Change the native code to use stream interfaces

Signed-off-by: Vadim Markovtsev <vadim@sourced.tech>

youtokentome/cpp/bpe.cpp

@@ -865,7 +865,7 @@ void rename_tokens(ska::flat_hash_map<uint32_t, uint32_t> &char2id,
 }
 
 BPEState learn_bpe_from_string(string &text_utf8, int n_tokens,
-                               const string &output_file,
+                               StreamWriter &output,
                                BpeConfig bpe_config) {
   vector<std::thread> threads;
   assert(bpe_config.n_threads >= 1 || bpe_config.n_threads == -1);
@@ -1294,8 +1294,8 @@ BPEState learn_bpe_from_string(string &text_utf8, int n_tokens,
   rename_tokens(char2id, rules, bpe_config.special_tokens, n_tokens);
 
   BPEState bpe_state = {char2id, rules, bpe_config.special_tokens};
-  bpe_state.dump(output_file);
-  std::cerr << "model saved to: " << output_file << std::endl;
+  bpe_state.dump(output);
+  std::cerr << "model saved to: " << output.name() << std::endl;
   return bpe_state;
 }
 
@@ -1450,7 +1450,8 @@ void train_bpe(const string &input_path, const string &model_path,
   std::cerr << "reading file..." << std::endl;
   auto data = fast_read_file_utf8(input_path);
   std::cerr << "learning bpe..." << std::endl;
-  learn_bpe_from_string(data, vocab_size, model_path, bpe_config);
+  auto fout = StreamWriter.open(model_path);
+  learn_bpe_from_string(data, vocab_size, fout, bpe_config);
 }
 
 DecodeResult BaseEncoder::encode_sentence(const std::string &sentence_utf8,

youtokentome/cpp/bpe.h

@@ -32,7 +32,7 @@ class BaseEncoder {
 
   explicit BaseEncoder(BPEState bpe_state, int _n_threads);
 
-  explicit BaseEncoder(const std::string& model_path, int n_threads);
+  explicit BaseEncoder(const StreamReader& model_path, int n_threads);
 
   void fill_from_state();
 

youtokentome/cpp/utils.cpp

@@ -11,6 +11,62 @@ namespace vkcom {
 using std::string;
 using std::vector;
 
+class FileWriter : public StreamWriter {
+ public:
+  FileWriter(const std::string &file_name) {
+    this->file_name = file_name;
+    this->fout = std::ofstream(file_name, std::ios::out | std::ios::binary);
+    if (fout.fail()) {
+      std::cerr << "Can't open file: " << file_name << std::endl;
+      assert(false);
+    }
+  }
+
+  virtual int write(const char *buffer, int size) override {
+    return fout.write(buffer, size);
+  }
+
+  virtual std::string name() const noexcept override {
+    return file_name;
+  }
+
+ private:
+  std::string file_name;
+  std::ofstream fout;
+};
+
+class FileReader : public StreamReader {
+ public:
+  FileReader(const std::string &file_name) {
+    this->file_name = file_name;
+    this->fin = std::ifstream(file_name, std::ios::in | std::ios::binary);
+    if (fin.fail()) {
+      std::cerr << "Can't open file: " << file_name << std::endl;
+      assert(false);
+    }
+  }
+
+  virtual int read(const char *buffer, int size) override {
+    return fin.read(buffer, size);
+  }
+
+  virtual std::string name() const noexcept override {
+    return file_name;
+  }
+
+ private:
+  std::string file_name;
+  std::ifstream fin;
+};
+
+StreamWriter StreamWriter::open(const std::string &file_name) {
+  return FileWriter(file_name);
+}
+
+StreamReader StreamReader::open(const std::string &file_name) {
+  return FileReader(file_name);
+}
+
 template<typename T, typename std::enable_if<std::is_integral<T>::value, int>::type = 0>
 T bin_to_int(const char *val) {
   uint32_t ret = static_cast<unsigned char>(val[0]);
@@ -31,7 +87,7 @@ std::unique_ptr<char[]> int_to_bin(T val) {
   return std::move(ret);
 }
 
-void SpecialTokens::dump(std::ofstream &fout) {
+void SpecialTokens::dump(StreamWriter &fout) {
   std::unique_ptr<char[]> unk_id_ptr(int_to_bin(unk_id)),
                           pad_id_ptr(int_to_bin(pad_id)),
                           bos_id_ptr(int_to_bin(bos_id)),
@@ -42,7 +98,7 @@ void SpecialTokens::dump(std::ofstream &fout) {
   fout.write(eos_id_ptr.get(), 4);
 }
 
-void SpecialTokens::load(std::ifstream &fin) {
+void SpecialTokens::load(StreamReader &fin) {
   char unk_id_bs[4], pad_id_bs[4], bos_id_bs[4], eos_id_bs[4];
   fin.read(unk_id_bs, 4);
   fin.read(pad_id_bs, 4);
@@ -85,13 +141,7 @@ bool BPE_Rule::operator==(const BPE_Rule &other) const {
 
 BPE_Rule::BPE_Rule(uint32_t x, uint32_t y, uint32_t z) : x(x), y(y), z(z) {}
 
-void BPEState::dump(const string &file_name) {
-  std::ofstream fout(file_name, std::ios::out | std::ios::binary);
-  if (fout.fail()) {
-    std::cerr << "Can't open file: " << file_name << std::endl;
-    assert(false);
-  }
-
+void BPEState::dump(StreamWriter &fout) {
   std::unique_ptr<char[]> char2id_ptr(int_to_bin(char2id.size())),
                           rules_ptr(int_to_bin(rules.size()));
   fout.write(char2id_ptr.get(), 4);
@@ -115,18 +165,11 @@ void BPEState::dump(const string &file_name) {
     fout.write(rule_ptr.get(), 4);
   }
   special_tokens.dump(fout);
-  fout.close();
 }
 
