[Patch v6 7/7] lib: add support for named queries

[David Bremner <david@tethera.net>]

This relies on the optional presense of xapian field processors, and the
library config API.
---
 doc/man7/notmuch-search-terms.rst |  8 ++++++++
 lib/Makefile.local                |  1 +
 lib/database-private.h            |  1 +
 lib/database.cc                   |  3 +++
 lib/query-fp.cc                   | 43 +++++++++++++++++++++++++++++++++++++++
 lib/query-fp.h                    | 42 ++++++++++++++++++++++++++++++++++++++
 test/T600-named-queries.sh        | 17 ++++++++++++++++
 7 files changed, 115 insertions(+)
 create mode 100644 lib/query-fp.cc
 create mode 100644 lib/query-fp.h

diff --git a/doc/man7/notmuch-search-terms.rst b/doc/man7/notmuch-search-terms.rst
index adedf5a..223031b 100644
--- a/doc/man7/notmuch-search-terms.rst
+++ b/doc/man7/notmuch-search-terms.rst
@@ -56,6 +56,8 @@ indicate user-supplied values):
 
 -  lastmod:<initial-revision>..<final-revision>
 
+-  query:<name>
+
 The **from:** prefix is used to match the name or address of the sender
 of an email message.
 
@@ -132,6 +134,11 @@ were added/removed or filenames changed).  This is usually used in
 conjunction with the **--uuid** argument to **notmuch search**
 to find messages that have changed since an earlier query.
 
+The **query:** prefix allows queries to refer to previously saved
+queries added with **notmuch-config(1)**. Named queries are only
+available if notmuch is built with **Xapian Field Processors** (see
+below).
+
 Operators
 ---------
 
@@ -385,6 +392,7 @@ notmuch was built against a sufficiently recent version of Xapian by running
 Currently the following features require field processor support:
 
 - non-range date queries, e.g. "date:today"
+- named queries e.g. "query:my_special_query"
 
 SEE ALSO
 ========
diff --git a/lib/Makefile.local b/lib/Makefile.local
index 76b57cb..beb9635 100644
--- a/lib/Makefile.local
+++ b/lib/Makefile.local
@@ -49,6 +49,7 @@ libnotmuch_cxx_srcs =		\
 	$(dir)/index.cc		\
 	$(dir)/message.cc	\
 	$(dir)/query.cc		\
+	$(dir)/query-fp.cc      \
 	$(dir)/config.cc	\
 	$(dir)/thread.cc
 
diff --git a/lib/database-private.h b/lib/database-private.h
index d2990b6..1a78b60 100644
--- a/lib/database-private.h
+++ b/lib/database-private.h
@@ -185,6 +185,7 @@ struct _notmuch_database {
     Xapian::ValueRangeProcessor *date_range_processor;
 #if HAVE_XAPIAN_FIELD_PROCESSOR
     Xapian::FieldProcessor *date_field_processor;
+    Xapian::FieldProcessor *query_field_processor;
 #endif
     Xapian::ValueRangeProcessor *last_mod_range_processor;
 };
diff --git a/lib/database.cc b/lib/database.cc
index ebe019f..9630000 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -20,6 +20,7 @@
 
 #include "database-private.h"
 #include "parse-time-vrp.h"
+#include "query-fp.h"
 #include "string-util.h"
 
 #include <iostream>
@@ -1005,6 +1006,8 @@ notmuch_database_open_verbose (const char *path,
 	 * with a .. to the range processor */
 	notmuch->date_field_processor = new DateFieldProcessor();
 	notmuch->query_parser->add_boolean_prefix("date", notmuch->date_field_processor);
+	notmuch->query_field_processor = new QueryFieldProcessor (*notmuch->query_parser, notmuch);
+	notmuch->query_parser->add_boolean_prefix("query", notmuch->query_field_processor);
 #endif
 	notmuch->last_mod_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_LAST_MOD, "lastmod:");
 
diff --git a/lib/query-fp.cc b/lib/query-fp.cc
new file mode 100644
index 0000000..4ffcb1e
--- /dev/null
+++ b/lib/query-fp.cc
@@ -0,0 +1,43 @@
+/* query-fp.cc - "query:" field processor glue
+ *
+ * This file is part of notmuch.
+ *
+ * Copyright © 2016 David Bremner
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: David Bremner <david@tethera.net>
+ */
+
+#include "database-private.h"
+#include "query-fp.h"
+#include <iostream>
+
+#if HAVE_XAPIAN_FIELD_PROCESSOR
+
+Xapian::Query
+QueryFieldProcessor::operator() (const std::string & name)
+{
+    std::string key = "query." + name;
+    char *expansion;
+    notmuch_status_t status;
+
+    status = notmuch_database_get_config (notmuch, key.c_str (), &expansion);
+    if (status) {
+	throw Xapian::QueryParserError ("error looking up key" + name);
+    }
+
+    return parser.parse_query (expansion, NOTMUCH_QUERY_PARSER_FLAGS);
+}
+#endif
diff --git a/lib/query-fp.h b/lib/query-fp.h
new file mode 100644
index 0000000..67f8705
--- /dev/null
+++ b/lib/query-fp.h
@@ -0,0 +1,42 @@
+/* query-fp.h - query field processor glue
+ *
+ * This file is part of notmuch.
+ *
+ * Copyright © 2016 David Bremner
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: David Bremner <david@tethera.net>
+ */
+
+#ifndef NOTMUCH_QUERY_FP_H
+#define NOTMUCH_QUERY_FP_H
+
+#include <xapian.h>
+#include "notmuch.h"
+
+#if HAVE_XAPIAN_FIELD_PROCESSOR
+class QueryFieldProcessor : public Xapian::FieldProcessor {
+ protected:
+    Xapian::QueryParser &parser;
+    notmuch_database_t *notmuch;
+
+ public:
+    QueryFieldProcessor (Xapian::QueryParser &parser_, notmuch_database_t *notmuch_)
+	: parser(parser_), notmuch(notmuch_) { };
+
+    Xapian::Query operator()(const std::string & str);
+};
+#endif
+#endif /* NOTMUCH_QUERY_FP_H */
diff --git a/test/T600-named-queries.sh b/test/T600-named-queries.sh
index 0922620..f0ae24f 100755
--- a/test/T600-named-queries.sh
+++ b/test/T600-named-queries.sh
@@ -50,4 +50,21 @@ notmuch restore < BEFORE
 notmuch dump | grep '^#@' > OUTPUT
 test_expect_equal_file QUERIES.BEFORE OUTPUT
 
+if [ $NOTMUCH_HAVE_XAPIAN_FIELD_PROCESSOR -eq 1 ]; then
+    test_begin_subtest "search named query"
+    notmuch search query:test > OUTPUT
+    notmuch search $QUERYSTR > EXPECTED
+    test_expect_equal_file EXPECTED OUTPUT
+
+    test_begin_subtest "search named query with other terms"
+    notmuch search query:test and subject:Maildir > OUTPUT
+    notmuch search $QUERYSTR and subject:Maildir > EXPECTED
+    test_expect_equal_file EXPECTED OUTPUT
+
+    test_begin_subtest "search nested named query"
+    notmuch search query:test2 > OUTPUT
+    notmuch search $QUERYSTR2 > EXPECTED
+    test_expect_equal_file EXPECTED OUTPUT
+fi
+
 test_done
-- 
2.8.1