Make NPLM wrapper compile again. Fixes #102.

3 files changed, 48 insertions, 19 deletions

diff --git a/lm/Jamfile b/lm/Jamfile
index 227b22014..0b5bbf259 100644
--- a/lm/Jamfile
+++ b/lm/Jamfile
@@ -16,10 +16,10 @@ max-order += <dependency>$(ORDER-LOG) ;
 wrappers = ;
 local with-nplm = [ option.get "with-nplm" ] ;
 if $(with-nplm) {
-  lib neuralLM : : <search>$(with-nplm)/src ;
+  lib nplm : : <search>$(with-nplm)/src ;
   obj nplm.o : wrappers/nplm.cc : <include>.. <include>$(with-nplm)/src <cxxflags>-fopenmp ;
-  alias nplm : nplm.o neuralLM ..//boost_thread : : : <cxxflags>-fopenmp <linkflags>-fopenmp <define>WITH_NPLM <library>..//boost_thread ;
-  wrappers += nplm ;
+  alias nplm-all : nplm.o nplm ..//boost_thread : : : <cxxflags>-fopenmp <linkflags>-fopenmp <define>WITH_NPLM <library>..//boost_thread ;
+  wrappers += nplm-all ;
 }
 
 fakelib kenlm : $(wrappers) [ glob *.cc : *main.cc *test.cc ] ../util//kenutil : <include>.. $(max-order) : : <include>.. $(max-order) ;
diff --git a/lm/wrappers/nplm.cc b/lm/wrappers/nplm.cc
index 70622bd2b..44fd75a83 100644
--- a/lm/wrappers/nplm.cc
+++ b/lm/wrappers/nplm.cc
@@ -21,6 +21,26 @@ WordIndex Vocabulary::Index(const std::string &str) const {
   return vocab_.lookup_word(str);
 }
 
+class Backend {
+  public:
+    Backend(const nplm::neuralLM &from, const std::size_t cache_size) : lm_(from), ngram_(from.get_order()) {
+      lm_.set_cache(cache_size);
+    }
+
+    nplm::neuralLM &LM() { return lm_; }
+    const nplm::neuralLM &LM() const { return lm_; }
+
+    Eigen::Matrix<int,Eigen::Dynamic,1> &staging_ngram() { return ngram_; }
+
+    double lookup_from_staging() { return lm_.lookup_ngram(ngram_); }
+
+    int order() const { return lm_.get_order(); }
+
+  private:
+    nplm::neuralLM lm_;
+    Eigen::Matrix<int,Eigen::Dynamic,1> ngram_;
+};
+
 bool Model::Recognize(const std::string &name) {
   try {
     util::scoped_fd file(util::OpenReadOrThrow(name.c_str()));
@@ -31,10 +51,18 @@ bool Model::Recognize(const std::string &name) {
   } catch (const util::Exception &) {
     return false;
   }
-} 
+}
+
+namespace {
+nplm::neuralLM *LoadNPLM(const std::string &file) {
+  util::scoped_ptr<nplm::neuralLM> ret(new nplm::neuralLM());
+  ret->read(file);
+  return ret.release();
+}
+} // namespace
 
 Model::Model(const std::string &file, std::size_t cache) 
-  : base_instance_(new nplm::neuralLM(file)), vocab_(base_instance_->get_vocabulary()), cache_size_(cache) {
+  : base_instance_(LoadNPLM(file)), vocab_(base_instance_->get_vocabulary()), cache_size_(cache) {
   UTIL_THROW_IF(base_instance_->get_order() > NPLM_MAX_ORDER, util::Exception, "This NPLM has order " << (unsigned int)base_instance_->get_order() << " but the KenLM wrapper was compiled with " << NPLM_MAX_ORDER << ".  Change the defintion of NPLM_MAX_ORDER and recompile.");
   // log10 compatible with backoff models.
   base_instance_->set_log_base(10.0);
@@ -49,26 +77,25 @@ Model::Model(const std::string &file, std::size_t cache)
 Model::~Model() {}
 
 FullScoreReturn Model::FullScore(const State &from, const WordIndex new_word, State &out_state) const {
-  nplm::neuralLM *lm = backend_.get();
-  if (!lm) {
-    lm = new nplm::neuralLM(*base_instance_);
-    backend_.reset(lm);
-    lm->set_cache(cache_size_);
+  Backend *backend = backend_.get();
+  if (!backend) {
+    backend = new Backend(*base_instance_, cache_size_);
+    backend_.reset(backend);
   }
   // State is in natural word order.
   FullScoreReturn ret;
-  for (int i = 0; i < lm->get_order() - 1; ++i) {
-    lm->staging_ngram()(i) = from.words[i];
+  for (int i = 0; i < backend->order() - 1; ++i) {
+    backend->staging_ngram()(i) = from.words[i];
   }
-  lm->staging_ngram()(lm->get_order() - 1) = new_word;
-  ret.prob = lm->lookup_from_staging();
+  backend->staging_ngram()(backend->order() - 1) = new_word;
+  ret.prob = backend->lookup_from_staging();
   // Always say full order.
-  ret.ngram_length = lm->get_order();
+  ret.ngram_length = backend->order();
   // Shift everything down by one.
-  memcpy(out_state.words, from.words + 1, sizeof(WordIndex) * (lm->get_order() - 2));
-  out_state.words[lm->get_order() - 2] = new_word;
+  memcpy(out_state.words, from.words + 1, sizeof(WordIndex) * (backend->order() - 2));
+  out_state.words[backend->order() - 2] = new_word;
   // Fill in trailing words with zeros so state comparison works.
-  memset(out_state.words + lm->get_order() - 1, 0, sizeof(WordIndex) * (NPLM_MAX_ORDER - lm->get_order()));
+  memset(out_state.words + backend->order() - 1, 0, sizeof(WordIndex) * (NPLM_MAX_ORDER - backend->order()));
   return ret;
 }
 
diff --git a/lm/wrappers/nplm.hh b/lm/wrappers/nplm.hh
index b7dd4a21e..416281de2 100644
--- a/lm/wrappers/nplm.hh
+++ b/lm/wrappers/nplm.hh
@@ -49,6 +49,8 @@ struct State {
   WordIndex words[NPLM_MAX_ORDER - 1];
 };
 
+class Backend;
+
 class Model : public lm::base::ModelFacade<Model, State, Vocabulary> {
   private:
     typedef lm::base::ModelFacade<Model, State, Vocabulary> P;
@@ -68,7 +70,7 @@ class Model : public lm::base::ModelFacade<Model, State, Vocabulary> {
   private:
     boost::scoped_ptr<nplm::neuralLM> base_instance_;
 
-    mutable boost::thread_specific_ptr<nplm::neuralLM> backend_;
+    mutable boost::thread_specific_ptr<Backend> backend_;
 
     Vocabulary vocab_;