X-Git-Url: https://git.notmuchmail.org/git?p=notmuch;a=blobdiff_plain;f=lib%2Fdatabase.cc;h=bab333412de1c9edb713b222ebad0400b6cf8987;hp=92a92d9ae1cc1b1bbf930d28aa17ecad373c51d9;hb=cb08a2ee019e52dc29ba393d139fce8d7282c632;hpb=58a4277d3b2ad88bc285f2dae998626b0aa73299

diff --git a/lib/database.cc b/lib/database.cc
index 92a92d9a..bab33341 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -101,6 +101,9 @@ typedef struct {
  *
  *	SUBJECT:	The value of the "Subject" header
  *
+ *	LAST_MOD:	The revision number as of the last tag or
+ *			filename change.
+ *
  * In addition, terms from the content of the message are added with
  * "from", "to", "attachment", and "subject" prefixes for use by the
  * user in searching. Similarly, terms from the path of the mail
@@ -254,6 +257,7 @@ static prefix_t PROBABILISTIC_PREFIX[]= {
     { "from",			"XFROM" },
     { "to",			"XTO" },
     { "attachment",		"XATTACHMENT" },
+    { "mimetype",		"XMIMETYPE"},
     { "subject",		"XSUBJECT"},
 };
 
@@ -304,6 +308,13 @@ static const struct {
       "exact folder:/path: search", "rw" },
     { NOTMUCH_FEATURE_GHOSTS,
       "mail documents for missing messages", "w"},
+    /* Knowledge of the index mime-types are not required for reading
+     * a database because a reader will just be unable to query
+     * them. */
+    { NOTMUCH_FEATURE_INDEXED_MIMETYPES,
+      "indexed MIME types", "w"},
+    { NOTMUCH_FEATURE_LAST_MOD,
+      "modification tracking", "w"},
 };
 
 const char *
@@ -336,12 +347,31 @@ notmuch_status_to_string (notmuch_status_t status)
 	return "Unsupported operation";
     case NOTMUCH_STATUS_UPGRADE_REQUIRED:
 	return "Operation requires a database upgrade";
+    case NOTMUCH_STATUS_PATH_ERROR:
+	return "Path supplied is illegal for this function";
     default:
     case NOTMUCH_STATUS_LAST_STATUS:
 	return "Unknown error status value";
     }
 }
 
+void
+_notmuch_database_log (notmuch_database_t *notmuch,
+		      const char *format,
+		      ...)
+{
+    va_list va_args;
+
+    va_start (va_args, format);
+
+    if (notmuch->status_string)
+	talloc_free (notmuch->status_string);
+
+    notmuch->status_string = talloc_vasprintf (notmuch, format, va_args);
+
+    va_end (va_args);
+}
+
 static void
 find_doc_ids_for_term (notmuch_database_t *notmuch,
 		       const char *term,
@@ -450,7 +480,7 @@ notmuch_database_find_message (notmuch_database_t *notmuch,
 
 	return NOTMUCH_STATUS_SUCCESS;
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred finding message: %s.\n",
+	_notmuch_database_log (notmuch, "A Xapian exception occurred finding message: %s.\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
 	*message_ret = NULL;
@@ -601,30 +631,57 @@ parse_references (void *ctx,
 
 notmuch_status_t
 notmuch_database_create (const char *path, notmuch_database_t **database)
+{
+    char *status_string = NULL;
+    notmuch_status_t status;
+
+    status = notmuch_database_create_verbose (path, database,
+					      &status_string);
+
+    if (status_string) {
+	fputs (status_string, stderr);
+	free (status_string);
+    }
+
+    return status;
+}
+
+notmuch_status_t
+notmuch_database_create_verbose (const char *path,
+				 notmuch_database_t **database,
+				 char **status_string)
 {
     notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
     notmuch_database_t *notmuch = NULL;
     char *notmuch_path = NULL;
+    char *message = NULL;
     struct stat st;
     int err;
 
     if (path == NULL) {
-	fprintf (stderr, "Error: Cannot create a database for a NULL path.\n");
+	message = strdup ("Error: Cannot create a database for a NULL path.\n");
 	status = NOTMUCH_STATUS_NULL_POINTER;
 	goto DONE;
     }
 
