ttl_reply.hpp

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#pragma once
 
/// @file userver/storages/redis/ttl_reply.hpp
/// @brief Redis TTL reply value and exception for invalid TTL queries
 
#include <chrono>
#include <cstdint>
#include <string>
 
#include <userver/storages/redis/exception.hpp>
#include <userver/storages/redis/fwd.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace storages::redis {
 
/// @brief Parsed TTL / HTTL reply (seconds precision).
///
/// Also used for HTTL replies — in which case the value semantics mirror
/// "field" instead of "key" (kKeyDoesNotExist=-2 means the field does not exist
/// or the parent hash does not exist; kKeyHasNoExpiration=-1 means the field has
/// no associated TTL).
///
/// For millisecond-precision commands (PTTL / HPTTL) use @c PttlReply.
class TtlReply final {
public:
    enum class TtlReplyValue { kKeyDoesNotExist = -2, kKeyHasNoExpiration = -1 };
 
    static constexpr TtlReplyValue kKeyDoesNotExist = TtlReplyValue::kKeyDoesNotExist;
    static constexpr TtlReplyValue kKeyHasNoExpiration = TtlReplyValue::kKeyHasNoExpiration;
 
    explicit TtlReply(int64_t value);
    TtlReply(TtlReplyValue value);
 
    static TtlReply Parse(ReplyData&& reply_data, const std::string& request_description = {});
 
    bool KeyExists() const;
    bool KeyHasExpiration() const;
    [[deprecated("Use GetExpire() instead")]] size_t GetExpireSeconds() const { return GetExpire().count(); }
 
    /// @brief Returns the expiration as `std::chrono::seconds`. Throws
    /// `KeyHasNoExpirationException` if the key/field has no expiration.
    std::chrono::seconds GetExpire() const;
 
private:
    int64_t value_;
};
 
/// @brief Thrown when reading TTL for a missing or persistent key
class KeyHasNoExpirationException : public Exception {
public:
    using Exception::Exception;
};
 
}  // namespace storages::redis
 
USERVER_NAMESPACE_END