mosesdecoder/moses/TranslationModel/PhraseDictionary.h

// $Id$

/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2006 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
***********************************************************************/

#ifndef moses_PhraseDictionary_h
#define moses_PhraseDictionary_h

#include <iostream>
#include <map>
#include <memory>
#include <list>
#include <stdexcept>
#include <vector>
#include <string>

#ifdef WITH_THREADS
#include <boost/thread/tss.hpp>
#endif

#include "moses/Phrase.h"
#include "moses/TargetPhrase.h"
#include "moses/Dictionary.h"
#include "moses/TargetPhraseCollection.h"
#include "moses/DecodeFeature.h"

namespace Moses
{

class StaticData;
class InputType;
class WordsRange;
class ChartCellCollectionBase;
class TranslationSystem;
class ChartRuleLookupManager;

class PhraseDictionaryFeature;
class SparsePhraseDictionaryFeature;

/**
  * Abstract base class for phrase dictionaries (tables).
  **/
class PhraseDictionary: public Dictionary
{
public:
  PhraseDictionary(size_t numScoreComponent, const PhraseDictionaryFeature* feature):
    Dictionary(numScoreComponent), m_tableLimit(0), m_feature(feature) {}
  //! table limit number.
  size_t GetTableLimit() const {
    return m_tableLimit;
  }
  DecodeType GetDecodeType() const    {
    return Translate;
  }
  const PhraseDictionaryFeature* GetFeature() const;

  //! find list of translations that can translates src. Only for phrase input
  virtual const TargetPhraseCollection *GetTargetPhraseCollection(const Phrase& src) const=0;
  //! find list of translations that can translates a portion of src. Used by confusion network decoding
  virtual const TargetPhraseCollection *GetTargetPhraseCollection(InputType const& src,WordsRange const& range) const;

  //! Create entry for translation of source to targetPhrase
  virtual void InitializeForInput(InputType const& source)
  {}
  // clean up temporary memory, called after processing each sentence
  virtual void CleanUpAfterSentenceProcessing(const InputType& source)
  {}

  //! Create a sentence-specific manager for SCFG rule lookup.
  virtual ChartRuleLookupManager *CreateRuleLookupManager(
    const InputType &,
    const ChartCellCollectionBase &) = 0;

protected:
  size_t m_tableLimit;
  const PhraseDictionaryFeature* m_feature;
};


/**
 * Represents a feature derived from a phrase table.
 */
class PhraseDictionaryFeature :  public DecodeFeature
{


public:
  PhraseDictionaryFeature(const std::string &line);
  PhraseDictionaryFeature(  PhraseTableImplementation implementation
                              , size_t numScoreComponent
                              , unsigned numInputScores
                              , const std::vector<FactorType> &input
                              , const std::vector<FactorType> &output
                              , const std::string &filePath
                              , size_t tableLimit
                              , const std::string &targetFile
                              , const std::string &alignmentsFile);

  virtual ~PhraseDictionaryFeature();

  virtual bool ComputeValueInTranslationOption() const;

  SparsePhraseDictionaryFeature* GetSparsePhraseDictionaryFeature() const {
    return m_sparsePhraseDictionaryFeature;
  }
  void SetSparsePhraseDictionaryFeature(SparsePhraseDictionaryFeature *spdf) {
    m_sparsePhraseDictionaryFeature = spdf;
  }

  //Initialises the dictionary (may involve loading from file)
  void InitDictionary(const TranslationSystem* system);

  //Get the dictionary. Be sure to initialise it first.
  const PhraseDictionary* GetDictionary() const;
  PhraseDictionary* GetDictionary();

  //Usual feature function methods are not implemented
  virtual void Evaluate(const PhraseBasedFeatureContext& context,
  											ScoreComponentCollection* accumulator) const 
  {
    throw std::logic_error("PhraseDictionary.Evaluate() Not implemented");
  }

  virtual void EvaluateChart(const ChartBasedFeatureContext& context,
                             ScoreComponentCollection* accumulator) const 
  {
    throw std::logic_error("PhraseDictionary.EvaluateChart() Not implemented");
  }

  virtual bool ComputeValueInTranslationTable() const {return true;}

  void InitializeForInput(const InputType& source);
  // clean up temporary memory, called after processing each sentence
  void CleanUpAfterSentenceProcessing(const InputType& source);

private:
  /** Load the appropriate phrase table */
  PhraseDictionary* LoadPhraseTable(const TranslationSystem* system);

  unsigned m_numInputScores;
  std::string m_filePath;
  size_t m_tableLimit;
  //We instantiate either the the thread-safe or non-thread-safe dictionary,
  //but not both. The thread-safe one can be instantiated in the constructor and shared
  //between threads, however the non-thread-safe one (eg PhraseDictionaryTree) must be instantiated
  //on demand, and stored in thread-specific storage.
  std::auto_ptr<PhraseDictionary> m_threadSafePhraseDictionary;
#ifdef WITH_THREADS
  boost::thread_specific_ptr<PhraseDictionary>  m_threadUnsafePhraseDictionary;
#else
  std::auto_ptr<PhraseDictionary> m_threadUnsafePhraseDictionary;
#endif

  bool m_useThreadSafePhraseDictionary;
  PhraseTableImplementation m_implementation;
  std::string m_targetFile;
  std::string m_alignmentsFile;
  SparsePhraseDictionaryFeature* m_sparsePhraseDictionaryFeature;

};



}
#endif