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unison/src/core/model/tuple.h

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/*
* Copyright (c) 2021 Universita' degli Studi di Napoli Federico II
*
* SPDX-License-Identifier: GPL-2.0-only
*
* Author: Stefano Avallone <stavallo@unina.it>
*/
#ifndef TUPLE_H
#define TUPLE_H
#include "attribute-helper.h"
#include "string.h"
#include <algorithm>
#include <sstream>
#include <tuple>
#include <type_traits>
#include <utility>
namespace ns3
{
/**
* @brief Stream insertion operator.
* See https://en.cppreference.com/w/cpp/utility/apply
*
* Prints tuple values separated by a comma. E.g., if the tuple contains
* v1, v2 and v3, then "v1, v2, v3" will be added to the stream.
*
* @tparam Args \deduced Tuple arguments
* @param os the output stream
* @param t the tuple
* @returns a reference to the stream
*/
template <class... Args>
std::ostream&
operator<<(std::ostream& os, const std::tuple<Args...>& t)
{
std::apply(
[&os](auto&&... args) {
std::size_t n{0};
((os << args << (++n != sizeof...(Args) ? ", " : "")), ...);
},
t);
return os;
}
/**
* @ingroup attributes
* @defgroup attribute_Tuple Tuple Attribute
* AttributeValue implementation for Tuple
*/
/**
* @ingroup attribute_Tuple
*
* AttributeValue implementation for Tuple.
*
* Hold objects of type std::tuple<Args...>.
* @tparam Args \explicit The list of AttributeValues to be held by this TupleValue
*
* @see AttributeValue
*/
template <class... Args>
class TupleValue : public AttributeValue
{
public:
/** Type of value stored in the TupleValue. */
typedef std::tuple<Args...> value_type;
/** Type returned by Get or passed in Set. */
typedef std::tuple<std::invoke_result_t<decltype(&Args::Get), Args>...> result_type;
TupleValue();
/**
* Construct this TupleValue from a std::tuple
*
* @param [in] value Value with which to construct.
*/
TupleValue(const result_type& value);
Ptr<AttributeValue> Copy() const override;
bool DeserializeFromString(std::string value, Ptr<const AttributeChecker> checker) override;
std::string SerializeToString(Ptr<const AttributeChecker> checker) const override;
/**
* Get the stored values as a std::tuple.
*
* This differs from the actual value stored in the object which is
* a tuple of Ptr<AV> where AV is a class derived from AttributeValue.
* @return stored values as a std::tuple
*/
result_type Get() const;
/**
* Set the stored values.
*
* @param value The stored value
*/
void Set(const result_type& value);
/**
* Get the attribute values as a tuple.
* @return the attribute values as a tuple
*/
value_type GetValue() const;
/**
* Set the given variable to the values stored by this TupleValue object.
*
* @tparam T \deduced the type of the given variable (normally, the argument type
* of a set method or the type of a data member)
* @param [out] value The stored value
* @return true if the given variable was set
*/
template <typename T>
bool GetAccessor(T& value) const;
private:
/**
* Set the attribute values starting from the given values.
* Used by DeserializeFromString method.
*
* @tparam Is \deduced index sequence
* @param values the given attribute values
* @return true if the attribute values of this object were set
*/
template <std::size_t... Is>
bool SetValueImpl(std::index_sequence<Is...>, const std::vector<Ptr<AttributeValue>>& values);
value_type m_value; //!< Tuple of attribute values
};
/**
* @ingroup attribute_Tuple
*
* Create a TupleValue object. Enable to write code like this snippet:
*
* @code
* typedef std::tuple<uint16_t, double> Tuple;
* typedef std::tuple<UintegerValue, DoubleValue> Pack;
*
* TupleValue<UintegerValue, DoubleValue> t = MakeTupleValue<Pack> (Tuple {10, 1.5});
* @endcode
*
* @tparam T1 \explicit A std::tuple of the AttributeValue types included in TupleValue
* @tparam T2 \deduced A std::tuple of the type of elements stored by TupleValue
* @param t the tuple of elements stored by TupleValue
* @return a TupleValue object
*/
template <class T1, class T2>
auto MakeTupleValue(T2 t);
/**
* @ingroup attribute_Tuple
*
* Checker for attribute values storing tuples.
*/
class TupleChecker : public AttributeChecker
{
public:
/**
* Get the checkers for all tuple elements.
*
* @return the checkers for all tuple elements
*/
virtual const std::vector<Ptr<const AttributeChecker>>& GetCheckers() const = 0;
};
/**
* @ingroup attribute_Tuple
*
* Create a TupleChecker from AttributeCheckers associated with TupleValue elements.
*
* @tparam Args \explicit Attribute value types
* @tparam Ts \deduced Attribute checker types
* @param checkers attribute checkers
* @return Pointer to TupleChecker instance.
