mirror of
https://github.com/moses-smt/mosesdecoder.git
synced 2024-09-11 11:25:40 +03:00
339 lines
12 KiB
C++
339 lines
12 KiB
C++
#include "Manager.h"
|
|
#include "Util.h"
|
|
#include "SearchCubePruning.h"
|
|
#include "StaticData.h"
|
|
#include "InputType.h"
|
|
#include "TranslationOptionCollection.h"
|
|
|
|
using namespace std;
|
|
|
|
namespace Moses
|
|
{
|
|
class BitmapContainerOrderer
|
|
{
|
|
public:
|
|
bool operator()(const BitmapContainer* A, const BitmapContainer* B) const {
|
|
if (B->Empty()) {
|
|
if (A->Empty()) {
|
|
return A < B;
|
|
}
|
|
return false;
|
|
}
|
|
if (A->Empty()) {
|
|
return true;
|
|
}
|
|
|
|
// Compare the top hypothesis of each bitmap container using the TotalScore, which includes future cost
|
|
const float scoreA = A->Top()->GetHypothesis()->GetTotalScore();
|
|
const float scoreB = B->Top()->GetHypothesis()->GetTotalScore();
|
|
|
|
if (scoreA < scoreB) {
|
|
return true;
|
|
} else if (scoreA > scoreB) {
|
|
return false;
|
|
} else {
|
|
return A < B;
|
|
}
|
|
}
|
|
};
|
|
|
|
SearchCubePruning::SearchCubePruning(Manager& manager, const InputType &source, const TranslationOptionCollection &transOptColl)
|
|
:Search(manager)
|
|
,m_source(source)
|
|
,m_hypoStackColl(source.GetSize() + 1)
|
|
,m_transOptColl(transOptColl)
|
|
{
|
|
const StaticData &staticData = StaticData::Instance();
|
|
|
|
std::vector < HypothesisStackCubePruning >::iterator iterStack;
|
|
for (size_t ind = 0 ; ind < m_hypoStackColl.size() ; ++ind) {
|
|
HypothesisStackCubePruning *sourceHypoColl = new HypothesisStackCubePruning(m_manager);
|
|
sourceHypoColl->SetMaxHypoStackSize(staticData.GetMaxHypoStackSize());
|
|
sourceHypoColl->SetBeamWidth(staticData.GetBeamWidth());
|
|
|
|
m_hypoStackColl[ind] = sourceHypoColl;
|
|
}
|
|
}
|
|
|
|
SearchCubePruning::~SearchCubePruning()
|
|
{
|
|
RemoveAllInColl(m_hypoStackColl);
|
|
}
|
|
|
|
/**
|
|
* Main decoder loop that translates a sentence by expanding
|
|
* hypotheses stack by stack, until the end of the sentence.
|
|
*/
|
|
void SearchCubePruning::ProcessSentence()
|
|
{
|
|
const StaticData &staticData = StaticData::Instance();
|
|
|
|
// initial seed hypothesis: nothing translated, no words produced
|
|
Hypothesis *hypo = Hypothesis::Create(m_manager,m_source, m_initialTransOpt);
|
|
|
|
HypothesisStackCubePruning &firstStack = *static_cast<HypothesisStackCubePruning*>(m_hypoStackColl.front());
|
|
firstStack.AddInitial(hypo);
|
|
// Call this here because the loop below starts at the second stack.
