[WIP PATCH 1/4] lib: Only sync modified message documents
Austin Clements
aclements at csail.mit.edu
Sun Oct 12 23:20:00 PDT 2014
From: Austin Clements <amdragon at mit.edu>
Previously, we updated the database copy of a message on every call to
_notmuch_message_sync, even if nothing had changed. In particular,
this always happens on a thaw, so a freeze/thaw pair with no
modifications between still caused a database update.
We only modify message documents in a handful of places, so keep track
of whether the document has been modified and only sync it when
necessary. This will be particularly important when we add message
revision tracking.
---
lib/message.cc | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/lib/message.cc b/lib/message.cc
index a7a13cc..cf2fd7c 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -43,6 +43,9 @@ struct visible _notmuch_message {
* if each flag has been initialized. */
unsigned long lazy_flags;
+ /* Message document modified since last sync */
+ notmuch_bool_t modified;
+
Xapian::Document doc;
Xapian::termcount termpos;
};
@@ -538,6 +541,7 @@ _notmuch_message_remove_terms (notmuch_message_t *message, const char *prefix)
try {
message->doc.remove_term ((*i));
+ message->modified = TRUE;
} catch (const Xapian::InvalidArgumentError) {
/* Ignore failure to remove non-existent term. */
}
@@ -791,6 +795,7 @@ void
_notmuch_message_clear_data (notmuch_message_t *message)
{
message->doc.set_data ("");
+ message->modified = TRUE;
}
static void
@@ -988,6 +993,7 @@ _notmuch_message_set_header_values (notmuch_message_t *message,
Xapian::sortable_serialise (time_value));
message->doc.add_value (NOTMUCH_VALUE_FROM, from);
message->doc.add_value (NOTMUCH_VALUE_SUBJECT, subject);
+ message->modified = TRUE;
}
/* Synchronize changes made to message->doc out into the database. */
@@ -999,8 +1005,12 @@ _notmuch_message_sync (notmuch_message_t *message)
if (message->notmuch->mode == NOTMUCH_DATABASE_MODE_READ_ONLY)
return;
+ if (! message->modified)
+ return;
+
db = static_cast <Xapian::WritableDatabase *> (message->notmuch->xapian_db);
db->replace_document (message->doc_id, message->doc);
+ message->modified = FALSE;
}
/* Delete a message document from the database. */
@@ -1075,6 +1085,7 @@ _notmuch_message_add_term (notmuch_message_t *message,
return NOTMUCH_PRIVATE_STATUS_TERM_TOO_LONG;
message->doc.add_term (term, 0);
+ message->modified = TRUE;
talloc_free (term);
@@ -1143,6 +1154,7 @@ _notmuch_message_remove_term (notmuch_message_t *message,
try {
message->doc.remove_term (term);
+ message->modified = TRUE;
} catch (const Xapian::InvalidArgumentError) {
/* We'll let the philosopher's try to wrestle with the
* question of whether failing to remove that which was not
--
2.1.0
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