From: David Bremner <david@tethera.net>
Date: Thu, 12 Jan 2017 02:01:15 +0000 (-0400)
Subject: lib: optimize counting documents
X-Git-Tag: 0.24_rc0~45
X-Git-Url: https://git.notmuchmail.org/git?p=notmuch;a=commitdiff_plain;h=70519319b59ca55d511c5b44ff8c299cbe93c572;hp=4a2ce7b5706b53cdd30c474d556f18d731c21bb5

lib: optimize counting documents

From #xapian

olly> bremner: btw, i noticed notmuch count see ms to request all the documents and then ignores them

bremner> hmm. There's something funny about the way that notmuch uses matches in general iirc

olly> it should be able to do: mset = enquire.get_mset (0, 0, notmuch->xapian_db->get_doccount ());
...
olly> get_matches_estimated() will be exact because check_at_least is the size of the database
---

diff --git a/lib/query.cc b/lib/query.cc
index 53efd4e1..4ccd8104 100644
--- a/lib/query.cc
+++ b/lib/query.cc
@@ -606,8 +606,9 @@ _notmuch_query_count_documents (notmuch_query_t *query, const char *type, unsign
 	/*
 	 * Set the checkatleast parameter to the number of documents
 	 * in the database to make get_matches_estimated() exact.
+	 * Set the max parameter to 0 to avoid fetching documents we will discard.
 	 */
-	mset = enquire.get_mset (0, notmuch->xapian_db->get_doccount (),
+	mset = enquire.get_mset (0, 0,
 				 notmuch->xapian_db->get_doccount ());
 
 	count = mset.get_matches_estimated();