/** * @file llpriqueuemap.h * @brief Priority queue implementation * * $LicenseInfo:firstyear=2003&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #ifndef LL_LLPRIQUEUEMAP_H #define LL_LLPRIQUEUEMAP_H #include <map> // // Priority queue, implemented under the hood as a // map. Needs to be done this way because none of the // standard STL containers provide a representation // where it's easy to reprioritize. // template <class DATA> class LLPQMKey { public: LLPQMKey(const F32 priority, DATA data) : mPriority(priority), mData(data) { } bool operator<(const LLPQMKey &b) const { if (mPriority > b.mPriority) { return TRUE; } if (mPriority < b.mPriority) { return FALSE; } if (mData > b.mData) { return TRUE; } return FALSE; } F32 mPriority; DATA mData; }; template <class DATA_TYPE> class LLPriQueueMap { public: typedef typename std::map<LLPQMKey<DATA_TYPE>, DATA_TYPE>::iterator pqm_iter; typedef std::pair<LLPQMKey<DATA_TYPE>, DATA_TYPE> pqm_pair; typedef void (*set_pri_fn)(DATA_TYPE &data, const F32 priority); typedef F32 (*get_pri_fn)(DATA_TYPE &data); LLPriQueueMap(set_pri_fn set_pri, get_pri_fn get_pri) : mSetPriority(set_pri), mGetPriority(get_pri) { } void push(const F32 priority, DATA_TYPE data) { #ifdef _DEBUG pqm_iter iter = mMap.find(LLPQMKey<DATA_TYPE>(priority, data)); if (iter != mMap.end()) { LL_ERRS() << "Pushing already existing data onto queue!" << LL_ENDL; } #endif mMap.insert(pqm_pair(LLPQMKey<DATA_TYPE>(priority, data), data)); } BOOL pop(DATA_TYPE *datap) { pqm_iter iter; iter = mMap.begin(); if (iter == mMap.end()) { return FALSE; } *datap = (*(iter)).second; mMap.erase(iter); return TRUE; } void reprioritize(const F32 new_priority, DATA_TYPE data) { pqm_iter iter; F32 cur_priority = mGetPriority(data); LLPQMKey<DATA_TYPE> cur_key(cur_priority, data); iter = mMap.find(cur_key); if (iter == mMap.end()) { LL_WARNS() << "Data not on priority queue!" << LL_ENDL; // OK, try iterating through all of the data and seeing if we just screwed up the priority // somehow. for (iter = mMap.begin(); iter != mMap.end(); iter++) { if ((*(iter)).second == data) { LL_ERRS() << "Data on priority queue but priority not matched!" << LL_ENDL; } } return; } mMap.erase(iter); mSetPriority(data, new_priority); push(new_priority, data); } S32 getLength() const { return (S32)mMap.size(); } // Hack: public for use by the transfer manager, ugh. std::map<LLPQMKey<DATA_TYPE>, DATA_TYPE> mMap; protected: void (*mSetPriority)(DATA_TYPE &data, const F32 priority); F32 (*mGetPriority)(DATA_TYPE &data); }; #endif // LL_LLPRIQUEUEMAP_H