+    if (path[0] != '/') {
+	message = strdup ("Error: Database path must be absolute.\n");
+	status = NOTMUCH_STATUS_PATH_ERROR;
+	goto DONE;
+    }
+
     err = stat (path, &st);
     if (err) {
-	fprintf (stderr, "Error: Cannot create database at %s: %s.\n",
-		 path, strerror (errno));
+	IGNORE_RESULT (asprintf (&message, "Error: Cannot create database at %s: %s.\n",
+				path, strerror (errno)));
 	status = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
     }
 
     if (! S_ISDIR (st.st_mode)) {
-	fprintf (stderr, "Error: Cannot create database at %s: Not a directory.\n",
-		 path);
+	IGNORE_RESULT (asprintf (&message, "Error: Cannot create database at %s: "
+				 "Not a directory.\n",
+				 path));
 	status = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
     }
@@ -634,21 +691,22 @@ notmuch_database_create (const char *path, notmuch_database_t **database)
     err = mkdir (notmuch_path, 0755);
 
     if (err) {
-	fprintf (stderr, "Error: Cannot create directory %s: %s.\n",
-		 notmuch_path, strerror (errno));
+	IGNORE_RESULT (asprintf (&message, "Error: Cannot create directory %s: %s.\n",
+				 notmuch_path, strerror (errno)));
 	status = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
     }
 
-    status = notmuch_database_open (path,
-				    NOTMUCH_DATABASE_MODE_READ_WRITE,
-				    &notmuch);
+    status = notmuch_database_open_verbose (path,
+					    NOTMUCH_DATABASE_MODE_READ_WRITE,
+					    &notmuch, &message);
     if (status)
 	goto DONE;
 
-    /* Upgrade doesn't add this feature to existing databases, but new
-     * databases have it. */
+    /* Upgrade doesn't add these feature to existing databases, but
+     * new databases have them. */
     notmuch->features |= NOTMUCH_FEATURE_FROM_SUBJECT_ID_VALUES;
+    notmuch->features |= NOTMUCH_FEATURE_INDEXED_MIMETYPES;
 
     status = notmuch_database_upgrade (notmuch, NULL, NULL);
     if (status) {
@@ -660,6 +718,12 @@ notmuch_database_create (const char *path, notmuch_database_t **database)
     if (notmuch_path)
 	talloc_free (notmuch_path);
 
+    if (message) {
+	if (status_string)
+	    *status_string = message;
+	else
+	    free (message);
+    }
     if (database)
 	*database = notmuch;
     else
@@ -671,13 +735,30 @@ notmuch_status_t
 _notmuch_database_ensure_writable (notmuch_database_t *notmuch)
 {
     if (notmuch->mode == NOTMUCH_DATABASE_MODE_READ_ONLY) {
-	fprintf (stderr, "Cannot write to a read-only database.\n");
+	_notmuch_database_log (notmuch, "Cannot write to a read-only database.\n");
 	return NOTMUCH_STATUS_READ_ONLY_DATABASE;
     }
 
