vertx / io.vertx.core.streams / Pump

Pump

interface Pump

Pumps data from a ReadStream to a WriteStream and performs flow control where necessary to prevent the write stream buffer from getting overfull.

Instances of this class read items from a ReadStream and write them to a WriteStream. If data can be read faster than it can be written this could result in the write queue of the WriteStream growing without bound, eventually causing it to exhaust all available RAM.

To prevent this, after each write, instances of this class check whether the write queue of the is full, and if so, the ReadStream is paused, and a drainHandler is set on the WriteStream.

When the WriteStream has processed half of its backlog, the drainHandler will be called, which results in the pump resuming the ReadStream.

This class can be used to pump from any ReadStream to any WriteStream, e.g. from an io.vertx.core.http.HttpServerRequest to an io.vertx.core.file.AsyncFile, or from io.vertx.core.net.NetSocket to a io.vertx.core.http.WebSocket.

Please see the documentation for more information.

Author
Tim Fox

Properties

factory

static val factory: PumpFactory

Functions

numberPumped

abstract fun numberPumped(): Int

Return the total number of items pumped by this pump.

pump

open static fun <T : Any> pump(rs: ReadStream<T>, ws: WriteStream<T>): Pump

Create a new Pump with the given ReadStream and WriteStream

open static fun <T : Any> pump(rs: ReadStream<T>, ws: WriteStream<T>, writeQueueMaxSize: Int): Pump

Create a new Pump with the given ReadStream and WriteStream and writeQueueMaxSize

setWriteQueueMaxSize

abstract fun setWriteQueueMaxSize(maxSize: Int): Pump

Set the write queue max size to maxSize

start

abstract fun start(): Pump

Start the Pump. The Pump can be started and stopped multiple times.

stop

abstract fun stop(): Pump

Stop the Pump. The Pump can be started and stopped multiple times.