concordia-library/concordia/concordia_index.cpp

#include "concordia/concordia_index.hpp"

#include "concordia/common/utils.hpp"
#include "concordia/common/config.hpp"
#include <boost/filesystem.hpp>
#include <boost/foreach.hpp>
#include <iostream>
#include <climits>

ConcordiaIndex::ConcordiaIndex(const std::string & hashedIndexFilePath,
                               const std::string & markersFilePath)
                                         throw(ConcordiaException) :
                           _hashedIndexFilePath(hashedIndexFilePath),
                           _markersFilePath(markersFilePath) {
}

ConcordiaIndex::~ConcordiaIndex() {
}

boost::shared_ptr<std::vector<saidx_t> > ConcordiaIndex::generateSuffixArray(
                boost::shared_ptr<std::vector<sauchar_t> > T) {
    saidx_t * SA_array = new saidx_t[T->size()];
    if (divsufsort(T->data(), SA_array, (saidx_t) T->size()) != 0) {
        throw ConcordiaException("Error creating suffix array.");
    }

    boost::shared_ptr<std::vector<saidx_t> > result =
             boost::shared_ptr<std::vector<saidx_t> >(new std::vector<saidx_t>);
    for (int i = 0; i < T->size(); i++) {
        result->push_back(SA_array[i]);
    }

    delete[] SA_array;
    return result;
}

std::vector<TokenizedSentence> ConcordiaIndex::addAllExamples(
                boost::shared_ptr<HashGenerator> hashGenerator,
                boost::shared_ptr<std::vector<sauchar_t> > T,
                boost::shared_ptr<std::vector<SUFFIX_MARKER_TYPE> > markers,
                const std::vector<Example> & examples) {
    std::ofstream hashedIndexFile;
    hashedIndexFile.open(_hashedIndexFilePath.c_str(), std::ios::out|
                                             std::ios::app|std::ios::binary);
    std::ofstream markersFile;
    markersFile.open(_markersFilePath.c_str(), std::ios::out|
                                             std::ios::app|std::ios::binary);

    std::vector<TokenizedSentence> hashedPatterns;
    BOOST_FOREACH(Example example, examples) {
        boost::shared_ptr<TokenizedSentence> hashedPattern = _addSingleExample(hashedIndexFile, markersFile, hashGenerator,
                                                      T, markers, example);
        hashedPatterns.push_back(*hashedPattern);
    }

    hashedIndexFile.close();
    markersFile.close();
    hashGenerator->serializeWordMap();
    
    return hashedPatterns;
}

boost::shared_ptr<TokenizedSentence> ConcordiaIndex::addExample(
                boost::shared_ptr<HashGenerator> hashGenerator,
                boost::shared_ptr<std::vector<sauchar_t> > T,
                boost::shared_ptr<std::vector<SUFFIX_MARKER_TYPE> > markers,
                const Example & example) {
    std::ofstream hashedIndexFile;
    hashedIndexFile.open(_hashedIndexFilePath.c_str(), std::ios::out|
                                             std::ios::app|std::ios::binary);
    std::ofstream markersFile;
    markersFile.open(_markersFilePath.c_str(), std::ios::out|
                                             std::ios::app|std::ios::binary);
    boost::shared_ptr<TokenizedSentence> hashedPattern = _addSingleExample(hashedIndexFile, markersFile, hashGenerator,
                                                      T, markers, example);
    hashedIndexFile.close();
    markersFile.close();
    hashGenerator->serializeWordMap();
    
    return hashedPattern;
}

boost::shared_ptr<TokenizedSentence> ConcordiaIndex::_addSingleExample(
                   std::ofstream & hashedIndexFile,
                   std::ofstream & markersFile,
                   boost::shared_ptr<HashGenerator> hashGenerator,
                   boost::shared_ptr<std::vector<sauchar_t> > T,
                   boost::shared_ptr<std::vector<SUFFIX_MARKER_TYPE> > markers,
                   const Example & example) {
    boost::shared_ptr<TokenizedSentence> hashedPattern = hashGenerator->generateHash(example.getSentence());
    std::vector<INDEX_CHARACTER_TYPE> hash = hashedPattern->getCodes();
                          
    int offset = 0;
    for (std::vector<INDEX_CHARACTER_TYPE>::iterator it = hash.begin();
                                          it != hash.end(); ++it) {
        INDEX_CHARACTER_TYPE character = *it;
        Utils::writeIndexCharacter(hashedIndexFile, character);
        Utils::appendCharToSaucharVector(T, character);

        // append to markersFile
        SUFFIX_MARKER_TYPE marker = Utils::createMarker(
                                           example.getId(),
                                           offset,
                                           hash.size());

        Utils::writeMarker(markersFile, marker);
        markers->push_back(marker);

        offset++;
    }

    // append sentence boundary marker
    INDEX_CHARACTER_TYPE sentenceBoundaryHI = INDEX_CHARACTER_TYPE_MAX_VALUE;
    Utils::writeIndexCharacter(hashedIndexFile, sentenceBoundaryHI);
    Utils::appendCharToSaucharVector(T, sentenceBoundaryHI);

    SUFFIX_MARKER_TYPE sentenceBoundaryMA = SUFFIX_MARKER_TYPE_MAX_VALUE;
    Utils::writeMarker(markersFile, sentenceBoundaryMA);
    markers->push_back(sentenceBoundaryMA);
    
    return hashedPattern;
}