public:

static constexpr std::chrono::milliseconds kDefaultTimeout =

std::chrono::seconds(300);

static constexpr std::chrono::milliseconds kNoTimeout =

std::chrono::milliseconds::zero();

Store() : timeout_(kDefaultTimeout) {}

explicit Store(const std::chrono::milliseconds& timeout)

: timeout_(timeout) {}

virtual ~Store();

virtual void set(

const std::string& key,

const std::vector<uint8_t>& value) = 0;

virtual std::vector<uint8_t> get(const std::string& key) = 0;

virtual int64_t add(const std::string& key, int64_t value) = 0;

virtual bool deleteKey(const std::string& key) = 0;

virtual bool check(const std::vector<std::string>& keys) = 0;

virtual int64_t getNumKeys() = 0;

virtual void wait(const std::vector<std::string>& keys) = 0;

virtual void wait(

const std::vector<std::string>& keys,

const std::chrono::milliseconds& timeout) = 0;

void setTimeout(const std::chrono::milliseconds& timeout);

protected:

std::chrono::milliseconds timeout_;