Create a Redis connection. This function is designed to be used
in other packages, and not directly by end-users. However, it is
possible and safe to use. See the hiredis package
for the user friendly interface.
redis_connection(config = redis_config())Configuration parameters as generated by
redis_config
This function creates a list of functions, appropriately bound to a pointer to a Redis connection. This is designed for package authors to use so without having to ever deal with the actual pointer itself (which cannot be directly manipulated from R anyway).
The returned list has elements, all of which are functions:
config()The configuration information
reconnect()Attempt reconnection of a connection that has been closed, through serialisation/deserialisation or through loss of internet connection.
Run a Redis command. The format of this command will be documented elsewhere.
Run a pipeline of Redis commands.
Subscribe to a
channel or pattern specifying channels. Here, channel must
be a character vector, pattern a logical indicating if
channel should be interpreted as a pattern, callback
is a function to apply to each received message, returning
TRUE when subscription should stop, and envir is the
environment in which to evaluate callback. See below.
The callback function must take a single argument; this will be
the received message with named elements type (which will
be message), channel (the name of the channel) and
value (the message contents). If pattern was
TRUE, then an additional element pattern will be
present (see the Redis docs). The callback must return
TRUE or FALSE; this indicates if the client should
continue quit (i.e., TRUE means return control to R,
FALSE means keep going).
Because the subscribe function is blocking and returns
nothing, so all data collection needs to happen as a side-effect
of the callback function.
There is currently no way of interrupting the client while it is waiting for a message.