gnss-sim/3rdparty/boost/mysql/static_results.hpp

298 lines
9.6 KiB
C++

//
// Copyright (c) 2019-2024 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_MYSQL_STATIC_RESULTS_HPP
#define BOOST_MYSQL_STATIC_RESULTS_HPP
#include <boost/mysql/detail/config.hpp>
#ifdef BOOST_MYSQL_CXX14
#include <boost/mysql/metadata_collection_view.hpp>
#include <boost/mysql/string_view.hpp>
#include <boost/mysql/underlying_row.hpp>
#include <boost/mysql/detail/access.hpp>
#include <boost/mysql/detail/execution_processor/static_results_impl.hpp>
#include <boost/assert.hpp>
namespace boost {
namespace mysql {
/**
* \brief Holds the results of a SQL query (static interface).
* \details
* This object can store the results of single and multi resultset queries
* in a type-safe manner.
*
* \tparam StaticRow The row or row types that will be returned by the server.
* There must be one for every resultset returned by the query, and always at least one.
* All the passed types must fulfill the `StaticRow` concept.
*
* \par Thread safety
* Distinct objects: safe. \n
* Shared objects: unsafe. \n
*/
template <class... StaticRow>
class static_results
{
public:
/**
* \brief Default constructor.
* \details Constructs an empty results object, with `this->has_value() == false`.
*
* \par Exception safety
* No-throw guarantee.
*/
static_results() = default;
/**
* \brief Copy constructor.
* \par Exception safety
* Strong guarantee. Internal allocations may throw.
*/
static_results(const static_results& other) = default;
/**
* \brief Move constructor.
* \par Exception safety
* No-throw guarantee.
*
* \par Object lifetimes
* View objects obtained from `other` remain valid.
*/
static_results(static_results&& other) = default;
/**
* \brief Copy assignment.
* \par Exception safety
* Basic guarantee. Internal allocations may throw.
*
* \par Object lifetimes
* Views referencing `*this` are invalidated.
*/
static_results& operator=(const static_results& other) = default;
/**
* \brief Move assignment.
* \par Exception safety
* Basic guarantee. Internal allocations may throw.
*
* \par Object lifetimes
* View objects obtained from `other` remain valid.
* Views and referencing `*this` are invalidated.
*/
static_results& operator=(static_results&& other) = default;
/// Destructor
~static_results() = default;
/**
* \brief Returns whether the object holds a valid result.
* \details Having `this->has_value()` is a precondition to call all data accessors.
* Objects populated by \ref connection::execute and \ref connection::async_execute
* are guaranteed to have `this->has_value() == true`.
*
* \par Exception safety
* No-throw guarantee.
*
* \par Complexity
* Constant.
*/
bool has_value() const noexcept { return impl_.get_interface().is_complete(); }
/**
* \brief Returns the rows retrieved by the SQL query.
* \details
*
* \tparam I Resultset index. For operations returning more than one resultset, you can explicitly
* specify this parameter to obtain the rows contained in the i-th resultset. If left unspecified,
* rows for the first resultset are returned.
*
* \return Returns a read-only span of the `I`-th row type.
*
* \par Preconditions
* `this->has_value() == true`
*
* \par Exception safety
* No-throw guarantee.
*
* \par Object lifetimes
* This function returns a view object, with reference semantics. The returned view points into
* memory owned by `*this`, and will be valid as long as `*this` or an object move-constructed
* from `*this` are alive.
*
* \par Complexity
* Constant.
*/
template <std::size_t I = 0>
#ifdef BOOST_MYSQL_DOXYGEN
boost::span<const StaticRow... [I]>
#else
detail::rows_span_t<I, StaticRow...>
#endif
rows() const noexcept {
static_assert(I < sizeof...(StaticRow), "Index I out of range");
BOOST_ASSERT(has_value());
return impl_.template get_rows<I>();
}
/**
* \brief Returns metadata about the columns in the query.
* \details
* The returned collection will have as many \ref metadata objects as columns retrieved by
* the SQL query, and in the same order. Note that this may not be the same order as in the `StaticRow`
* type, since columns may be mapped by name or discarded. This function returns the representation that
* was retrieved from the database.
