weh

include/rfl/flexbuf/Parser.hpp

@@ -0,0 +1,17 @@
+#ifndef FLEXBUF_PARSER_HPP_
+#define FLEXBUF_PARSER_HPP_
+
+#include "../parsing/Parser.hpp"
+#include "Reader.hpp"
+#include "Writer.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+template <class T, class ProcessorsType>
+using Parser = parsing::Parser<Reader, Writer, T, ProcessorsType>;
+
+}
+}  // namespace rfl
+
+#endif

include/rfl/flexbuf/Reader.hpp

@@ -0,0 +1,145 @@
+#ifndef FLEXBUF_READER_HPP_
+#define FLEXBUF_READER_HPP_
+
+#include <flatbuffers/flexbuffers.h>
+
+#include <exception>
+#include <map>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <vector>
+
+#include "../Result.hpp"
+#include "../always_false.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+struct Reader {
+  using InputArrayType = flexbuffers::Vector;
+  using InputObjectType = flexbuffers::Map;
+  using InputVarType = flexbuffers::Reference;
+
+  template <class T, class = void>
+  struct has_from_flexbuf : std::false_type {};
+
+  template <class T>
+  struct has_from_flexbuf<
+      T, std::enable_if_t<std::is_invocable_r<T, decltype(T::from_flexbuf),
+                                              InputVarType>::value>>
+      : std::true_type {};
+
+  template <class T>
+  struct has_from_flexbuf<
+      T, std::enable_if_t<std::is_invocable_r<
+             rfl::Result<T>, decltype(T::from_flexbuf), InputVarType>::value>>
+      : std::true_type {};
+
+  template <class T>
+  static constexpr bool has_custom_constructor = has_from_flexbuf<T>::value;
+
+  rfl::Result<InputVarType> get_field(
+      const std::string& _name, const InputObjectType& _obj) const noexcept {
+    const auto keys = _obj.Keys();
+    for (size_t i = 0; i < keys.size(); ++i) {
+      if (_name == keys[i].AsString().c_str()) {
+        return _obj.Values()[i];
+      }
+    }
+    return rfl::Error("Map does not contain any element called '" + _name +
+                      "'.");
+  }
+
+  bool is_empty(const InputVarType& _var) const noexcept {
+    return _var.IsNull();
+  }
+
+  template <class T>
+  rfl::Result<T> to_basic_type(const InputVarType& _var) const noexcept {
+    if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
+      if (!_var.IsString()) {
+        return rfl::Error("Could not cast to string.");
+      }
+      return std::string(_var.AsString().c_str());
+    } else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
+      if (!_var.IsBool()) {
+        return rfl::Error("Could not cast to boolean.");
+      }
+      return _var.AsBool();
+    } else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>()) {
+      if (!_var.IsNumeric()) {
+        return rfl::Error("Could not cast to double.");
+      }
+      return static_cast<T>(_var.AsDouble());
+    } else if constexpr (std::is_integral<std::remove_cvref_t<T>>()) {
+      if (!_var.IsNumeric()) {
+        return rfl::Error("Could not cast to int.");
+      }
+      return static_cast<T>(_var.AsInt64());
+    } else {
+      static_assert(rfl::always_false_v<T>, "Unsupported type.");
+    }
+  }
+
+  template <class ArrayReader>
+  std::optional<Error> read_array(const ArrayReader& _array_reader,
+                                  const InputArrayType& _arr) const noexcept {
+    const auto size = _arr.size();
+    for (size_t i = 0; i < size; ++i) {
+      const auto err = _array_reader.read(InputVarType(_arr[i]));
+      if (err) {
+        return err;
+      }
+    }
+    return std::nullopt;
+  }
+
+  template <class ObjectReader>
+  std::optional<Error> read_object(const ObjectReader& _object_reader,
+                                   const InputObjectType& _obj) const noexcept {
+    const auto keys = _obj.Keys();
+    const auto values = _obj.Values();
+    const auto num_values = std::min(keys.size(), values.size());
+
+    for (size_t i = 0; i < num_values; ++i) {
+      _object_reader.read(std::string_view(keys[i].AsString().c_str()),
+                          values[i]);
+    }
+
+    return std::nullopt;
+  }
+
+  rfl::Result<InputArrayType> to_array(
+      const InputVarType& _var) const noexcept {
+    if (!_var.IsVector()) {
+      return rfl::Error("Could not cast to Vector.");
+    }
+    return _var.AsVector();
+  }
+
+  rfl::Result<InputObjectType> to_object(
+      const InputVarType& _var) const noexcept {
+    if (!_var.IsMap()) {
+      return rfl::Error("Could not cast to Map!");
+    }
+    return _var.AsMap();
+  }
+
+  template <class T>
+  rfl::Result<T> use_custom_constructor(
+      const InputVarType& _var) const noexcept {
+    try {
+      return T::from_flexbuf(_var);
+    } catch (std::exception& e) {
+      return rfl::Error(e.what());
+    }
+  }
+};
+
+}  // namespace flexbuf
+}  // namespace rfl
+
+#endif

