90 lines
2.3 KiB
Markdown
90 lines
2.3 KiB
Markdown
# webworkify
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launch a web worker that can require() in the browser with browserify
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# example
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First, a `main.js` file will launch the `worker.js` and print its output:
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``` js
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var work = require('webworkify');
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var w = work(require('./worker.js'));
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w.addEventListener('message', function (ev) {
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console.log(ev.data);
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});
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w.postMessage(4); // send the worker a message
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```
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then `worker.js` can `require()` modules of its own. The worker function lives
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inside of the `module.exports`:
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``` js
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var gamma = require('gamma');
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module.exports = function (self) {
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self.addEventListener('message',function (ev){
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var startNum = parseInt(ev.data); // ev.data=4 from main.js
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setInterval(function () {
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var r = startNum / Math.random() - 1;
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self.postMessage([ startNum, r, gamma(r) ]);
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}, 500);
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});
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};
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```
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Now after [browserifying](http://browserify.org) this example, the console will
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contain output from the worker:
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```
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[ 4, 0.09162078520553618, 10.421030346237066 ]
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[ 4, 2.026562457360466, 1.011522336481017 ]
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[ 4, 3.1853125018703716, 2.3887589540750214 ]
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[ 4, 5.6989969260510005, 72.40768854476167 ]
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[ 4, 8.679491643020487, 20427.19357947782 ]
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[ 4, 0.8528139834191428, 1.1098187157762498 ]
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[ 4, 8.068322137547542, 5785.928308309402 ]
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...
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```
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# methods
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``` js
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var work = require('webworkify')
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```
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## var w = work(require(modulePath))
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Return a new
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[web worker](https://developer.mozilla.org/en-US/docs/Web/API/Worker)
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from the module at `modulePath`.
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The file at `modulePath` should export its worker code in `module.exports` as a
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function that will be run with no arguments.
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Note that all the code outside of the `module.exports` function will be run in
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the main thread too so don't put any computationally intensive code in that
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part. It is necessary for the main code to `require()` the worker code to fetch
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the module reference and load `modulePath`'s dependency graph into the bundle
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output.
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## Worker.objectURL
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The worker `w` returned by `webworkify` has the property `objectURL` attached.
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`w.objectURL` refers to the Object URL that was used to pass the module's source
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to the worker, and can be cleaned up using `URL.revokeObjectURL()`. (See [example](https://github.com/substack/webworkify/blob/master/example/main.js))
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# install
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With [npm](https://npmjs.org) do:
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```
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npm install webworkify
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```
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# license
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MIT
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