mosesdecoder/moses-cmd/Main.cpp

// $Id: MainMT.cpp 3045 2010-04-05 13:07:29Z hieuhoang1972 $

/***********************************************************************
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
***********************************************************************/

/**
 * Moses main, for single-threaded and multi-threaded.
 **/

#include <boost/algorithm/string/predicate.hpp>
#include <boost/filesystem.hpp>
#include <boost/iostreams/device/file.hpp>
#include <boost/iostreams/filter/bzip2.hpp>
#include <boost/iostreams/filter/gzip.hpp>
#include <boost/iostreams/filtering_stream.hpp>

#include <exception>
#include <fstream>
#include <sstream>
#include <vector>

#include "util/usage.hh"

#ifdef WIN32
// Include Visual Leak Detector
//#include <vld.h>
#endif

#include "TranslationAnalysis.h"
#include "IOWrapper.h"
#include "mbr.h"

#include "moses/Hypothesis.h"
#include "moses/Manager.h"
#include "moses/StaticData.h"
#include "moses/Util.h"
#include "moses/Timer.h"
#include "moses/ThreadPool.h"
#include "moses/OutputCollector.h"

#ifdef HAVE_PROTOBUF
#include "hypergraph.pb.h"
#endif

using namespace std;
using namespace Moses;
using namespace MosesCmd;

namespace MosesCmd
{
// output floats with three significant digits
static const size_t PRECISION = 3;

/** Enforce rounding */
void fix(std::ostream& stream, size_t size)
{
  stream.setf(std::ios::fixed);
  stream.precision(size);
}

/** Translates a sentence.
  * - calls the search (Manager)
  * - applies the decision rule
  * - outputs best translation and additional reporting
  **/
class TranslationTask : public Task
{

public:

  TranslationTask(size_t lineNumber,
                  InputType* source, OutputCollector* outputCollector, OutputCollector* nbestCollector,
                  OutputCollector* latticeSamplesCollector,
                  OutputCollector* wordGraphCollector, OutputCollector* searchGraphCollector,
                  OutputCollector* detailedTranslationCollector,
                  OutputCollector* alignmentInfoCollector,
                  OutputCollector* unknownsCollector,
                  bool outputSearchGraphSLF,
                  bool outputSearchGraphHypergraph) :
    m_source(source), m_lineNumber(lineNumber),
    m_outputCollector(outputCollector), m_nbestCollector(nbestCollector),
    m_latticeSamplesCollector(latticeSamplesCollector),
    m_wordGraphCollector(wordGraphCollector), m_searchGraphCollector(searchGraphCollector),
    m_detailedTranslationCollector(detailedTranslationCollector),
    m_alignmentInfoCollector(alignmentInfoCollector),
    m_unknownsCollector(unknownsCollector),
    m_outputSearchGraphSLF(outputSearchGraphSLF),
    m_outputSearchGraphHypergraph(outputSearchGraphHypergraph) {}

  /** Translate one sentence
   * gets called by main function implemented at end of this source file */
  void Run() {

    // report thread number
#if defined(WITH_THREADS) && defined(BOOST_HAS_PTHREADS)
    TRACE_ERR("Translating line " << m_lineNumber << "  in thread id " << pthread_self() << std::endl);
#endif

    Timer translationTime;
    translationTime.start();
    // shorthand for "global data"
    const StaticData &staticData = StaticData::Instance();
    // input sentence
    Sentence sentence;

    // execute the translation
    // note: this executes the search, resulting in a search graph
    //       we still need to apply the decision rule (MAP, MBR, ...)
    Manager manager(m_lineNumber, *m_source,staticData.GetSearchAlgorithm());
    manager.ProcessSentence();

    // output word graph
    if (m_wordGraphCollector) {
      ostringstream out;
      fix(out,PRECISION);
      manager.GetWordGraph(m_lineNumber, out);
      m_wordGraphCollector->Write(m_lineNumber, out.str());
    }

    // output search graph
    if (m_searchGraphCollector) {
      ostringstream out;
      fix(out,PRECISION);
      manager.OutputSearchGraph(m_lineNumber, out);
      m_searchGraphCollector->Write(m_lineNumber, out.str());

