cpp_redis::subscriber Class Reference

#include <subscriber.hpp>

Public Types
enum	connect_state {   dropped, start, sleeping, ok,   failed, lookup_failed, stopped }
typedef std::function< void(const std::string &host, std::size_t port, connect_state status)>	connect_callback_t
typedef std::function< void(reply &)>	reply_callback_t
typedef std::function< void(const std::string &, const std::string &)>	subscribe_callback_t
typedef std::function< void(int64_t)>	acknowledgement_callback_t

Public Member Functions
	subscriber (void)
	ctor
	subscriber (const std::shared_ptr< network::tcp_client_iface > &tcp_client)
	~subscriber (void)
	dtor
	subscriber (const subscriber &)=delete
	copy ctor
subscriber &	operator= (const subscriber &)=delete
	assignment operator
void	connect (const std::string &host="127.0.0.1", std::size_t port=6379, const connect_callback_t &connect_callback=nullptr, std::uint32_t timeout_msecs=0, std::int32_t max_reconnects=0, std::uint32_t reconnect_interval_msecs=0)
void	connect (const std::string &name, const connect_callback_t &connect_callback=nullptr, std::uint32_t timeout_msecs=0, std::int32_t max_reconnects=0, std::uint32_t reconnect_interval_msecs=0)
bool	is_connected (void) const
void	disconnect (bool wait_for_removal=false)
bool	is_reconnecting (void) const
void	cancel_reconnect (void)
subscriber &	auth (const std::string &password, const reply_callback_t &reply_callback=nullptr)
subscriber &	subscribe (const std::string &channel, const subscribe_callback_t &callback, const acknowledgement_callback_t &acknowledgement_callback=nullptr)
subscriber &	psubscribe (const std::string &pattern, const subscribe_callback_t &callback, const acknowledgement_callback_t &acknowledgement_callback=nullptr)
subscriber &	unsubscribe (const std::string &channel)
subscriber &	punsubscribe (const std::string &pattern)
subscriber &	commit (void)
void	add_sentinel (const std::string &host, std::size_t port, std::uint32_t timeout_msecs=0)
const sentinel &	get_sentinel (void) const
sentinel &	get_sentinel (void)
void	clear_sentinels (void)

Detailed Description

The cpp_redis::subscriber is meant to be used for PUB/SUB communication with the Redis server. Please do not use cpp_redis::client to subscribe to some Redis channels as:

• the behavior is undefined
• cpp_redis::client is not meant for that

Member Typedef Documentation

acknowledgement_callback_t

typedef std::function<void(int64_t)> cpp_redis::subscriber::acknowledgement_callback_t

acknowledgement callback called whenever a subscribe completes takes as parameter the int returned by the redis server (usually the number of channels you are subscribed to)

connect_callback_t

typedef std::function<void(const std::string& host, std::size_t port, connect_state status)> cpp_redis::subscriber::connect_callback_t

connect handler, called whenever a new connection even occurred

reply_callback_t

typedef std::function<void(reply&)> cpp_redis::subscriber::reply_callback_t

reply callback called whenever a reply is received takes as parameter the received reply

subscribe_callback_t

typedef std::function<void(const std::string&, const std::string&)> cpp_redis::subscriber::subscribe_callback_t

subscribe callback, called whenever a new message is published on a subscribed channel takes as parameter the channel and the message

Member Enumeration Documentation

connect_state

enum cpp_redis::subscriber::connect_state

strong

high availability (re)connection states

• dropped: connection has dropped
• start: attemp of connection has started
• sleeping: sleep between two attemps
• ok: connected
• failed: failed to connect
• lookup failed: failed to retrieve master sentinel
• stopped: stop to try to reconnect

Constructor & Destructor Documentation

subscriber()

cpp_redis::subscriber::subscriber ( const std::shared_ptr< network::tcp_client_iface > &  tcp_client )

explicit

custom ctor to specify custom tcp_client

Parameters

tcp_client

tcp client to be used for network communications

Member Function Documentation

add_sentinel()

void cpp_redis::subscriber::add_sentinel	(	const std::string &	host,
		std::size_t	port,
		std::uint32_t	timeout_msecs = 0
	)

add a sentinel definition. Required for connect() or get_master_addr_by_name() when autoconnect is enabled.

