox->deleted)
@@ -1366,10 +1396,7 @@ static int virtual_sync_backend_box(struct virtual_sync_context *ctx,
                        guid_128_copy(bbox->sync_guid, metadata.guid);
                        ctx->mbox->ext_header_rewrite = TRUE;
                }
-               if (status.uidvalidity == bbox->sync_uid_validity &&
-                   status.uidnext == bbox->sync_next_uid &&
-                   status.highest_modseq == bbox->sync_highest_modseq &&
-                   guid_128_equals(metadata.guid, bbox->sync_guid)) {
+               if (virtual_bbox_mailbox_equals(bbox, &status, &metadata, &reason)) {
                        /* mailbox hasn't changed since we last opened it,
                           skip it for now.
 
@@ -1379,6 +1406,8 @@ static int virtual_sync_backend_box(struct virtual_sync_context *ctx,
                                virtual_sync_backend_handle_old_vmsgs(ctx, bbox, NULL);
                        return 0;
                }
+               e_debug(ctx->mbox->box.event, "Backend mailbox %s changed: %s",
+                       bbox->box->vname, reason);
                if (!bbox->box->opened) {
                        /* first time we're opening the index */
                        if ((ret = virtual_try_open_and_sync_backend_box(ctx, bbox, sync_flags)) <= 0)