mosesdecoder/moses/TranslationOptionCollectionConfusionNet.cpp
2015-02-19 12:27:23 +00:00

307 lines
11 KiB
C++

// $Id$
#include <list>
#include <vector>
#include "TranslationOptionCollectionConfusionNet.h"
#include "ConfusionNet.h"
#include "DecodeGraph.h"
#include "DecodeStepTranslation.h"
#include "DecodeStepGeneration.h"
#include "FactorCollection.h"
#include "FF/InputFeature.h"
#include "TranslationModel/PhraseDictionaryTreeAdaptor.h"
#include "util/exception.hh"
#include <boost/foreach.hpp>
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)
{
// Prefix checkers are phrase dictionaries that provide a prefix check
// to indicate that a phrase table entry with a given prefix exists.
// If no entry with the given prefix exists, there is no point in
// expanding it further.
vector<PhraseDictionary*> prefixCheckers;
BOOST_FOREACH(PhraseDictionary* pd, PhraseDictionary::GetColl())
if (pd->ProvidesPrefixCheck()) prefixCheckers.push_back(pd);
const InputFeature &inputFeature = InputFeature::Instance();
UTIL_THROW_IF2(&inputFeature == NULL, "Input feature must be specified");
size_t inputSize = input.GetSize();
m_inputPathMatrix.resize(inputSize);
size_t maxSizePhrase = StaticData::Instance().GetMaxPhraseLength();
maxSizePhrase = std::min(inputSize, maxSizePhrase);
// 1-word phrases
for (size_t startPos = 0; startPos < inputSize; ++startPos) {
vector<InputPathList> &vec = m_inputPathMatrix[startPos];
vec.push_back(InputPathList());
InputPathList &list = vec.back();
WordsRange range(startPos, startPos);
const NonTerminalSet &labels = input.GetLabelSet(startPos, startPos);
const ConfusionNet::Column &col = input.GetColumn(startPos);
for (size_t i = 0; i < col.size(); ++i) {
const Word &word = col[i].first;
Phrase subphrase;
subphrase.AddWord(word);
const ScorePair &scores = col[i].second;
ScorePair *inputScore = new ScorePair(scores);
InputPath *path = new InputPath(subphrase, labels, range, NULL, inputScore);
list.push_back(path);
m_inputPathQueue.push_back(path);
}
}
// subphrases of 2+ words
for (size_t phraseSize = 2; phraseSize <= maxSizePhrase; ++phraseSize) {
for (size_t startPos = 0; startPos < inputSize - phraseSize + 1; ++startPos) {
size_t endPos = startPos + phraseSize -1;
WordsRange range(startPos, endPos);
const NonTerminalSet &labels = input.GetLabelSet(startPos, endPos);
vector<InputPathList> &vec = m_inputPathMatrix[startPos];
vec.push_back(InputPathList());
InputPathList &list = vec.back();
// loop thru every previous path
const InputPathList &prevPaths = GetInputPathList(startPos, endPos - 1);
int prevNodesInd = 0;
InputPathList::const_iterator iterPath;
for (iterPath = prevPaths.begin(); iterPath != prevPaths.end(); ++iterPath) {
//for (size_t pathInd = 0; pathInd < prevPaths.size(); ++pathInd) {
const InputPath &prevPath = **iterPath;
//const InputPath &prevPath = *prevPaths[pathInd];
const Phrase &prevPhrase = prevPath.GetPhrase();
const ScorePair *prevInputScore = prevPath.GetInputScore();
UTIL_THROW_IF2(prevInputScore == NULL,
"No input score for path: " << prevPath);
// loop thru every word at this position
const ConfusionNet::Column &col = input.GetColumn(endPos);
for (size_t i = 0; i < col.size(); ++i) {
const Word &word = col[i].first;
Phrase subphrase(prevPhrase);
subphrase.AddWord(word);
bool OK = prefixCheckers.size() == 0;
for (size_t k = 0; !OK && k < prefixCheckers.size(); ++k)
OK = prefixCheckers[k]->PrefixExists(subphrase);
if (!OK) continue;
const ScorePair &scores = col[i].second;
ScorePair *inputScore = new ScorePair(*prevInputScore);
inputScore->PlusEquals(scores);
InputPath *path = new InputPath(subphrase, labels, range, &prevPath, inputScore);
list.push_back(path);
m_inputPathQueue.push_back(path);
} // for (size_t i = 0; i < col.size(); ++i) {
++prevNodesInd;
} // for (iterPath = prevPaths.begin(); iterPath != prevPaths.end(); ++iterPath) {
}
}
// cerr << "HAVE " << m_inputPathQueue.size()
// << " input paths of max. length "
// << maxSizePhrase << "." << endl;
}
InputPathList &TranslationOptionCollectionConfusionNet::GetInputPathList(size_t startPos, size_t endPos)
