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sqlpp11/include/sqlpp11/limit.h

334 lines
9.5 KiB
C++

/*
* Copyright (c) 2013-2016, Roland Bock
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef SQLPP11_LIMIT_H
#define SQLPP11_LIMIT_H
#include <sqlpp11/detail/type_set.h>
#include <sqlpp11/policy_update.h>
#include <sqlpp11/type_traits.h>
namespace sqlpp
{
// LIMIT DATA
template <typename Limit>
struct limit_data_t
{
limit_data_t(Limit value) : _value(value)
{
}
limit_data_t(const limit_data_t&) = default;
limit_data_t(limit_data_t&&) = default;
limit_data_t& operator=(const limit_data_t&) = default;
limit_data_t& operator=(limit_data_t&&) = default;
~limit_data_t() = default;
Limit _value;
};
// LIMIT
template <typename Limit>
struct limit_t
{
using _traits = make_traits<no_value_t, tag::is_limit>;
using _nodes = detail::type_vector<Limit>;
// Data
using _data_t = limit_data_t<Limit>;
// Member implementation with data and methods
template <typename Policies>
struct _impl_t
{
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
_impl_t() = default;
_impl_t(const _data_t& data) : _data(data)
{
}
_data_t _data;
};
// Base template to be inherited by the statement
template <typename Policies>
struct _base_t
{
using _data_t = limit_data_t<Limit>;
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
template <typename... Args>
_base_t(Args&&... args) : limit{std::forward<Args>(args)...}
{
}
_impl_t<Policies> limit;
_impl_t<Policies>& operator()()
{
return limit;
}
const _impl_t<Policies>& operator()() const
{
return limit;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.limit)
{
return t.limit;
}
using _consistency_check = consistent_t;
};
};
// DYNAMIC LIMIT DATA
template <typename Database>
struct dynamic_limit_data_t
{
dynamic_limit_data_t() : _value(noop())
{
}
template <typename Limit>
dynamic_limit_data_t(Limit value) : _initialized(true), _value(wrap_operand_t<Limit>(value))
{
}
dynamic_limit_data_t(const dynamic_limit_data_t&) = default;
dynamic_limit_data_t(dynamic_limit_data_t&&) = default;
dynamic_limit_data_t& operator=(const dynamic_limit_data_t&) = default;
dynamic_limit_data_t& operator=(dynamic_limit_data_t&&) = default;
~dynamic_limit_data_t() = default;
bool _initialized = false;
interpretable_t<Database> _value;
};
// DYNAMIC LIMIT
template <typename Database>
struct dynamic_limit_t
{
using _traits = make_traits<no_value_t, tag::is_limit>;
using _nodes = detail::type_vector<>;
// Data
using _data_t = dynamic_limit_data_t<Database>;
// Member implementation with data and methods
template <typename Policies>
struct _impl_t
{
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
_impl_t() = default;
_impl_t(const _data_t& data) : _data(data)
{
}
template <typename Limit>
void set(Limit value)
{
// FIXME: Make sure that Limit does not require external tables? Need to read up on SQL
using arg_t = wrap_operand_t<Limit>;
static_assert(is_unsigned_integral_t<arg_t>::value,
"limit requires an unsigned integral value or unsigned integral parameter");
_data._value = arg_t{value};
_data._initialized = true;
}
public:
_data_t _data;
};
// Base template to be inherited by the statement
template <typename Policies>
struct _base_t
{
using _data_t = dynamic_limit_data_t<Database>;
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
template <typename... Args>
_base_t(Args&&... args) : limit{std::forward<Args>(args)...}
{
}
_impl_t<Policies> limit;
_impl_t<Policies>& operator()()
{
return limit;
}
const _impl_t<Policies>& operator()() const
{
return limit;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.limit)
{
return t.limit;
}
using _consistency_check = consistent_t;
};
};
SQLPP_PORTABLE_STATIC_ASSERT(assert_limit_is_unsigned_integral,
"argument for limit() must be an unsigned integral expressions");
template <typename T>
struct check_limit
{
using type =
static_combined_check_t<static_check_t<is_unsigned_integral_t<T>::value, assert_limit_is_unsigned_integral>>;
};
template <typename T>
using check_limit_t = typename check_limit<wrap_operand_t<T>>::type;
struct no_limit_t
{
using _traits = make_traits<no_value_t, tag::is_noop>;
using _nodes = detail::type_vector<>;
// Data
using _data_t = no_data_t;
// Member implementation with data and methods
template <typename Policies>
struct _impl_t
{
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
_impl_t() = default;
_impl_t(const _data_t& data) : _data(data)
{
}
_data_t _data;
};
// Base template to be inherited by the statement
template <typename Policies>
struct _base_t
{
using _data_t = no_data_t;
// workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
template <typename... Args>
_base_t(Args&&... args) : no_limit{std::forward<Args>(args)...}
{
}
_impl_t<Policies> no_limit;
_impl_t<Policies>& operator()()
{
return no_limit;
}
const _impl_t<Policies>& operator()() const
{
return no_limit;
}
template <typename T>
static auto _get_member(T t) -> decltype(t.no_limit)
{
return t.no_limit;
}
using _database_t = typename Policies::_database_t;
template <typename Check, typename T>
using _new_statement_t = new_statement_t<Check, Policies, no_limit_t, T>;
using _consistency_check = consistent_t;
template <typename Arg>
auto limit(Arg arg) const -> _new_statement_t<check_limit_t<Arg>, limit_t<wrap_operand_t<Arg>>>
{
return _limit_impl(check_limit_t<Arg>{}, wrap_operand_t<Arg>{arg});
}
auto dynamic_limit() const -> _new_statement_t<consistent_t, dynamic_limit_t<_database_t>>
{
return {static_cast<const derived_statement_t<Policies>&>(*this), dynamic_limit_data_t<_database_t>{}};
}
private:
template <typename Check, typename Arg>
auto _limit_impl(Check, Arg arg) const -> inconsistent<Check>;
template <typename Arg>
auto _limit_impl(consistent_t /*unused*/, Arg arg) const -> _new_statement_t<consistent_t, limit_t<Arg>>
{
return {static_cast<const derived_statement_t<Policies>&>(*this), limit_data_t<Arg>{arg}};
}
};
};
// Interpreters
template <typename Context, typename Database>
struct serializer_t<Context, dynamic_limit_data_t<Database>>
{
using _serialize_check = consistent_t;
using T = dynamic_limit_data_t<Database>;
static Context& _(const T& t, Context& context)
{
if (t._initialized)
{
context << " LIMIT ";
serialize(t._value, context);
}
return context;
}
};
template <typename Context, typename Limit>
struct serializer_t<Context, limit_data_t<Limit>>
{
using _serialize_check = serialize_check_of<Context, Limit>;
using T = limit_data_t<Limit>;
static Context& _(const T& t, Context& context)
{
context << " LIMIT ";
serialize_operand(t._value, context);
return context;
}
};
template <typename T>
auto limit(T&& t) -> decltype(statement_t<void, no_limit_t>().limit(std::forward<T>(t)))
{
return statement_t<void, no_limit_t>().limit(std::forward<T>(t));
}
template <typename Database>
auto dynamic_limit(const Database & /*unused*/) -> decltype(statement_t<Database, no_limit_t>().dynamic_limit())
{
return statement_t<Database, no_limit_t>().dynamic_limit();
}
} // namespace sqlpp
#endif