idata_reader.hpp

#pragma once
 
#include <launchdarkly/data_model/descriptors.hpp>
 
#include <tl/expected.hpp>
 
#include <optional>
#include <string>
#include <unordered_map>
 
namespace launchdarkly::server_side::data_interfaces {
 
class IDataReader {
   public:
    using Error = std::string;
 
    template <typename T>
    using Single = std::optional<data_model::ItemDescriptor<T>>;
 
    template <typename T>
    using SingleResult = tl::expected<Single<T>, Error>;
 
    template <typename T>
    using Collection =
        std::unordered_map<std::string, data_model::ItemDescriptor<T>>;
 
    template <typename T>
    using CollectionResult = tl::expected<Collection<T>, Error>;
 
    [[nodiscard]] virtual SingleResult<data_model::Flag> GetFlag(
        std::string const& key) const = 0;
 
    [[nodiscard]] virtual SingleResult<data_model::Segment> GetSegment(
        std::string const& key) const = 0;
 
    [[nodiscard]] virtual CollectionResult<data_model::Flag> AllFlags()
        const = 0;
 
    [[nodiscard]] virtual CollectionResult<data_model::Segment> AllSegments()
        const = 0;
 
    [[nodiscard]] virtual std::string const& Identity() const = 0;
 
    [[nodiscard]] virtual bool Initialized() const = 0;
 
    virtual ~IDataReader() = default;
    IDataReader(IDataReader const& item) = delete;
    IDataReader(IDataReader&& item) = delete;
    IDataReader& operator=(IDataReader const&) = delete;
    IDataReader& operator=(IDataReader&&) = delete;
 
   protected:
    IDataReader() = default;
};
 
}  // namespace launchdarkly::server_side::data_interfaces