From: Jani Nikula Date: Fri, 7 Dec 2012 23:08:04 +0000 (+0200) Subject: Re: [Patch v3b 9/9] tag-util: optimization of tag application X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=75e93ddf3e794366ab31bf0fc41c920c7a71b2ba;p=notmuch-archives.git Re: [Patch v3b 9/9] tag-util: optimization of tag application --- diff --git a/92/c6f98846b08965c26cc627f04f1a00b1c16fcc b/92/c6f98846b08965c26cc627f04f1a00b1c16fcc new file mode 100644 index 000000000..de7ab4caf --- /dev/null +++ b/92/c6f98846b08965c26cc627f04f1a00b1c16fcc @@ -0,0 +1,183 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id EC828431FAF + for ; Fri, 7 Dec 2012 15:08:09 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: -0.7 +X-Spam-Level: +X-Spam-Status: No, score=-0.7 tagged_above=-999 required=5 + tests=[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 bGWztGmn5j8s for ; + Fri, 7 Dec 2012 15:08:09 -0800 (PST) +Received: from mail-la0-f53.google.com (mail-la0-f53.google.com + [209.85.215.53]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) + (No client certificate requested) + by olra.theworths.org (Postfix) with ESMTPS id 1AAD2431FAE + for ; Fri, 7 Dec 2012 15:08:08 -0800 (PST) +Received: by mail-la0-f53.google.com with SMTP id w12so759565lag.26 + for ; Fri, 07 Dec 2012 15:08:07 -0800 (PST) +X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; + d=google.com; s=20120113; + h=from:to:cc:subject:in-reply-to:references:user-agent:date + :message-id:mime-version:content-type:x-gm-message-state; + bh=W3GtL9C/N4jEo4hdJ5LuhelJ4ShHs4BfkjWyTZIvI8E=; + b=VGCGNtR93kJmRW6nmw3NrzhBhMdxQSNPNNAF72Q/IzN5QRlQP9lHxhg+vLlh3encha + pccsvvUmYXSDlLstTaJDYs3iyr1llq61VZsxM2P2oULO4HLBBVzB+0ysKM4/n3tskHhx + TWVpfjNs1UQrlgQ/FzaOS9nTLTGoBzIgVU2tXrbfbHZgrv5v0jsccp0pm6YfLst06gqK + arG3jqeJkeNSV/AM9mv5pepMqeEqSsvKwPRSoraMSYcLmc6h4YeIVAKlcn/zVYfYFNmc + 2PNr4Q6m1AQAfvwOUDGcUZIxGeJjKW5lFnFlOZJ/r9ab+y55/jeyqRTddwV/08Yhee31 + 4rdA== +Received: by 10.152.122.133 with SMTP id ls5mr7068383lab.9.1354921687320; + Fri, 07 Dec 2012 15:08:07 -0800 (PST) +Received: from localhost (dsl-hkibrasgw4-fe51df00-27.dhcp.inet.fi. + [80.223.81.27]) + by mx.google.com with ESMTPS id pw17sm5111006lab.5.2012.12.07.15.08.05 + (version=SSLv3 cipher=OTHER); Fri, 07 Dec 2012 15:08:06 -0800 (PST) +From: Jani Nikula +To: david@tethera.net, notmuch@notmuchmail.org +Subject: Re: [Patch v3b 9/9] tag-util: optimization of tag application +In-Reply-To: <1354843607-17980-10-git-send-email-david@tethera.net> +References: <1354843607-17980-1-git-send-email-david@tethera.net> + <1354843607-17980-10-git-send-email-david@tethera.net> +User-Agent: Notmuch/0.14+138~g7041c56 (http://notmuchmail.org) Emacs/23.4.1 + (i686-pc-linux-gnu) +Date: Sat, 08 Dec 2012 01:08:04 +0200 +Message-ID: <87lid9xxyj.fsf@nikula.org> +MIME-Version: 1.0 +Content-Type: text/plain; charset=us-ascii +X-Gm-Message-State: + ALoCoQkvdwbESM9NtmeIMe7OgETTO3ZRPHpZ32rwp2oNRFo9TV4CrOsch+70qaNRIhLEDjmGd8O/ +Cc: David Bremner +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Fri, 07 Dec 2012 23:08:10 -0000 + +On Fri, 07 Dec 2012, david@tethera.net wrote: +> From: David Bremner +> +> The idea is not to bother with restore operations if they don't change +> the set of tags. This is actually a relatively common case. +> +> In order to avoid fancy datastructures, this method is quadratic in +> the number of tags; at least on my mail database this doesn't seem to +> be a big problem. +> --- +> tag-util.