vkurchatkin/nashorn-tasks

concurrent tasks for Nashorn

inspired by NSOperationQueue

Prerequisites

• Java 8;
• maven 3.x.x;
• node.js 0.10.x (optional);
• npm (optional);

Build

• mvn package or
• npm run build.

Run example

• npm run example or
• ./runtime example.js

Run tests

• npm test or
• ./runtime test/test.js

API

Require:

var tasks = require('tasks');

Create queue:

var queue = tasks.createQueue({ concurrency : 2 });

or use tasks as default queue.

Create a task:

var task = queue.createTask(function (numbers) {
  return numbers.reduce(function (p, q) {
    return p + q;
  }, 0);
}, [1, 2, 3]);

Caveats:

• task can't reference anything from outer scope;
• input and output are serialized via JSON.stringify;
• require doesn't work;

Set up dependencies:

var first = queue.createTask(function (numbers) {
  return numbers.map(function (n) {
    return n + 1;
  });
}, [1, 2, 3]);

var second = queue.createTask(function (numbers) {
  return numbers.reduce(function (p, q) {
    return p + q;
  }, 0);
});

second.addDependency(first);

first gets input (second argument of createTasks) as an argument. second has no input specified, so it gets output of it's dependencies.

Run queue:

queue.run();

This method blocks until queue is empty.

Check results:

console.log(first.result);
console.log(second.result);

License

MIT