send {nanonext} | R Documentation |
Send
Description
Send data over a connection (Socket, Context or Stream).
Usage
send(con, data, mode = c("serial", "raw"), block = NULL, pipe = 0L)
Arguments
con |
a Socket, Context or Stream. |
data |
an object (a vector, if |
mode |
[default 'serial'] character value or integer equivalent -
either |
block |
[default NULL] which applies the connection default (see
section 'Blocking' below). Specify logical |
pipe |
[default 0L] only applicable to Sockets using the 'poly' protocol, an integer pipe ID if directing the send via a specific pipe. |
Value
An integer exit code (zero on success).
Blocking
For Sockets and Contexts: the default behaviour is non-blocking with
block = FALSE
. This will return immediately with an error if the message
could not be queued for sending. Certain protocol / transport combinations
may limit the number of messages that can be queued if they have yet to be
received.
For Streams: the default behaviour is blocking with block = TRUE
. This will
wait until the send has completed. Set a timeout to ensure that the function
returns under all scenarios. As the underlying implementation uses an
asynchronous send with a wait, it is recommended to set a small positive
value for block
rather than FALSE
.
Send Modes
The default mode "serial"
sends serialised R objects to ensure perfect
reproducibility within R. When receiving, the corresponding mode "serial"
should be used. Custom serialization and unserialization functions for
reference objects may be enabled by the function serial_config()
.
Mode "raw"
sends atomic vectors of any type as a raw byte vector, and must
be used when interfacing with external applications or raw system sockets,
where R serialization is not in use. When receiving, the mode corresponding
to the vector sent should be used.
See Also
send_aio()
for asynchronous send.
Examples
pub <- socket("pub", dial = "inproc://nanonext")
send(pub, data.frame(a = 1, b = 2))
send(pub, c(10.1, 20.2, 30.3), mode = "raw", block = 100)
close(pub)
req <- socket("req", listen = "inproc://nanonext")
rep <- socket("rep", dial = "inproc://nanonext")
ctx <- context(req)
send(ctx, data.frame(a = 1, b = 2), block = 100)
msg <- recv_aio(rep, timeout = 100)
send(ctx, c(1.1, 2.2, 3.3), mode = "raw", block = 100)
close(req)
close(rep)