From 0487aa438bc1e10189ab018badd76bf10b3a01e9 Mon Sep 17 00:00:00 2001 From: David Bremner Date: Tue, 16 Dec 2014 09:02:17 +0100 Subject: [PATCH] Re: Python bindings and Xapian exceptions --- b5/08ac12a522923d8226436129272390db8c6b09 | 190 ++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 b5/08ac12a522923d8226436129272390db8c6b09 diff --git a/b5/08ac12a522923d8226436129272390db8c6b09 b/b5/08ac12a522923d8226436129272390db8c6b09 new file mode 100644 index 000000000..d6a1bb846 --- /dev/null +++ b/b5/08ac12a522923d8226436129272390db8c6b09 @@ -0,0 +1,190 @@ +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 8134A431FC7 + for ; Tue, 16 Dec 2014 00:02:27 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 0 +X-Spam-Level: +X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] + 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 eqqo3aD5Nyv5 for ; + Tue, 16 Dec 2014 00:02:24 -0800 (PST) +Received: from yantan.tethera.net (yantan.tethera.net [199.188.72.155]) + (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) + (No client certificate requested) + by olra.theworths.org (Postfix) with ESMTPS id CCC5B431FC4 + for ; Tue, 16 Dec 2014 00:02:24 -0800 (PST) +Received: from remotemail by yantan.tethera.net with local (Exim 4.80) + (envelope-from ) + id 1Y0n5L-00061g-F4; Tue, 16 Dec 2014 04:02:23 -0400 +Received: (nullmailer pid 4251 invoked by uid 1000); Tue, 16 Dec 2014 + 08:02:17 -0000 +From: David Bremner +To: Matt +Subject: Re: Python bindings and Xapian exceptions +In-Reply-To: + +References: <87k4q7s43v.fsf@ut.hh.sledj.net> <878w6gis5g.fsf@SSpaeth.de> + <871v70ril7.fsf@yoom.home.cworth.org> <871v70z0y5.fsf@SSpaeth.de> + + <87iohc7iiz.fsf@maritornes.cs.unb.ca> + +User-Agent: Notmuch/0.19+7~g5d7f7a6 (http://notmuchmail.org) Emacs/24.4.1 + (x86_64-pc-linux-gnu) +Date: Tue, 16 Dec 2014 09:02:17 +0100 +Message-ID: <87fvcg6n06.fsf@maritornes.cs.unb.ca> +MIME-Version: 1.0 +Content-Type: text/plain +Cc: notmuch@notmuchmail.org +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: Tue, 16 Dec 2014 08:02:27 -0000 + +Matt writes: + +> 2014-12-15 21:41 GMT+01:00 David Bremner : +>> Matt writes: +>> +>>>> > But for exceptions in general, yes the notmuch library does need to be +>>>> > fixed to allow the caller of functions to distinguish between things +>>>> > like "no matches found" and "an exception occurred, so it's unknown if +>>>> > any messages match the search". That's a general class of library +>>>> > interface bugs that all need to be fixed. +>>> +>>> I 've also hit this *API bug* and was wondering if a fix had been done since +>>> then (I use notmuch 0.17) ? I found nothing on http://notmuchmail.org/news/ +>> +>> Can you be more specific? I'd say in general no thorough overhaul of +>> error handling has happened, but if you can tell us what particular +>> libnotmuch function (or the equivalient python binding) you are having +>> trouble with, we may be able to give a more informative answer. +>> +> +> For instance when using the python bindings: +> In constructor I do +> self.db = notmuch.Database(self.db_path) +> and there I have a method called periodically that returns: +> returns notmuch.Query(self.db, "tag:unread and tag:inbox").count_messages() +> +> When it fails the previous method returns 0 and displays on stdout/stderr; +> "A Xapian exception occurred: The revision being read has been +> discarded - you should call Xapian::Database::reopen() and