External: Duplex

Duplex

Namespace provided by the core module

Methods

end(chunk, encoding, callback){null}

Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the finish event.

Name Type Description
chunk string | Buffer

The data to write

encoding string

The encoding, if chunk is a String

callback function

Callback for when this chunk of data is flushed

This method will cause a stream in flowing-mode to stop emitting data events. Any data that becomes available will remain in the internal buffer.

pipe(destination, options){null}

This method pulls all the data out of a readable stream, and writes it to the supplied destination, automatically managing the flow so that the destination is not overwhelmed by a fast readable stream.

Name Type Description
destination Writable

The destination for writing data

options object optional

Pipe options

read(size){String|Buffer|null}

The read() method pulls some data out of the internal buffer and returns it. If there is no data available, then it will return null.

Name Type Description
size number

Optional argument to specify how much data to read.

This method will cause the readable stream to resume emitting data events.

setEncoding(encoding){null}

Call this function to cause the stream to return strings of the specified encoding instead of Buffer objects.

Name Type Description
encoding string

The encoding to use.

unpipe(destination){null}

This method will remove the hooks set up for a previous pipe() call.

Name Type Description
destination Writable optional

The destination for writing data

unshift(chunk){null}

This is useful in certain cases where a stream is being consumed by a parser, which needs to "un-consume" some data that it has optimistically pulled out of the source, so that the stream can be passed on to some other party.

Name Type Description
chunk Buffer | string

Chunk of data to unshift onto the read queue.

wrap(stream){null}

Versions of Node prior to v0.10 had streams that did not implement the entire Streams API as it is today. (See "Compatibility" below for more information.)

Name Type Description
stream Stream

An "old style" readable stream.

write(chunk, encoding, callback){boolean}

This method writes some data to the underlying system, and calls the supplied callback once the data has been fully handled.

Name Type Description
chunk string | Buffer

The data to write

encoding string

The encoding, if chunk is a String

callback function

Callback for when this chunk of data is flushed