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#ifndef RFL_BSON_WRITER_HPP_
#define RFL_BSON_WRITER_HPP_
#include <bson/bson.h>
#include <cstddef>
#include <exception>
#include <map>
#include <sstream>
#include <stdexcept>
#include <string>
#include <string_view>
#include <type_traits>
#include <variant>
#include <vector>
#include "../Box.hpp"
#include "../Bytestring.hpp"
#include "../Ref.hpp"
#include "../Result.hpp"
#include "../always_false.hpp"
#include "../internal/ptr_cast.hpp"
namespace rfl {
namespace bson {
/// Please refer to https://mongoc.org/libbson/current/api.html
class Writer {
struct BSONType {
bson_t val_;
};
struct IsArray {
bson_array_builder_t* ptr_;
};
struct IsObject {
bson_t* ptr_;
};
struct IsRoot {};
using ParentType = std::variant<IsArray, IsObject, IsRoot>;
public:
struct BSONOutputArray {
BSONOutputArray(bson_array_builder_t* _val, ParentType _parent)
: parent_(_parent), val_(_val) {}
ParentType parent_;
bson_array_builder_t* val_;
};
struct BSONOutputObject {
BSONOutputObject(bson_t* _val, ParentType _parent)
: parent_(_parent), val_(_val) {}
ParentType parent_;
bson_t* val_;
};
struct BSONOutputVar {};
using OutputArrayType = BSONOutputArray;
using OutputObjectType = BSONOutputObject;
using OutputVarType = BSONOutputVar;
Writer(bson_t* _doc);
~Writer();
OutputArrayType array_as_root(const size_t _size) const noexcept;
OutputObjectType object_as_root(const size_t _size) const noexcept;
OutputVarType null_as_root() const noexcept;
template <class T>
OutputVarType value_as_root(const T& _var) const noexcept {
static_assert(rfl::always_false_v<T>,
"BSON only allows arrays or objects as its root.");
return OutputVarType{};
}
OutputArrayType add_array_to_array(const size_t _size,
OutputArrayType* _parent) const noexcept;
OutputArrayType add_array_to_object(const std::string_view& _name,
const size_t _size,
OutputObjectType* _parent) const noexcept;
OutputObjectType add_object_to_array(const size_t _size,
OutputArrayType* _parent) const noexcept;
OutputObjectType add_object_to_object(
const std::string_view& _name, const size_t _size,
OutputObjectType* _parent) const noexcept;
template <class T>
OutputVarType add_value_to_array(const T& _var,
OutputArrayType* _parent) const noexcept {
if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
bson_array_builder_append_utf8(_parent->val_, _var.c_str(),
static_cast<int>(_var.size()));
} else if constexpr (std::is_same<std::remove_cvref_t<T>,
rfl::Bytestring>()) {
bson_array_builder_append_binary(
_parent->val_, BSON_SUBTYPE_BINARY,
internal::ptr_cast<const uint8_t*>(_var.c_str()),
static_cast<uint32_t>(_var.size()));
} else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
bson_array_builder_append_bool(_parent->val_, _var);
} else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>()) {
bson_array_builder_append_double(_parent->val_,
static_cast<double>(_var));
} else if constexpr (std::is_integral<std::remove_cvref_t<T>>()) {
bson_array_builder_append_int64(_parent->val_,
static_cast<std::int64_t>(_var));
} else if constexpr (std::is_same<std::remove_cvref_t<T>, bson_oid_t>()) {
bson_array_builder_append_oid(_parent->val_, &_var);
} else {
static_assert(rfl::always_false_v<T>, "Unsupported type.");
}
return OutputVarType{};
}
template <class T>
OutputVarType add_value_to_object(const std::string_view& _name,
const T& _var,
OutputObjectType* _parent) const noexcept {
if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
bson_append_utf8(_parent->val_, _name.data(),
static_cast<int>(_name.size()), _var.c_str(),
static_cast<int>(_var.size()));
} else if constexpr (std::is_same<std::remove_cvref_t<T>,
rfl::Bytestring>()) {
bson_append_binary(_parent->val_, _name.data(),
static_cast<int>(_name.size()), BSON_SUBTYPE_BINARY,
internal::ptr_cast<const uint8_t*>(_var.c_str()),
static_cast<uint32_t>(_var.size()));
} else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
bson_append_bool(_parent->val_, _name.data(),
static_cast<int>(_name.size()), _var);
} else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>()) {
bson_append_double(_parent->val_, _name.data(),
static_cast<int>(_name.size()),
static_cast<double>(_var));
} else if constexpr (std::is_integral<std::remove_cvref_t<T>>()) {
bson_append_int64(_parent->val_, _name.data(),
static_cast<int>(_name.size()),
static_cast<std::int64_t>(_var));
} else if constexpr (std::is_same<std::remove_cvref_t<T>, bson_oid_t>()) {
bson_append_oid(_parent->val_, _name.data(),
static_cast<int>(_name.size()), &_var);
} else {
static_assert(rfl::always_false_v<T>, "Unsupported type.");
}
return OutputVarType{};
}
OutputVarType add_null_to_array(OutputArrayType* _parent) const noexcept;
OutputVarType add_null_to_object(const std::string_view& _name,
OutputObjectType* _parent) const noexcept;
void end_array(OutputArrayType* _arr) const noexcept;
void end_object(OutputObjectType* _obj) const noexcept;
private:
/// Pointer to the main document. In BSON, documents are what are usually
/// called objects.
bson_t* const doc_;
/// Contain all of the subdocuments.
const rfl::Ref<std::vector<rfl::Box<BSONType>>> subdocs_;
};
} // namespace bson
} // namespace rfl
#endif
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