Implement SSCAN Redis command.

src/backends/redis/command.cpp

@@ -133,4 +133,8 @@ namespace redis {
 	auto Command::hscan (boost::string_ref parKey) -> hscan_range {
 		return hscan_range(hscan_iterator(this, parKey, false), hscan_iterator(this, parKey, true));
 	}
+
+	auto Command::sscan (boost::string_ref parKey) -> sscan_range {
+		return sscan_range(sscan_iterator(this, parKey, false), sscan_iterator(this, parKey, true));
+	}
 } //namespace redis

src/backends/redis/command.hpp

@@ -41,6 +41,8 @@ namespace redis {
 		typedef boost::iterator_range<scan_iterator> scan_range;
 		typedef ScanIterator<ScanPairs<std::pair<std::string, std::string>>> hscan_iterator;
 		typedef boost::iterator_range<hscan_iterator> hscan_range;
+		typedef ScanIterator<ScanSingleValuesInKey<std::string>> sscan_iterator;
+		typedef boost::iterator_range<sscan_iterator> sscan_range;
 
 		Command ( std::string&& parAddress, uint16_t parPort );
 		~Command ( void ) noexcept;
@@ -56,6 +58,7 @@ namespace redis {
 		//Single Redis command wrappers
 		scan_range scan ( void );
 		hscan_range hscan ( boost::string_ref parKey );
+		sscan_range sscan ( boost::string_ref parKey );
 
 	private:
 		using RedisConnection = std::unique_ptr<redisContext, void(*)(redisContext*)>;

src/backends/redis/scan_iterator.hpp

@@ -95,6 +95,22 @@ namespace redis {
 		static const T& make_value ( const RedisReplyType* parItem );
 	};
 
+	template <typename T>
+	struct ScanSingleValuesInKey {
+		typedef T value_type;
+
+		explicit ScanSingleValuesInKey ( boost::string_ref parScanTarget ) : m_scan_target(parScanTarget) {}
+
+		static constexpr const char* command ( void ) { return "SSCAN"; }
+		static constexpr const std::size_t step = 1;
+
+		static const T& make_value ( const RedisReplyType* parItem );
+		boost::string_ref scan_target ( void ) const { return m_scan_target; }
+
+	private:
+		boost::string_ref m_scan_target;
+	};
+
 	template <typename P, typename A=decltype(P().first), typename B=decltype(P().second)>
 	struct ScanPairs {
 		typedef P value_type;
@@ -105,7 +121,7 @@ namespace redis {
 		static constexpr const std::size_t step = 2;
 
 		static value_type make_value ( const RedisReplyType* parItem );
-		boost::string_ref scan_target ( void );
+		boost::string_ref scan_target ( void ) const { return m_scan_target; }
 
 	private:
 		boost::string_ref m_scan_target;

src/backends/redis/scan_iterator.inl

@@ -147,14 +147,15 @@ namespace redis {
 		return get<T>(*parItem);
 	}
 
+	template <typename T>
+	auto ScanSingleValuesInKey<T>::make_value (const RedisReplyType* parItem) -> const value_type& {
+		assert(parItem);
+		return get<T>(*parItem);
+	}
+
 	template <typename P, typename A, typename B>
 	auto ScanPairs<P, A, B>::make_value (const RedisReplyType* parItem) -> value_type {
 		assert(parItem);
 		return value_type(get<A>(parItem[0]), get<B>(parItem[1]));
 	}
-
-	template <typename P, typename A, typename B>
-	boost::string_ref ScanPairs<P, A, B>::scan_target() {
-		return m_scan_target;
-	}
 } //namespace redis