|
|
firstStack.CleanupArcList();
|
|
CreateForwardTodos(firstStack);
|
|
|
|
const size_t PopLimit = StaticData::Instance().GetCubePruningPopLimit();
|
|
VERBOSE(3,"Cube Pruning pop limit is " << PopLimit << std::endl)
|
|
|
|
const size_t Diversity = StaticData::Instance().GetCubePruningDiversity();
|
|
VERBOSE(3,"Cube Pruning diversity is " << Diversity << std::endl)
|
|
|
|
// go through each stack
|
|
size_t stackNo = 1;
|
|
std::vector < HypothesisStack* >::iterator iterStack;
|
|
for (iterStack = m_hypoStackColl.begin() + 1 ; iterStack != m_hypoStackColl.end() ; ++iterStack) {
|
|
// check if decoding ran out of time
|
|
double _elapsed_time = GetUserTime();
|
|
if (_elapsed_time > staticData.GetTimeoutThreshold()) {
|
|
VERBOSE(1,"Decoding is out of time (" << _elapsed_time << "," << staticData.GetTimeoutThreshold() << ")" << std::endl);
|
|
return;
|
|
}
|
|
HypothesisStackCubePruning &sourceHypoColl = *static_cast<HypothesisStackCubePruning*>(*iterStack);
|
|
|
|
// priority queue which has a single entry for each bitmap container, sorted by score of top hyp
|
|
std::priority_queue< BitmapContainer*, std::vector< BitmapContainer* >, BitmapContainerOrderer> BCQueue;
|
|
|
|
_BMType::const_iterator bmIter;
|
|
const _BMType &accessor = sourceHypoColl.GetBitmapAccessor();
|
|
|
|
for(bmIter = accessor.begin(); bmIter != accessor.end(); ++bmIter) {
|
|
// build the first hypotheses
|
|
bmIter->second->InitializeEdges();
|
|
m_manager.GetSentenceStats().StartTimeManageCubes();
|
|
BCQueue.push(bmIter->second);
|
|
m_manager.GetSentenceStats().StopTimeManageCubes();
|
|
|
|
// old algorithm
|
|
// bmIter->second->EnsureMinStackHyps(PopLimit);
|
|
}
|
|
|
|
// main search loop, pop k best hyps
|
|
for (size_t numpops = 1; numpops <= PopLimit && !BCQueue.empty(); numpops++) {
|
|
// get currently best hypothesis in queue
|
|
m_manager.GetSentenceStats().StartTimeManageCubes();
|
|
BitmapContainer *bc = BCQueue.top();
|
|
BCQueue.pop();
|
|
m_manager.GetSentenceStats().StopTimeManageCubes();
|
|
IFVERBOSE(2) {
|
|
m_manager.GetSentenceStats().AddPopped();
|
|
}
|
|
// push on stack and create successors
|
|
bc->ProcessBestHypothesis();
|
|
// if there are any hypothesis left in this specific container, add back to queue
|
|
m_manager.GetSentenceStats().StartTimeManageCubes();
|
|
if (!bc->Empty())
|
|
BCQueue.push(bc);
|
|
m_manager.GetSentenceStats().StopTimeManageCubes();
|
|
}
|
|
|
|
// ensure diversity, a minimum number of inserted hyps for each bitmap container;
|
|
// NOTE: diversity doesn't ensure they aren't pruned at some later point
|
|
if (Diversity > 0) {
|
|
for(bmIter = accessor.begin(); bmIter != accessor.end(); ++bmIter) {
|
|
bmIter->second->EnsureMinStackHyps(Diversity);
|
|
}
|
|
}
|
|
|
|
// the stack is pruned before processing (lazy pruning):
|
|
VERBOSE(3,"processing hypothesis from next stack");
|
|
IFVERBOSE(2) {
|
|
m_manager.GetSentenceStats().StartTimeStack();
|
|
}
|
|
sourceHypoColl.PruneToSize(staticData.GetMaxHypoStackSize());
|
|
VERBOSE(3,std::endl);
|
|
sourceHypoColl.CleanupArcList();
|
|
IFVERBOSE(2) {
|
|
m_manager.GetSentenceStats().StopTimeStack();
|
|
}
|
|
|
|
IFVERBOSE(2) {
|
|
m_manager.GetSentenceStats().StartTimeSetupCubes();
|
|
}
|
|
CreateForwardTodos(sourceHypoColl);
|
|
IFVERBOSE(2) {
|
|
m_manager.GetSentenceStats().StopTimeSetupCubes();
|
|
}
|
|
|
|
stackNo++;
|
|
}
|
|
}
|
|
|
|
void SearchCubePruning::CreateForwardTodos(HypothesisStackCubePruning &stack)
|
|
{
|
|
const _BMType &bitmapAccessor = stack.GetBitmapAccessor();
|
|
_BMType::const_iterator iterAccessor;
|
|
size_t size = m_source.GetSize();
|
|
|
|
stack.AddHypothesesToBitmapContainers();
|
|
|
|
for (iterAccessor = bitmapAccessor.begin() ; iterAccessor != bitmapAccessor.end() ; ++iterAccessor) {
|
|
const WordsBitmap &bitmap = iterAccessor->first;
|
|
BitmapContainer &bitmapContainer = *iterAccessor->second;
|
|
|
|
if (bitmapContainer.GetHypothesesSize() == 0) {
|
|
// no hypothese to expand. don't bother doing it
|
|
continue;
|
|
}
|
|
|
|
// Sort the hypotheses inside the Bitmap Container as they are being used by now.