#ifdef HAVE_PROTOBUF
      if (staticData.GetOutputSearchGraphPB()) {
        ostringstream sfn;
        sfn << staticData.GetParam("output-search-graph-pb")[0] << '/' << m_lineNumber << ".pb" << ends;
        string fn = sfn.str();
        VERBOSE(2, "Writing search graph to " << fn << endl);
        fstream output(fn.c_str(), ios::trunc | ios::binary | ios::out);
        manager.SerializeSearchGraphPB(m_lineNumber, output);
      }
#endif
    }

    // Output search graph in HTK standard lattice format (SLF)
    if (m_outputSearchGraphSLF) {
      stringstream fileName;
      fileName << staticData.GetParam("output-search-graph-slf")[0] << "/" << m_lineNumber << ".slf";
      std::ofstream *file = new std::ofstream;
      file->open(fileName.str().c_str());
      if (file->is_open() && file->good()) {
        ostringstream out;
        fix(out,PRECISION);
        manager.OutputSearchGraphAsSLF(m_lineNumber, out);
        *file << out.str();
        file -> flush();
      } else {
        TRACE_ERR("Cannot output HTK standard lattice for line " << m_lineNumber << " because the output file is not open or not ready for writing" << std::endl);
      }
    }

    // Output search graph in hypergraph format for Kenneth Heafield's lazy hypergraph decoder
    if (m_outputSearchGraphHypergraph) {

      vector<string> hypergraphParameters = staticData.GetParam("output-search-graph-hypergraph");

      bool appendSuffix;
      if (hypergraphParameters.size() > 0 && hypergraphParameters[0] == "true") {
        appendSuffix = true;
      } else {
        appendSuffix = false;
      }

      string compression;
      if (hypergraphParameters.size() > 1) {
        compression = hypergraphParameters[1];
      } else {
        compression = "txt";
      }

      string hypergraphDir;
      if ( hypergraphParameters.size() > 2 ) {
        hypergraphDir = hypergraphParameters[2];
      } else {
        string nbestFile = staticData.GetNBestFilePath();
        if ( ! nbestFile.empty() && nbestFile!="-" && !boost::starts_with(nbestFile,"/dev/stdout") ) {
          boost::filesystem::path nbestPath(nbestFile);

          // In the Boost filesystem API version 2,
          //   which was the default prior to Boost 1.46,
          //   the filename() method returned a string.
          //
          // In the Boost filesystem API version 3,
          //   which is the default starting with Boost 1.46,
          //   the filename() method returns a path object.
          //
          // To get a string from the path object,
          //   the native() method must be called.
          //	  hypergraphDir = nbestPath.parent_path().filename()
          //#if BOOST_VERSION >= 104600
          //	    .native()
          //#endif
          //;

          // Hopefully the following compiles under all versions of Boost.
          //
          // If this line gives you compile errors,
          //   contact Lane Schwartz on the Moses mailing list
          hypergraphDir = nbestPath.parent_path().string();

        } else {
          stringstream hypergraphDirName;
          hypergraphDirName << boost::filesystem::current_path() << "/hypergraph";
          hypergraphDir = hypergraphDirName.str();
        }
      }

      if ( ! boost::filesystem::exists(hypergraphDir) ) {
        boost::filesystem::create_directory(hypergraphDir);
      }

      if ( ! boost::filesystem::exists(hypergraphDir) ) {
        TRACE_ERR("Cannot output hypergraphs to " << hypergraphDir << " because the directory does not exist" << std::endl);
      } else if ( ! boost::filesystem::is_directory(hypergraphDir) ) {
        TRACE_ERR("Cannot output hypergraphs to " << hypergraphDir << " because that path exists, but is not a directory" << std::endl);
      } else {
        stringstream fileName;
        fileName << hypergraphDir << "/" << m_lineNumber;
        if ( appendSuffix ) {
          fileName << "." << compression;
        }
        boost::iostreams::filtering_ostream *file = new boost::iostreams::filtering_ostream;