{
size_t offset = endPos - startPos;
UTIL_THROW_IF2(offset >= m_inputPathMatrix[startPos].size(),
"Out of bound access: " << offset);
return m_inputPathMatrix[startPos][offset];
}
/* 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);
const InputPathList &inputPathList = GetInputPathList(sourcePos, sourcePos);
ConfusionNet::Column::const_iterator iterCol;
InputPathList::const_iterator iterInputPath;
size_t j=0;
for(iterCol = coll.begin(), iterInputPath = inputPathList.begin();
iterCol != coll.end();
++iterCol , ++iterInputPath) {
const InputPath &inputPath = **iterInputPath;
size_t length = source.GetColumnIncrement(sourcePos, j++);
const ScorePair &inputScores = iterCol->second;
ProcessOneUnknownWord(inputPath ,sourcePos, length, &inputScores);
}
}
void TranslationOptionCollectionConfusionNet::CreateTranslationOptions()
{
if (!StaticData::Instance().GetUseLegacyPT()) {
GetTargetPhraseCollectionBatch();
}
TranslationOptionCollection::CreateTranslationOptions();
}
/** 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
* \return true if there is at least one path for the range has matches
* in the source side of the parallel data, i.e., the phrase prefix exists
* (abortion condition for trie-based lookup if false)
*/
bool
TranslationOptionCollectionConfusionNet::
CreateTranslationOptionsForRange(const DecodeGraph &decodeGraph,
size_t startPos, size_t endPos,
bool adhereTableLimit, size_t graphInd)
{
if (StaticData::Instance().GetUseLegacyPT()) {
return CreateTranslationOptionsForRangeLEGACY(decodeGraph, startPos, endPos,
adhereTableLimit, graphInd);
} else {
return CreateTranslationOptionsForRangeNew(decodeGraph, startPos, endPos,
adhereTableLimit, graphInd);
}
}
bool
TranslationOptionCollectionConfusionNet::
CreateTranslationOptionsForRangeNew(const DecodeGraph &decodeGraph, size_t startPos,
size_t endPos, bool adhereTableLimit, size_t graphInd)
{
InputPathList &inputPathList = GetInputPathList(startPos, endPos);
if (inputPathList.size() == 0) return false; // no input path matches!
InputPathList::iterator iter;
for (iter = inputPathList.begin(); iter != inputPathList.end(); ++iter) {
InputPath &inputPath = **iter;
TranslationOptionCollection::CreateTranslationOptionsForRange
(decodeGraph, startPos, endPos, adhereTableLimit, graphInd, inputPath);
}
return true;
}
bool
TranslationOptionCollectionConfusionNet::
CreateTranslationOptionsForRangeLEGACY(const DecodeGraph &decodeGraph, size_t startPos,
size_t endPos, bool adhereTableLimit, size_t graphInd)
{
bool retval = true;
XmlInputType intype = StaticData::Instance().GetXmlInputType();
if ((intype != XmlExclusive) || !HasXmlOptionsOverlappingRange(startPos,endPos)) {
InputPathList &inputPathList = GetInputPathList(startPos, endPos);
// 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).ProcessInitialTranslationLEGACY
(m_source, *oldPtoc, startPos, endPos, adhereTableLimit, inputPathList);
// do rest of decode steps
int indexStep = 0;
for (++iterStep ; iterStep != decodeGraph.end() ; ++iterStep) {
const DecodeStep *decodeStep = *iterStep;
const DecodeStepTranslation *transStep =dynamic_cast<const DecodeStepTranslation*>(decodeStep);
const DecodeStepGeneration *genStep =dynamic_cast<const DecodeStepGeneration*>(decodeStep);
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;
if (transStep) {
transStep->ProcessLEGACY(inputPartialTranslOpt
, *decodeStep
, *newPtoc
, this
, adhereTableLimit);
} else {
assert(genStep);
genStep->Process(inputPartialTranslOpt
, *decodeStep
, *newPtoc
, this
, adhereTableLimit);
}
}
// 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);
}
lastPartialTranslOptColl.DetachAll();
totalEarlyPruned += oldPtoc->GetPrunedCount();
delete oldPtoc;
// TRACE_ERR( "Early translation options pruned: " << totalEarlyPruned << endl);
} // if ((intype != XmlExclusive) || !HasXmlOptionsOverlappingRange(startPos,endPos))
if (graphInd == 0 && intype != XmlPassThrough &&
HasXmlOptionsOverlappingRange(startPos,endPos)) {
CreateXmlOptionsForRange(startPos, endPos);
}
return retval;
}
}