From 1d6009594c85e6ff8dcc5dad529a18650abe41c1 Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavelo@centrum.sk>
Date: Sun, 14 Feb 2010 20:36:17 +0100
Subject: [PATCH] Simplify data source creation, create it directly inside lua
 userdata

---
 src/data-source.cc |  8 ++++----
 src/data-source.hh | 16 ++++++----------
 src/lua-config.cc  |  4 ++--
 3 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/src/data-source.cc b/src/data-source.cc
index 0b0238b3..46697838 100644
--- a/src/data-source.cc
+++ b/src/data-source.cc
@@ -59,7 +59,7 @@ namespace conky {
 				throw std::logic_error("Data source with name '" + name + "' already registered");
 		}
 
-		static std::shared_ptr<data_source_base>
+		static void
 		disabled_source_factory(lua::state &l, const std::string &name, const std::string &setting)
 		{
 			// XXX some generic way of reporting errors? NORM_ERR?
@@ -67,7 +67,7 @@ namespace conky {
 					  << "' has been disabled during compilation. Please recompile with '"
 					  << setting << "'" << std::endl;
 
-			return simple_numeric_source<float>::factory(l, name, &NaN);
+			simple_numeric_source<float>::factory(l, name, &NaN);
 		}
 	}
 
@@ -82,11 +82,11 @@ namespace conky {
 	}
 
 	template<typename T>
-	std::shared_ptr<data_source_base>
+	void
 	simple_numeric_source<T>::factory(lua::state &l, const std::string &name, const T *source)
 	{
 		l.pop();
-		return std::shared_ptr<simple_numeric_source>(new simple_numeric_source(name, source));
+		l.createuserdata<simple_numeric_source<T>>(name, source);
 	}
 
 	register_data_source::register_data_source(const std::string &name, 
diff --git a/src/data-source.hh b/src/data-source.hh
index 11713784..bd72c77a 100644
--- a/src/data-source.hh
+++ b/src/data-source.hh
@@ -34,15 +34,12 @@
 
 namespace conky {
 
-    class data_source_base;
-
 	/*
 	 * Recieves a lua table on the stack and the name the object was registered with. It should
-	 * pop the table after consuming it and return the data source.
+	 * pop the table after consuming it. The result should be pushed on the stack as lua userdata
+	 * containing (a subclass of) data_source_base.
 	 */
-    typedef std::function<
-				std::shared_ptr<data_source_base> (lua::state &l, const std::string &name)
-			> data_source_factory;
+    typedef std::function<void (lua::state &l, const std::string &name)> data_source_factory;
 
 	/*
 	 * A base class for all data sources.
@@ -76,13 +73,12 @@ namespace conky {
 		static_assert(std::is_convertible<T, double>::value, "T must be convertible to double");
 
 		const T *source;
-
+	public:
 		simple_numeric_source(const std::string &name_, const T *source_)
 			: data_source_base(name_), source(source_)
 		{}
-	public:
-		static std::shared_ptr<data_source_base>
-		factory(lua::state &l, const std::string &name, const T *source);
+
+		static void factory(lua::state &l, const std::string &name, const T *source);
 
 		virtual double get_number() const
 		{ return *source; }
diff --git a/src/lua-config.cc b/src/lua-config.cc
index 455e871e..c1b32a68 100644
--- a/src/lua-config.cc
+++ b/src/lua-config.cc
@@ -40,7 +40,7 @@ namespace conky {
 			if(not l->getmetatable(-2) or not l->rawequal(-1, -2))
 				throw std::runtime_error("Invalid parameter");
 
-			return **static_cast<std::shared_ptr<data_source_base> *>(l->touserdata(1));
+			return *static_cast<data_source_base *>(l->touserdata(1));
 		}
 
 		int data_source_asnumber(lua::state *l)
@@ -59,7 +59,7 @@ namespace conky {
 
 		int create_data_source(lua::state *l, const data_sources_t::value_type &v)
 		{
-			l->createuserdata<std::shared_ptr<data_source_base>>(v.second(*l, v.first));
+			v.second(*l, v.first);
 			l->rawgetfield(lua::REGISTRYINDEX, data_source_metatable);
 			l->setmetatable(-2);
 			return 1;