     return NOTMUCH_STATUS_SUCCESS;
 }
 
+/* Allocate a revision number for the next change. */
+unsigned long
+_notmuch_database_new_revision (notmuch_database_t *notmuch)
+{
+    unsigned long new_revision = notmuch->revision + 1;
+
+    /* If we're in an atomic section, hold off on updating the
+     * committed revision number until we commit the atomic section.
+     */
+    if (notmuch->atomic_nesting)
+	notmuch->atomic_dirty = TRUE;
+    else
+	notmuch->revision = new_revision;
+
+    return new_revision;
+}
+
 /* Parse a database features string from the given database version.
  * Returns the feature bit set.
  *
@@ -759,38 +840,65 @@ notmuch_status_t
 notmuch_database_open (const char *path,
 		       notmuch_database_mode_t mode,
 		       notmuch_database_t **database)
+{
+    char *status_string = NULL;
+    notmuch_status_t status;
+
+    status = notmuch_database_open_verbose (path, mode, database,
+					   &status_string);
+
+    if (status_string) {
+	fputs (status_string, stderr);
+	free (status_string);
+    }
+
+    return status;
+}
+
+notmuch_status_t
+notmuch_database_open_verbose (const char *path,
+			       notmuch_database_mode_t mode,
+			       notmuch_database_t **database,
+			       char **status_string)
 {
     notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
     void *local = talloc_new (NULL);
     notmuch_database_t *notmuch = NULL;
     char *notmuch_path, *xapian_path, *incompat_features;
+    char *message = NULL;
     struct stat st;
     int err;
     unsigned int i, version;
     static int initialized = 0;
 
     if (path == NULL) {
-	fprintf (stderr, "Error: Cannot open a database for a NULL path.\n");
+	message = strdup ("Error: Cannot open a database for a NULL path.\n");
 	status = NOTMUCH_STATUS_NULL_POINTER;
 	goto DONE;
     }
 
+    if (path[0] != '/') {
+	message = strdup ("Error: Database path must be absolute.\n");
+	status = NOTMUCH_STATUS_PATH_ERROR;
+	goto DONE;
+    }
+
     if (! (notmuch_path = talloc_asprintf (local, "%s/%s", path, ".notmuch"))) {
-	fprintf (stderr, "Out of memory\n");
+	message = strdup ("Out of memory\n");
 	status = NOTMUCH_STATUS_OUT_OF_MEMORY;
 	goto DONE;
     }
 
     err = stat (notmuch_path, &st);
     if (err) {
-	fprintf (stderr, "Error opening database at %s: %s\n",
-		 notmuch_path, strerror (errno));
+	IGNORE_RESULT (asprintf (&message, "Error opening database at %s: %s\n",
+				 notmuch_path, strerror (errno)));
 	status = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
     }
 
     if (! (xapian_path = talloc_asprintf (local, "%s/%s", notmuch_path, "xapian"))) {
-	fprintf (stderr, "Out of memory\n");
+	message = strdup ("Out of memory\n");
 	status = NOTMUCH_STATUS_OUT_OF_MEMORY;
 	goto DONE;
     }
@@ -808,6 +916,7 @@ notmuch_database_open (const char *path,
 
     notmuch = talloc_zero (NULL, notmuch_database_t);
     notmuch->exception_reported = FALSE;
+    notmuch->status_string = NULL;
     notmuch->path = talloc_strdup (notmuch, path);
 
     if (notmuch->path[strlen (notmuch->path) - 1] == '/')
@@ -817,6 +926,7 @@ notmuch_database_open (const char *path,
     notmuch->atomic_nesting = 0;
     try {
 	string last_thread_id;
+	string last_mod;
 
