mosesdecoder/moses/TranslationOptionCollectionConfusionNet.cpp

// $Id$

#include "TranslationOptionCollectionConfusionNet.h"
#include "ConfusionNet.h"
#include "DecodeStep.h"
#include "DecodeStepTranslation.h"
#include "FactorCollection.h"
#include <list>

using namespace std;

namespace Moses
{

/** constructor; just initialize the base class */
TranslationOptionCollectionConfusionNet::TranslationOptionCollectionConfusionNet(
  const ConfusionNet &input
  , size_t maxNoTransOptPerCoverage, float translationOptionThreshold)
  : TranslationOptionCollection(input, maxNoTransOptPerCoverage, translationOptionThreshold) {}

/* forcibly create translation option for a particular source word.
	* call the base class' ProcessOneUnknownWord() for each possible word in the confusion network
	* at a particular source position
*/
void TranslationOptionCollectionConfusionNet::ProcessUnknownWord(size_t sourcePos)
{
  ConfusionNet const& source=dynamic_cast<ConfusionNet const&>(m_source);

  ConfusionNet::Column const& coll=source.GetColumn(sourcePos);
  size_t j=0;
  for(ConfusionNet::Column::const_iterator i=coll.begin(); i!=coll.end(); ++i) {
    ProcessOneUnknownWord(i->first ,sourcePos, source.GetColumnIncrement(sourcePos, j++),&(i->second));
  }

}

/** create translation options that exactly cover a specific input span.
 * Called by CreateTranslationOptions() and ProcessUnknownWord()
 * \param decodeGraph list of decoding steps
 * \param factorCollection input sentence with all factors
 * \param startPos first position in input sentence
 * \param lastPos last position in input sentence
 * \param adhereTableLimit whether phrase & generation table limits are adhered to
 */
void TranslationOptionCollectionConfusionNet::CreateTranslationOptionsForRange(
  const DecodeGraph &decodeGraph
  , size_t startPos
  , size_t endPos
  , bool adhereTableLimit
  , size_t graphInd)
{
  if ((StaticData::Instance().GetXmlInputType() != XmlExclusive) || !HasXmlOptionsOverlappingRange(startPos,endPos)) {
    Phrase *sourcePhrase = NULL; // can't initialise with substring, in case it's confusion network

    // consult persistent (cross-sentence) cache for stored translation options
    bool skipTransOptCreation = false
                                , useCache = StaticData::Instance().GetUseTransOptCache();
    if (useCache) {
      const WordsRange wordsRange(startPos, endPos);
      sourcePhrase = new Phrase(m_source.GetSubString(wordsRange));

      const TranslationOptionList *transOptList = StaticData::Instance().FindTransOptListInCache(decodeGraph, *sourcePhrase);
      // is phrase in cache?
      if (transOptList != NULL) {
        skipTransOptCreation = true;
        TranslationOptionList::const_iterator iterTransOpt;
        for (iterTransOpt = transOptList->begin() ; iterTransOpt != transOptList->end() ; ++iterTransOpt) {
          TranslationOption *transOpt = new TranslationOption(**iterTransOpt, wordsRange);
          Add(transOpt);
        }
      }
    } // useCache

    if (!skipTransOptCreation) {
      // partial trans opt stored in here
      PartialTranslOptColl* oldPtoc = new PartialTranslOptColl;
      size_t totalEarlyPruned = 0;

      // initial translation step
      list <const DecodeStep* >::const_iterator iterStep = decodeGraph.begin();
      const DecodeStep &decodeStep = **iterStep;

      static_cast<const DecodeStepTranslation&>(decodeStep).ProcessInitialTranslation
      (m_source, *oldPtoc
       , startPos, endPos, adhereTableLimit );

      // do rest of decode steps
      int indexStep = 0;

      for (++iterStep ; iterStep != decodeGraph.end() ; ++iterStep) {

        const DecodeStep &decodeStep = **iterStep;
        PartialTranslOptColl* newPtoc = new PartialTranslOptColl;

        // go thru each intermediate trans opt just created
        const vector<TranslationOption*>& partTransOptList = oldPtoc->GetList();
        vector<TranslationOption*>::const_iterator iterPartialTranslOpt;
        for (iterPartialTranslOpt = partTransOptList.begin() ; iterPartialTranslOpt != partTransOptList.end() ; ++iterPartialTranslOpt) {
          TranslationOption &inputPartialTranslOpt = **iterPartialTranslOpt;

          decodeStep.Process(inputPartialTranslOpt
                             , decodeStep
                             , *newPtoc
                             , this
                             , adhereTableLimit
                             , *sourcePhrase);
        }

        // last but 1 partial trans not required anymore
        totalEarlyPruned += newPtoc->GetPrunedCount();
        delete oldPtoc;
        oldPtoc = newPtoc;

        indexStep++;
      } // for (++iterStep

      // add to fully formed translation option list
      PartialTranslOptColl &lastPartialTranslOptColl	= *oldPtoc;
      const vector<TranslationOption*>& partTransOptList = lastPartialTranslOptColl.GetList();
      vector<TranslationOption*>::const_iterator iterColl;
      for (iterColl = partTransOptList.begin() ; iterColl != partTransOptList.end() ; ++iterColl) {
        TranslationOption *transOpt = *iterColl;
        Add(transOpt);
      }

      // storing translation options in persistent cache (kept across sentences)
      if (useCache) {
        if (partTransOptList.size() > 0) {
          TranslationOptionList &transOptList = GetTranslationOptionList(startPos, endPos);
          StaticData::Instance().AddTransOptListToCache(decodeGraph, *sourcePhrase, transOptList);
        }
      }

      lastPartialTranslOptColl.DetachAll();
      totalEarlyPruned += oldPtoc->GetPrunedCount();
      delete oldPtoc;
      // TRACE_ERR( "Early translation options pruned: " << totalEarlyPruned << endl);
    } // if (!skipTransOptCreation)

    if (useCache)
      delete sourcePhrase;
  } // if ((StaticData::Instance().GetXmlInputType() != XmlExclusive) || !HasXmlOptionsOverlappingRange(startPos,endPos))

  if (graphInd == 0 && StaticData::Instance().GetXmlInputType() != XmlPassThrough && HasXmlOptionsOverlappingRange(startPos,endPos)) {
    CreateXmlOptionsForRange(startPos, endPos);
  }
}

}