TargetPhraseVectorPtr PhraseDecoder::DecodeCollection(
TargetPhraseVectorPtr tpv, BitWrapper<> &encodedBitStream,
const Phrase &sourcePhrase, bool topLevel)
{
bool extending = tpv->size();
size_t bitsLeft = encodedBitStream.TellFromEnd();
typedef std::pair<size_t, size_t> AlignPointSizeT;
std::vector<int> sourceWords;
if(m_coding == REnc)
{
for(size_t i = 0; i < sourcePhrase.GetSize(); i++)
{
std::string sourceWord
= sourcePhrase.GetWord(i).GetString(*m_input, false);
unsigned idx = GetSourceSymbolId(sourceWord);
sourceWords.push_back(idx);
}
}
unsigned phraseStopSymbol = 0;
AlignPoint alignStopSymbol(-1, -1);
std::vector<float> scores;
std::set<AlignPointSizeT> alignment;
enum DecodeState { New, Symbol, Score, Alignment, Add } state = New;
size_t srcSize = sourcePhrase.GetSize();
TargetPhrase* targetPhrase = NULL;
while(encodedBitStream.TellFromEnd())
{
if(state == New)
{
// Creating new TargetPhrase on the heap
tpv->push_back(TargetPhrase());
targetPhrase = &tpv->back();
targetPhrase->SetSourcePhrase(sourcePhrase);
alignment.clear();
scores.clear();
state = Symbol;
}
if(state == Symbol)
{
unsigned symbol = m_symbolTree->Read(encodedBitStream);
if(symbol == phraseStopSymbol)
{
state = Score;
}
else
{
if(m_coding == REnc)
{
std::string wordString;
size_t type = GetREncType(symbol);
if(type == 1)
{
unsigned decodedSymbol = DecodeREncSymbol1(symbol);
wordString = GetTargetSymbol(decodedSymbol);
}
else if (type == 2)
{
size_t rank = DecodeREncSymbol2Rank(symbol);
size_t srcPos = DecodeREncSymbol2Position(symbol);
if(srcPos >= sourceWords.size())
return TargetPhraseVectorPtr();
wordString = GetTargetSymbol(GetTranslation(sourceWords[srcPos], rank));
if(m_phraseDictionary.m_useAlignmentInfo)
{
size_t trgPos = targetPhrase->GetSize();
alignment.insert(AlignPoint(srcPos, trgPos));
}
}
else if(type == 3)
{
size_t rank = DecodeREncSymbol3(symbol);
size_t srcPos = targetPhrase->GetSize();
if(srcPos >= sourceWords.size())
return TargetPhraseVectorPtr();
wordString = GetTargetSymbol(GetTranslation(sourceWords[srcPos], rank));
if(m_phraseDictionary.m_useAlignmentInfo)
{
size_t trgPos = srcPos;
alignment.insert(AlignPoint(srcPos, trgPos));
}
}
Word word;
word.CreateFromString(Output, *m_output, wordString, false);
targetPhrase->AddWord(word);
}
else if(m_coding == PREnc)
{
// if the symbol is just a word
if(GetPREncType(symbol) == 1)
{
unsigned decodedSymbol = DecodePREncSymbol1(symbol);
Word word;
word.CreateFromString(Output, *m_output,
GetTargetSymbol(decodedSymbol), false);
targetPhrase->AddWord(word);
}
// if the symbol is a subphrase pointer
else
{
int left = DecodePREncSymbol2Left(symbol);
int right = DecodePREncSymbol2Right(symbol);
unsigned rank = DecodePREncSymbol2Rank(symbol);
int srcStart = left + targetPhrase->GetSize();
int srcEnd = srcSize - right - 1;
// false positive consistency check
if(0 > srcStart || srcStart > srcEnd || unsigned(srcEnd) >= srcSize)
return TargetPhraseVectorPtr();
// false positive consistency check
if(m_maxRank && rank > m_maxRank)
return TargetPhraseVectorPtr();
// set subphrase by default to itself
TargetPhraseVectorPtr subTpv = tpv;
// if range smaller than source phrase retrieve subphrase
if(unsigned(srcEnd - srcStart + 1) != srcSize)
{
Phrase subPhrase = sourcePhrase.GetSubString(WordsRange(srcStart, srcEnd));
subTpv = CreateTargetPhraseCollection(subPhrase, false);
}
else {
// false positive consistency check
if(rank >= tpv->size()-1)
return TargetPhraseVectorPtr();
}
// false positive consistency check
if(subTpv != NULL && rank < subTpv->size())
{
// insert the subphrase into the main target phrase
TargetPhrase& subTp = subTpv->at(rank);
if(m_phraseDictionary.m_useAlignmentInfo)
{
// reconstruct the alignment data based on the alignment of the subphrase