 	if (mode == NOTMUCH_DATABASE_MODE_READ_WRITE) {
 	    notmuch->xapian_db = new Xapian::WritableDatabase (xapian_path,
@@ -830,11 +940,11 @@ notmuch_database_open (const char *path,
 	 * means a dramatically incompatible change. */
 	version = notmuch_database_get_version (notmuch);
 	if (version > NOTMUCH_DATABASE_VERSION) {
-	    fprintf (stderr,
-		     "Error: Notmuch database at %s\n"
-		     "       has a newer database format version (%u) than supported by this\n"
-		     "       version of notmuch (%u).\n",
-		     notmuch_path, version, NOTMUCH_DATABASE_VERSION);
+	    IGNORE_RESULT (asprintf (&message,
+		      "Error: Notmuch database at %s\n"
+		      "       has a newer database format version (%u) than supported by this\n"
+		      "       version of notmuch (%u).\n",
+				     notmuch_path, version, NOTMUCH_DATABASE_VERSION));
 	    notmuch->mode = NOTMUCH_DATABASE_MODE_READ_ONLY;
 	    notmuch_database_destroy (notmuch);
 	    notmuch = NULL;
@@ -849,11 +959,11 @@ notmuch_database_open (const char *path,
 	    version, mode == NOTMUCH_DATABASE_MODE_READ_WRITE ? 'w' : 'r',
 	    &incompat_features);
 	if (incompat_features) {
-	    fprintf (stderr,
-		     "Error: Notmuch database at %s\n"
-		     "       requires features (%s)\n"
-		     "       not supported by this version of notmuch.\n",
-		     notmuch_path, incompat_features);
+	    IGNORE_RESULT (asprintf (&message,
+		"Error: Notmuch database at %s\n"
+		"       requires features (%s)\n"
+		"       not supported by this version of notmuch.\n",
+				     notmuch_path, incompat_features));
 	    notmuch->mode = NOTMUCH_DATABASE_MODE_READ_ONLY;
 	    notmuch_database_destroy (notmuch);
 	    notmuch = NULL;
@@ -875,11 +985,22 @@ notmuch_database_open (const char *path,
 		INTERNAL_ERROR ("Malformed database last_thread_id: %s", str);
 	}
 
+	/* Get current highest revision number. */
+	last_mod = notmuch->xapian_db->get_value_upper_bound (
+	    NOTMUCH_VALUE_LAST_MOD);
+	if (last_mod.empty ())
+	    notmuch->revision = 0;
+	else
+	    notmuch->revision = Xapian::sortable_unserialise (last_mod);
+	notmuch->uuid = talloc_strdup (
+	    notmuch, notmuch->xapian_db->get_uuid ().c_str ());
+
 	notmuch->query_parser = new Xapian::QueryParser;
 	notmuch->term_gen = new Xapian::TermGenerator;
 	notmuch->term_gen->set_stemmer (Xapian::Stem ("english"));
 	notmuch->value_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_TIMESTAMP);
 	notmuch->date_range_processor = new ParseTimeValueRangeProcessor (NOTMUCH_VALUE_TIMESTAMP);
+	notmuch->last_mod_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_LAST_MOD, "lastmod:");
 
 	notmuch->query_parser->set_default_op (Xapian::Query::OP_AND);
 	notmuch->query_parser->set_database (*notmuch->xapian_db);
@@ -887,6 +1008,7 @@ notmuch_database_open (const char *path,
 	notmuch->query_parser->set_stemming_strategy (Xapian::QueryParser::STEM_SOME);
 	notmuch->query_parser->add_valuerangeprocessor (notmuch->value_range_processor);
 	notmuch->query_parser->add_valuerangeprocessor (notmuch->date_range_processor);
+	notmuch->query_parser->add_valuerangeprocessor (notmuch->last_mod_range_processor);
 
 	for (i = 0; i < ARRAY_SIZE (BOOLEAN_PREFIX_EXTERNAL); i++) {
 	    prefix_t *prefix = &BOOLEAN_PREFIX_EXTERNAL[i];
@@ -899,8 +1021,8 @@ notmuch_database_open (const char *path,
 	    notmuch->query_parser->add_prefix (prefix->name, prefix->prefix);
 	}
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred opening database: %s\n",
-		 error.get_msg().c_str());
+	IGNORE_RESULT (asprintf (&message, "A Xapian exception occurred opening database: %s\n",
+				 error.get_msg().c_str()));
 	notmuch_database_destroy (notmuch);
 	notmuch = NULL;
 	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
@@ -909,6 +1031,13 @@ notmuch_database_open (const char *path,
   DONE:
     talloc_free (local);
 
