[patch v2 3/4] lib: handle DatabaseModifiedError in _n_message_ensure_metadata
David Bremner
david at tethera.net
Sat Feb 25 17:35:11 PST 2017
The retries are hardcoded to a small number, and error handling aborts
than propagating errors from notmuch_database_reopen. These are both
somewhat justified by the assumption that most things that can go
wrong in Xapian::Database::reopen are rare and fatal. Here's the brief
discussion with Xapian upstream:
24-02-2017 08:12:57 < bremner> any intuition about how likely
Xapian::Database::reopen is to fail? I'm catching a
DatabaseModifiedError somewhere where handling any further errors is
tricky, and wondering about treating a failed reopen as as "the
impossible happened, stopping"
24-02-2017 16:22:34 < olly> bremner: there should not be much scope for
failure - stuff like out of memory or disk errors, which are probably a
good enough excuse to stop
---
lib/message.cc | 144 ++++++++++++++++++++++++-----------------
test/T640-database-modified.sh | 1 -
2 files changed, 83 insertions(+), 62 deletions(-)
diff --git a/lib/message.cc b/lib/message.cc
index 2fb67d85..9bafff0b 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -49,6 +49,9 @@ struct visible _notmuch_message {
/* Message document modified since last sync */
notmuch_bool_t modified;
+ /* last view of database the struct is synced with */
+ unsigned long last_view;
+
Xapian::Document doc;
Xapian::termcount termpos;
};
@@ -110,6 +113,9 @@ _notmuch_message_create_for_document (const void *talloc_owner,
message->flags = 0;
message->lazy_flags = 0;
+ /* the message is initially not synchronized with Xapian */
+ message->last_view = 0;
+
/* Each of these will be lazily created as needed. */
message->message_id = NULL;
message->thread_id = NULL;
@@ -314,6 +320,7 @@ static void
_notmuch_message_ensure_metadata (notmuch_message_t *message)
{
Xapian::TermIterator i, end;
+
const char *thread_prefix = _find_prefix ("thread"),
*tag_prefix = _find_prefix ("tag"),
*id_prefix = _find_prefix ("id"),
@@ -327,73 +334,88 @@ _notmuch_message_ensure_metadata (notmuch_message_t *message)
* slightly more costly than looking up individual fields if only
* one field of the message object is actually used, it's a huge
* win as more fields are used. */
+ for (int count=0; count < 3; count++) {
+ try {
+ i = message->doc.termlist_begin ();
+ end = message->doc.termlist_end ();
+
+ /* Get thread */
+ if (!message->thread_id)
+ message->thread_id =
+ _notmuch_message_get_term (message, i, end, thread_prefix);
+
+ /* Get tags */
+ assert (strcmp (thread_prefix, tag_prefix) < 0);
+ if (!message->tag_list) {
+ message->tag_list =
+ _notmuch_database_get_terms_with_prefix (message, i, end,
+ tag_prefix);
+ _notmuch_string_list_sort (message->tag_list);
+ }
- i = message->doc.termlist_begin ();
- end = message->doc.termlist_end ();
+ /* Get id */
+ assert (strcmp (tag_prefix, id_prefix) < 0);
+ if (!message->message_id)
+ message->message_id =
+ _notmuch_message_get_term (message, i, end, id_prefix);
+
+ /* Get document type */
+ assert (strcmp (id_prefix, type_prefix) < 0);
+ if (! NOTMUCH_TEST_BIT (message->lazy_flags, NOTMUCH_MESSAGE_FLAG_GHOST)) {
+ i.skip_to (type_prefix);
+ /* "T" is the prefix "type" fields. See
+ * BOOLEAN_PREFIX_INTERNAL. */
+ if (*i == "Tmail")
+ NOTMUCH_CLEAR_BIT (&message->flags, NOTMUCH_MESSAGE_FLAG_GHOST);
+ else if (*i == "Tghost")
+ NOTMUCH_SET_BIT (&message->flags, NOTMUCH_MESSAGE_FLAG_GHOST);
+ else
+ INTERNAL_ERROR ("Message without type term");
+ NOTMUCH_SET_BIT (&message->lazy_flags, NOTMUCH_MESSAGE_FLAG_GHOST);
+ }
- /* Get thread */
- if (!message->thread_id)
- message->thread_id =
- _notmuch_message_get_term (message, i, end, thread_prefix);
-
- /* Get tags */
- assert (strcmp (thread_prefix, tag_prefix) < 0);
- if (!message->tag_list) {
- message->tag_list =
- _notmuch_database_get_terms_with_prefix (message, i, end,
- tag_prefix);
- _notmuch_string_list_sort (message->tag_list);
- }
+ /* Get filename list. Here we get only the terms. We lazily
