From: Mark Walters Date: Sat, 8 Dec 2012 11:22:53 +0000 (+0000) Subject: Re: [Patch v3b 9/9] tag-util: optimization of tag application X-Git-Url: http://git.tremily.us/gitweb.cgi?a=commitdiff_plain;h=9a3555acda8a7037f79156752e71539b855b5ce4;p=notmuch-archives.git Re: [Patch v3b 9/9] tag-util: optimization of tag application --- diff --git a/ef/48c828ef4946c6e035ae1001d5905460862c60 b/ef/48c828ef4946c6e035ae1001d5905460862c60 new file mode 100644 index 000000000..be71d9cce --- /dev/null +++ b/ef/48c828ef4946c6e035ae1001d5905460862c60 @@ -0,0 +1,188 @@ +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 0F055431FAF + for ; Sat, 8 Dec 2012 03:22:51 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: -1.098 +X-Spam-Level: +X-Spam-Status: No, score=-1.098 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_MED=-2.3] 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 ap35AObs0HbJ for ; + Sat, 8 Dec 2012 03:22:50 -0800 (PST) +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 53F7C431FAE + for ; Sat, 8 Dec 2012 03:22:50 -0800 (PST) +Received: from smtp.qmul.ac.uk ([138.37.6.40]) + by mail2.qmul.ac.uk with esmtp (Exim 4.71) + (envelope-from ) + id 1ThIUa-0001Ld-J9; Sat, 08 Dec 2012 11:22:48 +0000 +Received: from 93-97-24-31.zone5.bethere.co.uk ([93.97.24.31] helo=localhost) + by smtp.qmul.ac.uk with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.69) + (envelope-from ) + id 1ThIUa-0006lB-67; Sat, 08 Dec 2012 11:22:48 +0000 +From: Mark Walters +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+81~g9730584 (http://notmuchmail.org) Emacs/23.4.1 + (x86_64-pc-linux-gnu) +Date: Sat, 08 Dec 2012 11:22:53 +0000 +Message-ID: <87zk1og54i.fsf@qmul.ac.uk> +MIME-Version: 1.0 +Content-Type: text/plain; charset=us-ascii +X-Sender-Host-Address: 93.97.24.31 +X-QM-SPAM-Info: Sender has good ham record. :) +X-QM-Body-MD5: 2100af87dc12ae39309909ab44db1033 (of first 20000 bytes) +X-SpamAssassin-Score: -1.8 +X-SpamAssassin-SpamBar: - +X-SpamAssassin-Report: The QM spam filters have analysed this message to + determine if it is + spam. We require at least 5.0 points to mark a message as spam. + This message scored -1.8 points. + Summary of the scoring: + * -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, + * medium trust + * [138.37.6.40 listed in list.dnswl.org] + * 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail + provider * (markwalters1009[at]gmail.com) + * 0.5 AWL AWL: From: address is in the auto white-list +X-QM-Scan-Virus: ClamAV says the message is clean +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: Sat, 08 Dec 2012 11:22:51 -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; +> + } +> + } + +I agree that this is a little ugly but ok I think. Is it worth adding a +comment as to why you are counting backwards? eg " we count backwards to +check whether the last change for the tag foo is removal" + +But basically LGTM + +Mark + + +> + +> + 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