concur

Description:

concur

Get your Web Workers on the same page with Concur!
This package is intended to provide a simplified model for multithreaded web
applications using Web Workers. You can make a small change
(useWorkers: false) to run the same code asynchronously on the UI thread if
you want to debug your application in webdev serve.
Each worker is given a name and they communicate with each other using
message streams. If you want a worker to send a message to another worker,
just invoke Concur.send() and name the destination worker. If you want a
worker to listen for messages from another worker, just get a stream from
Concur.getChannel() using that worker's name, and then you can listen to
events on that stream.
Usage #
A simple usage example:
import 'package:concur/concur.dart';

/// Starting up a web application using Concur is simple!
void main() {
// Start your workers up using Concur.start() as shown here. Each worker
// method will be invoked once in a separate threading context.
Concur.start({
'main': (x) {
// This is the main thread, because the second argument to Concur.start()
// was 'main'.

// The getChannel() method establishes communication with the named sender
// and returns a stream of MessageEvents that you can parse and process.
// This is a single-consumer stream, you'll need to wrap it if you want
// multiple consumers.
// Subsequent invocations will return the same stream, which will probably
// already have a consumer attached. If you want more than one channel
// between the same pair of workers, you can multiplex over a single
// channel by sending JSON graphs with a property labeling their purpose.
x.getChannel('other').listen((x) => print(x.data));

// Workers can also send messages to themselves!
x.getChannel('main').listen((x) => print(x.data));

// Loopback messages like this will be handled in an asynchronous
// microtask without blocking the sender.
x.send('main', 'loopback');
},
'other': (x) {
// This is the worker thread, you can create as many of these as you like
// by adding more elements to the map with different names.

// The send() method sends the provided payload in the 'data' property of
// the MessageEvent received by the other worker. You can generally send
// any type of data that fits in a JSON object.
x.send('main', 'fnord');
}
}, 'main');

// If this is the main worker then the worker method is invoked synchronously,
// so this block runs after the main worker method returns, but before any
// message handlers have a chance to run.
// If this is a worker instance, this block will be run before the worker
// callback because the worker is actually waiting on a control message from
// the main thread that tells it which worker method it is running.
print('Concur initialization complete!');
}

// Output of this example will be the messages 'fnord' and 'loopback' printed
// from the main thread.
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Features and bugs #
Please send feature requests and bugs to the author at [email protected].