[PATCH 2/2] Replace Xapian query parser with custom query parser.

[Austin Clements]

Note that the type:mail filter is implemented as a transform pass, so
it no longer has to be done everywhere queries are parsed.
Furthermore, this filter now depends on the prefixing logic in the
query parser instead of implementing this itself.
---
 lib/database-private.h |    3 +--
 lib/database.cc        |   36 ++++++++++++++++++++++--------------
 lib/query.cc           |   42 ++++++++++++------------------------------
 3 files changed, 35 insertions(+), 46 deletions(-)

diff --git a/lib/database-private.h b/lib/database-private.h
index 358a71b..578d1fe 100644
--- a/lib/database-private.h
+++ b/lib/database-private.h
@@ -48,9 +48,8 @@ struct _notmuch_database {
     unsigned int last_doc_id;
     uint64_t last_thread_id;
 
-    Xapian::QueryParser *query_parser;
     Xapian::TermGenerator *term_gen;
-    Xapian::ValueRangeProcessor *value_range_processor;
+    _notmuch_qparser_t *query_parser;
 };
 
 /* Return the list of terms from the given iterator matching a prefix.
diff --git a/lib/database.cc b/lib/database.cc
index f8245ab..d019777 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -571,6 +571,20 @@ _notmuch_database_ensure_writable (notmuch_database_t *notmuch)
     return NOTMUCH_STATUS_SUCCESS;
 }
 
+static _notmuch_token_t *
+transform_type_mail (_notmuch_token_t *root, void *opaque)
+{
+    _notmuch_token_t *nroot,
+	*mail_ast = _notmuch_token_create (root, TOK_LIT, "mail");
+    mail_ast->prefix = talloc_strdup (root, _find_prefix ("type"));
+    if (!root)
+	return mail_ast;
+    nroot = _notmuch_token_create (root, TOK_AND, NULL);
+    nroot->left = mail_ast;
+    nroot->right = root;
+    return nroot;
+}
+
 notmuch_database_t *
 notmuch_database_open (const char *path,
 		       notmuch_database_mode_t mode)
@@ -661,27 +675,24 @@ notmuch_database_open (const char *path,
 		INTERNAL_ERROR ("Malformed database last_thread_id: %s", str);
 	}
 
-	notmuch->query_parser = new Xapian::QueryParser;
 	notmuch->term_gen = new Xapian::TermGenerator;
 	notmuch->term_gen->set_stemmer (Xapian::Stem ("english"));
-	notmuch->value_range_processor = new Xapian::NumberValueRangeProcessor (NOTMUCH_VALUE_TIMESTAMP);
-
-	notmuch->query_parser->set_default_op (Xapian::Query::OP_AND);
-	notmuch->query_parser->set_database (*notmuch->xapian_db);
-	notmuch->query_parser->set_stemmer (Xapian::Stem ("english"));
-	notmuch->query_parser->set_stemming_strategy (Xapian::QueryParser::STEM_SOME);
-	notmuch->query_parser->add_valuerangeprocessor (notmuch->value_range_processor);
+	notmuch->query_parser = _notmuch_qparser_create (notmuch, notmuch);
 
 	for (i = 0; i < ARRAY_SIZE (BOOLEAN_PREFIX_EXTERNAL); i++) {
 	    prefix_t *prefix = &BOOLEAN_PREFIX_EXTERNAL[i];
-	    notmuch->query_parser->add_boolean_prefix (prefix->name,
-						       prefix->prefix);
+	    _notmuch_qparser_add_db_prefix (notmuch->query_parser, prefix->name,
+					    prefix->prefix, TRUE);
 	}
 
 	for (i = 0; i < ARRAY_SIZE (PROBABILISTIC_PREFIX); i++) {
 	    prefix_t *prefix = &PROBABILISTIC_PREFIX[i];
-	    notmuch->query_parser->add_prefix (prefix->name, prefix->prefix);
+	    _notmuch_qparser_add_db_prefix (notmuch->query_parser, prefix->name,
+					    prefix->prefix, FALSE);
 	}
+
+	_notmuch_qparser_add_transform (notmuch->query_parser,
+					transform_type_mail, NULL);
     } catch (const Xapian::Error &error) {
 	fprintf (stderr, "A Xapian exception occurred opening database: %s\n",
 		 error.get_msg().c_str());
@@ -711,9 +722,6 @@ notmuch_database_close (notmuch_database_t *notmuch)
     }
 
