Loading model from both path or array of bytes

Author: danielefernandes

native_client/Makefile

@@ -19,7 +19,7 @@ clean:
 	rm -f deepspeech
 
 $(DEEPSPEECH_BIN): client.cc Makefile
-	$(CXX) $(CFLAGS) $(CFLAGS_DEEPSPEECH) $(SOX_CFLAGS) client.cc $(LDFLAGS) $(SOX_LDFLAGS)
+	$(CXX) $(CFLAGS) $(CFLAGS_DEEPSPEECH) $(SOX_CFLAGS) client.cc $(LDFLAGS) $(SOX_LDFLAGS) -llzma -lbz2
 ifeq ($(OS),Darwin)
 	install_name_tool -change bazel-out/local-opt/bin/native_client/libdeepspeech.so @rpath/libdeepspeech.so deepspeech
 endif

native_client/alphabet.cc

@@ -34,6 +34,8 @@ bool extended_metadata = false;
 
 bool json_output = false;
 
+bool init_from_array_of_bytes = false;
+
 int json_candidate_transcripts = 3;
 
 int stream_size = 0;
@@ -59,6 +61,7 @@ void PrintHelp(const char* bin)
     "\t--candidate_transcripts NUMBER\tNumber of candidate transcripts to include in JSON output\n"
     "\t--stream size\t\t\tRun in stream mode, output intermediate results\n"
     "\t--hot_words\t\t\tHot-words and their boosts. Word:Boost pairs are comma-separated\n"
+    "\t--init_from_bytes\t\tTest init model and scorer from array of bytes\n"
     "\t--help\t\t\t\tShow help\n"
     "\t--version\t\t\tPrint version and exits\n";
     char* version = DS_Version();
@@ -80,6 +83,7 @@ bool ProcessArgs(int argc, char** argv)
             {"t", no_argument, nullptr, 't'},
             {"extended", no_argument, nullptr, 'e'},
             {"json", no_argument, nullptr, 'j'},
+            {"init_from_bytes", no_argument, nullptr, 'B'},
             {"candidate_transcripts", required_argument, nullptr, 150},
             {"stream", required_argument, nullptr, 's'},
             {"hot_words", required_argument, nullptr, 'w'},
@@ -135,6 +139,10 @@ bool ProcessArgs(int argc, char** argv)
         case 'j':
             json_output = true;
             break;
+        
+        case 'B':
+            init_from_array_of_bytes = true;
+            break;
 
         case 150:
             json_candidate_transcripts = atoi(optarg);

native_client/alphabet.h

@@ -33,6 +33,8 @@
 #include <unistd.h>
 #endif // NO_DIR
 #include <vector>
+#include <iostream>
+#include <fstream>
 
 #include "deepspeech.h"
 #include "args.h"
@@ -415,8 +417,21 @@ main(int argc, char **argv)
 
   // Initialise DeepSpeech
   ModelState* ctx;
+  std::string buffer_model_str;
   // sphinx-doc: c_ref_model_start
-  int status = DS_CreateModel(model, &ctx);
+  int status;
+  if (init_from_array_of_bytes){
+    // Reading model file to a char * buffer
+    std::ifstream is_model( model, std::ios::binary );
+    std::stringstream buffer_model;
+    buffer_model << is_model.rdbuf();
+    buffer_model_str = buffer_model.str();
+    status = DS_CreateModelFromBuffer(buffer_model_str.c_str(), buffer_model_str.size(), &ctx);
+  }else {
+    // Keep old method due to backwards compatibility
+    status = DS_CreateModel(model, &ctx);
+  }
+  
   if (status != 0) {
     char* error = DS_ErrorCodeToErrorMessage(status);
     fprintf(stderr, "Could not create model: %s\n", error);
@@ -433,7 +448,18 @@ main(int argc, char **argv)
   }
 
   if (scorer) {
-    status = DS_EnableExternalScorer(ctx, scorer);
+    if (init_from_array_of_bytes){
+      // Reading scorer file to a string buffer
+      std::ifstream is_scorer(scorer, std::ios::binary );
+      std::stringstream buffer_scorer;
+      buffer_scorer << is_scorer.rdbuf();
+      std::string tmp_str_scorer = buffer_scorer.str();
+      status = DS_EnableExternalScorerFromBuffer(ctx, tmp_str_scorer.c_str(), tmp_str_scorer.size());
+    } else {
+      // Keep old method due to backwards compatibility
+      status = DS_EnableExternalScorer(ctx, scorer);
+    }
+    
     if (status != 0) {
       fprintf(stderr, "Could not enable external scorer.\n");
       return 1;

native_client/args.h

@@ -29,22 +29,24 @@ static const int32_t FILE_VERSION = 6;
 
