score deltas in chart decoding

1 files changed, 79 insertions, 23 deletions

diff --git a/moses/ChartHypothesis.h b/moses/ChartHypothesis.h
index 8dc26e721..ecd35b867 100644
--- a/moses/ChartHypothesis.h
+++ b/moses/ChartHypothesis.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include <vector>
+#include <boost/scoped_ptr.hpp>
 #include "Util.h"
 #include "WordsRange.h"
 #include "ScoreComponentCollection.h"
@@ -45,7 +46,7 @@ typedef std::vector<ChartHypothesis*> ChartArcList;
 class ChartHypothesis
 {
   friend std::ostream& operator<<(std::ostream&, const ChartHypothesis&);
-  friend class ChartKBestExtractor;
+//  friend class ChartKBestExtractor;
 
 protected:
 #ifdef USE_HYPO_POOL
@@ -56,7 +57,10 @@ protected:
 
   WordsRange					m_currSourceWordsRange;
   std::vector<const FFState*> m_ffStates; /*! stateful feature function states */
-  ScoreComponentCollection m_scoreBreakdown /*! detailed score break-down by components (for instance language model, word penalty, etc) */
+  /*! sum of scores of this hypothesis, and previous hypotheses. Lazily initialised.  */
+  mutable boost::scoped_ptr<ScoreComponentCollection> m_scoreBreakdown; 
+  mutable boost::scoped_ptr<ScoreComponentCollection> m_deltaScoreBreakdown; 
+  ScoreComponentCollection m_currScoreBreakdown /*! scores for this hypothesis only */
   ,m_lmNGram
   ,m_lmPrefix;
   float m_totalScore;
@@ -76,23 +80,23 @@ protected:
   //! not implemented
   ChartHypothesis(const ChartHypothesis &copy);
 
-  //! only used by ChartKBestExtractor
-  ChartHypothesis(const ChartHypothesis &, const ChartKBestExtractor &);
-
 public:
 #ifdef USE_HYPO_POOL
-  void *operator new(size_t /* num_bytes */) {
+  void *operator new(size_t /* num_bytes */) 
+  {
     void *ptr = s_objectPool.getPtr();
     return ptr;
   }
 
   //! delete \param hypo. Works with object pool too
-  static void Delete(ChartHypothesis *hypo) {
+  static void Delete(ChartHypothesis *hypo) 
+  {
     s_objectPool.freeObject(hypo);
   }
 #else
   //! delete \param hypo. Works with object pool too
-  static void Delete(ChartHypothesis *hypo) {
+  static void Delete(ChartHypothesis *hypo) 
+  {
     delete hypo;
   }
 #endif
@@ -100,38 +104,48 @@ public:
   ChartHypothesis(const ChartTranslationOptions &, const RuleCubeItem &item,
                   ChartManager &manager);
 
+  //! only used by ChartKBestExtractor
+  ChartHypothesis(const ChartHypothesis &, const ChartKBestExtractor &);
+
   ~ChartHypothesis();
 
-  unsigned GetId() const {
+  unsigned GetId() const 
+  {
     return m_id;
   }
 
-  const ChartTranslationOption &GetTranslationOption()const {
+  const ChartTranslationOption &GetTranslationOption() const 
+  {
     return *m_transOpt;
   }
 
   //! Get the rule that created this hypothesis
-  const TargetPhrase &GetCurrTargetPhrase()const {
+  const TargetPhrase &GetCurrTargetPhrase() const 
+  {
     return m_transOpt->GetPhrase();
   }
 
   //! the source range that this hypothesis spans
-  const WordsRange &GetCurrSourceRange()const {
+  const WordsRange &GetCurrSourceRange() const 
+  {
     return m_currSourceWordsRange;
   }
 
   //! the arc list when creating n-best lists
-  inline const ChartArcList* GetArcList() const {
+  inline const ChartArcList* GetArcList() const 
+  {
     return m_arcList;
   }
 