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +> 1 file changed, 66 insertions(+) +> +> diff --git a/tag-util.c b/tag-util.c +> index 932ee7f..3d54e9e 100644 +> --- a/tag-util.c +> +++ b/tag-util.c +> @@ -124,6 +124,69 @@ message_error (notmuch_message_t *message, +> fprintf (stderr, "Status: %s\n", notmuch_status_to_string (status)); +> } +> +> +static int +> +makes_changes (notmuch_message_t *message, +> + tag_op_list_t *list, +> + tag_op_flag_t flags) +> +{ +> + +> + size_t i; +> + +> + notmuch_tags_t *tags; +> + notmuch_bool_t changes = FALSE; +> + +> + /* First, do we delete an existing tag? */ +> + changes = FALSE; +> + for (tags = notmuch_message_get_tags (message); +> + ! changes && notmuch_tags_valid (tags); +> + notmuch_tags_move_to_next (tags)) { +> + const char *cur_tag = notmuch_tags_get (tags); +> + int last_op = (flags & TAG_FLAG_REMOVE_ALL) ? -1 : 0; +> + +> + /* slight contortions to count down with an unsigned index */ +> + for (i = list->count; i-- > 0; /*nothing*/) { +> + if (strcmp (cur_tag, list->ops[i].tag) == 0) { +> + last_op = list->ops[i].remove ? -1 : 1; +> + break; +> + } +> + } + +After some eyeballing it looks correct, but not not exactly pretty. If +you insist on unsigned, you could also have a regular (i = 0; i < +list->count; i++) and use j = list->count - i - 1; within the block. But +that's just style bikeshedding after convincing you to use a count down +loop in the first place... + +Otherwise, the patch LGTM. + + +> + +> + changes = (last_op == -1); +> + } +> + notmuch_tags_destroy (tags); +> + +> + if (changes) +> + return TRUE; +> + +> + /* Now check for adding new tags */ +> + for (i = 0; i < list->count; i++) { +> + notmuch_bool_t exists = FALSE; +> + +> + if (list->ops[i].remove) +> + continue; +> + +> + for (tags = notmuch_message_get_tags (message); +> + notmuch_tags_valid (tags); +> + notmuch_tags_move_to_next (tags)) { +> + const char *cur_tag = notmuch_tags_get (tags); +> + if (strcmp (cur_tag, list->ops[i].tag) == 0) { +> + exists = TRUE; +> + break; +> + } +> + } +> + notmuch_tags_destroy (tags); +> + +> + /* the following test is conservative, +> + * in the sense it ignores cases like +foo ... -foo +> + * but this is OK from a correctness point of view +> + */ +> + if (! exists) +> + return TRUE; +> + } +> + return FALSE; +> + +> +} +> + +> notmuch_status_t +> tag_op_list_apply (notmuch_message_t *message, +> tag_op_list_t *list, +> @@ -133,6 +196,9 @@ tag_op_list_apply (notmuch_message_t *message, +> notmuch_status_t status = 0; +> tag_operation_t *tag_ops = list->ops; +> +> + if (! (flags & TAG_FLAG_PRE_OPTIMIZED) && ! makes_changes (message, list, flags)) +> + return NOTMUCH_STATUS_SUCCESS; +> + +> status = notmuch_message_freeze (message); +> if (status) { +> message_error (message, status, "freezing message"); +> -- +> 1.7.10.4 +> +> _______________________________________________ +> notmuch mailing list +> notmuch@notmuchmail.org +> http://notmuchmail.org/mailman/listinfo/notmuch