 int
 Scorer::init(const std::string& lm_path,
+             bool load_from_bytes,
              const Alphabet& alphabet)
 {
   set_alphabet(alphabet);
-  return load_lm(lm_path);
+  return load_lm(lm_path, load_from_bytes);
 }
 
 int
 Scorer::init(const std::string& lm_path,
+             bool load_from_bytes,
              const std::string& alphabet_config_path)
 {
-  int err = alphabet_.init(alphabet_config_path.c_str());
+  int err = alphabet_.init(alphabet_config_path.c_str()); // Do we need to make this initiable from bytes?
   if (err != 0) {
     return err;
   }
   setup_char_map();
-  return load_lm(lm_path);
+  return load_lm(lm_path, load_from_bytes);
 }
 
 void
@@ -69,45 +71,60 @@ void Scorer::setup_char_map()
   }
 }
 
-int Scorer::load_lm(const std::string& lm_path)
+int Scorer::load_lm(const std::string& lm_string, bool load_from_bytes)
 {
-  // Check if file is readable to avoid KenLM throwing an exception
-  const char* filename = lm_path.c_str();
-  if (access(filename, R_OK) != 0) {
-    return DS_ERR_SCORER_UNREADABLE;
-  }
-
-  // Check if the file format is valid to avoid KenLM throwing an exception
-  lm::ngram::ModelType model_type;
-  if (!lm::ngram::RecognizeBinary(filename, model_type)) {
-    return DS_ERR_SCORER_INVALID_LM;
+  if (!load_from_bytes){
+      // Check if file is readable to avoid KenLM throwing an exception
+      const char* filename = lm_string.c_str();
+      if (access(filename, R_OK) != 0) {
+        return DS_ERR_SCORER_UNREADABLE;
+      }
+
+      // Check if the file format is valid to avoid KenLM throwing an exception
+      lm::ngram::ModelType model_type;
+      if (!lm::ngram::RecognizeBinary(filename, model_type)) {
+        return DS_ERR_SCORER_INVALID_LM;
+      }
   }
 
   // Load the LM
   lm::ngram::Config config;
   config.load_method = util::LoadMethod::LAZY;
-  language_model_.reset(lm::ngram::LoadVirtual(filename, config));
-  max_order_ = language_model_->Order();
-
-  uint64_t package_size;
-  {
-    util::scoped_fd fd(util::OpenReadOrThrow(filename));
-    package_size = util::SizeFile(fd.get());
+  if (load_from_bytes){
+    language_model_.reset(lm::ngram::LoadVirtual(lm_string.c_str(), lm_string.size(), config));
+  } else {
+    language_model_.reset(lm::ngram::LoadVirtual(lm_string.c_str(), config));
   }
+  
+  max_order_ = language_model_->Order();
+  std::stringstream stst;
   uint64_t trie_offset = language_model_->GetEndOfSearchOffset();
-  if (package_size <= trie_offset) {
-    // File ends without a trie structure
-    return DS_ERR_SCORER_NO_TRIE;
+
+  if (!load_from_bytes){
+    uint64_t package_size;
+    {
+      util::scoped_fd fd(util::OpenReadOrThrow(lm_string.c_str()));
+      package_size = util::SizeFile(fd.get());
+    }
+
+    if (package_size <= trie_offset) {
+      // File ends without a trie structure
+      return DS_ERR_SCORER_NO_TRIE;
+    }
+    // Read metadata and trie from file
+    std::ifstream fin(lm_string.c_str(), std::ios::binary);
+    stst<<fin.rdbuf();
+  } else {
+    stst = std::stringstream(lm_string);
   }
 
-  // Read metadata and trie from file
-  std::ifstream fin(lm_path, std::ios::binary);
-  fin.seekg(trie_offset);
-  return load_trie(fin, lm_path);
+  stst.seekg(trie_offset);
+  return load_trie(stst, lm_string, load_from_bytes);
 }
 
-int Scorer::load_trie(std::ifstream& fin, const std::string& file_path)
+int Scorer::load_trie(std::stringstream& fin, const std::string& file_path, bool load_from_bytes)
 {
+
   int magic;
   fin.read(reinterpret_cast<char*>(&magic), sizeof(magic));
   if (magic != MAGIC) {
@@ -140,9 +157,13 @@ int Scorer::load_trie(std::ifstream& fin, const std::string& file_path)
   reset_params(alpha, beta);
 
   fst::FstReadOptions opt;
-  opt.mode = fst::FstReadOptions::MAP;
-  opt.source = file_path;
-  dictionary.reset(FstType::Read(fin, opt));
+  if (load_from_bytes) {
+    dictionary.reset(fst::ConstFst<fst::StdArc>::Read(fin, opt));
+  } else {
+    opt.mode = fst::FstReadOptions::MAP;
+    opt.source = file_path;
+    dictionary.reset(FstType::Read(fin, opt));
+  }
   return DS_ERR_OK;
 }
 

native_client/client.cc

@@ -39,9 +39,11 @@ class Scorer {
   Scorer& operator=(const Scorer&) = delete;
 
   int init(const std::string &lm_path,
+           bool load_from_bytes,
            const Alphabet &alphabet);
 
   int init(const std::string &lm_path,
+           bool load_from_bytes,
            const std::string &alphabet_config_path);
 
   double get_log_cond_prob(const std::vector<std::string> &words,
@@ -84,7 +86,7 @@ class Scorer {
   void fill_dictionary(const std::unordered_set<std::string> &vocabulary);
 
