/** * @file llinstancetracker.h * @brief LLInstanceTracker is a mixin class that automatically tracks object * instances with or without an associated key * * $LicenseInfo:firstyear=2000&license=viewergpl$ * * Copyright (c) 2000-2009, Linden Research, Inc. * * Second Life Viewer Source Code * The source code in this file ("Source Code") is provided by Linden Lab * to you under the terms of the GNU General Public License, version 2.0 * ("GPL"), unless you have obtained a separate licensing agreement * ("Other License"), formally executed by you and Linden Lab. Terms of * the GPL can be found in doc/GPL-license.txt in this distribution, or * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2 * * There are special exceptions to the terms and conditions of the GPL as * it is applied to this Source Code. View the full text of the exception * in the file doc/FLOSS-exception.txt in this software distribution, or * online at * http://secondlifegrid.net/programs/open_source/licensing/flossexception * * By copying, modifying or distributing this software, you acknowledge * that you have read and understood your obligations described above, * and agree to abide by those obligations. * * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, * COMPLETENESS OR PERFORMANCE. * $/LicenseInfo$ */ #ifndef LL_LLINSTANCETRACKER_H #define LL_LLINSTANCETRACKER_H #include <map> #include "string_table.h" #include <boost/utility.hpp> #include <boost/function.hpp> #include <boost/bind.hpp> #include <boost/iterator/transform_iterator.hpp> #include <boost/iterator/indirect_iterator.hpp> /// This mix-in class adds support for tracking all instances of the specified class parameter T /// The (optional) key associates a value of type KEY with a given instance of T, for quick lookup /// If KEY is not provided, then instances are stored in a simple set /// @NOTE: see explicit specialization below for default KEY==T* case template<typename T, typename KEY = T*> class LLInstanceTracker : boost::noncopyable { typedef typename std::map<KEY, T*> InstanceMap; typedef boost::function<const KEY&(typename InstanceMap::value_type&)> KeyGetter; typedef boost::function<T*(typename InstanceMap::value_type&)> InstancePtrGetter; public: /// Dereferencing key_iter gives you a const KEY& typedef boost::transform_iterator<KeyGetter, typename InstanceMap::iterator> key_iter; /// Dereferencing instance_iter gives you a T& typedef boost::indirect_iterator< boost::transform_iterator<InstancePtrGetter, typename InstanceMap::iterator> > instance_iter; static T* getInstance(const KEY& k) { typename InstanceMap::const_iterator found = getMap_().find(k); return (found == getMap_().end()) ? NULL : found->second; } static key_iter beginKeys() { return boost::make_transform_iterator(getMap_().begin(), boost::bind(&InstanceMap::value_type::first, _1)); } static key_iter endKeys() { return boost::make_transform_iterator(getMap_().end(), boost::bind(&InstanceMap::value_type::first, _1)); } static instance_iter beginInstances() { return instance_iter(boost::make_transform_iterator(getMap_().begin(), boost::bind(&InstanceMap::value_type::second, _1))); } static instance_iter endInstances() { return instance_iter(boost::make_transform_iterator(getMap_().end(), boost::bind(&InstanceMap::value_type::second, _1))); } static S32 instanceCount() { return getMap_().size(); } protected: LLInstanceTracker(KEY key) { add_(key); } virtual ~LLInstanceTracker() { remove_(); } virtual void setKey(KEY key) { remove_(); add_(key); } virtual const KEY& getKey() const { return mKey; } private: void add_(KEY key) { mKey = key; getMap_()[key] = static_cast<T*>(this); } void remove_() { getMap_().erase(mKey); } static InstanceMap& getMap_() { if (! sInstances) { sInstances = new InstanceMap; } return *sInstances; } private: KEY mKey; static InstanceMap* sInstances; }; /// explicit specialization for default case where KEY is T* /// use a simple std::set<T*> template<typename T> class LLInstanceTracker<T, T*> { typedef typename std::set<T*> InstanceSet; public: /// Dereferencing key_iter gives you a T* (since T* is the key) typedef typename InstanceSet::iterator key_iter; /// Dereferencing instance_iter gives you a T& typedef boost::indirect_iterator<key_iter> instance_iter; /// for completeness of analogy with the generic implementation static T* getInstance(T* k) { return k; } static key_iter beginKeys() { return getSet_().begin(); } static key_iter endKeys() { return getSet_().end(); } static instance_iter beginInstances() { return instance_iter(getSet_().begin()); } static instance_iter endInstances() { return instance_iter(getSet_().end()); } static S32 instanceCount() { return getSet_().size(); } protected: LLInstanceTracker() { getSet_().insert(static_cast<T*>(this)); } virtual ~LLInstanceTracker() { getSet_().erase(static_cast<T*>(this)); } LLInstanceTracker(const LLInstanceTracker& other) { getSet_().insert(static_cast<T*>(this)); } static InstanceSet& getSet_() // called after getReady() but before go() { if (! sInstances) { sInstances = new InstanceSet; } return *sInstances; } static InstanceSet* sInstances; }; template <typename T, typename KEY> typename LLInstanceTracker<T, KEY>::InstanceMap* LLInstanceTracker<T, KEY>::sInstances = NULL; template <typename T> typename LLInstanceTracker<T, T*>::InstanceSet* LLInstanceTracker<T, T*>::sInstances = NULL; #endif