*
* \tparam I Resultset index. For operations returning more than one resultset, you can explicitly
* specify this parameter to obtain metadata for the i-th resultset. If left unspecified,
* metadata for the first resultset is returned.
*
* \par Preconditions
* `this->has_value() == true`
*
* \par Exception safety
* No-throw guarantee.
*
* \par Object lifetimes
* This function returns a view object, with reference semantics. The returned view points into
* memory owned by `*this`, and will be valid as long as `*this` or an object move-constructed
* from `*this` are alive.
*
* \par Complexity
* Constant.
*/
template <std::size_t I = 0>
metadata_collection_view meta() const noexcept
{
static_assert(I < sizeof...(StaticRow), "Index I out of range");
BOOST_ASSERT(has_value());
return impl_.get_interface().get_meta(I);
}
/**
* \brief Returns the number of rows affected by the executed SQL statement.
* \details
* \tparam I Resultset index. For operations returning more than one resultset, you can explicitly
* specify this parameter to obtain the number of affected rows by the i-th resultset. If left
* unspecified, the number of affected rows by the first resultset is returned.
*
* \par Preconditions
* `this->has_value() == true`
*
* \par Exception safety
* No-throw guarantee.
*
* \par Complexity
* Constant.
*/
template <std::size_t I = 0>
std::uint64_t affected_rows() const noexcept
{
static_assert(I < sizeof...(StaticRow), "Index I out of range");
BOOST_ASSERT(has_value());
return impl_.get_interface().get_affected_rows(I);
}
/**
* \brief Returns the last insert ID produced by the executed SQL statement.
* \details
* \tparam I Resultset index. For operations returning more than one resultset, you can explicitly
* specify this parameter to obtain the last insert ID for the i-th resultset. If left unspecified,
* the last insert ID for the first resultset is returned.
*
* \par Preconditions
* `this->has_value() == true`
*
* \par Exception safety
* No-throw guarantee.
*
* \par Complexity
* Constant.
*/
template <std::size_t I = 0>
std::uint64_t last_insert_id() const noexcept
{
static_assert(I < sizeof...(StaticRow), "I index out of range");
BOOST_ASSERT(has_value());
return impl_.get_interface().get_last_insert_id(I);
}
/**
* \brief Returns the number of warnings produced by the executed SQL statement.
* \details
* \tparam I Resultset index. For operations returning more than one resultset, you can explicitly
* specify this parameter to obtain the warning count for the i-th resultset. If left unspecified,
* the warning count for the first resultset is returned.
*
* \par Preconditions
* `this->has_value() == true`
*
* \par Exception safety
* No-throw guarantee.
*
* \par Complexity
* Constant.
*/
template <std::size_t I = 0>
unsigned warning_count() const noexcept
{
static_assert(I < sizeof...(StaticRow), "I index out of range");
BOOST_ASSERT(has_value());
return impl_.get_interface().get_warning_count(I);
}
/**
* \brief Returns additional text information about the execution of the SQL statement.
* \details
* The format of this information is documented by MySQL <a
* href="https://dev.mysql.com/doc/c-api/8.0/en/mysql-info.html">here</a>.
* \n
* The returned string always uses ASCII encoding, regardless of the connection's character set.
*
* \tparam I Resultset index. For operations returning more than one resultset, you can explicitly
* specify this parameter to obtain the value for the i-th resultset. If left unspecified,
* the value for the first resultset is returned.
*
* \par Preconditions
* `this->has_value() == true`
*
* \par Exception safety
* No-throw guarantee.
*
* \par Object lifetimes
* This function returns a view object, with reference semantics. The returned view points into
* memory owned by `*this`, and will be valid as long as `*this` or an object move-constructed
* from `*this` are alive.
*
* \par Complexity
* Constant.
*/
template <std::size_t I = 0>
string_view info() const noexcept
{
static_assert(I < sizeof...(StaticRow), "I index out of range");
BOOST_ASSERT(has_value());
return impl_.get_interface().get_info(I);
}
private:
detail::static_results_impl<StaticRow...> impl_;
#ifndef BOOST_MYSQL_DOXYGEN
friend struct detail::access;
#endif
};
} // namespace mysql
} // namespace boost
#endif // BOOST_MYSQL_CXX14
#endif