multipipe

What is multipipe?

The 'multipipe' npm package is a utility for creating a pipeline of streams in Node.js. It allows you to easily combine multiple streams into a single pipeline, handling errors and ensuring proper cleanup of resources.

What are multipipe's main functionalities?

Combining Multiple Streams

This feature allows you to combine multiple streams into a single pipeline. In this example, a file is read, decompressed using gzip, and then extracted using tar-stream. The 'multipipe' function handles the piping and error management.

const multipipe = require('multipipe');
const fs = require('fs');
const zlib = require('zlib');
const tar = require('tar-stream');

const extract = tar.extract();
extract.on('entry', (header, stream, next) => {
  stream.on('end', next);
  stream.resume();
});

const pipeline = multipipe(
  fs.createReadStream('archive.tar.gz'),
  zlib.createGunzip(),
  extract
);

pipeline.on('error', (err) => {
  console.error('Pipeline failed:', err);
});

pipeline.on('finish', () => {
  console.log('Pipeline succeeded');
});

Error Handling

This feature demonstrates how 'multipipe' handles errors in the pipeline. If any stream in the pipeline encounters an error, the 'error' event is emitted, and you can handle it appropriately. In this example, an error will occur because the input file does not exist.

const multipipe = require('multipipe');
const fs = require('fs');
const zlib = require('zlib');

const pipeline = multipipe(
  fs.createReadStream('nonexistentfile.gz'),
  zlib.createGunzip(),
  fs.createWriteStream('output.txt')
);

pipeline.on('error', (err) => {
  console.error('Pipeline error:', err);
});

Other packages similar to multipipe

pump

'pump' is a similar package that also helps in piping streams together and managing errors. It is simpler and more lightweight compared to 'multipipe', but it does not offer the same level of flexibility in terms of combining multiple streams.

stream-combiner2

'stream-combiner2' is another package that allows you to combine multiple streams into one. It is similar to 'multipipe' but focuses more on simplicity and ease of use. It also handles errors and ensures proper cleanup of resources.

README

multipipe

A better Stream#pipe that creates duplex streams and lets you handle errors in one place.

Example

var pipe = require('multipipe');

// pipe streams
var stream = pipe(streamA, streamB, streamC);

// centralized error handling
stream.on('error', fn);

// creates a new stream
source.pipe(stream).pipe(dest);

Duplex streams

Write to the pipe and you'll really write to the first stream, read from the pipe and you'll read from the last stream.

var stream = pipe(a, b, c);

source
  .pipe(stream)
  .pipe(destination);

In this example the flow of data is:

• source ->
• a ->
• b ->
• c ->
• destination

Error handling

Each pipe forwards the errors the streams it wraps emit, so you have one central place to handle errors:

var stream = pipe(a, b, c);

stream.on('error', function(err){
  // called three times
});

a.emit('error', new Error);
b.emit('error', new Error);
c.emit('error', new Error);

API

pipe(stream, ...)

Pass a variable number of streams and each will be piped to the next one.

A stream will be returned that wraps passed in streams in a way that errors will be forwarded and you can write to and/or read from it.

Installation

$ npm install multipipe

License

MIT