phoenix-firestorm/indra/llcommon/llinstancetracker.h

122 lines
4.1 KiB
C++

/**
* @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>
// 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
{
public:
typedef typename std::map<KEY, T*>::iterator instance_iter;
typedef typename std::map<KEY, T*>::const_iterator instance_const_iter;
static T* getInstance(const KEY& k) { instance_iter found = getMap().find(k); return (found == getMap().end()) ? NULL : found->second; }
static instance_iter beginInstances() { return getMap().begin(); }
static instance_iter endInstances() { return getMap().end(); }
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 std::map<KEY, T*>& getMap()
{
if (! sInstances)
{
sInstances = new std::map<KEY, T*>;
}
return *sInstances;
}
private:
KEY mKey;
static std::map<KEY, T*>* sInstances;
};
// explicit specialization for default case where KEY is T*
// use a simple std::set<T*>
template<typename T>
class LLInstanceTracker<T, T*>
{
public:
typedef typename std::set<T*>::iterator instance_iter;
typedef typename std::set<T*>::const_iterator instance_const_iter;
static instance_iter beginInstances() { return getSet().begin(); }
static instance_iter endInstances() { return 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 std::set<T*>& getSet() // called after getReady() but before go()
{
if (! sInstances)
{
sInstances = new std::set<T*>;
}
return *sInstances;
}
static std::set<T*>* sInstances;
};
template <typename T, typename KEY> std::map<KEY, T*>* LLInstanceTracker<T, KEY>::sInstances = NULL;
template <typename T> std::set<T*>* LLInstanceTracker<T, T*>::sInstances = NULL;
#endif