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1 | 'use strict' |
2 | const { |
3 | isMainThread, parentPort |
4 | } = require('worker_threads') |
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5 | const { AsyncResource } = require('async_hooks') |
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6 | |
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7 | /** |
8 | * An example worker that will be always alive, you just need to extend this class if you want a static pool.<br> |
9 | * When this worker is inactive for more than 1 minute, it will send this info to the main thread,<br> |
10 | * if you are using DynamicThreadPool, the workers created after will be killed, the min num of thread will be guaranteed |
11 | * @author Alessandro Pio Ardizio |
12 | * @since 0.0.1 |
13 | */ |
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14 | class ThreadWorker extends AsyncResource { |
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15 | constructor (fn, opts) { |
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16 | super('worker-thread-pool:pioardi') |
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17 | this.opts = opts || {} |
18 | this.maxInactiveTime = this.opts.maxInactiveTime || (1000 * 60) |
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19 | this.async = !!this.opts.async |
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20 | this.lastTask = Date.now() |
21 | if (!fn) throw new Error('Fn parameter is mandatory') |
22 | // keep the worker active |
23 | if (!isMainThread) { |
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24 | this.interval = setInterval(this._checkAlive.bind(this), this.maxInactiveTime / 2) |
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25 | this._checkAlive.bind(this)() |
26 | } |
27 | parentPort.on('message', (value) => { |
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28 | if (value && value.data && value._id) { |
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29 | // here you will receive messages |
30 | // console.log('This is the main thread ' + isMainThread) |
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31 | if (this.async) { |
32 | this.runInAsyncScope(this._runAsync.bind(this), this, fn, value) |
33 | } else { |
34 | this.runInAsyncScope(this._run.bind(this), this, fn, value) |
35 | } |
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36 | } else if (value.parent) { |
37 | // save the port to communicate with the main thread |
38 | // this will be received once |
39 | this.parent = value.parent |
40 | } else if (value.kill) { |
41 | // here is time to kill this thread, just clearing the interval |
42 | clearInterval(this.interval) |
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43 | this.emitDestroy() |
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44 | } |
45 | }) |
46 | } |
47 | |
48 | _checkAlive () { |
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49 | if ((Date.now() - this.lastTask) > this.maxInactiveTime) { |
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50 | this.parent.postMessage({ kill: 1 }) |
51 | } |
52 | } |
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53 | |
54 | _run (fn, value) { |
55 | try { |
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56 | const res = fn(value.data) |
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57 | this.parent.postMessage({ data: res, _id: value._id }) |
58 | this.lastTask = Date.now() |
59 | } catch (e) { |
60 | this.parent.postMessage({ error: e, _id: value._id }) |
61 | this.lastTask = Date.now() |
62 | } |
63 | } |
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64 | |
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65 | _runAsync (fn, value) { |
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66 | fn(value.data).then(res => { |
67 | this.parent.postMessage({ data: res, _id: value._id }) |
68 | this.lastTask = Date.now() |
69 | }).catch(e => { |
70 | this.parent.postMessage({ error: e, _id: value._id }) |
71 | this.lastTask = Date.now() |
72 | }) |
73 | } |
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74 | } |
75 | |
76 | module.exports.ThreadWorker = ThreadWorker |