Parameters

host	sentinel host
port	sentinel port
timeout_msecs	maximum time to connect

auth()

subscriber& cpp_redis::subscriber::auth	(	const std::string &	password,
		const reply_callback_t &	reply_callback = nullptr
	)

ability to authenticate on the redis server if necessary this method should not be called repeatedly as the storage of reply_callback is NOT threadsafe (only one reply callback is stored for the subscriber client) calling repeatedly auth() is undefined concerning the execution of the associated callbacks

Parameters

password	password to be used for authentication
reply_callback	callback to be called on auth completion (nullable)

Returns

current instance

cancel_reconnect()

void cpp_redis::subscriber::cancel_reconnect

(

void

)

stop any reconnect in progress

clear_sentinels()

void cpp_redis::subscriber::clear_sentinels

(

void

)

clear all existing sentinels.

commit()

subscriber& cpp_redis::subscriber::commit

(

void

)

commit pipelined transaction that is, send to the network all commands pipelined by calling send() / subscribe() / ...

Returns

current instance

connect() [1/2]

void cpp_redis::subscriber::connect	(	const std::string &	host = "127.0.0.1",
		std::size_t	port = 6379,
		const connect_callback_t &	connect_callback = nullptr,
		std::uint32_t	timeout_msecs = 0,
		std::int32_t	max_reconnects = 0,
		std::uint32_t	reconnect_interval_msecs = 0
	)

Connect to redis server

Parameters

host	host to be connected to
port	port to be connected to
connect_callback	connect handler to be called on connect events (may be null)
timeout_msecs	maximum time to connect
max_reconnects	maximum attemps of reconnection if connection dropped
reconnect_interval_msecs	time between two attemps of reconnection

connect() [2/2]

void cpp_redis::subscriber::connect	(	const std::string &	name,
		const connect_callback_t &	connect_callback = nullptr,
		std::uint32_t	timeout_msecs = 0,
		std::int32_t	max_reconnects = 0,
		std::uint32_t	reconnect_interval_msecs = 0
	)

Connect to redis server

Parameters

name	sentinel name
connect_callback	connect handler to be called on connect events (may be null)
timeout_msecs	maximum time to connect
max_reconnects	maximum attemps of reconnection if connection dropped
reconnect_interval_msecs	time between two attemps of reconnection

disconnect()

void cpp_redis::subscriber::disconnect

(

bool

wait_for_removal = false

)

disconnect from redis server

Parameters

wait_for_removal

when sets to true, disconnect blocks until the underlying TCP client has been effectively removed from the io_service and that all the underlying callbacks have completed.

get_sentinel() [1/2]

const sentinel& cpp_redis::subscriber::get_sentinel

(

void

)

const

retrieve sentinel for current client

Returns

sentinel associated to current client

get_sentinel() [2/2]

sentinel& cpp_redis::subscriber::get_sentinel

(

void

)

retrieve sentinel for current client non-const version

Returns

sentinel associated to current client

is_connected()

bool cpp_redis::subscriber::is_connected

(

void

)

const

Returns

whether we are connected to the redis server

is_reconnecting()

bool cpp_redis::subscriber::is_reconnecting

(

void

)

const

Returns

whether an attemp to reconnect is in progress

psubscribe()

subscriber& cpp_redis::subscriber::psubscribe	(	const std::string &	pattern,
		const subscribe_callback_t &	callback,
		const acknowledgement_callback_t &	acknowledgement_callback = nullptr
	)

PSubscribes to the given channel and:

• calls acknowledgement_callback once the server has acknowledged about the subscription.
• calls subscribe_callback each time a message is published on this channel. The command is not effectively sent immediately but stored in an internal buffer until commit() is called.

Parameters

pattern	pattern to psubscribe
callback	callback to be called whenever a message is received for this pattern
acknowledgement_callback	callback to be called on subscription completion (nullable)

Returns

current instance

punsubscribe()

subscriber& cpp_redis::subscriber::punsubscribe

(

const std::string &

pattern

)

punsubscribe from the given pattern The command is not effectively sent immediately, but stored inside an internal buffer until commit() is called.

Parameters

pattern

pattern to punsubscribe from

Returns

current instance

subscribe()

subscriber& cpp_redis::subscriber::subscribe	(	const std::string &	channel,
		const subscribe_callback_t &	callback,
		const acknowledgement_callback_t &	acknowledgement_callback = nullptr
	)

Subscribes to the given channel and:

• calls acknowledgement_callback once the server has acknowledged about the subscription.
• calls subscribe_callback each time a message is published on this channel. The command is not effectively sent immediately but stored in an internal buffer until commit() is called.

Parameters

channel	channel to subscribe
callback	callback to be called whenever a message is received for this channel
acknowledgement_callback	callback to be called on subscription completion (nullable)

Returns

current instance

unsubscribe()

subscriber& cpp_redis::subscriber::unsubscribe

(

const std::string &

channel

)

unsubscribe from the given channel The command is not effectively sent immediately, but stored inside an internal buffer until commit() is called.

Parameters

channel

channel to unsubscribe from

Returns

current instance

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The documentation for this class was generated from the following file:

• includes/cpp_redis/core/subscriber.hpp