mosesdecoder/moses/ChartTrellisDetourQueue.h
2012-11-12 19:56:18 +00:00

64 lines
2.2 KiB
C++

/***********************************************************************
Moses - statistical machine translation system
Copyright (C) 2006-2011 University of Edinburgh
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; either
version 2.1 of the License, or (at your option) any later version.
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
***********************************************************************/
#pragma once
#include "ChartTrellisDetour.h"
#include <set>
namespace Moses {
/** A bounded priority queue of ChartTrellisDetour pointers. The top item is
* the best scoring detour. The queue assumes ownership of pushed items and
* relinquishes ownership when they are popped. Any remaining items at the
* time of the queue's destruction are deleted.
*/
class ChartTrellisDetourQueue {
public:
// Create empty queue with fixed capacity of c. Capacity 0 means unbounded.
ChartTrellisDetourQueue(size_t c) : m_capacity(c) {}
~ChartTrellisDetourQueue();
bool Empty() const { return m_queue.empty(); }
// Add the detour to the queue or delete it if the queue is full and the
// score is no better than the queue's worst score.
void Push(const ChartTrellisDetour *detour);
// Remove the best-scoring detour from the queue and return it. The
// caller is responsible for deleting the object.
const ChartTrellisDetour *Pop();
private:
struct DetourOrderer {
bool operator()(const ChartTrellisDetour* a,
const ChartTrellisDetour* b) const {
return (a->GetTotalScore() > b->GetTotalScore());
}
};
typedef std::multiset<const ChartTrellisDetour *, DetourOrderer> QueueType;
QueueType m_queue;
const size_t m_capacity;
};
} // namespace Moses