KenLM e3b5c55910 including rest costs for probing

1 files changed, 35 insertions, 58 deletions

diff --git a/lm/model.hh b/lm/model.hh
index 6ea62a789..be8721788 100644
--- a/lm/model.hh
+++ b/lm/model.hh
@@ -9,6 +9,8 @@
 #include "lm/quantize.hh"
 #include "lm/search_hashed.hh"
 #include "lm/search_trie.hh"
+#include "lm/state.hh"
+#include "lm/value.hh"
 #include "lm/vocab.hh"
 #include "lm/weights.hh"
 
@@ -23,48 +25,6 @@ namespace util { class FilePiece; }
 
 namespace lm {
 namespace ngram {
-
-// This is a POD but if you want memcmp to return the same as operator==, call
-// ZeroRemaining first.    
-class State {
-  public:
-    bool operator==(const State &other) const {
-      if (length != other.length) return false;
-      return !memcmp(words, other.words, length * sizeof(WordIndex));
-    }
-
-    // Three way comparison function.  
-    int Compare(const State &other) const {
-      if (length != other.length) return length < other.length ? -1 : 1;
-      return memcmp(words, other.words, length * sizeof(WordIndex));
-    }
-
-    bool operator<(const State &other) const {
-      if (length != other.length) return length < other.length;
-      return memcmp(words, other.words, length * sizeof(WordIndex)) < 0;
-    }
-
-    // Call this before using raw memcmp.  
-    void ZeroRemaining() {
-      for (unsigned char i = length; i < kMaxOrder - 1; ++i) {
-        words[i] = 0;
-        backoff[i] = 0.0;
-      }
-    }
-
-    unsigned char Length() const { return length; }
-
-    // You shouldn't need to touch anything below this line, but the members are public so FullState will qualify as a POD.  
-    // This order minimizes total size of the struct if WordIndex is 64 bit, float is 32 bit, and alignment of 64 bit integers is 64 bit.  
-    WordIndex words[kMaxOrder - 1];
-    float backoff[kMaxOrder - 1];
-    unsigned char length;
-};
-
-inline size_t hash_value(const State &state) {
-  return util::MurmurHashNative(state.words, sizeof(WordIndex) * state.length);
-}
-
 namespace detail {
 
 // Should return the same results as SRI.  
@@ -119,8 +79,7 @@ template <class Search, class VocabularyT> class GenericModel : public base::Mod
 
     /* More efficient version of FullScore where a partial n-gram has already
      * been scored.  
-     * NOTE: THE RETURNED .prob IS RELATIVE, NOT ABSOLUTE.  So for example, if
-     * the n-gram does not end up extending further left, then 0 is returned.
+     * NOTE: THE RETURNED .rest AND .prob ARE RELATIVE TO THE .rest RETURNED BEFORE.  
      */
     FullScoreReturn ExtendLeft(
         // Additional context in reverse order.  This will update add_rend to 
@@ -136,12 +95,24 @@ template <class Search, class VocabularyT> class GenericModel : public base::Mod
         // Amount of additional content that should be considered by the next call.
         unsigned char &next_use) const;
 
+    /* Return probabilities minus rest costs for an array of pointers.  The
+     * first length should be the length of the n-gram to which pointers_begin
+     * points.  
+     */
+    float UnRest(const uint64_t *pointers_begin, const uint64_t *pointers_end, unsigned char first_length) const {
+      // Compiler should optimize this if away.  
+      return Search::kDifferentRest ? InternalUnRest(pointers_begin, pointers_end, first_length) : 0.0;
+    }
+
   private:
     friend void lm::ngram::LoadLM<>(const char *file, const Config &config, GenericModel<Search, VocabularyT> &to);
 
     static void UpdateConfigFromBinary(int fd, const std::vector<uint64_t> &counts, Config &config);
 