        if ( compression == "gz" ) {
          file->push( boost::iostreams::gzip_compressor() );
        } else if ( compression == "bz2" ) {
          file->push( boost::iostreams::bzip2_compressor() );
        } else if ( compression != "txt" ) {
          TRACE_ERR("Unrecognized hypergraph compression format (" << compression << ") - using uncompressed plain txt" << std::endl);
          compression = "txt";
        }

        file->push( boost::iostreams::file_sink(fileName.str(), ios_base::out) );

        if (file->is_complete() && file->good()) {
          fix(*file,PRECISION);
          manager.OutputSearchGraphAsHypergraph(m_lineNumber, *file);
          file -> flush();
        } else {
          TRACE_ERR("Cannot output hypergraph for line " << m_lineNumber << " because the output file " << fileName.str() << " is not open or not ready for writing" << std::endl);
        }
        file -> pop();
        delete file;
      }
    }

    // apply decision rule and output best translation(s)
    if (m_outputCollector) {
      ostringstream out;
      ostringstream debug;
      fix(debug,PRECISION);

      // all derivations - send them to debug stream
      if (staticData.PrintAllDerivations()) {
        manager.PrintAllDerivations(m_lineNumber, debug);
      }

      // MAP decoding: best hypothesis
      const Hypothesis* bestHypo = NULL;
      if (!staticData.UseMBR()) {
        bestHypo = manager.GetBestHypothesis();
        if (bestHypo) {
          if (staticData.IsPathRecoveryEnabled()) {
            OutputInput(out, bestHypo);
            out << "||| ";
          }
          if (staticData.GetParam("print-id").size() && Scan<bool>(staticData.GetParam("print-id")[0]) ) {
            out << m_source->GetTranslationId() << " ";
          }

          OutputBestSurface(
            out,
            bestHypo,
            staticData.GetOutputFactorOrder(),
            staticData.GetReportSegmentation(),
            staticData.GetReportAllFactors());
          if (staticData.PrintAlignmentInfo()) {
            out << "||| ";
            OutputAlignment(out, bestHypo);
          }

          OutputAlignment(m_alignmentInfoCollector, m_lineNumber, bestHypo);
          IFVERBOSE(1) {
            debug << "BEST TRANSLATION: " << *bestHypo << endl;
          }
        } else {
          VERBOSE(1, "NO BEST TRANSLATION" << endl);
        }

        out << endl;
      }

      // MBR decoding (n-best MBR, lattice MBR, consensus)
      else {
        // we first need the n-best translations
        size_t nBestSize = staticData.GetMBRSize();
        if (nBestSize <= 0) {
          cerr << "ERROR: negative size for number of MBR candidate translations not allowed (option mbr-size)" << endl;
          exit(1);
        }
        TrellisPathList nBestList;
        manager.CalcNBest(nBestSize, nBestList,true);
        VERBOSE(2,"size of n-best: " << nBestList.GetSize() << " (" << nBestSize << ")" << endl);
        IFVERBOSE(2) {
          PrintUserTime("calculated n-best list for (L)MBR decoding");
        }

        // lattice MBR
        if (staticData.UseLatticeMBR()) {
          if (m_nbestCollector) {
            //lattice mbr nbest
            vector<LatticeMBRSolution> solutions;
            size_t n  = min(nBestSize, staticData.GetNBestSize());
            getLatticeMBRNBest(manager,nBestList,solutions,n);
            ostringstream out;
            OutputLatticeMBRNBest(out, solutions,m_lineNumber);
            m_nbestCollector->Write(m_lineNumber, out.str());
          } else {
            //Lattice MBR decoding
            vector<Word> mbrBestHypo = doLatticeMBR(manager,nBestList);
            OutputBestHypo(mbrBestHypo, m_lineNumber, staticData.GetReportSegmentation(),
                           staticData.GetReportAllFactors(),out);
            IFVERBOSE(2) {
              PrintUserTime("finished Lattice MBR decoding");
            }
          }
        }