retry the +> operation +> Query string was: tag:unread and tag:inbox" + +Right, this seems to be a particularly heinous example. + +Any objections (or better ideas) from fellow developers to something +along the lines of the following? It isn't a huge improvement, and I +didn't update the other 3 places it's called (or the bindings), but it +seems like a step forward. I guess something similar should be done for +notmuch_query_count_threads. + +Alternatively, we could follow unix tradition and return -1 on error. +The only argument I can see either way at the moment is that fewer error +return styles is better than more. + +diff --git a/lib/notmuch.h b/lib/notmuch.h +index 220839b..06228bc 100644 +--- a/lib/notmuch.h ++++ b/lib/notmuch.h +@@ -901,8 +901,8 @@ notmuch_threads_destroy (notmuch_threads_t *threads); + * If a Xapian exception occurs, this function may return 0 (after + * printing a message). + */ +-unsigned +-notmuch_query_count_messages (notmuch_query_t *query); ++notmuch_status_t ++notmuch_query_count_messages (notmuch_query_t *query, unsigned *count); + + /** + * Return the number of threads matching a search. +diff --git a/lib/query.cc b/lib/query.cc +index 60ff8bd..a623ea8 100644 +--- a/lib/query.cc ++++ b/lib/query.cc +@@ -508,8 +508,8 @@ notmuch_threads_destroy (notmuch_threads_t *threads) + talloc_free (threads); + } + +-unsigned +-notmuch_query_count_messages (notmuch_query_t *query) ++notmuch_status_t ++notmuch_query_count_messages (notmuch_query_t *query, unsigned *count_out) + { + notmuch_database_t *notmuch = query->notmuch; + const char *query_string = query->query_string; +@@ -562,12 +562,11 @@ notmuch_query_count_messages (notmuch_query_t *query) + count = mset.get_matches_estimated(); + + } catch (const Xapian::Error &error) { +- fprintf (stderr, "A Xapian exception occurred: %s\n", +- error.get_msg().c_str()); +- fprintf (stderr, "Query string was: %s\n", query->query_string); ++ return NOTMUCH_STATUS_XAPIAN_EXCEPTION; + } +- +- return count; ++ ++ *count_out=count; ++ return NOTMUCH_STATUS_SUCCESS; + } + + unsigned +diff --git a/notmuch-count.c b/notmuch-count.c +index 6058f7c..db43959 100644 +--- a/notmuch-count.c ++++ b/notmuch-count.c +@@ -71,6 +71,7 @@ print_count (notmuch_database_t *notmuch, const char *query_str, + { + notmuch_query_t *query; + size_t i; ++ unsigned count; + + query = notmuch_query_create (notmuch, query_str); + if (query == NULL) { +@@ -83,7 +84,9 @@ print_count (notmuch_database_t *notmuch, const char *query_str, + + switch (output) { + case OUTPUT_MESSAGES: +- printf ("%u\n", notmuch_query_count_messages (query)); ++ if (notmuch_query_count_messages (query, &count)) ++ return 1; ++ printf ("%u\n", count); + break; + case OUTPUT_THREADS: + printf ("%u\n", notmuch_query_count_threads (query)); +diff --git a/notmuch-reply.c b/notmuch-reply.c +index 7c1c809..5b7c0e1 100644 +--- a/notmuch-reply.c ++++ b/notmuch-reply.c +@@ -650,8 +650,13 @@ notmuch_reply_format_sprinter(void *ctx, + notmuch_messages_t *messages; + notmuch_message_t *message; + mime_node_t *node; ++ unsigned count; + +- if (notmuch_query_count_messages (query) != 1) { ++ if (notmuch_query_count_messages (query, &count)) { ++ fprintf (stderr, "Error: Xapian exception counting messages.\n"); ++ return 1; ++ } ++ if (count != 1) { + fprintf (stderr, "Error: search term did not match precisely one message.\n"); + return 1; + } -- 2.26.2