-    FullScoreReturn ScoreExceptBackoff(const WordIndex *context_rbegin, const WordIndex *context_rend, const WordIndex new_word, State &out_state) const;
+    FullScoreReturn ScoreExceptBackoff(const WordIndex *const context_rbegin, const WordIndex *const context_rend, const WordIndex new_word, State &out_state) const;
+
+    // Score bigrams and above.  Do not include backoff.   
+    void ResumeScore(const WordIndex *context_rbegin, const WordIndex *const context_rend, unsigned char starting_order_minus_2, typename Search::Node &node, float *backoff_out, unsigned char &next_use, FullScoreReturn &ret) const;
 
     // Appears after Size in the cc file.
     void SetupMemory(void *start, const std::vector<uint64_t> &counts, const Config &config);
@@ -150,32 +121,38 @@ template <class Search, class VocabularyT> class GenericModel : public base::Mod
 
     void InitializeFromARPA(const char *file, const Config &config);
 
+    float InternalUnRest(const uint64_t *pointers_begin, const uint64_t *pointers_end, unsigned char first_length) const;
+
     Backing &MutableBacking() { return backing_; }
 
     Backing backing_;
     
     VocabularyT vocab_;
 
-    typedef typename Search::Middle Middle;
-
     Search search_;
 };
 
 } // namespace detail
 
-// These must also be instantiated in the cc file.  
-typedef ::lm::ngram::ProbingVocabulary Vocabulary;
-typedef detail::GenericModel<detail::ProbingHashedSearch, Vocabulary> ProbingModel; // HASH_PROBING
-// Default implementation.  No real reason for it to be the default.  
-typedef ProbingModel Model;
+// Instead of typedef, inherit.  This allows the Model etc to be forward declared.  
+// Oh the joys of C and C++. 
+#define LM_COMMA() ,
+#define LM_NAME_MODEL(name, from)\
+class name : public from {\
+  public:\
+    name(const char *file, const Config &config = Config()) : from(file, config) {}\
+};
 
-// Smaller implementation.
-typedef ::lm::ngram::SortedVocabulary SortedVocabulary;
-typedef detail::GenericModel<trie::TrieSearch<DontQuantize, trie::DontBhiksha>, SortedVocabulary> TrieModel; // TRIE_SORTED
-typedef detail::GenericModel<trie::TrieSearch<DontQuantize, trie::ArrayBhiksha>, SortedVocabulary> ArrayTrieModel;
+LM_NAME_MODEL(ProbingModel, detail::GenericModel<detail::HashedSearch<BackoffValue> LM_COMMA() ProbingVocabulary>);
+LM_NAME_MODEL(RestProbingModel, detail::GenericModel<detail::HashedSearch<RestValue> LM_COMMA() ProbingVocabulary>);
+LM_NAME_MODEL(TrieModel, detail::GenericModel<trie::TrieSearch<DontQuantize LM_COMMA() trie::DontBhiksha> LM_COMMA() SortedVocabulary>);
+LM_NAME_MODEL(ArrayTrieModel, detail::GenericModel<trie::TrieSearch<DontQuantize LM_COMMA() trie::ArrayBhiksha> LM_COMMA() SortedVocabulary>);
+LM_NAME_MODEL(QuantTrieModel, detail::GenericModel<trie::TrieSearch<SeparatelyQuantize LM_COMMA() trie::DontBhiksha> LM_COMMA() SortedVocabulary>);
+LM_NAME_MODEL(QuantArrayTrieModel, detail::GenericModel<trie::TrieSearch<SeparatelyQuantize LM_COMMA() trie::ArrayBhiksha> LM_COMMA() SortedVocabulary>);
 
-typedef detail::GenericModel<trie::TrieSearch<SeparatelyQuantize, trie::DontBhiksha>, SortedVocabulary> QuantTrieModel; // QUANT_TRIE_SORTED
-typedef detail::GenericModel<trie::TrieSearch<SeparatelyQuantize, trie::ArrayBhiksha>, SortedVocabulary> QuantArrayTrieModel;
+// Default implementation.  No real reason for it to be the default.  
+typedef ::lm::ngram::ProbingVocabulary Vocabulary;
+typedef ProbingModel Model;
 
 } // namespace ngram
 } // namespace lm