+    if (message) {
+	if (status_string)
+	    *status_string = message;
+	else
+	    free (message);
+    }
+
     if (database)
 	*database = notmuch;
     else
@@ -942,7 +1071,7 @@ notmuch_database_close (notmuch_database_t *notmuch)
 	} catch (const Xapian::Error &error) {
 	    status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 	    if (! notmuch->exception_reported) {
-		fprintf (stderr, "Error: A Xapian exception occurred closing database: %s\n",
+		_notmuch_database_log (notmuch, "Error: A Xapian exception occurred closing database: %s\n",
 			 error.get_msg().c_str());
 	    }
 	}
@@ -958,6 +1087,8 @@ notmuch_database_close (notmuch_database_t *notmuch)
     notmuch->value_range_processor = NULL;
     delete notmuch->date_range_processor;
     notmuch->date_range_processor = NULL;
+    delete notmuch->last_mod_range_processor;
+    notmuch->last_mod_range_processor = NULL;
 
     return status;
 }
@@ -1032,13 +1163,18 @@ notmuch_database_compact (const char *path,
     notmuch_database_t *notmuch = NULL;
     struct stat statbuf;
     notmuch_bool_t keep_backup;
+    char *message = NULL;
 
     local = talloc_new (NULL);
     if (! local)
 	return NOTMUCH_STATUS_OUT_OF_MEMORY;
 
-    ret = notmuch_database_open (path, NOTMUCH_DATABASE_MODE_READ_WRITE, &notmuch);
+    ret = notmuch_database_open_verbose (path,
+					 NOTMUCH_DATABASE_MODE_READ_WRITE,
+					 &notmuch,
+					 &message);
     if (ret) {
+	if (status_cb) status_cb (message, closure);
 	goto DONE;
     }
 
@@ -1069,12 +1205,12 @@ notmuch_database_compact (const char *path,
     }
 
     if (stat (backup_path, &statbuf) != -1) {
-	fprintf (stderr, "Path already exists: %s\n", backup_path);
+	_notmuch_database_log (notmuch, "Path already exists: %s\n", backup_path);
 	ret = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
     }
     if (errno != ENOENT) {
-	fprintf (stderr, "Unknown error while stat()ing path: %s\n",
+	_notmuch_database_log (notmuch, "Unknown error while stat()ing path: %s\n",
 		 strerror (errno));
 	ret = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
@@ -1094,20 +1230,20 @@ notmuch_database_compact (const char *path,
 	compactor.set_destdir (compact_xapian_path);
 	compactor.compact ();
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "Error while compacting: %s\n", error.get_msg().c_str());
+	_notmuch_database_log (notmuch, "Error while compacting: %s\n", error.get_msg().c_str());
 	ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 	goto DONE;
     }
 
     if (rename (xapian_path, backup_path)) {
-	fprintf (stderr, "Error moving %s to %s: %s\n",
+	_notmuch_database_log (notmuch, "Error moving %s to %s: %s\n",
 		 xapian_path, backup_path, strerror (errno));
 	ret = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
     }
 
     if (rename (compact_xapian_path, xapian_path)) {
-	fprintf (stderr, "Error moving %s to %s: %s\n",
+	_notmuch_database_log (notmuch, "Error moving %s to %s: %s\n",
 		 compact_xapian_path, xapian_path, strerror (errno));
 	ret = NOTMUCH_STATUS_FILE_ERROR;
 	goto DONE;
@@ -1115,7 +1251,7 @@ notmuch_database_compact (const char *path,
 
     if (! keep_backup) {
 	if (rmtree (backup_path)) {
-	    fprintf (stderr, "Error removing old database %s: %s\n",
+	    _notmuch_database_log (notmuch, "Error removing old database %s: %s\n",
 		     backup_path, strerror (errno));
 	    ret = NOTMUCH_STATUS_FILE_ERROR;
 	    goto DONE;
@@ -1126,6 +1262,10 @@ notmuch_database_compact (const char *path,
     if (notmuch) {
 	notmuch_status_t ret2;
 