include/rfl/flexbuf/Writer.hpp

@@ -0,0 +1,176 @@
+#ifndef FLEXBUF_WRITER_HPP_
+#define FLEXBUF_WRITER_HPP_
+
+#include <flatbuffers/flexbuffers.h>
+
+#include <exception>
+#include <functional>
+#include <map>
+#include <optional>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <vector>
+
+#include "../Ref.hpp"
+#include "../Result.hpp"
+#include "../always_false.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+struct Writer {
+  struct OutputArray {
+    size_t start_;
+  };
+
+  struct OutputObject {
+    size_t start_;
+  };
+
+  struct OutputVar {};
+
+  using OutputArrayType = OutputArray;
+  using OutputObjectType = OutputObject;
+  using OutputVarType = OutputVar;
+
+  Writer(const Ref<flexbuffers::Builder>& _fbb) : fbb_(_fbb) {}
+
+  ~Writer() = default;
+
+  OutputArrayType array_as_root(const size_t _size) const noexcept {
+    return new_array();
+  }
+
+  OutputObjectType object_as_root(const size_t _size) const noexcept {
+    return new_object();
+  }
+
+  OutputVarType null_as_root() const noexcept {
+    fbb_->Null();
+    return OutputVarType{};
+  }
+
+  template <class T>
+  OutputVarType value_as_root(const T& _var) const noexcept {
+    return insert_value(_var);
+  }
+
+  OutputArrayType add_array_to_array(const size_t _size,
+                                     OutputArrayType* _parent) const noexcept {
+    return new_array();
+  }
+
+  OutputArrayType add_array_to_object(
+      const std::string_view& _name, const size_t _size,
+      OutputObjectType* _parent) const noexcept {
+    return new_array(_name);
+  }
+
+  OutputObjectType add_object_to_array(
+      const size_t _size, OutputArrayType* _parent) const noexcept {
+    return new_object();
+  }
+
+  OutputObjectType add_object_to_object(
+      const std::string_view& _name, const size_t _size,
+      OutputObjectType* _parent) const noexcept {
+    return new_object(_name);
+  }
+
+  template <class T>
+  OutputVarType add_value_to_array(const T& _var,
+                                   OutputArrayType* _parent) const noexcept {
+    return insert_value(_var);
+  }
+
+  template <class T>
+  OutputVarType add_value_to_object(const std::string_view& _name,
+                                    const T& _var,
+                                    OutputObjectType* _parent) const noexcept {
+    return insert_value(_name, _var);
+  }
+
+  OutputVarType add_null_to_array(OutputArrayType* _parent) const noexcept {
+    fbb_->Null();
+    return OutputVarType{};
+  }
+
+  OutputVarType add_null_to_object(const std::string_view& _name,
+                                   OutputObjectType* _parent) const noexcept {
+    fbb_->Null(_name.data());
+    return OutputVarType{};
+  }
+
+  void end_array(OutputArrayType* _arr) const noexcept {
+    fbb_->EndVector(_arr->start_, false, false);
+  }
+
+  void end_object(OutputObjectType* _obj) const noexcept {
+    fbb_->EndMap(_obj->start_);
+  }
+
+ private:
+  template <class T>
+  OutputVarType insert_value(const std::string_view& _name,
+                             const T& _var) const noexcept {
+    if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
+      fbb_->String(_name.data(), _var);
+    } else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
+      fbb_->Bool(_name.data(), _var);
+    } else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>()) {
+      fbb_->Double(_name.data(), _var);
+    } else if constexpr (std::is_integral<std::remove_cvref_t<T>>()) {
+      fbb_->Int(_name.data(), _var);
+    } else {
+      static_assert(always_false_v<T>, "Unsupported type");
+    }
+    return OutputVarType{};
+  }
+
+  template <class T>
+  OutputVarType insert_value(const T& _var) const noexcept {
+    if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
+      fbb_->String(_var);
+    } else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
+      fbb_->Bool(_var);
+    } else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>()) {
+      fbb_->Double(_var);
+    } else if constexpr (std::is_integral<std::remove_cvref_t<T>>()) {
+      fbb_->Int(_var);
+    } else {
+      static_assert(always_false_v<T>, "Unsupported type");
+    }
+    return OutputVarType{};
+  }
+
+  OutputArrayType new_array(const std::string_view& _name) const noexcept {
+    const auto start = fbb_->StartVector(_name.data());
+    return OutputArrayType{start};
+  }
+
+  OutputArrayType new_array() const noexcept {
+    const auto start = fbb_->StartVector();
+    return OutputArrayType{start};
+  }
+
+  OutputObjectType new_object(const std::string_view& _name) const noexcept {
+    const auto start = fbb_->StartMap(_name.data());
+    return OutputObjectType{start};
+  }
+
+  OutputObjectType new_object() const noexcept {
+    const auto start = fbb_->StartMap();
+    return OutputObjectType{start};
+  }
+
+ private:
+  Ref<flexbuffers::Builder> fbb_;
+};
+
+}  // namespace flexbuf
+}  // namespace rfl
+
+#endif