   // load language model from given path
-  int load_lm(const std::string &lm_path);
+  int load_lm(const std::string &lm_path, bool load_from_bytes=false);
 
   // language model weight
   double alpha = 0.;
@@ -98,7 +100,7 @@ class Scorer {
   // necessary setup after setting alphabet
   void setup_char_map();
 
-  int load_trie(std::ifstream& fin, const std::string& file_path);
+  int load_trie(std::stringstream& fin, const std::string& file_path, bool load_from_bytes=false);
 
 private:
   std::unique_ptr<lm::base::Model> language_model_;

native_client/ctcdecode/scorer.cpp

@@ -263,8 +263,9 @@ StreamingState::processBatch(const vector<float>& buf, unsigned int n_steps)
 }
 
 int
-DS_CreateModel(const char* aModelPath,
-               ModelState** retval)
+DS_CreateModel_(const std::string &aModelString,
+                bool init_from_bytes,
+                ModelState** retval)
 {
   *retval = nullptr;
 
@@ -277,7 +278,7 @@ DS_CreateModel(const char* aModelPath,
   LOGD("DeepSpeech: %s", ds_git_version());
 #endif
 
-  if (!aModelPath || strlen(aModelPath) < 1) {
+  if ( (!init_from_bytes && (strlen(aModelString) < 1)) || (init_from_bytes && (bufferSize<1))) {
     std::cerr << "No model specified, cannot continue." << std::endl;
     return DS_ERR_NO_MODEL;
   }
@@ -294,8 +295,8 @@ DS_CreateModel(const char* aModelPath,
     std::cerr << "Could not allocate model state." << std::endl;
     return DS_ERR_FAIL_CREATE_MODEL;
   }
-
-  int err = model->init(aModelPath);
+  
+  int err = model->init(aModelString, init_from_bytes, bufferSize);
   if (err != DS_ERR_OK) {
     return err;
   }
@@ -304,6 +305,22 @@ DS_CreateModel(const char* aModelPath,
   return DS_ERR_OK;
 }
 
+int
+DS_CreateModel(const char* aModelPath,
+               ModelState** retval)
+{
+  return DS_CreateModel_(aModelPath, false, retval);
+}
+
+int
+DS_CreateModelFromBuffer(const char* aModelBuffer,
+                         size_t bufferSize,
+                         ModelState** retval)
+{
+  return DS_CreateModel_(aModelBuffer, true, retval, bufferSize);
+}
+
+
 unsigned int
 DS_GetModelBeamWidth(const ModelState* aCtx)
 {
@@ -330,18 +347,41 @@ DS_FreeModel(ModelState* ctx)
 }
 
 int
-DS_EnableExternalScorer(ModelState* aCtx,
-                        const char* aScorerPath)
+DS_EnableExternalScorer_(ModelState* aCtx,
+                         const std::string &aScorerString,
+                         bool init_from_bytes)
 {
   std::unique_ptr<Scorer> scorer(new Scorer());
-  int err = scorer->init(aScorerPath, aCtx->alphabet_);
+
+  int err;
+  if (init_from_bytes)
+    err = scorer->init(std::string(aScorerString, bufferSize), init_from_bytes, aCtx->alphabet_);
+  else
+    err = scorer->init(aScorerString, init_from_bytes, aCtx->alphabet_);
+  
+  
   if (err != 0) {
     return DS_ERR_INVALID_SCORER;
   }
   aCtx->scorer_ = std::move(scorer);
   return DS_ERR_OK;
 }
 
+int
+DS_EnableExternalScorer(ModelState* aCtx,
+                        const char* aScorerPath)
+{
+  return DS_EnableExternalScorer_(aCtx, aScorerPath, false);
+}
+
+int
+DS_EnableExternalScorerFromBuffer(ModelState* aCtx,
+                                  const char* aScorerBuffer,
+                                  size_t bufferSize)
+{
+  return DS_EnableExternalScorer_(aCtx, aScorerBuffer, true, bufferSize);
+}
+
 int
 DS_AddHotWord(ModelState* aCtx,
               const char* word,