mosesdecoder/mira/HypothesisQueue.h
2013-05-29 18:16:15 +01:00

70 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 <set>
namespace Moses
{
// pair of Bleu score and index
typedef std::pair<float, size_t> BleuIndexPair;
// A bounded priority queue of BleuIndexPairs. The top item is
// the best scoring hypothesis. 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 HypothesisQueue
{
public:
// Create empty queue with fixed capacity of c. Capacity 0 means unbounded.
HypothesisQueue(size_t c) : m_capacity(c) {}
~HypothesisQueue();
bool Empty() {
return m_queue.empty();
}
// Add the hypo 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(BleuIndexPair hypo);
// Remove the best-scoring detour from the queue and return it. The
// caller is responsible for deleting the object.
BleuIndexPair Pop();
private:
struct HypothesisOrderer {
bool operator()(BleuIndexPair a,
BleuIndexPair b) {
return (a.first > b.first);
}
};
typedef std::multiset<BleuIndexPair, HypothesisOrderer> HypoQueueType;
//typedef std::set<BleuIndexPair, HypothesisOrderer> HypoQueueType;
HypoQueueType m_queue;
const size_t m_capacity;
};
} // namespace Moses