     delete notmuch->term_gen;
-    delete notmuch->query_parser;
-    delete notmuch->xapian_db;
-    delete notmuch->value_range_processor;
     talloc_free (notmuch);
 }
 
diff --git a/lib/query.cc b/lib/query.cc
index c7ae4ee..d68e408 100644
--- a/lib/query.cc
+++ b/lib/query.cc
@@ -131,28 +131,19 @@ notmuch_query_search_messages (notmuch_query_t *query)
 	talloc_set_destructor (messages, _notmuch_messages_destructor);
 
 	Xapian::Enquire enquire (*notmuch->xapian_db);
-	Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
-						   _find_prefix ("type"),
-						   "mail"));
-	Xapian::Query string_query, final_query;
+	_notmuch_token_t *ast;
+	Xapian::Query final_query;
 	Xapian::MSet mset;
-	unsigned int flags = (Xapian::QueryParser::FLAG_BOOLEAN |
-			      Xapian::QueryParser::FLAG_PHRASE |
-			      Xapian::QueryParser::FLAG_LOVEHATE |
-			      Xapian::QueryParser::FLAG_BOOLEAN_ANY_CASE |
-			      Xapian::QueryParser::FLAG_WILDCARD |
-			      Xapian::QueryParser::FLAG_PURE_NOT);
 
 	if (strcmp (query_string, "") == 0 ||
 	    strcmp (query_string, "*") == 0)
 	{
-	    final_query = mail_query;
+	    ast = NULL;
 	} else {
-	    string_query = notmuch->query_parser->
-		parse_query (query_string, flags);
-	    final_query = Xapian::Query (Xapian::Query::OP_AND,
-					 mail_query, string_query);
+	    ast = _notmuch_qparser_parse (notmuch->query_parser, query_string);
 	}
+	ast = _notmuch_qparser_transform (notmuch->query_parser, ast);
+	final_query = _notmuch_qparser_generate (notmuch->query_parser, ast);
 
 	enquire.set_weighting_scheme (Xapian::BoolWeight());
 
@@ -412,28 +403,19 @@ notmuch_query_count_messages (notmuch_query_t *query)
 
     try {
 	Xapian::Enquire enquire (*notmuch->xapian_db);
-	Xapian::Query mail_query (talloc_asprintf (query, "%s%s",
-						   _find_prefix ("type"),
-						   "mail"));
-	Xapian::Query string_query, final_query;
+	_notmuch_token_t *ast;
+	Xapian::Query final_query;
 	Xapian::MSet mset;
-	unsigned int flags = (Xapian::QueryParser::FLAG_BOOLEAN |
-			      Xapian::QueryParser::FLAG_PHRASE |
-			      Xapian::QueryParser::FLAG_LOVEHATE |
-			      Xapian::QueryParser::FLAG_BOOLEAN_ANY_CASE |
-			      Xapian::QueryParser::FLAG_WILDCARD |
-			      Xapian::QueryParser::FLAG_PURE_NOT);
 
 	if (strcmp (query_string, "") == 0 ||
 	    strcmp (query_string, "*") == 0)
 	{
-	    final_query = mail_query;
+	    ast = NULL;
 	} else {
-	    string_query = notmuch->query_parser->
-		parse_query (query_string, flags);
-	    final_query = Xapian::Query (Xapian::Query::OP_AND,
-					 mail_query, string_query);
+	    ast = _notmuch_qparser_parse (notmuch->query_parser, query_string);
 	}
+	ast = _notmuch_qparser_transform (notmuch->query_parser, ast);
+	final_query = _notmuch_qparser_generate (notmuch->query_parser, ast);
 
 	enquire.set_weighting_scheme(Xapian::BoolWeight());
 	enquire.set_docid_order(Xapian::Enquire::ASCENDING);
-- 
1.7.2.3