Speed up recent session display (for many large sessions)

- don't parse XML into XMLTree
- only read the file, extract relevant elements
- don't read session-template contents, only test file

libs/ardour/ardour/session.h

@@ -2050,7 +2050,6 @@ class LIBARDOUR_API Session : public PBD::StatefulDestructible, public PBD::Scop
 
 	void save_as_bring_callback (uint32_t, uint32_t, std::string);
 
-	static int get_session_info_from_path (XMLTree& state_tree, const std::string& xmlpath);
 	static const uint32_t session_end_shift;
 
 	std::string _template_state_dir;

libs/ardour/ardour/template_utils.h

@@ -40,7 +40,7 @@ namespace ARDOUR {
 	};
 
 	LIBARDOUR_API void find_route_templates (std::vector<TemplateInfo>& template_names);
-	LIBARDOUR_API void find_session_templates (std::vector<TemplateInfo>& template_names);
+	LIBARDOUR_API void find_session_templates (std::vector<TemplateInfo>& template_names, bool read_xml = false);
 
 	LIBARDOUR_API std::string session_template_dir_to_file (std::string const &);
 

libs/ardour/session_state.cc

@@ -4353,70 +4353,70 @@ Session::rename (const std::string& new_name)
 	return 0;
 }
 
-int
-Session::get_session_info_from_path (XMLTree& tree, const string& xmlpath)
-{
-	if (!Glib::file_test (xmlpath, Glib::FILE_TEST_EXISTS)) {
-		return -1;
-        }
-
-	if (!tree.read (xmlpath)) {
-		return -1;
-	}
-
-	return 0;
-}
-
 int
 Session::get_info_from_path (const string& xmlpath, float& sample_rate, SampleFormat& data_format)
 {
-	XMLTree tree;
 	bool found_sr = false;
 	bool found_data_format = false;
 
-	if (get_session_info_from_path (tree, xmlpath)) {
+	if (!Glib::file_test (xmlpath, Glib::FILE_TEST_EXISTS)) {
+		return -1;
+	}
+
+	xmlParserCtxtPtr ctxt = xmlNewParserCtxt();
+	if (ctxt == NULL) {
+		return -1;
+	}
+	xmlDocPtr doc = xmlCtxtReadFile (ctxt, xmlpath.c_str(), NULL, XML_PARSE_HUGE);
+
+	if (doc == NULL) {
+		xmlFreeParserCtxt(ctxt);
+		return -1;
+	}
+
+	xmlNodePtr node = xmlDocGetRootElement(doc);
+
+	if (node == NULL) {
+		xmlFreeParserCtxt(ctxt);
 		return -1;
 	}
 
 	/* sample rate */
 
-	XMLProperty const * prop;
+	xmlAttrPtr attr;
-	XMLNode const * root (tree.root());
+	for (attr = node->properties; attr; attr = attr->next) {
-
+		if (!strcmp ((const char*)attr->name, "sample-rate") && attr->children) {
-	if ((prop = root->property (X_("sample-rate"))) != 0) {
+			sample_rate = atoi ((char*)attr->children->content);
-		sample_rate = atoi (prop->value());
+			found_sr = true;
-		found_sr = true;
-	}
-
-	const XMLNodeList& children (root->children());
-	for (XMLNodeList::const_iterator c = children.begin(); c != children.end(); ++c) {
-		const XMLNode* child = *c;
-		if (child->name() == "Config") {
-			const XMLNodeList& options (child->children());
-			for (XMLNodeList::const_iterator oc = options.begin(); oc != options.end(); ++oc) {
-				XMLNode const * option = *oc;
-				XMLProperty const * name = option->property("name");
-
-				if (!name) {
-					continue;
-				}
-
-				if (name->value() == "native-file-data-format") {
-					XMLProperty const * value = option->property ("value");
-					if (value) {
-						SampleFormat fmt = (SampleFormat) string_2_enum (option->property ("value")->value(), fmt);
-						data_format = fmt;
-						found_data_format = true;
-						break;
-					}
-				}
-			}
-		}
-		if (found_data_format) {
-			break;
 		}
 	}
 
+	node = node->children;
+	while (node != NULL) {
+		 if (strcmp((const char*) node->name, "Config")) {
+			 node = node->next;
+			 continue;
+		 }
+		 for (node = node->children; node; node = node->next) {
+			 xmlChar* pv = xmlGetProp (node, (const xmlChar*)"name");
+			 if (pv && !strcmp ((const char*)pv, "native-file-data-format")) {
+				 xmlFree (pv);
+				 xmlChar* val = xmlGetProp (node, (const xmlChar*)"value");
+				 if (val) {
+					 SampleFormat fmt = (SampleFormat) string_2_enum (string ((const char*)val), fmt);
+					 data_format = fmt;
+					 found_data_format = true;
+				 }
+				 xmlFree (val);
+				 break;
+			 }
+			 xmlFree (pv);
+		 }
+		 break;
+	}
+
+	xmlFreeParserCtxt(ctxt);
+
 	return !(found_sr && found_data_format); // zero if they are both found
 }
 

libs/ardour/template_utils.cc

@@ -79,7 +79,7 @@ session_template_dir_to_file (string const & dir)
 
 
 void
-find_session_templates (vector<TemplateInfo>& template_names)
+find_session_templates (vector<TemplateInfo>& template_names, bool read_xml)
 {
 	vector<string> templates;
 
@@ -95,10 +95,11 @@ find_session_templates (vector<TemplateInfo>& template_names)
 	for (vector<string>::iterator i = templates.begin(); i != templates.end(); ++i) {
 		string file = session_template_dir_to_file (*i);
 
-		XMLTree tree;
+		if (read_xml) {
-
+			XMLTree tree;
-		if (!tree.read (file.c_str())) {
+			if (!tree.read (file.c_str())) {
-			continue;
+				continue;
+			}
 		}
 
 		TemplateInfo rti;