        // consensus decoding
        else if (staticData.UseConsensusDecoding()) {
          const TrellisPath &conBestHypo = doConsensusDecoding(manager,nBestList);
          OutputBestHypo(conBestHypo, m_lineNumber,
                         staticData.GetReportSegmentation(),
                         staticData.GetReportAllFactors(),out);
          OutputAlignment(m_alignmentInfoCollector, m_lineNumber, conBestHypo);
          IFVERBOSE(2) {
            PrintUserTime("finished Consensus decoding");
          }
        }

        // n-best MBR decoding
        else {
          const Moses::TrellisPath &mbrBestHypo = doMBR(nBestList);
          OutputBestHypo(mbrBestHypo, m_lineNumber,
                         staticData.GetReportSegmentation(),
                         staticData.GetReportAllFactors(),out);
          OutputAlignment(m_alignmentInfoCollector, m_lineNumber, mbrBestHypo);
          IFVERBOSE(2) {
            PrintUserTime("finished MBR decoding");
          }
        }
      }

      // report best translation to output collector
      m_outputCollector->Write(m_lineNumber,out.str(),debug.str());
    }

    // output n-best list
    if (m_nbestCollector && !staticData.UseLatticeMBR()) {
      TrellisPathList nBestList;
      ostringstream out;
      manager.CalcNBest(staticData.GetNBestSize(), nBestList,staticData.GetDistinctNBest());
      OutputNBest(out, nBestList, staticData.GetOutputFactorOrder(), m_lineNumber,
                  staticData.GetReportSegmentation());
      m_nbestCollector->Write(m_lineNumber, out.str());
    }

    //lattice samples
    if (m_latticeSamplesCollector) {
      TrellisPathList latticeSamples;
      ostringstream out;
      manager.CalcLatticeSamples(staticData.GetLatticeSamplesSize(), latticeSamples);
      OutputNBest(out,latticeSamples, staticData.GetOutputFactorOrder(), m_lineNumber,
                  staticData.GetReportSegmentation());
      m_latticeSamplesCollector->Write(m_lineNumber, out.str());
    }

    // detailed translation reporting
    if (m_detailedTranslationCollector) {
      ostringstream out;
      fix(out,PRECISION);
      TranslationAnalysis::PrintTranslationAnalysis(out, manager.GetBestHypothesis());
      m_detailedTranslationCollector->Write(m_lineNumber,out.str());
    }

    //list of unknown words
    if (m_unknownsCollector) {
      const vector<const Phrase*>& unknowns = manager.getSntTranslationOptions()->GetUnknownSources();
      ostringstream out;
      for (size_t i = 0; i < unknowns.size(); ++i) {
        out << *(unknowns[i]);
      }
      out << endl;
      m_unknownsCollector->Write(m_lineNumber, out.str());
    }

    // report additional statistics
    IFVERBOSE(2) {
      PrintUserTime("Sentence Decoding Time:");
    }
    manager.CalcDecoderStatistics();

    VERBOSE(1, "Line " << m_lineNumber << ": Translation took " << translationTime << " seconds total" << endl);
  }

  ~TranslationTask() {
    delete m_source;
  }

private:
  InputType* m_source;
  size_t m_lineNumber;
  OutputCollector* m_outputCollector;
  OutputCollector* m_nbestCollector;
  OutputCollector* m_latticeSamplesCollector;
  OutputCollector* m_wordGraphCollector;
  OutputCollector* m_searchGraphCollector;
  OutputCollector* m_detailedTranslationCollector;
  OutputCollector* m_alignmentInfoCollector;
  OutputCollector* m_unknownsCollector;
  bool m_outputSearchGraphSLF;
  bool m_outputSearchGraphHypergraph;
  std::ofstream *m_alignmentStream;