*/
template <class... Args, class... Ts>
Ptr<const AttributeChecker> MakeTupleChecker(Ts... checkers);
/**
* @ingroup attribute_Tuple
*
* Create an AttributeAccessor for a class data member of type tuple,
* or a lone class get functor or set method.
*
* @tparam Args \explicit Attribute value types
* @tparam T1 \deduced The type of the class data member,
* or the type of the class get functor or set method.
* @param a1 The address of the data member,
* or the get or set method.
* @return the AttributeAccessor
*/
template <class... Args, class T1>
Ptr<const AttributeAccessor> MakeTupleAccessor(T1 a1);
/**
* @ingroup attribute_Tuple
*
* Create an AttributeAccessor using a pair of get functor
* and set methods from a class.
*
* @tparam Args \explicit Attribute value types
* @tparam T1 \deduced The type of the class data member,
* or the type of the class get functor or set method.
* @tparam T2 \deduced The type of the getter class functor method.
* @param a2 The address of the class method to set the attribute.
* @param a1 The address of the data member, or the get or set method.
* @return the AttributeAccessor
*/
template <class... Args, class T1, class T2>
Ptr<const AttributeAccessor> MakeTupleAccessor(T1 a1, T2 a2);
} // namespace ns3
/*****************************************************************************
* Implementation below
*****************************************************************************/
namespace ns3
{
template <class... Args>
TupleValue<Args...>::TupleValue()
: m_value(std::make_tuple(Args()...))
{
}
template <class... Args>
TupleValue<Args...>::TupleValue(const result_type& value)
{
Set(value);
}
template <class... Args>
Ptr<AttributeValue>
TupleValue<Args...>::Copy() const
{
return Create<TupleValue<Args...>>(Get());
}
template <class... Args>
template <std::size_t... Is>
bool
TupleValue<Args...>::SetValueImpl(std::index_sequence<Is...>,
const std::vector<Ptr<AttributeValue>>& values)
{
auto valueTuple = std::make_tuple(DynamicCast<Args>(values[Is])...);
bool ok = ((std::get<Is>(valueTuple) != nullptr) && ...);
if (ok)
{
m_value = std::make_tuple(Args(*std::get<Is>(valueTuple))...);
}
return ok;
}
template <class... Args>
bool
TupleValue<Args...>::DeserializeFromString(std::string value, Ptr<const AttributeChecker> checker)
{
auto tupleChecker = DynamicCast<const TupleChecker>(checker);
if (!tupleChecker)
{
return false;
}
auto count = tupleChecker->GetCheckers().size();
if (count != sizeof...(Args))
{
return false;
}
if (value.empty() || value.front() != '{' || value.back() != '}')
{
return false;
}
value.erase(value.begin());
value.pop_back();
std::istringstream iss(value);
std::vector<Ptr<AttributeValue>> values;
std::size_t i = 0;
for (std::string elem; std::getline(iss, elem, ',');)
{
// remove leading whitespaces
std::istringstream tmp{elem};
std::getline(tmp >> std::ws, value);
if (i >= count)
{
return false;
}
values.push_back(tupleChecker->GetCheckers().at(i++)->CreateValidValue(StringValue(value)));
if (!values.back())
{
return false;
}
}
if (i != count)
{
return false;
}
return SetValueImpl(std::index_sequence_for<Args...>{}, values);
}
template <class... Args>
std::string
TupleValue<Args...>::SerializeToString(Ptr<const AttributeChecker> checker) const
{
std::ostringstream oss;
oss << "{" << Get() << "}";
return oss.str();
}
template <class... Args>
typename TupleValue<Args...>::result_type
TupleValue<Args...>::Get() const
{
return std::apply([](Args... values) { return std::make_tuple(values.Get()...); }, m_value);
}
template <class... Args>
void
TupleValue<Args...>::Set(const typename TupleValue<Args...>::result_type& value)
{
m_value = std::apply([](auto&&... args) { return std::make_tuple(Args(args)...); }, value);
}
template <class... Args>
typename TupleValue<Args...>::value_type
TupleValue<Args...>::GetValue() const
{
return m_value;
}
template <class... Args>
template <typename T>
bool
TupleValue<Args...>::GetAccessor(T& value) const
{
value = T(Get());
return true;
}
// This internal class defines templated TupleChecker class that is instantiated
// in MakeTupleChecker. The non-templated base ns3::TupleChecker is returned in that
// function. This is the same pattern as ObjectPtrContainer.
namespace internal
{
/**
* @ingroup attribute_Tuple
*
* Internal checker class templated to each AttributeChecker
* for each entry in the tuple.
*/
template <class... Args>
class TupleChecker : public ns3::TupleChecker
{
public:
/**
* Constructor.