+	const char *str = notmuch_database_status_string (notmuch);
+	if (status_cb && str)
+	    status_cb (str, closure);
+
 	ret2 = notmuch_database_destroy (notmuch);
 
 	/* don't clobber previous error status */
@@ -1144,7 +1284,7 @@ notmuch_database_compact (unused (const char *path),
 			  unused (notmuch_compact_status_cb_t status_cb),
 			  unused (void *closure))
 {
-    fprintf (stderr, "notmuch was compiled against a xapian version lacking compaction support.\n");
+    _notmuch_database_log (notmuch, "notmuch was compiled against a xapian version lacking compaction support.\n");
     return NOTMUCH_STATUS_UNSUPPORTED_OPERATION;
 }
 #endif
@@ -1231,6 +1371,7 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
     notmuch_bool_t timer_is_active = FALSE;
     enum _notmuch_features target_features, new_features;
     notmuch_status_t status;
+    notmuch_private_status_t private_status;
     unsigned int count = 0, total = 0;
 
     status = _notmuch_database_ensure_writable (notmuch);
@@ -1246,7 +1387,7 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
 	return NOTMUCH_STATUS_SUCCESS;
 
     if (progress_notify) {
-	/* Setup our handler for SIGALRM */
+	/* Set up our handler for SIGALRM */
 	memset (&action, 0, sizeof (struct sigaction));
 	action.sa_handler = handle_sigalrm;
 	sigemptyset (&action.sa_mask);
@@ -1265,7 +1406,8 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
 
     /* Figure out how much total work we need to do. */
     if (new_features &
-	(NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_BOOL_FOLDER)) {
+	(NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_BOOL_FOLDER |
+	 NOTMUCH_FEATURE_LAST_MOD)) {
 	notmuch_query_t *query = notmuch_query_create (notmuch, "");
 	total += notmuch_query_count_messages (query);
 	notmuch_query_destroy (query);
@@ -1275,6 +1417,13 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
 	for (t = db->allterms_begin ("XTIMESTAMP"); t != t_end; t++)
 	    ++total;
     }
+    if (new_features & NOTMUCH_FEATURE_GHOSTS) {
+	/* The ghost message upgrade converts all thread_id_*
+	 * metadata values into ghost message documents. */
+	t_end = db->metadata_keys_end ("thread_id_");
+	for (t = db->metadata_keys_begin ("thread_id_"); t != t_end; ++t)
+	    ++total;
+    }
 
     /* Perform the upgrade in a transaction. */
     db->begin_transaction (true);
@@ -1285,7 +1434,8 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
 
     /* Perform per-message upgrades. */
     if (new_features &
-	(NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_BOOL_FOLDER)) {
+	(NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_BOOL_FOLDER |
+	 NOTMUCH_FEATURE_LAST_MOD)) {
 	notmuch_query_t *query = notmuch_query_create (notmuch, "");
 	notmuch_messages_t *messages;
 	notmuch_message_t *message;
@@ -1322,6 +1472,14 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
 	    if (new_features & NOTMUCH_FEATURE_BOOL_FOLDER)
 		_notmuch_message_upgrade_folder (message);
 
+	    /* Prior to NOTMUCH_FEATURE_LAST_MOD, messages did not
+	     * track modification revisions.  Give all messages the
+	     * next available revision; since we just started tracking
+	     * revisions for this database, that will be 1.
+	     */
+	    if (new_features & NOTMUCH_FEATURE_LAST_MOD)
+		_notmuch_message_upgrade_last_mod (message);
+
 	    _notmuch_message_sync (message);
 
 	    notmuch_message_destroy (message);
@@ -1378,10 +1536,64 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
 	}
     }
 