};

static void PrintFeatureWeight(const FeatureFunction* ff)
{
  cout << ff->GetScoreProducerDescription() << "=";
  size_t numScoreComps = ff->GetNumScoreComponents();
  vector<float> values = StaticData::Instance().GetAllWeights().GetScoresForProducer(ff);
  for (size_t i = 0; i < numScoreComps; ++i) {
    cout << " " << values[i];
  }
  cout << endl;
}

static void ShowWeights()
{
  //TODO: Find a way of ensuring this order is synced with the nbest
  fix(cout,6);
  const StaticData& staticData = StaticData::Instance();
  const vector<const StatelessFeatureFunction*>& slf = StatelessFeatureFunction::GetStatelessFeatureFunctions();
  const vector<const StatefulFeatureFunction*>& sff = StatefulFeatureFunction::GetStatefulFeatureFunctions();

  for (size_t i = 0; i < sff.size(); ++i) {
    const StatefulFeatureFunction *ff = sff[i];
    if (ff->IsTuneable()) {
      PrintFeatureWeight(ff);
    }
  }
  for (size_t i = 0; i < slf.size(); ++i) {
    const StatelessFeatureFunction *ff = slf[i];
    if (ff->IsTuneable()) {
      PrintFeatureWeight(ff);
    }
  }
}

size_t OutputFeatureWeightsForHypergraph(size_t index, const FeatureFunction* ff, std::ostream &outputSearchGraphStream)
{
  size_t numScoreComps = ff->GetNumScoreComponents();
  if (numScoreComps != 0) {
    vector<float> values = StaticData::Instance().GetAllWeights().GetScoresForProducer(ff);
    if (numScoreComps > 1) {
      for (size_t i = 0; i < numScoreComps; ++i) {
        outputSearchGraphStream << ff->GetScoreProducerDescription()
                                << i
                                << "=" << values[i] << endl;
      }
    } else {
      outputSearchGraphStream << ff->GetScoreProducerDescription()
                              << "=" << values[0] << endl;
    }
    return index+numScoreComps;
  } else {
    cerr << "Sparse features are not yet supported when outputting hypergraph format" << endl;
    assert(false);
    return 0;
  }
}

void OutputFeatureWeightsForHypergraph(std::ostream &outputSearchGraphStream)
{
  outputSearchGraphStream.setf(std::ios::fixed);
  outputSearchGraphStream.precision(6);

  const StaticData& staticData = StaticData::Instance();
  const vector<const StatelessFeatureFunction*>& slf =StatelessFeatureFunction::GetStatelessFeatureFunctions();
  const vector<const StatefulFeatureFunction*>& sff = StatefulFeatureFunction::GetStatefulFeatureFunctions();
  size_t featureIndex = 1;
  for (size_t i = 0; i < sff.size(); ++i) {
    featureIndex = OutputFeatureWeightsForHypergraph(featureIndex, sff[i], outputSearchGraphStream);
  }
  for (size_t i = 0; i < slf.size(); ++i) {
    /*
    if (slf[i]->GetScoreProducerWeightShortName() != "u" &&
          slf[i]->GetScoreProducerWeightShortName() != "tm" &&
          slf[i]->GetScoreProducerWeightShortName() != "I" &&
          slf[i]->GetScoreProducerWeightShortName() != "g")
    */
    {
      featureIndex = OutputFeatureWeightsForHypergraph(featureIndex, slf[i], outputSearchGraphStream);
    }
  }
  const vector<PhraseDictionary*>& pds = staticData.GetPhraseDictionaries();
  for( size_t i=0; i<pds.size(); i++ ) {
    featureIndex = OutputFeatureWeightsForHypergraph(featureIndex, pds[i], outputSearchGraphStream);
  }
  const vector<const GenerationDictionary*>& gds = staticData.GetGenerationDictionaries();
  for( size_t i=0; i<gds.size(); i++ ) {
    featureIndex = OutputFeatureWeightsForHypergraph(featureIndex, gds[i], outputSearchGraphStream);
  }

}


} //namespace

/** main function of the command line version of the decoder **/
int main(int argc, char** argv)
{
  try {

#ifdef HAVE_PROTOBUF
    GOOGLE_PROTOBUF_VERIFY_VERSION;
#endif

    // echo command line, if verbose
    IFVERBOSE(1) {
      TRACE_ERR("command: ");
      for(int i=0; i<argc; ++i) TRACE_ERR(argv[i]<<" ");
      TRACE_ERR(endl);
    }

