Load combined format from Scorer

native_client/ctcdecode/scorer.cpp

@@ -88,46 +88,56 @@ void Scorer::load_lm(const std::string& lm_path, const std::string& trie_path)
   const char* filename = lm_path.c_str();
   VALID_CHECK_EQ(access(filename, R_OK), 0, "Invalid language model path");
 
-  bool has_trie = trie_path.size() && access(trie_path.c_str(), R_OK) == 0;
-  // VALID_CHECK(has_trie, "Invalid trie path");
-
   lm::ngram::Config config;
   config.load_method = util::LoadMethod::LAZY;
   language_model_.reset(lm::ngram::LoadVirtual(filename, config));
 
+  uint64_t package_size;
+  {
+    util::scoped_fd fd(util::OpenReadOrThrow(filename));
+    package_size = util::SizeFile(fd.get());
+  }
+  uint64_t trie_offset = language_model_->GetEndOfSearchOffset();
+  bool has_trie = package_size > trie_offset;
+
   if (has_trie) {
     // Read metadata and trie from file
-    std::ifstream fin(trie_path, std::ios::binary);
-
-    int magic;
-    fin.read(reinterpret_cast<char*>(&magic), sizeof(magic));
-    if (magic != MAGIC) {
-      std::cerr << "Error: Can't parse trie file, invalid header. Try updating "
-                   "your trie file." << std::endl;
-      throw 1;
-    }
-
-    int version;
-    fin.read(reinterpret_cast<char*>(&version), sizeof(version));
-    if (version != FILE_VERSION) {
-      std::cerr << "Error: Trie file version mismatch (" << version
-                << " instead of expected " << FILE_VERSION
-                << "). Update your trie file."
-                << std::endl;
-      throw 1;
-    }
-
-    fin.read(reinterpret_cast<char*>(&is_utf8_mode_), sizeof(is_utf8_mode_));
-
-    fst::FstReadOptions opt;
-    opt.mode = fst::FstReadOptions::MAP;
-    opt.source = trie_path;
-    dictionary.reset(FstType::Read(fin, opt));
+    std::ifstream fin(lm_path, std::ios::binary);
+    fin.seekg(trie_offset);
+    load_trie(fin, lm_path);
   }
 
   max_order_ = language_model_->Order();
 }
 
+void Scorer::load_trie(std::ifstream& fin, const std::string& file_path)
+{
+  int magic;
+  fin.read(reinterpret_cast<char*>(&magic), sizeof(magic));
+  if (magic != MAGIC) {
+    std::cerr << "Error: Can't parse trie file, invalid header. Try updating "
+                 "your trie file." << std::endl;
+    throw 1;
+  }
+
+  int version;
+  fin.read(reinterpret_cast<char*>(&version), sizeof(version));
+  if (version != FILE_VERSION) {
+    std::cerr << "Error: Trie file version mismatch (" << version
+              << " instead of expected " << FILE_VERSION
+              << "). Update your trie file."
+              << std::endl;
+    throw 1;
+  }
+
+  fin.read(reinterpret_cast<char*>(&is_utf8_mode_), sizeof(is_utf8_mode_));
+
+  fst::FstReadOptions opt;
+  opt.mode = fst::FstReadOptions::MAP;
+  opt.source = file_path;
+  dictionary.reset(FstType::Read(fin, opt));
+}
+
 void Scorer::save_dictionary(const std::string& path, bool append_instead_of_overwrite)
 {
   std::ios::openmode om;

native_client/ctcdecode/scorer.h

@@ -118,6 +118,8 @@ protected:
   // necessary setup after setting alphabet
   void setup_char_map();
 
+  void load_trie(std::ifstream& fin, const std::string& file_path);
+
 private:
   std::unique_ptr<lm::base::Model> language_model_;
   bool is_utf8_mode_ = true;

native_client/kenlm/lm/model.cc

@@ -226,6 +226,10 @@ template <class Search, class VocabularyT> FullScoreReturn GenericModel<Search,
   return ret;
 }
 
+template <class Search, class VocabularyT> uint64_t GenericModel<Search, VocabularyT>::GetEndOfSearchOffset() const {
+  return backing_.VocabStringReadingOffset();
+}
+
 namespace {
 // Do a paraonoid copy of history, assuming new_word has already been copied
 // (hence the -1).  out_state.length could be zero so I avoided using

native_client/kenlm/lm/model.hh

@@ -102,6 +102,8 @@ template <class Search, class VocabularyT> class GenericModel : public base::Mod
       return Search::kDifferentRest ? InternalUnRest(pointers_begin, pointers_end, first_length) : 0.0;
     }
 
+    uint64_t GetEndOfSearchOffset() const;
+
   private:
     FullScoreReturn ScoreExceptBackoff(const WordIndex *const context_rbegin, const WordIndex *const context_rend, const WordIndex new_word, State &out_state) const;
 

native_client/kenlm/lm/virtual_interface.hh

@@ -137,6 +137,8 @@ class Model {
 
     const Vocabulary &BaseVocabulary() const { return *base_vocab_; }
 
+    virtual uint64_t GetEndOfSearchOffset() const = 0;
+
   private:
     template <class T, class U, class V> friend class ModelFacade;
     explicit Model(size_t state_size) : state_size_(state_size) {}