request_evalsha.hpp

#pragma once
 
#include <userver/storages/redis/parse_reply.hpp>
#include <userver/storages/redis/reply.hpp>
#include <userver/storages/redis/request.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace storages::redis {
 
template <typename ScriptResult, typename ReplyType = ScriptResult>
class [[nodiscard]] RequestEvalSha final {
public:
    class EvalShaResult final {
    public:
        bool IsNoScriptError() const { return no_script_error_; }
        bool HasValue() const { return reply_.has_value(); }
        const ReplyType& Get() const { return *reply_; }
        ReplyType Extract() { return std::move(*reply_); }
 
    private:
        friend class RequestEvalSha;
        EvalShaResult() = default;
        explicit EvalShaResult(bool no_script) : no_script_error_{no_script} {}
        EvalShaResult(ReplyType&& reply) : reply_(std::move(reply)) {}
        std::optional<ReplyType> reply_;
        bool no_script_error_ = false;
    };
 
    explicit RequestEvalSha(RequestEvalShaCommon&& request) : request_(std::move(request)) {}
 
    void Wait() { request_.Wait(); }
 
    void IgnoreResult() const { request_.IgnoreResult(); }
 
    EvalShaResult Get(const std::string& request_description = {}) {
        auto reply_ptr = request_.GetRaw();
        const auto& reply_data = reply_ptr->data;
        if (reply_data.IsError()) {
            const auto& msg = reply_data.GetError();
            if (msg.find("NOSCRIPT", 0) == 0) {
                return EvalShaResult(true);
            }
        }
        /// no error try treat as usual eval
        return ParseReply<ScriptResult, ReplyType>(std::move(reply_ptr), request_description);
    }
 
private:
    RequestEvalShaCommon request_;
};
 
}  // namespace storages::redis
 
USERVER_NAMESPACE_END