|
|
bitmapContainer.SortHypotheses();
|
|
|
|
// check bitamp and range doesn't overlap
|
|
size_t startPos, endPos;
|
|
for (startPos = 0 ; startPos < size ; startPos++) {
|
|
if (bitmap.GetValue(startPos))
|
|
continue;
|
|
|
|
// not yet covered
|
|
WordsRange applyRange(startPos, startPos);
|
|
if (CheckDistortion(bitmap, applyRange)) {
|
|
// apply range
|
|
CreateForwardTodos(bitmap, applyRange, bitmapContainer);
|
|
}
|
|
|
|
size_t maxSize = size - startPos;
|
|
size_t maxSizePhrase = StaticData::Instance().GetMaxPhraseLength();
|
|
maxSize = std::min(maxSize, maxSizePhrase);
|
|
|
|
for (endPos = startPos+1; endPos < startPos + maxSize; endPos++) {
|
|
if (bitmap.GetValue(endPos))
|
|
break;
|
|
|
|
WordsRange applyRange(startPos, endPos);
|
|
if (CheckDistortion(bitmap, applyRange)) {
|
|
// apply range
|
|
CreateForwardTodos(bitmap, applyRange, bitmapContainer);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void SearchCubePruning::CreateForwardTodos(const WordsBitmap &bitmap, const WordsRange &range, BitmapContainer &bitmapContainer)
|
|
{
|
|
WordsBitmap newBitmap = bitmap;
|
|
newBitmap.SetValue(range.GetStartPos(), range.GetEndPos(), true);
|
|
|
|
size_t numCovered = newBitmap.GetNumWordsCovered();
|
|
const TranslationOptionList &transOptList = m_transOptColl.GetTranslationOptionList(range);
|
|
const SquareMatrix &futureScore = m_transOptColl.GetFutureScore();
|
|
|
|
if (transOptList.size() > 0) {
|
|
HypothesisStackCubePruning &newStack = *static_cast<HypothesisStackCubePruning*>(m_hypoStackColl[numCovered]);
|
|
newStack.SetBitmapAccessor(newBitmap, newStack, range, bitmapContainer, futureScore, transOptList);
|
|
}
|
|
}
|
|
|
|
bool SearchCubePruning::CheckDistortion(const WordsBitmap &hypoBitmap, const WordsRange &range) const
|
|
{
|
|
// since we check for reordering limits, its good to have that limit handy
|
|
int maxDistortion = StaticData::Instance().GetMaxDistortion();
|
|
|
|
// if there are reordering limits, make sure it is not violated
|
|
// the coverage bitmap is handy here (and the position of the first gap)
|
|
const size_t hypoFirstGapPos = hypoBitmap.GetFirstGapPos()
|
|
, startPos = range.GetStartPos()
|
|
, endPos = range.GetEndPos();
|
|
|
|
// if reordering constraints are used (--monotone-at-punctuation or xml), check if passes all
|
|
if (! m_source.GetReorderingConstraint().Check( hypoBitmap, startPos, endPos ) ) {
|
|
return false;
|
|
}
|
|
|
|
// no limit of reordering: no problem
|
|
if (maxDistortion < 0) {
|
|
return true;
|
|
}
|
|
|
|
bool leftMostEdge = (hypoFirstGapPos == startPos);
|
|
// any length extension is okay if starting at left-most edge
|
|
if (leftMostEdge) {
|
|
return true;
|
|
}
|
|
// starting somewhere other than left-most edge, use caution
|
|
// the basic idea is this: we would like to translate a phrase starting
|
|
// from a position further right than the left-most open gap. The
|
|
// distortion penalty for the following phrase will be computed relative
|
|
// to the ending position of the current extension, so we ask now what
|
|
// its maximum value will be (which will always be the value of the
|
|
// hypothesis starting at the left-most edge). If this vlaue is than
|
|
// the distortion limit, we don't allow this extension to be made.