    // set number of significant decimals in output
    fix(cout,PRECISION);
    fix(cerr,PRECISION);

    // load all the settings into the Parameter class
    // (stores them as strings, or array of strings)
    Parameter params;
    if (!params.LoadParam(argc,argv)) {
      exit(1);
    }


    // initialize all "global" variables, which are stored in StaticData
    // note: this also loads models such as the language model, etc.
    if (!StaticData::LoadDataStatic(&params, argv[0])) {
      exit(1);
    }

    // setting "-show-weights" -> just dump out weights and exit
    if (params.isParamSpecified("show-weights")) {
      ShowWeights();
      exit(0);
    }

    // shorthand for accessing information in StaticData
    const StaticData& staticData = StaticData::Instance();


    //initialise random numbers
    srand(time(NULL));

    // set up read/writing class
    IOWrapper* ioWrapper = GetIOWrapper(staticData);
    if (!ioWrapper) {
      cerr << "Error; Failed to create IO object" << endl;
      exit(1);
    }

    // check on weights
    const ScoreComponentCollection& weights = staticData.GetAllWeights();
    IFVERBOSE(2) {
      TRACE_ERR("The global weight vector looks like this: ");
      TRACE_ERR(weights);
      TRACE_ERR("\n");
    }
    if (staticData.GetOutputSearchGraphHypergraph()) {
      ofstream* weightsOut = new std::ofstream;
      stringstream weightsFilename;
      if (staticData.GetParam("output-search-graph-hypergraph").size() > 3) {
        weightsFilename << staticData.GetParam("output-search-graph-hypergraph")[3];
      } else {
        string nbestFile = staticData.GetNBestFilePath();
        if ( ! nbestFile.empty() && nbestFile!="-" && !boost::starts_with(nbestFile,"/dev/stdout") ) {
          boost::filesystem::path nbestPath(nbestFile);
          weightsFilename << nbestPath.parent_path().filename() << "/weights";
        } else {
          weightsFilename << boost::filesystem::current_path() << "/hypergraph/weights";
        }
      }
      boost::filesystem::path weightsFilePath(weightsFilename.str());
      if ( ! boost::filesystem::exists(weightsFilePath.parent_path()) ) {
        boost::filesystem::create_directory(weightsFilePath.parent_path());
      }
      TRACE_ERR("The weights file is " << weightsFilename.str() << "\n");
      weightsOut->open(weightsFilename.str().c_str());
      OutputFeatureWeightsForHypergraph(*weightsOut);
      weightsOut->flush();
      weightsOut->close();
      delete weightsOut;
    }


    // initialize output streams
    // note: we can't just write to STDOUT or files
    // because multithreading may return sentences in shuffled order
    auto_ptr<OutputCollector> outputCollector; // for translations
    auto_ptr<OutputCollector> nbestCollector;  // for n-best lists
    auto_ptr<OutputCollector> latticeSamplesCollector; //for lattice samples
    auto_ptr<ofstream> nbestOut;
    auto_ptr<ofstream> latticeSamplesOut;
    size_t nbestSize = staticData.GetNBestSize();
    string nbestFile = staticData.GetNBestFilePath();
    bool output1best = true;
    if (nbestSize) {
      if (nbestFile == "-" || nbestFile == "/dev/stdout") {
        // nbest to stdout, no 1-best
        nbestCollector.reset(new OutputCollector());
        output1best = false;
      } else {
        // nbest to file, 1-best to stdout
        nbestOut.reset(new ofstream(nbestFile.c_str()));
        if (!nbestOut->good()) {
          TRACE_ERR("ERROR: Failed to open " << nbestFile << " for nbest lists" << endl);
          exit(1);
        }
        nbestCollector.reset(new OutputCollector(nbestOut.get()));
      }
    }
    size_t latticeSamplesSize = staticData.GetLatticeSamplesSize();
    string latticeSamplesFile = staticData.GetLatticeSamplesFilePath();
    if (latticeSamplesSize) {
      if (latticeSamplesFile == "-" || latticeSamplesFile == "/dev/stdout") {
        latticeSamplesCollector.reset(new OutputCollector());
        output1best = false;
      } else {
        latticeSamplesOut.reset(new ofstream(latticeSamplesFile.c_str()));
        if (!latticeSamplesOut->good()) {
          TRACE_ERR("ERROR: Failed to open " << latticeSamplesFile << " for lattice samples" << endl);
          exit(1);
        }
        latticeSamplesCollector.reset(new OutputCollector(latticeSamplesOut.get()));
      }
    }
    if (output1best) {
      outputCollector.reset(new OutputCollector());
    }

