Skip to content
master
Switch branches/tags
Code

Latest commit

Files

Permalink
Failed to load latest commit information.
Type
Name
Latest commit message
Commit time
Jul 30, 2013
Sep 5, 2019

parallel-transform

Transform stream for Node.js that allows you to run your transforms in parallel without changing the order of the output.

npm install parallel-transform

It is easy to use

var transform = require('parallel-transform');

var stream = transform(10, function(data, callback) { // 10 is the parallism level
	setTimeout(function() {
		callback(null, data);
	}, Math.random() * 1000);
});

for (var i = 0; i < 10; i++) {
	stream.write(''+i);
}
stream.end();

stream.on('data', function(data) {
	console.log(data); // prints 0,1,2,...
});
stream.on('end', function() {
	console.log('stream has ended');
});

If you run the above example you'll notice that it runs in parallel (does not take ~1 second between each print) and that the order is preserved

Stream options

All transforms are Node 0.10 streams. Per default they are created with the options {objectMode:true}. If you want to use your own stream options pass them as the second parameter

var stream = transform(10, {objectMode:false}, function(data, callback) {
	// data is now a buffer
	callback(null, data);
});

fs.createReadStream('filename').pipe(stream).pipe(process.stdout);

Unordered

Passing the option {ordered:false} will output the data as soon as it's processed by a transform, without waiting to respect the order.

License

MIT

About

Transform stream for Node.js that allows you to run your transforms in parallel without changing the order

Resources

License

Sponsor this project

 

Packages

No packages published