From: Tomi Ollila <tomi.ollila@iki.fi>
To: David Bremner <david@tethera.net>, notmuch@notmuchmail.org
Subject: Re: [PATCH] lib: add new status reporting API
	for	notmuch_query_search_{m, t}
In-Reply-To: <1421740421-10401-1-git-send-email-david@tethera.net>
References: <1421740421-10401-1-git-send-email-david@tethera.net>
User-Agent: Notmuch/0.19+29~g7367d27 (http://notmuchmail.org) Emacs/24.3.1
	(x86_64-unknown-linux-gnu)
Date: Tue, 20 Jan 2015 13:01:06 +0200
Message-ID: <m2a91dbtsd.fsf@guru.guru-group.fi>
MIME-Version: 1.0
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Precedence: list

On Tue, Jan 20 2015, David Bremner <david@tethera.net> wrote:

> This at least allows distinguishing between out of memory and Xapian
> exceptions. Adding finer grained status codes would allow different
> Xapian exceptions to be preserved.
>
> Adding wrappers allows people to transition gradually to the new API,
> at the cost of bloating the library API a bit.
> ---
>  lib/notmuch.h | 10 ++++++++++
>  lib/query.cc  | 50 ++++++++++++++++++++++++++++++++++++++++----------
>  2 files changed, 50 insertions(+), 10 deletions(-)
>
> diff --git a/lib/notmuch.h b/lib/notmuch.h
> index 220839b..58052f1 100644
> --- a/lib/notmuch.h
> +++ b/lib/notmuch.h
> @@ -780,10 +780,15 @@ notmuch_query_add_tag_exclude (notmuch_query_t *query, const char *tag);
>   * to call it if the query is about to be destroyed).
>   *
>   * If a Xapian exception occurs this function will return NULL.
> + * For better error reporting, use the _st variant.
>   */
>  notmuch_threads_t *
>  notmuch_query_search_threads (notmuch_query_t *query);
>  
> +notmuch_status_t
> +notmuch_query_search_threads_st (notmuch_query_t *query,
> +				 notmuch_threads_t **out);
> +
>  /**
>   * Execute a query for messages, returning a notmuch_messages_t object
>   * which can be used to iterate over the results. The returned
> @@ -822,10 +827,15 @@ notmuch_query_search_threads (notmuch_query_t *query);
>   * reason to call it if the query is about to be destroyed).
>   *
>   * If a Xapian exception occurs this function will return NULL.
> + * For better error reporting, use the _st variant.
>   */
>  notmuch_messages_t *
>  notmuch_query_search_messages (notmuch_query_t *query);
>  
> +notmuch_status_t
> +notmuch_query_search_messages_st (notmuch_query_t *query,
> +				  notmuch_messages_t **mesages);

prototype has **mesages, definition **out ;D -- otherwise looks pretty good.

Tomi

> +
>  /**
>   * Destroy a notmuch_query_t along with any associated resources.
>   *
> diff --git a/lib/query.cc b/lib/query.cc
> index 60ff8bd..9279915 100644
> --- a/lib/query.cc
> +++ b/lib/query.cc
> @@ -174,13 +174,26 @@ _notmuch_exclude_tags (notmuch_query_t *query, Xapian::Query xquery)
>  notmuch_messages_t *
>  notmuch_query_search_messages (notmuch_query_t *query)
>  {
> +    notmuch_status_t status;
> +    notmuch_messages_t *messages;
> +    status = notmuch_query_search_messages_st (query, &messages);
> +    if (status)
> +	return NULL;
> +    else
> +	return messages;
> +}
> +
> +notmuch_status_t
> +notmuch_query_search_messages_st (notmuch_query_t *query,
> +				  notmuch_messages_t **out)
> +{
>      notmuch_database_t *notmuch = query->notmuch;
>      const char *query_string = query->query_string;
>      notmuch_mset_messages_t *messages;
>  
>      messages = talloc (query, notmuch_mset_messages_t);
>      if (unlikely (messages == NULL))
> -	return NULL;
> +	return NOTMUCH_STATUS_OUT_OF_MEMORY;
>  
>      try {
>  
> @@ -279,7 +292,8 @@ notmuch_query_search_messages (notmuch_query_t *query)
>  	messages->iterator = mset.begin ();
>  	messages->iterator_end = mset.end ();
>  
> -	return &messages->base;
> +	*out = &messages->base;
> +	return NOTMUCH_STATUS_SUCCESS;
>  
>      } catch (const Xapian::Error &error) {
>  	fprintf (stderr, "A Xapian exception occurred performing query: %s\n",
> @@ -287,7 +301,7 @@ notmuch_query_search_messages (notmuch_query_t *query)
>  	fprintf (stderr, "Query string was: %s\n", query->query_string);
>  	notmuch->exception_reported = TRUE;
>  	talloc_free (messages);
> -	return NULL;
> +	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
>      }
>  }
>  
> @@ -412,24 +426,39 @@ _notmuch_threads_destructor (notmuch_threads_t *threads)
>      return 0;
>  }
>  
> +
>  notmuch_threads_t *
>  notmuch_query_search_threads (notmuch_query_t *query)
>  {
> +    notmuch_status_t status;
> +    notmuch_threads_t *threads;
> +    status = notmuch_query_search_threads_st (query, &threads);
> +    if (status)
> +	return NULL;
> +    else
> +	return threads;
> +}
> +
> +notmuch_status_t
> +notmuch_query_search_threads_st (notmuch_query_t *query,
> +				 notmuch_threads_t **out)
> +{
>      notmuch_threads_t *threads;
>      notmuch_messages_t *messages;
> +    notmuch_status_t status;
>  
>      threads = talloc (query, notmuch_threads_t);
>      if (threads == NULL)
> -	return NULL;
> +	return NOTMUCH_STATUS_OUT_OF_MEMORY;
>      threads->doc_ids = NULL;
>      talloc_set_destructor (threads, _notmuch_threads_destructor);
>  
>      threads->query = query;
>  
> -    messages = notmuch_query_search_messages (query);
> -    if (messages == NULL) {
> -	    talloc_free (threads);
> -	    return NULL;
> +    status = notmuch_query_search_messages_st (query, &messages);
> +    if (status) {
> +	talloc_free (threads);
> +	return status;
>      }
>  
>      threads->doc_ids = g_array_new (FALSE, FALSE, sizeof (unsigned int));
> @@ -445,10 +474,11 @@ notmuch_query_search_threads (notmuch_query_t *query)
>      if (! _notmuch_doc_id_set_init (threads, &threads->match_set,
>  				    threads->doc_ids)) {
>  	talloc_free (threads);
> -	return NULL;
> +	return NOTMUCH_STATUS_OUT_OF_MEMORY;
>      }
>  
> -    return threads;
> +    *out = threads;
> +    return NOTMUCH_STATUS_SUCCESS;
>  }
>  
>  void
> -- 
> 2.1.4
>
> _______________________________________________
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> notmuch@notmuchmail.org
> http://notmuchmail.org/mailman/listinfo/notmuch