+ id_str = message->doc.get_value (NOTMUCH_VALUE_THREAD);
+ thread_ids->next = talloc_strdup (message, id_str.c_str ());
+
+ /* Initialize thread_ids->current and terminate first ID. */
+ notmuch_thread_ids_advance (thread_ids);
+
+ return thread_ids;
+}
+
+void
+_notmuch_message_set_date (notmuch_message_t *message,
+ const char *date)
+{
+ time_t time_value;
+
+ time_value = notmuch_parse_date (date, NULL);
+
+ message->doc.add_value (NOTMUCH_VALUE_TIMESTAMP,
+ Xapian::sortable_serialise (time_value));
+}
+
+void
+_notmuch_message_add_thread_id (notmuch_message_t *message,
+ const char *thread_id)
+{
+ std::string id_str;
+
+ _notmuch_message_add_term (message, "thread", thread_id);
+
+ id_str = message->doc.get_value (NOTMUCH_VALUE_THREAD);
+
+ if (id_str.empty ()) {
+ message->doc.add_value (NOTMUCH_VALUE_THREAD, thread_id);
+ } else {
+ size_t pos;
+
+ /* Think about using a hash here if there's any performance
+ * problem. */
+ pos = id_str.find (thread_id);
+ if (pos == std::string::npos) {
+ id_str.append (",");
+ id_str.append (thread_id);
+ message->doc.add_value (NOTMUCH_VALUE_THREAD, id_str);
+ }
+ }
+}
+
+static void
+thread_id_generate (thread_id_t *thread_id)
+{
+ static int seeded = 0;
+ FILE *dev_random;
+ uint32_t value;
+ char *s;
+ int i;
+
+ if (! seeded) {
+ dev_random = fopen ("/dev/random", "r");
+ if (dev_random == NULL) {
+ srand (time (NULL));
+ } else {
+ fread ((void *) &value, sizeof (value), 1, dev_random);
+ srand (value);
+ fclose (dev_random);
+ }
+ seeded = 1;
+ }
+
+ s = thread_id->str;
+ for (i = 0; i < NOTMUCH_THREAD_ID_DIGITS; i += 8) {
+ value = rand ();
+ sprintf (s, "%08x", value);
+ s += 8;
+ }
+}
+
+void
+_notmuch_message_ensure_thread_id (notmuch_message_t *message)
+{
+ /* If not part of any existing thread, generate a new thread_id. */
+ thread_id_t thread_id;
+
+ thread_id_generate (&thread_id);
+ _notmuch_message_add_term (message, "thread", thread_id.str);
+ message->doc.add_value (NOTMUCH_VALUE_THREAD, thread_id.str);
+}
+
+/* Synchronize changes made to message->doc out into the database. */
+void
+_notmuch_message_sync (notmuch_message_t *message)
+{
+ Xapian::WritableDatabase *db = message->notmuch->xapian_db;
+
+ db->replace_document (message->doc_id, message->doc);
+}
+
+/* Add a name:value term to 'message', (the actual term will be
+ * encoded by prefixing the value with a short prefix). See
+ * NORMAL_PREFIX and BOOLEAN_PREFIX arrays for the mapping of term
+ * names to prefix values.
+ *
+ * This change will not be reflected in the database until the next
+ * call to _notmuch_message_set_sync. */
+notmuch_private_status_t
+_notmuch_message_add_term (notmuch_message_t *message,
+ const char *prefix_name,
+ const char *value)
+{
+
+ char *term;