    // initialize stream for word graph (aka: output lattice)
    auto_ptr<OutputCollector> wordGraphCollector;
    if (staticData.GetOutputWordGraph()) {
      wordGraphCollector.reset(new OutputCollector(&(ioWrapper->GetOutputWordGraphStream())));
    }

    // initialize stream for search graph
    // note: this is essentially the same as above, but in a different format
    auto_ptr<OutputCollector> searchGraphCollector;
    if (staticData.GetOutputSearchGraph()) {
      searchGraphCollector.reset(new OutputCollector(&(ioWrapper->GetOutputSearchGraphStream())));
    }

    // initialize stram for details about the decoder run
    auto_ptr<OutputCollector> detailedTranslationCollector;
    if (staticData.IsDetailedTranslationReportingEnabled()) {
      detailedTranslationCollector.reset(new OutputCollector(&(ioWrapper->GetDetailedTranslationReportingStream())));
    }

    // initialize stram for word alignment between input and output
    auto_ptr<OutputCollector> alignmentInfoCollector;
    if (!staticData.GetAlignmentOutputFile().empty()) {
      alignmentInfoCollector.reset(new OutputCollector(ioWrapper->GetAlignmentOutputStream()));
    }

    //initialise stream for unknown (oov) words
    auto_ptr<OutputCollector> unknownsCollector;
    auto_ptr<ofstream> unknownsStream;
    if (!staticData.GetOutputUnknownsFile().empty()) {
      unknownsStream.reset(new ofstream(staticData.GetOutputUnknownsFile().c_str()));
      if (!unknownsStream->good()) {
        TRACE_ERR("Unable to open " << staticData.GetOutputUnknownsFile() << " for unknowns");
        exit(1);
      }
      unknownsCollector.reset(new OutputCollector(unknownsStream.get()));
    }

#ifdef WITH_THREADS
    ThreadPool pool(staticData.ThreadCount());
#endif

    // main loop over set of input sentences
    InputType* source = NULL;
    size_t lineCount = staticData.GetStartTranslationId();
    while(ReadInput(*ioWrapper,staticData.GetInputType(),source)) {
      IFVERBOSE(1) {
        ResetUserTime();
      }
      // set up task of translating one sentence
      TranslationTask* task =
        new TranslationTask(lineCount,source, outputCollector.get(),
                            nbestCollector.get(),
                            latticeSamplesCollector.get(),
                            wordGraphCollector.get(),
                            searchGraphCollector.get(),
                            detailedTranslationCollector.get(),
                            alignmentInfoCollector.get(),
                            unknownsCollector.get(),
                            staticData.GetOutputSearchGraphSLF(),
                            staticData.GetOutputSearchGraphHypergraph());
      // execute task
#ifdef WITH_THREADS
      pool.Submit(task);
#else
      task->Run();
      delete task;
#endif

      source = NULL; //make sure it doesn't get deleted
      ++lineCount;
    }

    // we are done, finishing up
#ifdef WITH_THREADS
    pool.Stop(true); //flush remaining jobs
#endif

    delete ioWrapper;

  } catch (const std::exception &e) {
    std::cerr << "Exception: " << e.what() << std::endl;
    return EXIT_FAILURE;
  }

  IFVERBOSE(1) util::PrintUsage(std::cerr);

#ifndef EXIT_RETURN
  //This avoids that destructors are called (it can take a long time)
  exit(EXIT_SUCCESS);
#else
  return EXIT_SUCCESS;
#endif
}