data_source_update_sink.hpp

#pragma once
 
#include <optional>
#include <ostream>
#include <string>
#include <unordered_map>
#include <vector>
 
#include <launchdarkly/client_side/data_source_status.hpp>
#include <launchdarkly/config/shared/built/service_endpoints.hpp>
#include <launchdarkly/context.hpp>
#include <launchdarkly/data/evaluation_result.hpp>
#include <launchdarkly/data_model/change_set.hpp>
#include <launchdarkly/data_model/item_descriptor.hpp>
 
namespace launchdarkly::client_side {
 
using ItemDescriptor = data_model::ItemDescriptor<EvaluationResult>;
 
// One flag's new state: an evaluation result, or an empty descriptor
// (tombstone) if the flag was deleted.
struct FlagChange {
    std::string key;
    ItemDescriptor item;
};
 
using FlagChangeSetData = std::vector<FlagChange>;
 
using FlagChangeSet = data_model::ChangeSet<FlagChangeSetData>;
 
class IDataSourceUpdateSink {
   public:
    virtual void Init(Context const& context,
                      std::unordered_map<std::string, ItemDescriptor> data) = 0;
    virtual void Upsert(Context const& context,
                        std::string key,
                        ItemDescriptor item) = 0;
 
    virtual void Apply(Context const& context,
                       FlagChangeSet change_set,
                       bool from_cache) = 0;
 
    IDataSourceUpdateSink(IDataSourceUpdateSink const& item) = delete;
    IDataSourceUpdateSink(IDataSourceUpdateSink&& item) = delete;
    IDataSourceUpdateSink& operator=(IDataSourceUpdateSink const&) = delete;
    IDataSourceUpdateSink& operator=(IDataSourceUpdateSink&&) = delete;
    virtual ~IDataSourceUpdateSink() = default;
 
   protected:
    IDataSourceUpdateSink() = default;
};
 
}  // namespace launchdarkly::client_side