   //! the feature function states for a particular feature \param featureID
-  inline const FFState* GetFFState( size_t featureID ) const {
+  inline const FFState* GetFFState( size_t featureID ) const 
+  {
     return m_ffStates[ featureID ];
   }
 
   //! reference back to the manager
-  inline const ChartManager& GetManager() const {
+  inline const ChartManager& GetManager() const 
+  {
     return m_manager;
   }
 
@@ -140,7 +154,7 @@ public:
 
   // get leftmost/rightmost words only
   // leftRightMost: 1=left, 2=right
-  void GetOutputPhrase(int leftRightMost, int numWords, Phrase &outPhrase) const;
+  void GetOutputPhrase(size_t leftRightMost, size_t numWords, Phrase &outPhrase) const;
 
   int RecombineCompare(const ChartHypothesis &compare) const;
 
@@ -151,32 +165,74 @@ public:
   void SetWinningHypo(const ChartHypothesis *hypo);
 
   //! get the unweighted score for each feature function
-  const ScoreComponentCollection &GetScoreBreakdown() const {
-    return m_scoreBreakdown;
+  const ScoreComponentCollection &GetScoreBreakdown() const 
+  {
+    // Note: never call this method before m_currScoreBreakdown is fully computed
+    if (!m_scoreBreakdown.get()) 
+    {
+      m_scoreBreakdown.reset(new ScoreComponentCollection());
+      // score breakdown from current translation rule
+      if (m_transOpt)
+      {
+        m_scoreBreakdown->PlusEquals(GetTranslationOption().GetScores());
+      }
+      m_scoreBreakdown->PlusEquals(m_currScoreBreakdown);
+      // score breakdowns from prev hypos
+      for (std::vector<const ChartHypothesis*>::const_iterator iter = m_prevHypos.begin(); iter != m_prevHypos.end(); ++iter) 
+      {
+        const ChartHypothesis &prevHypo = **iter;
+        m_scoreBreakdown->PlusEquals(prevHypo.GetScoreBreakdown());
+      }
+    }
+    return *(m_scoreBreakdown.get());
+  }
+
+  //! get the unweighted score delta for each feature function
+  const ScoreComponentCollection &GetDeltaScoreBreakdown() const 
+  {
+    // Note: never call this method before m_currScoreBreakdown is fully computed
+    if (!m_deltaScoreBreakdown.get()) 
+    {
+      m_deltaScoreBreakdown.reset(new ScoreComponentCollection());
+      // score breakdown from current translation rule
+      if (m_transOpt)
+      {
+        m_deltaScoreBreakdown->PlusEquals(GetTranslationOption().GetScores());
+      }
+      m_deltaScoreBreakdown->PlusEquals(m_currScoreBreakdown);
+      // delta: score breakdowns from prev hypos _not_ added
+    }
+    return *(m_deltaScoreBreakdown.get());
   }
 
   //! Get the weighted total score
-  float GetTotalScore() const {
+  float GetTotalScore() const 
+  {
+    // scores from current translation rule. eg. translation models & word penalty
     return m_totalScore;
   }
 
   //! vector of previous hypotheses this hypo is built on
-  const std::vector<const ChartHypothesis*> &GetPrevHypos() const {
+  const std::vector<const ChartHypothesis*> &GetPrevHypos() const 
+  {
     return m_prevHypos;
   }
 
   //! get a particular previous hypos
-  const ChartHypothesis* GetPrevHypo(size_t pos) const {
+  const ChartHypothesis* GetPrevHypo(size_t pos) const 
+  {
     return m_prevHypos[pos];
   }
 
   //! get the constituency label that covers this hypo
-  const Word &GetTargetLHS() const {
+  const Word &GetTargetLHS() const 
+  {
     return GetCurrTargetPhrase().GetTargetLHS();
   }
 
   //! get the best hypo in the arc list when doing n-best list creation. It's either this hypothesis, or the best hypo is this hypo is in the arc list
-  const ChartHypothesis* GetWinningHypothesis() const {
+  const ChartHypothesis* GetWinningHypothesis() const 
+  {
     return m_winningHypo;
   }