Introduce Registry::GetInstance() to deduplicate such methods

in derived classes and inline them, as side effect, to speed up calls.

lib/base/registry.hpp

@@ -7,6 +7,7 @@
 #include "base/atomic.hpp"
 #include "base/exception.hpp"
 #include "base/string.hpp"
+#include "base/singleton.hpp"
 #include <shared_mutex>
 #include <stdexcept>
 #include <unordered_map>
@@ -26,6 +27,11 @@ class Registry
 public:
 	typedef std::unordered_map<String, T> ItemMap;
 
+	static Registry* GetInstance()
+	{
+		return Singleton<Registry>::GetInstance();
+	}
+
 	void Register(const String& name, const T& item)
 	{
 		std::unique_lock lock (m_Mutex);

lib/db_ido/dbtype.cpp

@@ -133,8 +133,3 @@ std::set<DbType::Ptr> DbType::GetAllTypes()
 
 	return result;
 }
-
-DbTypeRegistry *DbTypeRegistry::GetInstance()
-{
-	return Singleton<DbTypeRegistry>::GetInstance();
-}

lib/db_ido/dbtype.hpp

@@ -6,7 +6,6 @@
 #include "db_ido/i2-db_ido.hpp"
 #include "base/object.hpp"
 #include "base/registry.hpp"
-#include "base/singleton.hpp"
 #include <set>
 
 namespace icinga
@@ -64,8 +63,6 @@ private:
  */
 class DbTypeRegistry : public Registry<DbTypeRegistry, DbType::Ptr>
 {
-public:
-	static DbTypeRegistry *GetInstance();
 };
 
 /**

lib/remote/apiaction.cpp

@@ -1,7 +1,6 @@
 /* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
 
 #include "remote/apiaction.hpp"
-#include "base/singleton.hpp"
 
 using namespace icinga;
 
@@ -28,8 +27,3 @@ void ApiAction::Register(const String& name, const ApiAction::Ptr& action)
 {
 	ApiActionRegistry::GetInstance()->Register(name, action);
 }
-
-ApiActionRegistry *ApiActionRegistry::GetInstance()
-{
-	return Singleton<ApiActionRegistry>::GetInstance();
-}

lib/remote/apiaction.hpp

@@ -47,8 +47,6 @@ private:
  */
 class ApiActionRegistry : public Registry<ApiActionRegistry, ApiAction::Ptr>
 {
-public:
-	static ApiActionRegistry *GetInstance();
 };
 
 #define REGISTER_APIACTION(name, types, callback) \

lib/remote/apifunction.cpp

@@ -1,7 +1,6 @@
 /* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
 
 #include "remote/apifunction.hpp"
-#include "base/singleton.hpp"
 
 using namespace icinga;
 
@@ -23,8 +22,3 @@ void ApiFunction::Register(const String& name, const ApiFunction::Ptr& function)
 {
 	ApiFunctionRegistry::GetInstance()->Register(name, function);
 }
-
-ApiFunctionRegistry *ApiFunctionRegistry::GetInstance()
-{
-	return Singleton<ApiFunctionRegistry>::GetInstance();
-}

lib/remote/apifunction.hpp

@@ -43,8 +43,6 @@ private:
  */
 class ApiFunctionRegistry : public Registry<ApiFunctionRegistry, ApiFunction::Ptr>
 {
-public:
-	static ApiFunctionRegistry *GetInstance();
 };
 
 #define REGISTER_APIFUNCTION(name, ns, callback) \

lib/remote/eventqueue.cpp

@@ -4,7 +4,6 @@
 #include "remote/eventqueue.hpp"
 #include "remote/filterutility.hpp"
 #include "base/io-engine.hpp"
-#include "base/singleton.hpp"
 #include "base/logger.hpp"
 #include "base/utility.hpp"
 #include <boost/asio/spawn.hpp>
@@ -127,11 +126,6 @@ void EventQueue::Register(const String& name, const EventQueue::Ptr& function)
 	EventQueueRegistry::GetInstance()->Register(name, function);
 }
 
-EventQueueRegistry *EventQueueRegistry::GetInstance()
-{
-	return Singleton<EventQueueRegistry>::GetInstance();
-}
-
 std::mutex EventsInbox::m_FiltersMutex;
 std::map<String, EventsInbox::Filter> EventsInbox::m_Filters ({{"", EventsInbox::Filter{1, Expression::Ptr()}}});
 

lib/remote/eventqueue.hpp

@@ -61,8 +61,6 @@ private:
  */
 class EventQueueRegistry : public Registry<EventQueueRegistry, EventQueue::Ptr>
 {
-public:
-	static EventQueueRegistry *GetInstance();
 };
 
 enum class EventType : uint_fast8_t