Whole new plugin system

1 files changed, 163 insertions, 0 deletions

diff --git a/libadhocutil/plugins.h b/libadhocutil/plugins.h
new file mode 100644
index 0000000..69dd05c
--- /dev/null
+++ b/libadhocutil/plugins.h
@@ -0,0 +1,163 @@
+#ifndef ADHOCUTIL_PLUGINS_H
+#define ADHOCUTIL_PLUGINS_H
+
+#include <boost/shared_ptr.hpp>
+#include <boost/multi_index_container_fwd.hpp>
+#include <boost/multi_index/ordered_index_fwd.hpp>
+#include <boost/multi_index/member.hpp>
+#include <boost/multi_index/mem_fun.hpp>
+#include <boost/multi_index/composite_key.hpp>
+#include <typeinfo>
+#include <set>
+#include <algorithm>
+#include "visibility.h"
+
+namespace std {
+	DLL_PUBLIC
+	std::ostream &
+	operator<<(std::ostream & s, const std::type_info & t);
+}
+
+namespace AdHoc {
+	/// Thrown when no matching plugin can be found.
+	class NoSuchPluginException : public std::runtime_error {
+		public:
+			/// Constructor taking name and type of plugin requested.
+			NoSuchPluginException(const std::string &, const std::type_info &);
+	};
+
+	/// Base class for untyped plugins.
+	class DLL_PUBLIC Plugin {
+		public:
+			/// Constructor taking name, filename and line of install.
+			Plugin(const std::string &, const std::string &, int);
+			virtual ~Plugin();
+
+			/// Get the plugin type from the subclass.
+			virtual const std::type_info & type() const = 0;
+
+			/// The name the plugin was installed with.
+			const std::string name;
+			/// The filename the plugin was installed in.
+			const std::string filename;
+			/// The line of file the plugin was installed in.
+			const int lineno;
+	};
+	typedef boost::shared_ptr<const Plugin> PluginPtr;
+
+	/// Thrown when a plugin with the same name and base is loaded into a manager.
+	class DuplicatePluginException : public std::runtime_error {
+		public:
+			/// Constructor taking the original and offending plugin.
+			DuplicatePluginException(PluginPtr p1, PluginPtr p2);
+	};
+
+	template <typename T>
+	/// Typed plugin and handle to implementation.
+	class DLL_PUBLIC PluginOf : public Plugin {
+		public:
+			/// Constructor taking an instance and name, filename and line of install for Plugin.
+			PluginOf(const T * t, const std::string & n, const std::string & f, int l);
+			~PluginOf();
+
+			/// Get the type of this plugin.
+			const std::type_info & type() const override;
+			/// Get the implementation of this plugin.
+			const T * implementation() const;
+
+		private:
+			const T * impl;
+	};
+
+	/// Container for loaded plugins.
+	class DLL_PUBLIC PluginManager {
+		public:
+			PluginManager();
+			virtual ~PluginManager();
+
+			/// Install a plugin.
+			void add(PluginPtr);
+			/// Uninstall a plugin.
+			void remove(const std::string &, const std::type_info &);
+			/// Get a specific plugin.
+			PluginPtr get(const std::string &, const std::type_info &) const;
+			/// Get all plugins.
+			std::set<PluginPtr> getAll() const;
+			/// Get all plugins of a specific type.
+			std::set<PluginPtr> getAll(const std::type_info &) const;
+
+			/**
+			 * Install a plugin.
+			 * @param i Implementation instance.
+			 * @param n Name of plugin.
+			 * @param f Filename of plugin.
+			 * @param l Line number.
+			 */
+			template<typename T> void add(const T * i, const std::string & n, const std::string & f, int l);
+
+			/**
+			 * Uninstall a plugin.
+			 * @param n Name of plugin.
+			 */
+			template<typename T> void remove(const std::string & n);
+
+			/**
+			 * Get a specific plugin.
+			 * @param n Name of plugin.
+			 */
+			template<typename T> boost::shared_ptr<const PluginOf<T>> get(const std::string & n) const;
+
+			/**
+			 * Get the implementation from specific plugin.
+			 * @param n Name of plugin.
+			 */
+			template<typename T> const T * getImplementation(const std::string & n) const;
+
+			/**
+			 * Get all plugins of a given time.
+			 */
+			template<typename T> std::set<boost::shared_ptr<const PluginOf<T>>> getAll() const;
+
+			/**
+			 * The number of installed plugins.
+			 */
+			size_t count() const;
+
+			/**
+			 * Get the default plugin manager instance.
+			 */
+			static PluginManager * getDefault();
+
+		private:
+			typedef boost::multi_index_container<PluginPtr,
+							boost::multi_index::indexed_by<
+								boost::multi_index::ordered_non_unique<boost::multi_index::member<Plugin, const std::string, &Plugin::name>>,
+								boost::multi_index::ordered_non_unique<boost::multi_index::const_mem_fun<Plugin, const std::type_info &, &Plugin::type>>,
+								boost::multi_index::ordered_unique<
+									boost::multi_index::composite_key<
+										Plugin,
+										boost::multi_index::member<Plugin, const std::string, &Plugin::name>,
+										boost::multi_index::const_mem_fun<Plugin, const std::type_info &, &Plugin::type>
+										>>
+								>> PluginStore;
+
+			PluginStore * plugins;
+	};
+}
+
+#define NAMEDPLUGIN(Name, Implementation, Base) \
+	namespace { \
+		static void InstallPlugin() __attribute__((constructor(102))); \
+		void InstallPlugin() { \
+			::AdHoc::PluginManager::getDefault()->add<Base>(new Implementation(), Name, __FILE__, __LINE__); \
+		} \
+		static void UninstallPlugin() __attribute__((destructor(102))); \
+		void UninstallPlugin() { \
+			::AdHoc::PluginManager::getDefault()->remove<Base>(Name); \
+		} \
+	}
+#define PLUGIN(Implementation, Base) \
+	NAMEDPLUGIN(#Implementation, Implementation, Base)
+
+#endif
+