From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by olra.theworths.org (Postfix) with ESMTP id 17198431FBC for ; Sun, 27 Jul 2014 02:36:09 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at olra.theworths.org X-Spam-Flag: NO X-Spam-Score: 0.502 X-Spam-Level: X-Spam-Status: No, score=0.502 tagged_above=-999 required=5 tests=[DKIM_ADSP_CUSTOM_MED=0.001, FREEMAIL_FROM=0.001, NML_ADSP_CUSTOM_MED=1.2, RCVD_IN_DNSWL_LOW=-0.7] autolearn=disabled Received: from olra.theworths.org ([127.0.0.1]) by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lWWKcPL7ktD6 for ; Sun, 27 Jul 2014 02:36:01 -0700 (PDT) Received: from mail2.qmul.ac.uk (mail2.qmul.ac.uk [138.37.6.6]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by olra.theworths.org (Postfix) with ESMTPS id 740E7431FB6 for ; Sun, 27 Jul 2014 02:36:01 -0700 (PDT) Received: from smtp.qmul.ac.uk ([138.37.6.40]) by mail2.qmul.ac.uk with esmtp (Exim 4.71) (envelope-from ) id 1XBKs2-0006Xu-HR; Sun, 27 Jul 2014 10:35:58 +0100 Received: from 94.196.249.126.threembb.co.uk ([94.196.249.126] helo=localhost) by smtp.qmul.ac.uk with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.71) (envelope-from ) id 1XBKs1-0003Km-Gn; Sun, 27 Jul 2014 10:35:58 +0100 From: Mark Walters To: Austin Clements , notmuch@notmuchmail.org Subject: Re: [PATCH 08/14] lib: Simplify upgrade code using a transaction In-Reply-To: <1406433173-19169-9-git-send-email-amdragon@mit.edu> References: <1406433173-19169-1-git-send-email-amdragon@mit.edu> <1406433173-19169-9-git-send-email-amdragon@mit.edu> User-Agent: Notmuch/0.15.2+615~g78e3a93 (http://notmuchmail.org) Emacs/23.4.1 (x86_64-pc-linux-gnu) Date: Sun, 27 Jul 2014 10:35:53 +0100 Message-ID: <87vbqjywhy.fsf@qmul.ac.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Sender-Host-Address: 94.196.249.126 X-QM-Geographic: According to ripencc, this message was delivered by a machine in Britain (UK) (GB). 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List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 27 Jul 2014 09:36:09 -0000 Hi On Sun, 27 Jul 2014, Austin Clements wrote: > Previously, the upgrade was organized as two passes -- an upgrade > pass, and a separate cleanup pass -- so the database was always in a > valid state. This change substantially simplifies this code by > performing the upgrade in a transaction and combining both passes in > to one. This 1) eliminates a lot of duplicate code between the > passes, 2) speeds up the upgrade process, 3) makes progress reporting > more accurate, 4) eliminates the potential for stale data if the > upgrade is interrupted during the cleanup pass, and 5) makes it easier > to reason about the safety of the upgrade code. I like this but I wonder if it has a side effect: I think with the current code the user can interrupt the upgrade (ctrl-c) and continue roughly where it left off. This looks like it means the whole upgrade needs to be done in one go. Will this be a problem on large mail stores (eg rlb with over 1M messages)? I am not sure what could be done during the interrupted upgrade before so maybe this is not a problem. Best wishes Mark > --- > lib/database.cc | 67 ++++++--------------------------------------------------- > 1 file changed, 7 insertions(+), 60 deletions(-) > > diff --git a/lib/database.cc b/lib/database.cc > index 03eef3e..0be7180 100644 > --- a/lib/database.cc > +++ b/lib/database.cc > @@ -1238,6 +1238,9 @@ notmuch_database_upgrade (notmuch_database_t *notmuch, > timer_is_active = TRUE; > } > > + /* Perform the upgrade in a transaction. */ > + db->begin_transaction (true); > + > /* Before version 1, each message document had its filename in the > * data field. Copy that into the new format by calling > * notmuch_message_add_filename. > @@ -1265,6 +1268,7 @@ notmuch_database_upgrade (notmuch_database_t *notmuch, > filename = _notmuch_message_talloc_copy_data (message); > if (filename && *filename != '\0') { > _notmuch_message_add_filename (message, filename); > + _notmuch_message_clear_data (message); > _notmuch_message_sync (message); > } > talloc_free (filename); > @@ -1312,6 +1316,8 @@ notmuch_database_upgrade (notmuch_database_t *notmuch, > NOTMUCH_FIND_CREATE, &status); > notmuch_directory_set_mtime (directory, mtime); > notmuch_directory_destroy (directory); > + > + db->delete_document (*p); > } > } > } > @@ -1353,67 +1359,8 @@ notmuch_database_upgrade (notmuch_database_t *notmuch, > notmuch->features |= NOTMUCH_FEATURES_CURRENT; > db->set_metadata ("features", _print_features (local, notmuch->features)); > db->set_metadata ("version", STRINGIFY (NOTMUCH_DATABASE_VERSION)); > - db->flush (); > - > - /* Now that the upgrade is complete we can remove the old data > - * and documents that are no longer needed. */ > - if (version < 1) { > - notmuch_query_t *query = notmuch_query_create (notmuch, ""); > - notmuch_messages_t *messages; > - notmuch_message_t *message; > - char *filename; > - > - for (messages = notmuch_query_search_messages (query); > - notmuch_messages_valid (messages); > - notmuch_messages_move_to_next (messages)) > - { > - if (do_progress_notify) { > - progress_notify (closure, (double) count / total); > - do_progress_notify = 0; > - } > - > - message = notmuch_messages_get (messages); > - > - filename = _notmuch_message_talloc_copy_data (message); > - if (filename && *filename != '\0') { > - _notmuch_message_clear_data (message); > - _notmuch_message_sync (message); > - } > - talloc_free (filename); > - > - notmuch_message_destroy (message); > - } > > - notmuch_query_destroy (query); > - } > - > - if (version < 1) { > - Xapian::TermIterator t, t_end; > - > - t_end = notmuch->xapian_db->allterms_end ("XTIMESTAMP"); > - > - for (t = notmuch->xapian_db->allterms_begin ("XTIMESTAMP"); > - t != t_end; > - t++) > - { > - Xapian::PostingIterator p, p_end; > - std::string term = *t; > - > - p_end = notmuch->xapian_db->postlist_end (term); > - > - for (p = notmuch->xapian_db->postlist_begin (term); > - p != p_end; > - p++) > - { > - if (do_progress_notify) { > - progress_notify (closure, (double) count / total); > - do_progress_notify = 0; > - } > - > - db->delete_document (*p); > - } > - } > - } > + db->commit_transaction (); > > if (timer_is_active) { > /* Now stop the timer. */ > -- > 2.0.0 > > _______________________________________________ > notmuch mailing list > notmuch@notmuchmail.org > http://notmuchmail.org/mailman/listinfo/notmuch