InventoryTrack/node_modules/duplexer3/readme.md
2022-11-02 22:16:03 -04:00

2.0 KiB

duplexer3

Like duplexer2 but using Streams3 without readable-stream dependency

var stream = require("stream");
var duplexer3 = require("duplexer3");

var writable = new stream.Writable({objectMode: true}),
		readable = new stream.Readable({objectMode: true});

writable._write = function _write(input, encoding, done) {
	if (readable.push(input)) {
		return done();
	} else {
		readable.once("drain", done);
	}
};

readable._read = function _read(n) {
	// no-op
};

// simulate the readable thing closing after a bit
writable.once("finish", function() {
	setTimeout(function() {
		readable.push(null);
	}, 500);
});

var duplex = duplexer3(writable, readable);

duplex.on("data", function(e) {
	console.log("got data", JSON.stringify(e));
});

duplex.on("finish", function() {
	console.log("got finish event");
});

duplex.on("end", function() {
	console.log("got end event");
});

duplex.write("oh, hi there", function() {
	console.log("finished writing");
});

duplex.end(function() {
	console.log("finished ending");
});
got data "oh, hi there"
finished writing
got finish event
finished ending
got end event

Overview

This is a reimplementation of duplexer using the Streams3 API which is standard in Node as of v4. Everything largely works the same.

Install

npm install duplexer3

API

duplexer3

Creates a new DuplexWrapper object, which is the actual class that implements most of the fun stuff. All that fun stuff is hidden. DON'T LOOK.

duplexer3([options], writable, readable)
const duplex = duplexer3(new stream.Writable(), new stream.Readable());

Arguments

  • options - an object specifying the regular stream.Duplex options, as well as the properties described below.
  • writable - a writable stream
  • readable - a readable stream

Options

  • bubbleErrors - a boolean value that specifies whether to bubble errors from the underlying readable/writable streams. Default is true.