include/rfl/flexbuf/load.hpp

@@ -0,0 +1,22 @@
+#ifndef RFL_FLEXBUF_LOAD_HPP_
+#define RFL_FLEXBUF_LOAD_HPP_
+
+#include "../Result.hpp"
+#include "../io/load_bytes.hpp"
+#include "read.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+template <class T, class... Ps>
+Result<T> load(const std::string& _fname) {
+  const auto read_bytes = [](const auto& _bytes) {
+    return read<T, Ps...>(_bytes);
+  };
+  return rfl::io::load_bytes(_fname).and_then(read_bytes);
+}
+
+}  // namespace flexbuf
+}  // namespace rfl
+
+#endif

include/rfl/flexbuf/read.hpp

@@ -0,0 +1,50 @@
+#ifndef FLEXBUF_READ_HPP_
+#define FLEXBUF_READ_HPP_
+
+#include <flatbuffers/flexbuffers.h>
+
+#include <istream>
+#include <vector>
+
+#include "../Processors.hpp"
+#include "../Result.hpp"
+#include "Parser.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+using InputVarType = typename Reader::InputVarType;
+
+/// Parses an object from flexbuf var.
+template <class T, class... Ps>
+auto read(const InputVarType& _obj) {
+  const auto r = Reader();
+  return Parser<T, Processors<Ps...>>::read(r, _obj);
+}
+
+/// Parses an object from flexbuf using reflection.
+template <class T, class... Ps>
+auto read(const char* _bytes, const size_t _size) {
+  const InputVarType root =
+      flexbuffers::GetRoot(reinterpret_cast<const uint8_t*>(_bytes), _size);
+  return read<T, Ps...>(root);
+}
+
+/// Parses an object from flexbuf using reflection.
+template <class T, class... Ps>
+auto read(const std::vector<char>& _bytes) {
+  return read<T, Ps...>(_bytes.data(), _bytes.size());
+}
+
+/// Parses an object directly from a stream.
+template <class T, class... Ps>
+auto read(std::istream& _stream) {
+  std::istreambuf_iterator<char> begin(_stream), end;
+  const auto bytes = std::vector<char>(begin, end);
+  return read<T, Ps...>(bytes.data(), bytes.size());
+}
+
+}  // namespace flexbuf
+}  // namespace rfl
+
+#endif

include/rfl/flexbuf/save.hpp

@@ -0,0 +1,26 @@
+#ifndef RFL_FLEXBUF_SAVE_HPP_
+#define RFL_FLEXBUF_SAVE_HPP_
+
+#include <fstream>
+#include <iostream>
+#include <string>
+
+#include "../Result.hpp"
+#include "../io/save_bytes.hpp"
+#include "write.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+template <class... Ps>
+Result<Nothing> save(const std::string& _fname, const auto& _obj) {
+  const auto write_func = [](const auto& _obj, auto& _stream) -> auto& {
+    return write<Ps...>(_obj, _stream);
+  };
+  return rfl::io::save_bytes(_fname, _obj, write_func);
+}
+
+}  // namespace flexbuf
+}  // namespace rfl
+
+#endif

include/rfl/flexbuf/write.hpp

@@ -0,0 +1,50 @@
+#ifndef FLEXBUF_WRITE_HPP_
+#define FLEXBUF_WRITE_HPP_
+
+#include <flatbuffers/flexbuffers.h>
+
+#include <cstddef>
+#include <ostream>
+#include <sstream>
+#include <vector>
+
+#include "../Processors.hpp"
+#include "../Ref.hpp"
+#include "../parsing/Parent.hpp"
+#include "Parser.hpp"
+
+namespace rfl {
+namespace flexbuf {
+
+template <class... Ps>
+std::vector<uint8_t> to_buffer(const auto& _obj) {
+  using T = std::remove_cvref_t<decltype(_obj)>;
+  using ParentType = parsing::Parent<Writer>;
+  const auto fbb = Ref<flexbuffers::Builder>::make();
+  auto w = Writer(fbb);
+  Parser<T, Processors<Ps...>>::write(w, _obj, typename ParentType::Root{});
+  fbb->Finish();
+  return fbb->GetBuffer();
+}
+
+/// Writes an object to flexbuf.
+template <class... Ps>
+std::vector<char> write(const auto& _obj) {
+  const auto buffer = to_buffer<Ps...>(_obj);
+  const auto data = reinterpret_cast<const char*>(buffer.data());
+  return std::vector<char>(data, data + buffer.size());
+}
+
+/// Writes an object to an ostream.
+template <class... Ps>
+std::ostream& write(const auto& _obj, std::ostream& _stream) {
+  const auto buffer = to_buffer<Ps...>(_obj);
+  const auto data = reinterpret_cast<const char*>(buffer.data());
+  _stream.write(data, buffer.size());
+  return _stream;
+}
+
+}  // namespace flexbuf
+}  // namespace rfl
+
+#endif