Began implementing the CBOR reader

Author: liuzicheng1987

include/rfl/cbor/Reader.hpp

@@ -1,7 +1,7 @@
 #ifndef RFL_CBOR_READER_HPP_
 #define RFL_CBOR_READER_HPP_
 
-#include <bson/bson.h>
+#include <cbor.h>
 
 #include <array>
 #include <concepts>
@@ -25,20 +25,16 @@ namespace cbor {
 
 /// Please refer to https://mongoc.org/libbson/current/api.html
 struct Reader {
-  struct CBORValue {
-    bson_value_t val_;
-  };
-
   struct CBORInputArray {
-    CBORValue* val_;
+    CborValue* val_;
   };
 
   struct CBORInputObject {
-    CBORValue* val_;
+    CborValue* val_;
   };
 
   struct CBORInputVar {
-    CBORValue* val_;
+    CborValue* val_;
   };
 
   using InputArrayType = CBORInputArray;
@@ -47,22 +43,27 @@ struct Reader {
 
   template <class T>
   static constexpr bool has_custom_constructor = (requires(InputVarType var) {
-    T::from_bson_obj(var);
+    T::from_cbor_obj(var);
   });
 
   rfl::Result<InputVarType> get_field(
       const std::string& _name, const InputObjectType& _obj) const noexcept {
-    bson_t b;
-    bson_iter_t iter;
-    const auto doc = _obj.val_->val_.value.v_doc;
-    if (bson_init_static(&b, doc.data, doc.data_len)) {
-      if (bson_iter_init(&iter, &b)) {
-        while (bson_iter_next(&iter)) {
-          auto key = std::string(bson_iter_key(&iter));
-          if (key == _name) {
-            return to_input_var(&iter);
-          }
+    CborValue val;
+    size_t length = 0;
+    auto buffer = std::vector<char>();
+    if (cbor_value_enter_container(_obj.val_, &val) != CborError) {
+      while (!cbor_value_at_end(&val)) {
+        if (!cbor_value_is_text_string(&val)) {
+          return Error("Expected the key to be a string value.");
+        }
+        cbor_value_get_string_length(&val, &length);
+        buffer.resize(length + 1);
+        buffer[length] = '\0';
+        cbor_copy_text_string(&val, buffer.data(), &length, &val);
+        if (key == buffer.data()) {
+          return to_input_var(&val);
         }
+        cbor_value_advance(&val);
       }
     }
     return Error("No field named '" + _name + "' was found.");
@@ -74,9 +75,9 @@ struct Reader {
 
   template <class T>
   rfl::Result<T> to_basic_type(const InputVarType& _var) const noexcept {
-    const auto btype = _var.val_->val_.value_type;
-    const auto value = _var.val_->val_.value;
     if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
+      const auto btype = _var.val_->val_.value_type;
+
       switch (btype) {
         case CBOR_TYPE_UTF8:
           return std::string(value.v_utf8.str, value.v_utf8.len);
@@ -89,10 +90,12 @@ struct Reader {
               "Could not cast to string. The type must be UTF8 or symbol.");
       }
     } else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
-      if (btype != CBOR_TYPE_BOOL) {
+      if (!cbor_value_is_boolean(_var->val_)) {
         return rfl::Error("Could not cast to boolean.");
       }
-      return value.v_bool;
+      bool result = false;
+      cbor_value_get_boolean(_var->val_, &result);
+      return result;
     } else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>() ||
                          std::is_integral<std::remove_cvref_t<T>>()) {
       switch (btype) {
@@ -193,33 +196,22 @@ struct Reader {
   rfl::Result<T> use_custom_constructor(
       const InputVarType& _var) const noexcept {
     try {
-      return T::from_bson_obj(_var);
+      return T::from_cbor_obj(_var);
     } catch (std::exception& e) {
       return rfl::Error(e.what());
     }
   }
 
  private:
-  struct CBORValues {
-    std::vector<rfl::Box<CBORValue>> vec_;
-    ~CBORValues() {
-      for (auto& v : vec_) {
-        bson_value_destroy(&(v->val_));
-      }
-    }
-  };
-
- private:
-  InputVarType to_input_var(bson_iter_t* _iter) const noexcept {
-    values_->vec_.emplace_back(rfl::Box<CBORValue>::make());
+  InputVarType to_input_var(CborValur* _ptr) const noexcept {
+    values_->emplace_back(rfl::Box<CborValue>::make(*_ptr));
     auto* last_value = values_->vec_.back().get();
-    bson_value_copy(bson_iter_value(_iter), &last_value->val_);
     return InputVarType{last_value};
   }
 
  private:
   /// Contains the values inside the object.
-  rfl::Ref<CBORValues> values_;
+  rfl::Box<std::vector<rfl::Box<CborValue>>> values_;
 };
 
 }  // namespace cbor