mosesdecoder/mira/Decoder.cpp

/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2009 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
***********************************************************************/

#include "Decoder.h"
#include "moses/Manager.h"
#include "moses/ChartManager.h"
#include "moses/Sentence.h"
#include "moses/InputType.h"
#include "moses/Phrase.h"
#include "moses/TrellisPathList.h"
#include "moses/ChartTrellisPathList.h"
#include "moses/ChartTrellisPath.h"

using namespace std;
using namespace Moses;


namespace Mira
{

/**
  * Allocates a char* and copies string into it.
**/
static char* strToChar(const string& s)
{
  char* c = new char[s.size()+1];
  strcpy(c,s.c_str());
  return c;
}

MosesDecoder::MosesDecoder(const string& inifile, int debuglevel, int argc, vector<string> decoder_params)
  : m_manager(NULL)
{
  static int BASE_ARGC = 8;
  Parameter* params = new Parameter();
  char ** mosesargv = new char*[BASE_ARGC + argc];
  mosesargv[0] = strToChar("-f");
  mosesargv[1] = strToChar(inifile);
  mosesargv[2] = strToChar("-v");
  stringstream dbgin;
  dbgin << debuglevel;
  mosesargv[3] = strToChar(dbgin.str());
  mosesargv[4] = strToChar("-use-persistent-cache");
  mosesargv[5] = strToChar("0");
  mosesargv[6] = strToChar("-persistent-cache-size");
  mosesargv[7] = strToChar("0");

  for (int i = 0; i < argc; ++i) {
    char *cstr = &(decoder_params[i])[0];
    mosesargv[BASE_ARGC + i] = cstr;
  }

  if (!params->LoadParam(BASE_ARGC + argc,mosesargv)) {
    cerr << "Loading static data failed, exit." << endl;
    exit(1);
  }
  StaticData::LoadDataStatic(params, "mira");
  for (int i = 0; i < BASE_ARGC; ++i) {
    delete[] mosesargv[i];
  }
  delete[] mosesargv;

  //m_bleuScoreFeature = staticData.GetBleuScoreFeature(); TODO
  assert(false);
}

void MosesDecoder::cleanup(bool chartDecoding)
{
  delete m_manager;
  if (chartDecoding)
    delete m_chartManager;
  else
    delete m_sentence;
}

vector< vector<const Word*> > MosesDecoder::getNBest(const std::string& source,
    size_t sentenceid,
    size_t nBestSize,
    float bleuObjectiveWeight,
    float bleuScoreWeight,
    vector< ScoreComponentCollection>& featureValues,
    vector< float>& bleuScores,
    vector< float>& modelScores,
    size_t numReturnedTranslations,
    bool realBleu,
    bool distinct,
    bool avgRefLength,
    size_t rank,
    size_t epoch,
    string filename)
{
  StaticData &staticData = StaticData::InstanceNonConst();
  bool chartDecoding = staticData.IsChart();
  initialize(staticData, source, sentenceid, bleuObjectiveWeight, bleuScoreWeight, avgRefLength, chartDecoding);

  // run the decoder
  if (chartDecoding) {
    return runChartDecoder(source, sentenceid, nBestSize, bleuObjectiveWeight, bleuScoreWeight,
                           featureValues, bleuScores, modelScores, numReturnedTranslations, realBleu, distinct, rank, epoch);
  } else {
    SearchAlgorithm search = staticData.GetSearchAlgorithm();
    return runDecoder(source, sentenceid, nBestSize, bleuObjectiveWeight, bleuScoreWeight,
                      featureValues, bleuScores, modelScores, numReturnedTranslations, realBleu, distinct, rank, epoch,
                      search, filename);
  }
}

vector< vector<const Word*> > MosesDecoder::runDecoder(const std::string& source,
    size_t sentenceid,
    size_t nBestSize,
    float bleuObjectiveWeight,
    float bleuScoreWeight,
    vector< ScoreComponentCollection>& featureValues,
    vector< float>& bleuScores,
    vector< float>& modelScores,
    size_t numReturnedTranslations,
    bool realBleu,
    bool distinct,
    size_t rank,
    size_t epoch,
    SearchAlgorithm& search,
    string filename)
{
  // run the decoder
  m_manager = new Moses::Manager(0,*m_sentence, search);
  m_manager->ProcessSentence();
  TrellisPathList nBestList;
  m_manager->CalcNBest(nBestSize, nBestList, distinct);