* @tparam Ts \deduced the type of the attribute checkers
* @param checkers the attribute checkers for individual elements of the tuple
*/
template <class... Ts>
TupleChecker(Ts... checkers)
: m_checkers{checkers...}
{
}
const std::vector<Ptr<const AttributeChecker>>& GetCheckers() const override
{
return m_checkers;
}
bool Check(const AttributeValue& value) const override
{
const auto v = dynamic_cast<const TupleValue<Args...>*>(&value);
if (v == nullptr)
{
return false;
}
return std::apply(
[this](Args... values) {
std::size_t n{0};
return (m_checkers[n++]->Check(values) && ...);
},
v->GetValue());
}
std::string GetValueTypeName() const override
{
return "ns3::TupleValue";
}
bool HasUnderlyingTypeInformation() const override
{
return false;
}
std::string GetUnderlyingTypeInformation() const override
{
return "";
}
Ptr<AttributeValue> Create() const override
{
return ns3::Create<TupleValue<Args...>>();
}
bool Copy(const AttributeValue& source, AttributeValue& destination) const override
{
const auto src = dynamic_cast<const TupleValue<Args...>*>(&source);
auto dst = dynamic_cast<TupleValue<Args...>*>(&destination);
if (src == nullptr || dst == nullptr)
{
return false;
}
*dst = *src;
return true;
}
private:
std::vector<Ptr<const AttributeChecker>> m_checkers; //!< attribute checkers
};
/**
* @ingroup attribute_Tuple
*
* Helper class defining static methods for MakeTupleChecker and MakeTupleAccessor
* that are called when user specifies the list of AttributeValue types included
* in a TupleValue type.
*/
template <class... Args>
struct TupleHelper
{
/**
* @copydoc ns3::MakeTupleChecker
*/
template <class... Ts>
static Ptr<const AttributeChecker> MakeTupleChecker(Ts... checkers)
{
return Create<internal::TupleChecker<Args...>>(checkers...);
}
/**
* @copydoc ns3::MakeTupleAccessor(T1)
*/
template <class T1>
static Ptr<const AttributeAccessor> MakeTupleAccessor(T1 a1)
{
return MakeAccessorHelper<TupleValue<Args...>>(a1);
}
/**
* @copydoc ns3::MakeTupleAccessor(T1,T2)
*/
template <class T1, class T2>
static Ptr<const AttributeAccessor> MakeTupleAccessor(T1 a1, T2 a2)
{
return MakeAccessorHelper<TupleValue<Args...>>(a1, a2);
}
};
/**
* @ingroup attribute_Tuple
*
* Helper class defining static methods for MakeTupleValue, MakeTupleChecker and
* MakeTupleAccessor that are called when user provides a std::tuple of the
* AttributeValue types included in a TupleValue type.
* This struct is a partial specialization of struct TupleHelper.
*/
template <class... Args>
struct TupleHelper<std::tuple<Args...>>
{
/**
* @copydoc ns3::MakeTupleValue
*/
static TupleValue<Args...> MakeTupleValue(const typename TupleValue<Args...>::result_type& t)
{
return TupleValue<Args...>(t);
}
/**
* @copydoc ns3::MakeTupleChecker
*/
template <class... Ts>
static Ptr<const AttributeChecker> MakeTupleChecker(Ts... checkers)
{
return Create<internal::TupleChecker<Args...>>(checkers...);
}
/**
* @copydoc ns3::MakeTupleAccessor(T1)
*/
template <class T1>
static Ptr<const AttributeAccessor> MakeTupleAccessor(T1 a1)
{
return MakeAccessorHelper<TupleValue<Args...>>(a1);
}
/**
* @copydoc ns3::MakeTupleAccessor(T1,T2)
*/
template <class T1, class T2>
static Ptr<const AttributeAccessor> MakeTupleAccessor(T1 a1, T2 a2)
{
return MakeAccessorHelper<TupleValue<Args...>>(a1, a2);
}
};
} // namespace internal
template <class T1, class T2>
auto
MakeTupleValue(T2 t)
{
return internal::TupleHelper<T1>::MakeTupleValue(t);
}
template <class... Args, class... Ts>
Ptr<const AttributeChecker>
MakeTupleChecker(Ts... checkers)
{
return internal::TupleHelper<Args...>::template MakeTupleChecker<Ts...>(checkers...);
}
template <class... Args, class T1>
Ptr<const AttributeAccessor>
MakeTupleAccessor(T1 a1)
{
return internal::TupleHelper<Args...>::template MakeTupleAccessor<T1>(a1);
}
template <class... Args, class T1, class T2>
Ptr<const AttributeAccessor>
MakeTupleAccessor(T1 a1, T2 a2)
{
return internal::TupleHelper<Args...>::template MakeTupleAccessor<T1, T2>(a1, a2);
}
} // namespace ns3
#endif // TUPLE_H