ordered-read-streams

What is ordered-read-streams?

The ordered-read-streams npm package allows you to combine multiple readable streams into a single readable stream, ensuring that the data from each stream is read in the order the streams were provided. This can be particularly useful when you need to process multiple streams sequentially.

What are ordered-read-streams's main functionalities?

Combining Multiple Streams

This feature allows you to combine multiple readable streams into a single stream. The data from each stream is read in the order the streams were provided. In this example, the contents of 'file1.txt', 'file2.txt', and 'file3.txt' are read sequentially and output to the console.

const OrderedReadStreams = require('ordered-read-streams');
const fs = require('fs');

const stream1 = fs.createReadStream('file1.txt');
const stream2 = fs.createReadStream('file2.txt');
const stream3 = fs.createReadStream('file3.txt');

const combinedStream = new OrderedReadStreams([stream1, stream2, stream3]);

combinedStream.on('data', (chunk) => {
  console.log(chunk.toString());
});

combinedStream.on('end', () => {
  console.log('All streams have been read in order.');
});

Other packages similar to ordered-read-streams

multistream

The multistream package also allows you to combine multiple streams into a single stream. However, unlike ordered-read-streams, multistream provides more flexibility by allowing you to dynamically add streams during the reading process. This can be useful if the streams to be combined are not known upfront.

merge-stream

The merge-stream package allows you to merge multiple streams into one. Unlike ordered-read-streams, merge-stream does not guarantee the order of the streams. It is useful when you need to process multiple streams concurrently and do not require the data to be in a specific order.

stream-combiner2

The stream-combiner2 package allows you to combine multiple streams into a pipeline. While it does not specifically focus on maintaining the order of streams, it is useful for creating complex stream processing pipelines where the output of one stream is the input to another.

README

ordered-read-streams

Combines array of streams into one read stream in strict order.

Installation

npm install ordered-read-streams

Overview

ordered-read-streams handles all data/errors from input streams in parallel, but emits data/errors in strict order in which streams are passed to constructor. This is objectMode = true stream.

Example

var through = require('through2');
var Ordered = require('ordered-read-streams');

var s1 = through.obj(function (data, enc, next) {
  var self = this;
  setTimeout(function () {
    self.push(data);
    next();
  }, 200)
});
var s2 = through.obj(function (data, enc, next) {
  var self = this;
  setTimeout(function () {
    self.push(data);
    next();
  }, 30)
});
var s3 = through.obj(function (data, enc, next) {
  var self = this;
  setTimeout(function () {
    self.push(data);
    next();
  }, 100)
});

var streams = new Ordered([s1, s2, s3]);
streams.on('data', function (data) {
  console.log(data);
})

s1.write('stream 1');
s1.end();

s2.write('stream 2');
s2.end();

s3.write('stream 3');
s3.end();

Ouput will be:

stream 1
stream 2
stream 3

Licence

MIT

Changelog

2.0.0 (2022-10-10)

⚠ BREAKING CHANGES

• Avoid eagerly reading streams
• Destroy all streams correctly when another is destroyed
• Switch to streamx (#27)
• Normalize repository, dropping node <10.13 support (#25)

Features

• Avoid eagerly reading streams (edb9aa1)
• Ensure readable does not end until read from (87c871c)
• Provide addSource function on the OrderedReadable stream (#28) (87c871c)
• Switch to streamx (#27) (edb9aa1)

Bug Fixes

• Destroy all streams correctly when another is destroyed (edb9aa1)

Miscellaneous Chores

• Normalize repository, dropping node <10.13 support (#25) (f6e5671)