wire-runtime/com.squareup.wire/MessageSink

MessageSink

expect interface MessageSink<in T : Any>

A writable stream of messages.

Typical implementations will immediately encode messages and enqueue them for transmission, such as for client-to-server or server-to-client networking. But this interface is not limited to 1-1 networking use cases and implementations may persist, broadcast, validate, or take any other action with the messages.

There is no flushing mechanism. Messages are flushed one-by-one as they are written. This minimizes latency at a potential cost of throughput.

On its own this offers no guarantees that messages are delivered. For example, a message may accepted by write could be lost due to a network partition or crash. It is the caller's responsibility to confirm delivery and to retransmit as necessary.

It is possible for a writer to saturate the transmission channel, such as when a writer writes faster than the corresponding reader can read. In such cases calls to write will block until there is capacity in the outbound channel. You may use this as a basic backpressure mechanism. You should ensure that such backpressure propagates to the originator of outbound messages.

Instances of this interface are not safe for concurrent use.

actual interface MessageSink<in T : Any>

actual interface MessageSink<in T : Any> : Closeable

actual interface MessageSink<in T : Any>

Functions

cancel

expect abstract fun cancel()

Truncate this stream abnormally. This attempts to signal to readers of this data that it is incomplete. Note that unlike some cancel methods this is not safe for concurrent use.

actual abstract fun cancel()

expect abstract fun close()

Terminate the stream and release its resources. If this has not been canceled this signals a normal completion of the stream.

actual abstract fun close()

abstract override fun close()

actual abstract fun close()

write

expect abstract fun write(message: T)

Encode message to bytes and enqueue the bytes for delivery, waiting if necessary until the delivery channel has capacity for the encoded message.

actual abstract fun write(message: T)