-void BPEState::load(const string &file_name) {
+void BPEState::load(StreamReader &fin) {
   char2id.clear();
   rules.clear();
-  std::ifstream fin(file_name, std::ios::in | std::ios::binary);
-  if (fin.fail()) {
-    std::cerr << "Error. Can not open file with model: " << file_name
-              << std::endl;
-    exit(EXIT_FAILURE);
-  }
   char n_bs[4], m_bs[4];
   fin.read(n_bs, 4);
   fin.read(m_bs, 4);
@@ -161,7 +204,6 @@ void BPEState::load(const string &file_name) {
     rules.emplace_back(std::get<0>(rules_xyz[i]), std::get<1>(rules_xyz[i]), std::get<2>(rules_xyz[i]));
   }
   special_tokens.load(fin);
-  fin.close();
 }
 
 BpeConfig::BpeConfig(double _character_coverage, int _n_threads,

youtokentome/cpp/utils.h

@@ -8,6 +8,22 @@
 namespace vkcom {
 const uint32_t SPACE_TOKEN = 9601;
 
+struct StreamWriter {
+  virtual int write(const char *buffer, int size) = 0;
+  virtual std::string name() const noexcept = 0;
+  virtual ~StreamWriter() = default;
+
+  static StreamWriter open(const std::string &file_name);
+};
+
+struct StreamReader {
+  virtual int read(const char *buffer, int size) = 0;
+  virtual std::string name() const noexcept = 0;
+  virtual ~StreamReader() = default;
+
+  static StreamReader open(const std::string &file_name);
+};
+
 struct BPE_Rule {
   // x + y -> z
   uint32_t x{0};
@@ -31,9 +47,9 @@ struct SpecialTokens {
 
   SpecialTokens(int pad_id, int unk_id, int bos_id, int eos_id);
 
-  void dump(std::ofstream &fout);
+  void dump(StreamWriter &fout);
 
-  void load(std::ifstream &fin);
+  void load(StreamReader &fin);
 
   uint32_t max_id() const;
 
@@ -58,9 +74,9 @@ struct BPEState {
   std::vector<BPE_Rule> rules;
   SpecialTokens special_tokens;
 
-  void dump(const std::string &file_name);
+  void dump(StreamWriter &fout);
 
-  void load(const std::string &file_name);
+  void load(StreamReader &fin);
 };
 
 struct DecodeResult {

youtokentome/youtokentome.py

@@ -1,22 +1,32 @@
 from enum import Enum
-from typing import List, Union
+from functools import wraps
+from typing import BinaryIO, List, Optional, Union
 
 import _youtokentome_cython
 
+
 class OutputType(Enum):
     ID = 1
     SUBWORD = 2
 
+
 class BPE:
-    def __init__(self, model: str, n_threads: int = -1):
-        self.bpe_cython = _youtokentome_cython.BPE(
-            model_path=model, n_threads=n_threads
-        )
+    def __init__(self, model: Union[str, BinaryIO], n_threads: int = -1):
+        own_obj = isinstance(model, str)
+        if own_obj:
+            model = open(model, "rb")
+        try:
+            self.bpe_cython = _youtokentome_cython.BPE(
+                model_fobj=model, n_threads=n_threads
+            )
+        finally:
+            if own_obj:
+                model.close()
 
     @staticmethod
     def train(
         data: str,
-        model: str,
+        model: Optional[Union[str, BinaryIO]],
         vocab_size: int,
         coverage: float = 1.0,
         n_threads: int = -1,
@@ -25,17 +35,24 @@ def train(
         bos_id: int = 2,
         eos_id: int = 3,
     ) -> "BPE":
-        _youtokentome_cython.BPE.train(
-            data=data,
-            model=model,
-            vocab_size=vocab_size,
-            n_threads=n_threads,
-            coverage=coverage,
-            pad_id=pad_id,
-            unk_id=unk_id,
-            bos_id=bos_id,
-            eos_id=eos_id,
-        )
+        own_obj = isinstance(model, str)
+        if own_obj:
+            model = open(model, "wb")
+        try:
+            _youtokentome_cython.BPE.train(
+                data=data,
+                model=model,
+                vocab_size=vocab_size,
+                n_threads=n_threads,
+                coverage=coverage,
+                pad_id=pad_id,
+                unk_id=unk_id,
+                bos_id=bos_id,
+                eos_id=eos_id,
+            )
+        finally:
+            if own_obj:
+                model.close()
 
         return BPE(model=model, n_threads=n_threads)
 
@@ -61,6 +78,22 @@ def encode(
             reverse=reverse,
         )
 
+    def save(self, where: Union[str, BinaryIO]):
+        """
+        Write the model to FS or any writeable file object.
+
+        :param where: FS path or writeable file object.
+        :return: None
+        """
+        own_obj = isinstance(where, str)
+        if own_obj:
+            where = open(where, "wb")
+        try:
+            self.bpe_cython.save(where=where)
+        finally:
+            if own_obj:
+                where.close()
+
     def vocab_size(self) -> int:
         return self.bpe_cython.vocab_size()