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https://github.com/avoidwork/tiny-worker
Tiny WebWorker for the Server
https://github.com/avoidwork/tiny-worker
node nodejs worker-script workers
Last synced: 5 days ago
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Tiny WebWorker for the Server
- Host: GitHub
- URL: https://github.com/avoidwork/tiny-worker
- Owner: avoidwork
- License: bsd-3-clause
- Created: 2015-09-29T18:35:00.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2022-10-22T21:17:35.000Z (about 2 years ago)
- Last Synced: 2024-10-18T07:30:51.518Z (17 days ago)
- Topics: node, nodejs, worker-script, workers
- Language: JavaScript
- Homepage: http://avoidwork.github.io/tiny-worker
- Size: 203 KB
- Stars: 245
- Watchers: 9
- Forks: 23
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
# tiny-worker
Tiny WebWorker for Server
`require()` is available for flexible inline Worker scripts. Optional parameters `args` Array & `options` Object; see `child_process.fork()` documentation.
[](http://travis-ci.org/avoidwork/tiny-worker)
## Example
#### Creating a Worker from a file
The worker script:
```javascript
onmessage = function (ev) {
postMessage(ev.data);
};
```
The core script:
```javascript
var Worker = require("tiny-worker");
var worker = new Worker("repeat.js");
worker.onmessage = function (ev) {
console.log(ev.data);
worker.terminate();
};
worker.postMessage("Hello World!");
```
#### Enable ES6 import/export within Worker file
The worker helper script (helper.js):
```javascript
export const dataFormatter = (data) => {
return `${data} World!`;
};
```
The worker script (repeat.js):
```javascript
import { dataFormatter } from "./helper";
onmessage = function (ev) {
const data = dataFormatter(ev.data);
postMessage(data);
};
```
The core script:
```javascript
var Worker = require("tiny-worker");
var worker = new Worker("repeat.js", [], {esm: true});
worker.onmessage = function (ev) {
console.log(ev.data);
worker.terminate();
};
worker.postMessage("Hello");
```
#### Creating a Worker from a Function
```javascript
var Worker = require("tiny-worker");
var worker = new Worker(function () {
self.onmessage = function (ev) {
postMessage(ev.data);
};
});
worker.onmessage = function (ev) {
console.log(ev.data);
worker.terminate();
};
worker.postMessage("Hello World!");
```
# Debugging
To be able to debug a child process, it must have a differnt debug port than the parent.
Tiny worker does this by adding a random port within a range to the parents debug port.
The default Range is `[1, 300]`, it can be changed with the `setRange(min, max)` method.
To disable any automatic port redirection set `options.noDebugRedirection = true`.
### automatic redirection
```javascript
//parent is started with '--debug=1234'
var Worker = require("tiny-worker");
Worker.setRange(2, 20);
var worker = new Worker(function () {
postMessage(process.debugPort);
});
worker.onmessage = function (ev) {
console.log(ev.data); //prints any number between 1236 and 1254
worker.terminate();
}
```
### manual redirection
```javascript
//parent is started with '--debug=1234'
var Worker = require("tiny-worker");
var worker = new Worker(function () {
postMessage(process.debugPort);
}, [], {noDebugRedirection: true, execArgv: ["--debug=1235"]});
worker.onmessage = function (ev) {
console.log(ev.data); //prints 1235
worker.terminate();
}
```
## Properties
#### onmessage
Message handler, accepts an `Event`
#### onerror
Error handler, accepts an `Event`
## API
#### addEventListener(event, fn)
Adds an event listener
#### postMessage()
Broadcasts a message to the `Worker`
#### terminate()
Terminates the `Worker`
#### static setRange(min, max)
Sets range for debug ports, only affects current process.
Returns true if successful.
## FAQ
1. I have an orphaned child process that lives on past the parent process' lifespan
* Most likely a `SIGTERM` or `SIGINT` is not reaching the child process
2. How do I insure all process are terminated?
* In your core script register a listener for `SIGTERM` or `SIGINT` via `process.on()` which terminates (all) worker process(es) and then gracefully shutdowns via `process.exit(0);`
3. Why `SIGTERM` or `SIGINT`?
* Unix/BSD will work with `SIGTERM`, but if you also need to support Windows use `SIGINT`
## License
Copyright (c) 2019 Jason Mulligan
Licensed under the BSD-3 license