+    /* Perform metadata upgrades. */
+
+    /* Prior to NOTMUCH_FEATURE_GHOSTS, thread IDs for missing
+     * messages were stored as database metadata. Change these to
+     * ghost messages.
+     */
+    if (new_features & NOTMUCH_FEATURE_GHOSTS) {
+	notmuch_message_t *message;
+	std::string message_id, thread_id;
+
+	t_end = db->metadata_keys_end (NOTMUCH_METADATA_THREAD_ID_PREFIX);
+	for (t = db->metadata_keys_begin (NOTMUCH_METADATA_THREAD_ID_PREFIX);
+	     t != t_end; ++t) {
+	    if (do_progress_notify) {
+		progress_notify (closure, (double) count / total);
+		do_progress_notify = 0;
+	    }
+
+	    message_id = (*t).substr (
+		strlen (NOTMUCH_METADATA_THREAD_ID_PREFIX));
+	    thread_id = db->get_metadata (*t);
+
+	    /* Create ghost message */
+	    message = _notmuch_message_create_for_message_id (
+		notmuch, message_id.c_str (), &private_status);
+	    if (private_status == NOTMUCH_PRIVATE_STATUS_SUCCESS) {
+		/* Document already exists; ignore the stored thread ID */
+	    } else if (private_status ==
+		       NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND) {
+		private_status = _notmuch_message_initialize_ghost (
+		    message, thread_id.c_str ());
+		if (! private_status)
+		    _notmuch_message_sync (message);
+	    }
+
+	    if (private_status) {
+		_notmuch_database_log (notmuch,
+			 "Upgrade failed while creating ghost messages.\n");
+		status = COERCE_STATUS (private_status, "Unexpected status from _notmuch_message_initialize_ghost");
+		goto DONE;
+	    }
+
+	    /* Clear saved metadata thread ID */
+	    db->set_metadata (*t, "");
+
+	    ++count;
+	}
+    }
+
+    status = NOTMUCH_STATUS_SUCCESS;
     db->set_metadata ("features", _print_features (local, notmuch->features));
     db->set_metadata ("version", STRINGIFY (NOTMUCH_DATABASE_VERSION));
 
-    db->commit_transaction ();
+ DONE:
+    if (status == NOTMUCH_STATUS_SUCCESS)
+	db->commit_transaction ();
+    else
+	db->cancel_transaction ();
 
     if (timer_is_active) {
 	/* Now stop the timer. */
@@ -1397,7 +1609,7 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
     }
 
     talloc_free (local);
-    return NOTMUCH_STATUS_SUCCESS;
+    return status;
 }
 
 notmuch_status_t
@@ -1410,7 +1622,7 @@ notmuch_database_begin_atomic (notmuch_database_t *notmuch)
     try {
 	(static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db))->begin_transaction (false);
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred beginning transaction: %s.\n",
+	_notmuch_database_log (notmuch, "A Xapian exception occurred beginning transaction: %s.\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
 	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
@@ -1444,17 +1656,31 @@ notmuch_database_end_atomic (notmuch_database_t *notmuch)
 	if (thresh && atoi (thresh) == 1)
 	    db->flush ();
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred committing transaction: %s.\n",
+	_notmuch_database_log (notmuch, "A Xapian exception occurred committing transaction: %s.\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
 	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
     }
 
+    if (notmuch->atomic_dirty) {
+	++notmuch->revision;
+	notmuch->atomic_dirty = FALSE;
+    }
+
 DONE:
     notmuch->atomic_nesting--;
     return NOTMUCH_STATUS_SUCCESS;
 }
 
