Batched Send and Receive

At target rates the R call boundary is a first-order cost. mizu_send_batch() moves a list of payloads in a single .Call and publishes them to the peer in one batched tail store. mizu_recv_batch() drains up to n messages in a single park cycle and a single batched head publication.

Usage

mizu_send_batch(ch, xs)

mizu_recv_batch(ch, n = 256L, timeout = Inf)

Arguments

ch

a channel handle from mizu_channel() (or the ch binding inside a peer expression).

xs

a list of payloads.

n

maximum number of messages to return.

timeout

seconds to wait for a message before returning the mizu_timeout sentinel. Inf (the default) waits indefinitely; 0 does not wait.

Value

mizu_send_batch() returns the number of messages accepted. This is less than length(xs) when the ring filled or the channel closed midway. Send the next element with mizu_send() to learn which. mizu_recv_batch() waits for the first message like mizu_recv() and returns its sentinels on timeout, close, or peer death. It then returns a list of 1 to n already-published messages without waiting further. A batch that reaches a message it cannot read (a foreign Python payload) returns what it read before it, and the failure surfaces on the next receive, which raises like mizu_recv() — as does the batch itself when the first message is the one declined.

Examples

ch <- mizu_channel(quote(mizu_send_batch(ch, mizu_recv_batch(ch, 3L))))
mizu_send_batch(ch, list(1, 2, 3))
#> [1] 3
mizu_recv_batch(ch, 3L, timeout = 5)
#> [[1]]
#> [1] 1
#> 
#> [[2]]
#> [1] 2
#> 
#> [[3]]
#> [1] 3
#> 
mizu_close(ch)