lib: autocommit after some number of completed transactions

[notmuch] / lib / database.cc

diff --git a/lib/database.cc b/lib/database.cc
index 6db82373dddecb09df66521dd3f69c3cdd1d6fd3..31794900a392194e641675b2ec15df3214b075f8 100644 (file)
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -502,17 +502,9 @@ notmuch_database_close (notmuch_database_t *notmuch)
      * close it.  Thus, we explicitly close it here. */
     if (notmuch->open) {
        try {
-           /* If there's an outstanding transaction, it's unclear if
-            * closing the Xapian database commits everything up to
-            * that transaction, or may discard committed (but
-            * unflushed) transactions.  To be certain, explicitly
-            * cancel any outstanding transaction before closing. */
-           if (_notmuch_database_mode (notmuch) == NOTMUCH_DATABASE_MODE_READ_WRITE &&
-               notmuch->atomic_nesting)
-               notmuch->writable_xapian_db->cancel_transaction ();
-
            /* Close the database.  This implicitly flushes
-            * outstanding changes. */
+            * outstanding changes. If there is an open (non-flushed)
+            * transaction, ALL pending changes will be discarded */
            notmuch->xapian_db->close ();
        } catch (const Xapian::Error &error) {
            status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
@@ -1142,13 +1134,21 @@ notmuch_database_end_atomic (notmuch_database_t *notmuch)
     db = notmuch->writable_xapian_db;
     try {
        db->commit_transaction ();
-
-       /* This is a hack for testing.  Xapian never flushes on a
-        * non-flushed commit, even if the flush threshold is 1.
-        * However, we rely on flushing to test atomicity. */
+       notmuch->transaction_count++;
+
+       /* Xapian never flushes on a non-flushed commit, even if the
+        * flush threshold is 1.  However, we rely on flushing to test
+        * atomicity. On the other hand, we can't straight replace
+        * XAPIAN_FLUSH_THRESHOLD with our autocommit counter, because
+        * the former also applies outside notmuch atomic
+        * commits. Hence the follow complicated  test */
        const char *thresh = getenv ("XAPIAN_FLUSH_THRESHOLD");
-       if (thresh && atoi (thresh) == 1)
+       if ((notmuch->transaction_threshold > 0 &&
+            notmuch->transaction_count >= notmuch->transaction_threshold) ||
+           (thresh && atoi (thresh) == 1)) {
            db->commit ();
+           notmuch->transaction_count = 0;
+       }
     } catch (const Xapian::Error &error) {
        _notmuch_database_log (notmuch, "A Xapian exception occurred committing transaction: %s.\n",
                               error.get_msg ().c_str ());