+unsigned long
+notmuch_database_get_revision (notmuch_database_t *notmuch,
+				const char **uuid)
+{
+    if (uuid)
+	*uuid = notmuch->uuid;
+    return notmuch->revision;
+}
+
 /* We allow the user to use arbitrarily long paths for directories. But
  * we have a term-length limit. So if we exceed that, we'll use the
  * SHA-1 of the path for the database term.
@@ -1690,7 +1916,7 @@ notmuch_database_get_directory (notmuch_database_t *notmuch,
 	*directory = _notmuch_directory_create (notmuch, path,
 						NOTMUCH_FIND_LOOKUP, &status);
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred getting directory: %s.\n",
+	_notmuch_database_log (notmuch, "A Xapian exception occurred getting directory: %s.\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
 	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
@@ -2074,11 +2300,11 @@ _consume_metadata_thread_id (void *ctx, notmuch_database_t *notmuch,
  * reference 'message'.
  *
  * In all cases, we assign to the current message the first thread ID
- * found (through either parent or child). We will also merge any
- * existing, distinct threads where this message belongs to both,
- * (which is not uncommon when messages are processed out of order).
+ * found. We will also merge any existing, distinct threads where this
+ * message belongs to both, (which is not uncommon when messages are
+ * processed out of order).
  *
- * Finally, if no thread ID has been found through parent or child, we
+ * Finally, if no thread ID has been found through referenced messages, we
  * call _notmuch_message_generate_thread_id to generate a new thread
  * ID. This should only happen for new, top-level messages, (no
  * References or In-Reply-To header in this message, and no previously
@@ -2110,10 +2336,23 @@ _notmuch_database_link_message (notmuch_database_t *notmuch,
     if (status)
 	goto DONE;
 
-    status = _notmuch_database_link_message_to_children (notmuch, message,
-							 &thread_id);
-    if (status)
-	goto DONE;
+    if (! (notmuch->features & NOTMUCH_FEATURE_GHOSTS)) {
+	/* In general, it shouldn't be necessary to link children,
+	 * since the earlier indexing of those children will have
+	 * stored a thread ID for the missing parent.  However, prior
+	 * to ghost messages, these stored thread IDs were NOT
+	 * rewritten during thread merging (and there was no
+	 * performant way to do so), so if indexed children were
+	 * pulled into a different thread ID by a merge, it was
+	 * necessary to pull them *back* into the stored thread ID of
+	 * the parent.  With ghost messages, we just rewrite the
+	 * stored thread IDs during merging, so this workaround isn't
+	 * necessary. */
+	status = _notmuch_database_link_message_to_children (notmuch, message,
+							     &thread_id);
+	if (status)
+	    goto DONE;
+    }
 
     /* If not part of any existing thread, generate a new thread ID. */
     if (thread_id == NULL) {
@@ -2150,7 +2389,7 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
     if (ret)
 	return ret;
 
-    message_file = _notmuch_message_file_open (filename);
+    message_file = _notmuch_message_file_open (notmuch, filename);
     if (message_file == NULL)
 	return NOTMUCH_STATUS_FILE_ERROR;
 
@@ -2259,7 +2498,7 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 
 	_notmuch_message_sync (message);
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred adding message: %s.\n",
+	_notmuch_database_log (notmuch, "A Xapian exception occurred adding message: %s.\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
 	ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
@@ -2351,7 +2590,7 @@ notmuch_database_find_message_by_filename (notmuch_database_t *notmuch,
 		status = NOTMUCH_STATUS_OUT_OF_MEMORY;
 	}
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "Error: A Xapian exception occurred finding message by filename: %s\n",
+	_notmuch_database_log (notmuch, "Error: A Xapian exception occurred finding message by filename: %s\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
 	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
@@ -2404,9 +2643,15 @@ notmuch_database_get_all_tags (notmuch_database_t *db)
 	_notmuch_string_list_sort (tags);
 	return _notmuch_tags_create (db, tags);
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred getting tags: %s.\n",
+	_notmuch_database_log (db, "A Xapian exception occurred getting tags: %s.\n",
 		 error.get_msg().c_str());
 	db->exception_reported = TRUE;
 	return NULL;
     }
 }
+
+const char *
+notmuch_database_status_string (notmuch_database_t *notmuch)
+{
+    return notmuch->status_string;
+}