VILLASnode/include/villas/nodes/redis.hpp

/** Redis node-type
 *
 * @file
 * @author Steffen Vogel <post@steffenvogel.de>
 * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
 * @license Apache 2.0
 *********************************************************************************/

#pragma once

#include <atomic>
#include <thread>
#include <unordered_map>

#include <sw/redis++/redis++.h>

#include <villas/node/config.hpp>
#include <villas/node.hpp>
#include <villas/timing.hpp>
#include <villas/format.hpp>
#include <villas/task.hpp>
#include <villas/pool.hpp>
#include <villas/queue_signalled.h>

namespace villas {
namespace node {

enum class RedisMode {
	KEY,
	HASH,
	CHANNEL
};

class RedisConnection {

public:
	sw::redis::Redis context;

protected:
	enum State {
		INITIALIZED,
		RUNNING,
		STOPPING
	};

	std::thread thread;
	std::atomic<enum State> state;

	void onMessage(const std::string &channel, const std::string &msg);

	void loop();

	std::unordered_multimap<std::string, NodeCompat *> subscriberMap;

	sw::redis::Subscriber subscriber;

	villas::Logger logger;

public:

	RedisConnection(const sw::redis::ConnectionOptions &opts);

	static
	RedisConnection * get(const sw::redis::ConnectionOptions &opts);

	void start();
	void stop();

	void subscribe(NodeCompat *n, const std::string &channel);
	void unsubscribe(NodeCompat *n, const std::string &channel);
};

struct redis {
	sw::redis::ConnectionOptions options;

	RedisConnection *conn;

	enum RedisMode mode;

	std::string key;

	bool notify;			/**< Use Redis Keyspace notifications to listen for updates. */

	struct Task task;		/**< Timer for periodic events. */
	double rate;			/**< Rate for polling key updates if keyspace notifications are disabled. */

	Format *formatter;

	struct Pool pool;
	struct CQueueSignalled queue;
};

int redis_init(NodeCompat *n);

int redis_destroy(NodeCompat *n);

int redis_parse(NodeCompat *n, json_t *json);

char * redis_print(NodeCompat *n);

int redis_check(NodeCompat *n);

int redis_prepare(NodeCompat *n);

int redis_start(NodeCompat *n);

int redis_stop(NodeCompat *n);

int redis_pause(NodeCompat *n);

int redis_resume(NodeCompat *n);

int redis_write(NodeCompat *n, struct Sample * const smps[], unsigned cnt);

int redis_read(NodeCompat *n, struct Sample * const smps[], unsigned cnt);

int redis_reverse(NodeCompat *n);

int redis_poll_fds(NodeCompat *n, int fds[]);

int redis_netem_fds(NodeCompat *n, int fds[]);

} // namespace node
} // namespace villas