|
|
WordsRange bestNextExtension(hypoFirstGapPos, hypoFirstGapPos);
|
|
int required_distortion =
|
|
m_source.ComputeDistortionDistance(range, bestNextExtension);
|
|
|
|
if (required_distortion > maxDistortion) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Find best hypothesis on the last stack.
|
|
* This is the end point of the best translation, which can be traced back from here
|
|
*/
|
|
const Hypothesis *SearchCubePruning::GetBestHypothesis() const
|
|
{
|
|
// const HypothesisStackCubePruning &hypoColl = m_hypoStackColl.back();
|
|
const HypothesisStack &hypoColl = *m_hypoStackColl.back();
|
|
return hypoColl.GetBestHypothesis();
|
|
}
|
|
|
|
/**
|
|
* Logging of hypothesis stack sizes
|
|
*/
|
|
void SearchCubePruning::OutputHypoStackSize()
|
|
{
|
|
std::vector < HypothesisStack* >::const_iterator iterStack = m_hypoStackColl.begin();
|
|
TRACE_ERR( "Stack sizes: " << (int)(*iterStack)->size());
|
|
for (++iterStack; iterStack != m_hypoStackColl.end() ; ++iterStack) {
|
|
TRACE_ERR( ", " << (int)(*iterStack)->size());
|
|
}
|
|
TRACE_ERR( endl);
|
|
}
|
|
|
|
void SearchCubePruning::PrintBitmapContainerGraph()
|
|
{
|
|
HypothesisStackCubePruning &lastStack = *static_cast<HypothesisStackCubePruning*>(m_hypoStackColl.back());
|
|
const _BMType &bitmapAccessor = lastStack.GetBitmapAccessor();
|
|
|
|
_BMType::const_iterator iterAccessor;
|
|
for (iterAccessor = bitmapAccessor.begin(); iterAccessor != bitmapAccessor.end(); ++iterAccessor) {
|
|
cerr << iterAccessor->first << endl;
|
|
//BitmapContainer &container = *iterAccessor->second;
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* Logging of hypothesis stack contents
|
|
* \param stack number of stack to be reported, report all stacks if 0
|
|
*/
|
|
void SearchCubePruning::OutputHypoStack(int stack)
|
|
{
|
|
if (stack >= 0) {
|
|
TRACE_ERR( "Stack " << stack << ": " << endl << m_hypoStackColl[stack] << endl);
|
|
} else {
|
|
// all stacks
|
|
int i = 0;
|
|
vector < HypothesisStack* >::iterator iterStack;
|
|
for (iterStack = m_hypoStackColl.begin() ; iterStack != m_hypoStackColl.end() ; ++iterStack) {
|
|
HypothesisStackCubePruning &hypoColl = *static_cast<HypothesisStackCubePruning*>(*iterStack);
|
|
TRACE_ERR( "Stack " << i++ << ": " << endl << hypoColl << endl);
|
|
}
|
|
}
|
|
}
|
|
|
|
const std::vector < HypothesisStack* >& SearchCubePruning::GetHypothesisStacks() const
|
|
{
|
|
return m_hypoStackColl;
|
|
}
|
|
|
|
}
|
|
|