+ * expand them to full file names when needed in
+ * _notmuch_message_ensure_filename_list. */
+ assert (strcmp (type_prefix, filename_prefix) < 0);
+ if (!message->filename_term_list && !message->filename_list)
+ message->filename_term_list =
+ _notmuch_database_get_terms_with_prefix (message, i, end,
+ filename_prefix);
- /* Get id */
- assert (strcmp (tag_prefix, id_prefix) < 0);
- if (!message->message_id)
- message->message_id =
- _notmuch_message_get_term (message, i, end, id_prefix);
-
- /* Get document type */
- assert (strcmp (id_prefix, type_prefix) < 0);
- if (! NOTMUCH_TEST_BIT (message->lazy_flags, NOTMUCH_MESSAGE_FLAG_GHOST)) {
- i.skip_to (type_prefix);
- /* "T" is the prefix "type" fields. See
- * BOOLEAN_PREFIX_INTERNAL. */
- if (*i == "Tmail")
- NOTMUCH_CLEAR_BIT (&message->flags, NOTMUCH_MESSAGE_FLAG_GHOST);
- else if (*i == "Tghost")
- NOTMUCH_SET_BIT (&message->flags, NOTMUCH_MESSAGE_FLAG_GHOST);
- else
- INTERNAL_ERROR ("Message without type term");
- NOTMUCH_SET_BIT (&message->lazy_flags, NOTMUCH_MESSAGE_FLAG_GHOST);
- }
- /* Get filename list. Here we get only the terms. We lazily
- * expand them to full file names when needed in
- * _notmuch_message_ensure_filename_list. */
- assert (strcmp (type_prefix, filename_prefix) < 0);
- if (!message->filename_term_list && !message->filename_list)
- message->filename_term_list =
- _notmuch_database_get_terms_with_prefix (message, i, end,
- filename_prefix);
-
-
- /* Get property terms. Mimic the setup with filenames above */
- assert (strcmp (filename_prefix, property_prefix) < 0);
- if (!message->property_map && !message->property_term_list)
- message->property_term_list =
- _notmuch_database_get_terms_with_prefix (message, i, end,
- property_prefix);
-
- /* Get reply to */
- assert (strcmp (property_prefix, replyto_prefix) < 0);
- if (!message->in_reply_to)
- message->in_reply_to =
- _notmuch_message_get_term (message, i, end, replyto_prefix);
+ /* Get property terms. Mimic the setup with filenames above */
+ assert (strcmp (filename_prefix, property_prefix) < 0);
+ if (!message->property_map && !message->property_term_list)
+ message->property_term_list =
+ _notmuch_database_get_terms_with_prefix (message, i, end,
+ property_prefix);
+ /* Get reply to */
+ assert (strcmp (property_prefix, replyto_prefix) < 0);
+ if (!message->in_reply_to)
+ message->in_reply_to =
+ _notmuch_message_get_term (message, i, end, replyto_prefix);
- /* It's perfectly valid for a message to have no In-Reply-To
- * header. For these cases, we return an empty string. */
- if (!message->in_reply_to)
- message->in_reply_to = talloc_strdup (message, "");
+
+ /* It's perfectly valid for a message to have no In-Reply-To
+ * header. For these cases, we return an empty string. */
+ if (!message->in_reply_to)
+ message->in_reply_to = talloc_strdup (message, "");
+
+ /* all the way without an exception */
+ break;
+ } catch (const Xapian::DatabaseModifiedError &error) {
+ notmuch_status_t status = _notmuch_database_reopen (message->notmuch);
+ if (status != NOTMUCH_STATUS_SUCCESS)
+ INTERNAL_ERROR ("unhandled error from notmuch_database_reopen: %s\n",
+ notmuch_status_to_string (status));
+ } catch (const Xapian::Error &error) {
+ INTERNAL_ERROR ("A Xapian exception occurred fetching message metadata: %s\n",
+ error.get_msg().c_str());
+ }
+ }
+ message->last_view = message->notmuch->view;
}
void
diff --git a/test/T640-database-modified.sh b/test/T640-database-modified.sh
index b5b3bc2b..516836b0 100755
--- a/test/T640-database-modified.sh
+++ b/test/T640-database-modified.sh
@@ -6,7 +6,6 @@ test_description="DatabaseModifiedError handling"
add_email_corpus
test_begin_subtest "catching DatabaseModifiedError in _notmuch_message_ensure_metadata"
-test_subtest_known_broken
# it seems to need to be an early document to trigger the exception
first_id=$(notmuch search --output=messages '*'| head -1 | sed s/^id://)
--
2.11.0
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