lib: Add support for automatically excluding tags from queries

This is useful for tags like "deleted" and "spam" that people
generally want to exclude from query results.  These exclusions will
be overridden if a tag is explicitly mentioned in a query.

diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 60a932fc936324fc39fedb3b736d86aeaa4857e5..7bf153e03fcd1b35bcc697f505e9d6441ecef9c4 100644 (file)
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -458,7 +458,7 @@ typedef struct _notmuch_string_node {
     struct _notmuch_string_node *next;
 } notmuch_string_node_t;
 
-typedef struct _notmuch_string_list {
+typedef struct visible _notmuch_string_list {
     int length;
     notmuch_string_node_t *head;
     notmuch_string_node_t **tail;

diff --git a/lib/notmuch.h b/lib/notmuch.h
index 9f23a106e53b7acef19d1bf26036ed6993a361df..7929fe7222ea0bc92d0842a2444d92373a0fc4c9 100644 (file)
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -457,6 +457,12 @@ notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort);
 notmuch_sort_t
 notmuch_query_get_sort (notmuch_query_t *query);
 
+/* Add a tag that will be excluded from the query results by default.
+ * This exclusion will be overridden if this tag appears explicitly in
+ * the query. */
+void
+notmuch_query_add_tag_exclude (notmuch_query_t *query, const char *tag);
+
 /* Execute a query for threads, returning a notmuch_threads_t object
  * which can be used to iterate over the results. The returned threads
  * object is owned by the query and as such, will only be valid until

diff --git a/lib/query.cc b/lib/query.cc
index b6c0f12d9cd87f73993be6ef6c822319df888995..0b366025ba847314605157e23b193410a792e801 100644 (file)
--- a/lib/query.cc
+++ b/lib/query.cc
@@ -27,6 +27,7 @@ struct _notmuch_query {
     notmuch_database_t *notmuch;
     const char *query_string;
     notmuch_sort_t sort;
+    notmuch_string_list_t *exclude_terms;
 };
 
 typedef struct _notmuch_mset_messages {
@@ -76,6 +77,8 @@ notmuch_query_create (notmuch_database_t *notmuch,
 
     query->sort = NOTMUCH_SORT_NEWEST_FIRST;
 
+    query->exclude_terms = _notmuch_string_list_create (query);
+
     return query;
 }
 
@@ -97,6 +100,13 @@ notmuch_query_get_sort (notmuch_query_t *query)
     return query->sort;
 }
 
+void
+notmuch_query_add_tag_exclude (notmuch_query_t *query, const char *tag)
+{
+    char *term = talloc_asprintf (query, "%s%s", _find_prefix ("tag"), tag);
+    _notmuch_string_list_append (query->exclude_terms, term);
+}
+
 /* We end up having to call the destructors explicitly because we had
  * to use "placement new" in order to initialize C++ objects within a
  * block that we allocated with talloc. So C++ is making talloc
@@ -112,6 +122,27 @@ _notmuch_messages_destructor (notmuch_mset_messages_t *messages)
     return 0;
 }
 
+/* Return a query that does not match messages with the excluded tags
+ * registered with the query.  Any tags that explicitly appear in
+ * xquery will not be excluded. */
+static Xapian::Query
+_notmuch_exclude_tags (notmuch_query_t *query, Xapian::Query xquery)
+{
+    for (notmuch_string_node_t *term = query->exclude_terms->head; term;
+        term = term->next) {
+       Xapian::TermIterator it = xquery.get_terms_begin ();
+       Xapian::TermIterator end = xquery.get_terms_end ();
+       for (; it != end; it++) {
+           if ((*it).compare (term->string) == 0)
+               break;
+       }
+       if (it == end)
+           xquery = Xapian::Query (Xapian::Query::OP_AND_NOT,
+                                   xquery, Xapian::Query (term->string));
+    }
+    return xquery;
+}
+
 notmuch_messages_t *
 notmuch_query_search_messages (notmuch_query_t *query)
 {
@@ -157,6 +188,8 @@ notmuch_query_search_messages (notmuch_query_t *query)
                                         mail_query, string_query);
        }
 
+       final_query = _notmuch_exclude_tags (query, final_query);
+
        enquire.set_weighting_scheme (Xapian::BoolWeight());
 
        switch (query->sort) {
@@ -436,6 +469,8 @@ notmuch_query_count_messages (notmuch_query_t *query)
                                         mail_query, string_query);
        }
 
+       final_query = _notmuch_exclude_tags (query, final_query);
+
        enquire.set_weighting_scheme(Xapian::BoolWeight());
        enquire.set_docid_order(Xapian::Enquire::ASCENDING);