archive_binary_field_max_size_calculator.h

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#ifndef MYSQL_SERIALIZATION_ARCHIVE_BINARY_FIELD_MAX_SIZE_CALCULATOR_H
#define MYSQL_SERIALIZATION_ARCHIVE_BINARY_FIELD_MAX_SIZE_CALCULATOR_H
 
#include <sstream>
 
#include "mysql/serialization/primitive_type_codec.h"
#include "mysql/serialization/serializable_type_traits.h"
#include "mysql/serialization/serialization_types.h"
 
/// @file
/// Experimental API header
 
/// @addtogroup GroupLibsMysqlSerialization
/// @{
 
namespace mysql::serialization {
 
/// @brief helper structure created for partial specialization of get_max_size
/// function of Archive_binary, default version
template <class T, Field_size S>
struct Archive_binary_field_max_size_calculator {
  /// @brief Calculates maximum encoded size of the fixed-length integer and
  /// floating point fields
  /// @return maximum encoded byte length
  static constexpr std::size_t get_max_size() { return S; }
};
 
/// @brief helper structure created for partial specialization of get_max_size
/// function of Archive_binary, specialization for defined size equal to 0.
/// 0 means default maximum size: for std::string default maximum size is
/// unlimited, for variable length integer - sizeof(Type)+1, for double Type
/// it equals to sizeof(Type)
/// For unlimited strings, get_max_size is disabled (code won't compile)
/// @tparam T type of field
template <class T>
struct Archive_binary_field_max_size_calculator<T, 0> {
  /// @brief Calculates maximum encoded size of the
  /// variable-length integer fields
  /// @return maximum encoded byte length
  template <typename = std::enable_if_t<is_string_type<T>() == false>>
  static constexpr std::size_t get_max_size() {
    return sizeof(T) + is_integral_type<T>();  // + 1 for variable length
  }
};
 
/// @brief helper structure created for partial specialization of get_max_size
/// function of Archive_binary, version for std::string fields
/// @tparam S Bound size for the string field
template <Field_size S>
struct Archive_binary_field_max_size_calculator<std::string, S> {
  /// @brief Calculates maximum encoded size of the bounded
  /// std::string field
  /// @return maximum encoded byte length
  static constexpr std::size_t get_max_size() {
    return S + Archive_binary_field_max_size_calculator<uint64_t,
                                                        0>::get_max_size();
  }
};
 
}  // namespace mysql::serialization
 
/// @}
 
#endif  // MYSQL_SERIALIZATION_ARCHIVE_BINARY_FIELD_MAX_SIZE_CALCULATOR_H