  // optionally print nbest to file (to extract scores and features.. currently just for sentence bleu scoring)
  /*if (filename != "") {
    ofstream out(filename.c_str());
    if (!out) {
      ostringstream msg;
      msg << "Unable to open " << filename;
      throw runtime_error(msg.str());
    }
    // TODO: handle sentence id (for now always 0)
    //OutputNBest(out, nBestList, StaticData::Instance().GetOutputFactorOrder(), 0, false);
    out.close();
  }*/

  // read off the feature values and bleu scores for each sentence in the nbest list
  Moses::TrellisPathList::const_iterator iter;
  for (iter = nBestList.begin() ; iter != nBestList.end() ; ++iter) {
    const Moses::TrellisPath &path = **iter;
    featureValues.push_back(path.GetScoreBreakdown());
    float bleuScore, dynBleuScore, realBleuScore;
    if (realBleu) realBleuScore = m_bleuScoreFeature->CalculateBleu(path.GetTargetPhrase());
    else dynBleuScore = getBleuScore(featureValues.back());
    bleuScore = realBleu ? realBleuScore : dynBleuScore;
    bleuScores.push_back(bleuScore);

    //std::cout << "Score breakdown: " << path.GetScoreBreakdown() << endl;
    float scoreWithoutBleu = path.GetTotalScore() - (bleuObjectiveWeight * bleuScoreWeight * bleuScore);
    modelScores.push_back(scoreWithoutBleu);

    if (iter != nBestList.begin())
      cerr << endl;
    cerr << "Rank " << rank << ", epoch " << epoch << ", \"" << path.GetTargetPhrase() << "\", score: "
         << scoreWithoutBleu << ", Bleu: " << bleuScore << ", total: " << path.GetTotalScore();
    if (m_bleuScoreFeature->Enabled() && realBleu)
      cerr << " (d-bleu: " << dynBleuScore << ", r-bleu: " << realBleuScore << ") ";

    // set bleu score to zero in the feature vector since we do not want to optimise its weight
    setBleuScore(featureValues.back(), 0);
  }

  // prepare translations to return
  vector< vector<const Word*> > translations;
  for (size_t i=0; i < numReturnedTranslations && i < nBestList.GetSize(); ++i) {
    const TrellisPath &path = nBestList.at(i);
    Phrase phrase = path.GetTargetPhrase();

    vector<const Word*> translation;
    for (size_t pos = 0; pos < phrase.GetSize(); ++pos) {
      const Word &word = phrase.GetWord(pos);
      Word *newWord = new Word(word);
      translation.push_back(newWord);
    }
    translations.push_back(translation);
  }

  return translations;
}

vector< vector<const Word*> > MosesDecoder::runChartDecoder(const std::string& source,
    size_t sentenceid,
    size_t nBestSize,
    float bleuObjectiveWeight,
    float bleuScoreWeight,
    vector< ScoreComponentCollection>& featureValues,
    vector< float>& bleuScores,
    vector< float>& modelScores,
    size_t numReturnedTranslations,
    bool realBleu,
    bool distinct,
    size_t rank,
    size_t epoch)
{
  // run the decoder
  m_chartManager = new ChartManager(*m_sentence);
  m_chartManager->ProcessSentence();
  ChartTrellisPathList nBestList;
  m_chartManager->CalcNBest(nBestSize, nBestList, distinct);

  // read off the feature values and bleu scores for each sentence in the nbest list
  ChartTrellisPathList::const_iterator iter;
  for (iter = nBestList.begin() ; iter != nBestList.end() ; ++iter) {
    const Moses::ChartTrellisPath &path = **iter;
    featureValues.push_back(path.GetScoreBreakdown());
    float bleuScore, dynBleuScore, realBleuScore;
    dynBleuScore = getBleuScore(featureValues.back());
    realBleuScore = m_bleuScoreFeature->CalculateBleu(path.GetOutputPhrase());
    bleuScore = realBleu ? realBleuScore : dynBleuScore;
    bleuScores.push_back(bleuScore);

    //std::cout << "Score breakdown: " << path.GetScoreBreakdown() << endl;
    float scoreWithoutBleu = path.GetTotalScore() - (bleuObjectiveWeight * bleuScoreWeight * bleuScore);
    modelScores.push_back(scoreWithoutBleu);

    if (iter != nBestList.begin())
      cerr << endl;
    cerr << "Rank " << rank << ", epoch " << epoch << ", \"" << path.GetOutputPhrase() << "\", score: "
         << scoreWithoutBleu << ", Bleu: " << bleuScore << ", total: " << path.GetTotalScore();
    if (m_bleuScoreFeature->Enabled() && realBleu)
      cerr << " (d-bleu: " << dynBleuScore << ", r-bleu: " << realBleuScore << ") ";

