nanonext (version 1.4.0)

dial: Dial an Address from a Socket

Description

Creates a new Dialer and binds it to a Socket.

Usage

dial(
  socket,
  url = "inproc://nanonext",
  tls = NULL,
  autostart = TRUE,
  error = FALSE
)

Value

Invisibly, an integer exit code (zero on success). A new Dialer (object of class ‘nanoDialer’ and ‘nano’) is created and bound to the Socket if successful.

Arguments

socket

a Socket.

url

[default 'inproc://nanonext'] a URL to dial, specifying the transport and address as a character string e.g. 'inproc://anyvalue' or 'tcp://127.0.0.1:5555' (see transports).

tls

[default NULL] for secure tls+tcp:// or wss:// connections only, provide a TLS configuration object created by tls_config.

autostart

[default TRUE] whether to start the dialer (by default asynchronously). Set to NA to start synchronously - this is less resilient if a connection is not immediately possible, but avoids subtle errors from attempting to use the socket before an asynchronous dial has completed. Set to FALSE if setting configuration options on the dialer as it is not generally possible to change these once started.

error

[default FALSE] behaviour on error: if FALSE, returns an integer exit code accompanied by a warning, or, if TRUE, generates an error and halts execution.

Further details

Dialers and Listeners are always associated with a single socket. A given socket may have multiple Listeners and/or multiple Dialers.

The client/server relationship described by dialer/listener is completely orthogonal to any similar relationship in the protocols. For example, a rep socket may use a dialer to connect to a listener on an req socket. This orthogonality can lead to innovative solutions to otherwise challenging communications problems.

Any configuration options on the dialer/listener should be set by opt<- before starting the dialer/listener with start.

Dialers/Listeners may be destroyed by close. They are also closed when their associated socket is closed.

Details

To view all Dialers bound to a socket use $dialer on the socket, which returns a list of Dialer objects. To access any individual Dialer (e.g. to set options on it), index into the list e.g. $dialer[[1]] to return the first Dialer.

A Dialer is an external pointer to a dialer object, which creates a single outgoing connection at a time. If the connection is broken, or fails, the dialer object will automatically attempt to reconnect, and will keep doing so until the dialer or socket is destroyed.

Examples

socket <- socket("rep")
dial(socket, url = "tcp://127.0.0.1:6545", autostart = FALSE)
socket$dialer
start(socket$dialer[[1]])
socket$dialer
close(socket$dialer[[1]])
close(socket)

nano <- nano("bus")
nano$dial(url = "tcp://127.0.0.1:6546", autostart = FALSE)
nano$dialer
nano$dialer_start()
nano$dialer
close(nano$dialer[[1]])
nano$close()