builder.hpp

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#pragma once
 
/// @file userver/ydb/builder.hpp
/// @brief @copybrief ydb::PreparedArgsBuilder
 
#include <ydb-cpp-sdk/client/params/params.h>
 
#include <string>
#include <type_traits>
#include <utility>
 
#include <userver/ydb/impl/cast.hpp>
#include <userver/ydb/io/traits.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace ydb {
 
class TableClient;
class Transaction;
 
/// @brief Builder for prepared query parameters
class PreparedArgsBuilder final {
public:
    PreparedArgsBuilder() = default;
 
    PreparedArgsBuilder(PreparedArgsBuilder&&) noexcept = default;
    PreparedArgsBuilder& operator=(PreparedArgsBuilder&&) = delete;
 
    explicit PreparedArgsBuilder(NYdb::TParamsBuilder&& builder)
        : builder_(std::move(builder))
    {}
 
    /// Supported types and required includes are documented in:
    /// <userver/ydb/io/supported_types.hpp>
    template <typename T>
    void Add(const std::string& name, T&& value);
 
    /// @cond
    // For internal use only.
    template <typename... NamesValues>
    void AddParams(NamesValues&&... names_values);
    /// @endcond
 
private:
    friend class Transaction;
    friend class TableClient;
    friend class TxActor;
    struct PreparedArgsWithKey;
 
    NYdb::TParams Build() && { return std::move(builder_).Build(); }
 
    PreparedArgsWithKey operator<<(const std::string& key);
 
    NYdb::TParamsBuilder builder_;
};
 
template <typename T>
void PreparedArgsBuilder::Add(const std::string& name, T&& value) {
    auto& param_builder = builder_.AddParam(impl::ToString(name));
    Write(param_builder, std::forward<T>(value));
    param_builder.Build();
}
 
/// @cond
template <typename... NamesValues>
void PreparedArgsBuilder::AddParams(NamesValues&&... names_values) {
    [[maybe_unused]] decltype(auto) result = (*this << ... << std::forward<NamesValues>(names_values));
    static_assert(std::is_same_v<decltype(result), PreparedArgsBuilder&>);
}
/// @endcond
 
struct PreparedArgsBuilder::PreparedArgsWithKey final {
    PreparedArgsBuilder& builder;
    const std::string& key;
 
    template <typename T>
    PreparedArgsBuilder& operator<<(T&& value) const {
        builder.Add(key, std::forward<T>(value));
        return builder;
    }
};
 
inline auto PreparedArgsBuilder::operator<<(const std::string& key) -> PreparedArgsWithKey {
    return PreparedArgsWithKey{*this, key};
}
 
}  // namespace ydb
 
USERVER_NAMESPACE_END