    // set bleu score to zero in the feature vector since we do not want to optimise its weight
    setBleuScore(featureValues.back(), 0);
  }

  // prepare translations to return
  vector< vector<const Word*> > translations;
  for (iter = nBestList.begin() ; iter != nBestList.end() ; ++iter) {
    const ChartTrellisPath &path = **iter;
    Phrase phrase = path.GetOutputPhrase();

    vector<const Word*> translation;
    for (size_t pos = 0; pos < phrase.GetSize(); ++pos) {
      const Word &word = phrase.GetWord(pos);
      Word *newWord = new Word(word);
      translation.push_back(newWord);
    }
    translations.push_back(translation);
  }

  return translations;
}

void MosesDecoder::initialize(StaticData& staticData, const std::string& source, size_t sentenceid,
                              float bleuObjectiveWeight, float bleuScoreWeight, bool avgRefLength, bool chartDecoding)
{
  m_sentence = new Sentence();
  stringstream in(source + "\n");
  const std::vector<FactorType> &inputFactorOrder = staticData.GetInputFactorOrder();
  m_sentence->Read(in,inputFactorOrder);

  // set weight of BleuScoreFeature
  //cerr << "Reload Bleu feature weight: " << bleuObjectiveWeight*bleuScoreWeight << " (" << bleuObjectiveWeight << "*" << bleuScoreWeight << ")" << endl;
  staticData.ReLoadBleuScoreFeatureParameter(bleuObjectiveWeight*bleuScoreWeight);

  m_bleuScoreFeature->SetCurrSourceLength((*m_sentence).GetSize());
  if (chartDecoding)
    m_bleuScoreFeature->SetCurrNormSourceLength((*m_sentence).GetSize()-2);
  else
    m_bleuScoreFeature->SetCurrNormSourceLength((*m_sentence).GetSize());

  if (avgRefLength)
    m_bleuScoreFeature->SetCurrAvgRefLength(sentenceid);
  else
    m_bleuScoreFeature->SetCurrShortestRefLength(sentenceid);
  m_bleuScoreFeature->SetCurrReferenceNgrams(sentenceid);
}

float MosesDecoder::getBleuScore(const ScoreComponentCollection& scores)
{
  return scores.GetScoreForProducer(m_bleuScoreFeature);
}

void MosesDecoder::setBleuScore(ScoreComponentCollection& scores, float bleu)
{
  scores.Assign(m_bleuScoreFeature, bleu);
}

ScoreComponentCollection MosesDecoder::getWeights()
{
  return StaticData::Instance().GetAllWeights();
}

void MosesDecoder::setWeights(const ScoreComponentCollection& weights)
{
  StaticData::InstanceNonConst().SetAllWeights(weights);
}

void MosesDecoder::updateHistory(const vector<const Word*>& words)
{
  m_bleuScoreFeature->UpdateHistory(words);
}

void MosesDecoder::updateHistory(const vector< vector< const Word*> >& words, vector<size_t>& sourceLengths, vector<size_t>& ref_ids, size_t rank, size_t epoch)
{
  m_bleuScoreFeature->UpdateHistory(words, sourceLengths, ref_ids, rank, epoch);
}

void MosesDecoder::printBleuFeatureHistory(std::ostream& out)
{
  m_bleuScoreFeature->PrintHistory(out);
}

size_t MosesDecoder::getClosestReferenceLength(size_t ref_id, int hypoLength)
{
  return m_bleuScoreFeature->GetClosestRefLength(ref_id, hypoLength);
}

size_t MosesDecoder::getShortestReferenceIndex(size_t ref_id)
{
  return m_bleuScoreFeature->GetShortestRefIndex(ref_id);
}

void MosesDecoder::setBleuParameters(bool disable, bool sentenceBleu, bool scaleByInputLength, bool scaleByAvgInputLength,
                                     bool scaleByInverseLength, bool scaleByAvgInverseLength,
                                     float scaleByX, float historySmoothing, size_t scheme, bool simpleHistoryBleu)
{
  m_bleuScoreFeature->SetBleuParameters(disable, sentenceBleu, scaleByInputLength, scaleByAvgInputLength,
                                        scaleByInverseLength, scaleByAvgInverseLength,
                                        scaleByX, historySmoothing, scheme, simpleHistoryBleu);
}
}