notmuch_message_get_message_id: Fix to cache result

Previously, this would allocate new memory with every call. That
was with talloc, of course, so there wasn't any leaking (eventually).
But since we're now calling this internally we want to be a little
less wasteful. It's easy enough to just stash the result into the
message on the first call, and then just return that on subsequent
calls.

1 files changed, 19 insertions, 5 deletions

diff --git a/message.cc b/message.cc
index 0efa470a..22c7598d 100644
--- a/message.cc
+++ b/message.cc
@@ -24,6 +24,9 @@
 #include <xapian.h>
 
 struct _notmuch_message {
+    notmuch_database_t *notmuch;
+    Xapian::docid doc_id;
+    char *message_id;
     Xapian::Document doc;
 };
 
@@ -66,6 +69,7 @@ prefix_t BOOLEAN_PREFIX[] = {
     { "email", "E" },
     { "date", "D" },
     { "label", "L" },
+    { "tag", "L" },
     { "source_id", "I" },
     { "attachment_extension", "O" },
     { "msgid", "Q" },
@@ -114,6 +118,9 @@ _notmuch_message_create (const void *talloc_owner,
     if (unlikely (message == NULL))
 	return NULL;
 
+    message->notmuch = notmuch;
+    message->doc_id = doc_id;
+    message->message_id = NULL; /* lazily created */
     new (&message->doc) Xapian::Document;
 
     talloc_set_destructor (message, _notmuch_message_destructor);
@@ -128,12 +135,19 @@ notmuch_message_get_message_id (notmuch_message_t *message)
 {
     Xapian::TermIterator i;
 
+    if (message->message_id)
+	return message->message_id;
+
     i = message->doc.termlist_begin ();
-    i.skip_to ("Q");
-    if (i != message->doc.termlist_end ())
-	return talloc_strdup (message, (*i).c_str () + 1);
-    else
+    i.skip_to (_find_prefix ("msgid"));
+
+    /* XXX: This should really be an internal error, but we'll need to
+     * fix the add_message side of things first. */
+    if (i == message->doc.termlist_end ())
 	return NULL;
+
+    message->message_id = talloc_strdup (message, (*i).c_str () + 1);
+    return message->message_id;
 }
 
 /* We end up having to call the destructors explicitly because we had
@@ -166,7 +180,7 @@ notmuch_message_get_tags (notmuch_message_t *message)
     talloc_set_destructor (tags, _notmuch_tags_destructor);
 
     tags->iterator = message->doc.termlist_begin ();
-    tags->iterator.skip_to ("L");
+    tags->iterator.skip_to (_find_prefix ("tag"));
     tags->iterator_end = message->doc.termlist_end ();
 
     return tags;