for(AlignmentInfo::const_iterator it = subTp.GetAlignTerm().begin();
it != subTp.GetAlignTerm().end(); it++)
{
alignment.insert(AlignPointSizeT(srcStart + it->first,
targetPhrase->GetSize() + it->second));
}
}
targetPhrase->Append(subTp);
}
else
return TargetPhraseVectorPtr();
}
}
else
{
Word word;
word.CreateFromString(Output, *m_output,
GetTargetSymbol(symbol), false);
targetPhrase->AddWord(word);
}
}
}
else if(state == Score)
{
size_t idx = m_multipleScoreTrees ? scores.size() : 0;
float score = m_scoreTrees[idx]->Read(encodedBitStream);
scores.push_back(score);
if(scores.size() == m_numScoreComponent)
{
targetPhrase->SetScore(m_feature, scores, ScoreComponentCollection() /*sparse*/,*m_weight, m_weightWP, *m_languageModels);
if(m_containsAlignmentInfo)
state = Alignment;
else
state = Add;
}
}
else if(state == Alignment)
{
AlignPoint alignPoint = m_alignTree->Read(encodedBitStream);
if(alignPoint == alignStopSymbol)
{
state = Add;
}
else
{
if(m_phraseDictionary.m_useAlignmentInfo)
alignment.insert(AlignPointSizeT(alignPoint));
}
}
if(state == Add)
{
if(m_phraseDictionary.m_useAlignmentInfo) {
targetPhrase->SetAlignTerm(alignment);
}
if(m_coding == PREnc)
{
if(!m_maxRank || tpv->size() <= m_maxRank)
bitsLeft = encodedBitStream.TellFromEnd();
if(!topLevel && m_maxRank && tpv->size() >= m_maxRank)
break;
}
if(encodedBitStream.TellFromEnd() <= 8)
break;
state = New;
}
}
if(m_coding == PREnc && !extending)
{
bitsLeft = bitsLeft > 8 ? bitsLeft : 0;
m_decodingCache.Cache(sourcePhrase, tpv, bitsLeft, m_maxRank);
}
return tpv;
}
const TargetPhraseCollection*
PhraseDictionaryInterpolated::GetTargetPhraseCollection(const Phrase& src) const {
delete m_targetPhrases;
m_targetPhrases = new TargetPhraseCollection();
PhraseSet allPhrases;
vector<PhraseSet> phrasesByTable(m_dictionaries.size());
for (size_t i = 0; i < m_dictionaries.size(); ++i) {
const TargetPhraseCollection* phrases = m_dictionaries[i]->GetTargetPhraseCollection(src);
if (phrases) {
for (TargetPhraseCollection::const_iterator j = phrases->begin();
j != phrases->end(); ++j) {
allPhrases.insert(*j);
phrasesByTable[i].insert(*j);
}
}
}
ScoreComponentCollection sparseVector;
for (PhraseSet::const_iterator i = allPhrases.begin(); i != allPhrases.end(); ++i) {
TargetPhrase* combinedPhrase = new TargetPhrase((Phrase)**i);
//combinedPhrase->ResetScore();
//cerr << *combinedPhrase << " " << combinedPhrase->GetScoreBreakdown() << endl;
combinedPhrase->SetSourcePhrase((*i)->GetSourcePhrase());
combinedPhrase->SetAlignTerm(&((*i)->GetAlignTerm()));
combinedPhrase->SetAlignNonTerm(&((*i)->GetAlignTerm()));
Scores combinedScores(GetFeature()->GetNumScoreComponents());
for (size_t j = 0; j < phrasesByTable.size(); ++j) {
PhraseSet::const_iterator tablePhrase = phrasesByTable[j].find(combinedPhrase);
if (tablePhrase != phrasesByTable[j].end()) {
Scores tableScores = (*tablePhrase)->GetScoreBreakdown()
.GetScoresForProducer(GetFeature());
//cerr << "Scores from " << j << " table: ";
for (size_t k = 0; k < tableScores.size()-1; ++k) {
//cerr << tableScores[k] << "(" << exp(tableScores[k]) << ") ";
combinedScores[k] += m_weights[k][j] * exp(tableScores[k]);
//cerr << m_weights[k][j] * exp(tableScores[k]) << " ";
}
//cerr << endl;
}
}
//map back to log space
//cerr << "Combined ";
for (size_t k = 0; k < combinedScores.size()-1; ++k) {
//cerr << combinedScores[k] << " ";
combinedScores[k] = log(combinedScores[k]);
//cerr << combinedScores[k] << " ";
}
//cerr << endl;
combinedScores.back() = 1; //assume last is penalty
combinedPhrase->SetScore(
GetFeature(),
combinedScores,
sparseVector,
m_weightT,
m_weightWP,
*m_languageModels);
//cerr << *combinedPhrase << " " << combinedPhrase->GetScoreBreakdown() << endl;
m_targetPhrases->Add(combinedPhrase);
}
m_targetPhrases->Prune(true,m_tableLimit);
return m_targetPhrases;
}
