send_aio {nanonext} | R Documentation |
Send Async
Description
Send data asynchronously over a connection (Socket, Context or Stream).
Usage
send_aio(con, data, mode = c("serial", "raw", "next"), timeout = NULL)
Arguments
con |
a Socket, Context or Stream. |
data |
an object (a vector, if mode = ‘raw’). |
mode |
[default 'serial'] character value or integer equivalent - one of ‘serial’ (1L) to send serialised R objects, ‘raw’ (2L) to send atomic vectors of any type as a raw byte vector, or ‘next’ (3L) - see ‘Send Modes’ section below. For Streams, ‘raw’ is the only option and this argument is ignored. |
timeout |
[default NULL] integer value in milliseconds or NULL, which applies a socket-specific default, usually the same as no timeout. |
Details
Async send is always non-blocking and returns a ‘sendAio’ immediately.
For a ‘sendAio’, the send result is available at $result
.
An ‘unresolved’ logical NA is returned if the async operation is
yet to complete. The resolved value will be zero on success, or else an
integer error code.
To wait for and check the result of the send operation, use
call_aio
on the returned ‘sendAio’ object.
Alternatively, to stop the async operation, use stop_aio
.
Value
A ‘sendAio’ (object of class ‘sendAio’) (invisibly).
Send Modes
The default mode ‘serial’ sends serialised R objects to ensure perfect reproducibility within R. When receiving, the corresponding mode ‘serial’ should be used.
Mode ‘raw’ sends atomic vectors of any type as a raw byte vector, and must be used when interfacing with external applications or raw system sockets, where R serialization is not in use. When receiving, the mode corresponding to the vector sent should be used.
Mode ‘next’ sends serialised R objects, with native extensions
enabled by next_config
. This configures custom
serialization and unserialization functions for reference objects. When
receiving, mode ‘serial’ should be used as ‘next’ sends are
fully compatible.
Examples
pub <- socket("pub", dial = "inproc://nanonext")
res <- send_aio(pub, data.frame(a = 1, b = 2), timeout = 100)
res
res$result
res <- send_aio(pub, "example message", mode = "raw", timeout = 100)
call_aio(res)$result
close(pub)