| 1 | import { AsyncResource } from 'node:async_hooks' |
| 2 | import type { Worker } from 'node:cluster' |
| 3 | import type { MessagePort } from 'node:worker_threads' |
| 4 | import type { |
| 5 | MessageValue, |
| 6 | WorkerAsyncFunction, |
| 7 | WorkerFunction, |
| 8 | WorkerSyncFunction |
| 9 | } from '../utility-types' |
| 10 | import { EMPTY_FUNCTION } from '../utils' |
| 11 | import type { KillBehavior, WorkerOptions } from './worker-options' |
| 12 | import { KillBehaviors } from './worker-options' |
| 13 | |
| 14 | const DEFAULT_MAX_INACTIVE_TIME = 60000 |
| 15 | const DEFAULT_KILL_BEHAVIOR: KillBehavior = KillBehaviors.SOFT |
| 16 | |
| 17 | /** |
| 18 | * Base class that implements some shared logic for all poolifier workers. |
| 19 | * |
| 20 | * @typeParam MainWorker - Type of main worker. |
| 21 | * @typeParam Data - Type of data this worker receives from pool's execution. This can only be serializable data. |
| 22 | * @typeParam Response - Type of response the worker sends back to the main worker. This can only be serializable data. |
| 23 | */ |
| 24 | export abstract class AbstractWorker< |
| 25 | MainWorker extends Worker | MessagePort, |
| 26 | Data = unknown, |
| 27 | Response = unknown |
| 28 | > extends AsyncResource { |
| 29 | /** |
| 30 | * Timestamp of the last task processed by this worker. |
| 31 | */ |
| 32 | protected lastTaskTimestamp!: number |
| 33 | /** |
| 34 | * Handler id of the `aliveInterval` worker alive check. |
| 35 | */ |
| 36 | protected readonly aliveInterval?: NodeJS.Timeout |
| 37 | /** |
| 38 | * Constructs a new poolifier worker. |
| 39 | * |
| 40 | * @param type - The type of async event. |
| 41 | * @param isMain - Whether this is the main worker or not. |
| 42 | * @param fn - Function processed by the worker when the pool's `execution` function is invoked. |
| 43 | * @param mainWorker - Reference to main worker. |
| 44 | * @param opts - Options for the worker. |
| 45 | */ |
| 46 | public constructor ( |
| 47 | type: string, |
| 48 | protected readonly isMain: boolean, |
| 49 | fn: WorkerFunction<Data, Response>, |
| 50 | protected mainWorker: MainWorker | undefined | null, |
| 51 | protected readonly opts: WorkerOptions = { |
| 52 | /** |
| 53 | * The kill behavior option on this worker or its default value. |
| 54 | */ |
| 55 | killBehavior: DEFAULT_KILL_BEHAVIOR, |
| 56 | /** |
| 57 | * The maximum time to keep this worker alive while idle. |
| 58 | * The pool automatically checks and terminates this worker when the time expires. |
| 59 | */ |
| 60 | maxInactiveTime: DEFAULT_MAX_INACTIVE_TIME |
| 61 | } |
| 62 | ) { |
| 63 | super(type) |
| 64 | this.checkWorkerOptions(this.opts) |
| 65 | this.checkFunctionInput(fn) |
| 66 | if (!this.isMain) { |
| 67 | this.lastTaskTimestamp = performance.now() |
| 68 | this.aliveInterval = setInterval( |
| 69 | this.checkAlive.bind(this), |
| 70 | (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2 |
| 71 | ) |
| 72 | this.checkAlive.bind(this)() |
| 73 | } |
| 74 | |
| 75 | this.mainWorker?.on( |
| 76 | 'message', |
| 77 | (message: MessageValue<Data, MainWorker>) => { |
| 78 | this.messageListener(message, fn) |
| 79 | } |
| 80 | ) |
| 81 | } |
| 82 | |
| 83 | private checkWorkerOptions (opts: WorkerOptions): void { |
| 84 | this.opts.killBehavior = opts.killBehavior ?? DEFAULT_KILL_BEHAVIOR |
| 85 | this.opts.maxInactiveTime = |
| 86 | opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME |
| 87 | this.opts.async = opts.async ?? false |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Checks if the `fn` parameter is passed to the constructor. |
| 92 | * |
| 93 | * @param fn - The function that should be defined. |
| 94 | */ |
| 95 | private checkFunctionInput (fn: WorkerFunction<Data, Response>): void { |
| 96 | if (fn == null) throw new Error('fn parameter is mandatory') |
| 97 | if (typeof fn !== 'function') { |
| 98 | throw new TypeError('fn parameter is not a function') |
| 99 | } |
| 100 | if (fn.constructor.name === 'AsyncFunction' && this.opts.async === false) { |
| 101 | throw new Error( |
| 102 | 'fn parameter is an async function, please set the async option to true' |
| 103 | ) |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Worker message listener. |
| 109 | * |
| 110 | * @param message - Message received. |
| 111 | * @param fn - Function processed by the worker when the pool's `execution` function is invoked. |
| 112 | */ |
| 113 | protected messageListener ( |
| 114 | message: MessageValue<Data, MainWorker>, |
| 115 | fn: WorkerFunction<Data, Response> |
| 116 | ): void { |
| 117 | if (message.id != null && message.data != null) { |
| 118 | // Task message received |
| 119 | if (this.opts.async === true) { |
| 120 | this.runInAsyncScope(this.runAsync.bind(this), this, fn, message) |
| 121 | } else { |
| 122 | this.runInAsyncScope(this.run.bind(this), this, fn, message) |
| 123 | } |
| 124 | } else if (message.parent != null) { |
| 125 | // Main worker reference message received |
| 126 | this.mainWorker = message.parent |
| 127 | } else if (message.kill != null) { |
| 128 | // Kill message received |
| 129 | this.aliveInterval != null && clearInterval(this.aliveInterval) |
| 130 | this.emitDestroy() |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Returns the main worker. |
| 136 | * |
| 137 | * @returns Reference to the main worker. |
| 138 | */ |
| 139 | protected getMainWorker (): MainWorker { |
| 140 | if (this.mainWorker == null) { |
| 141 | throw new Error('Main worker was not set') |
| 142 | } |
| 143 | return this.mainWorker |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * Sends a message to the main worker. |
| 148 | * |
| 149 | * @param message - The response message. |
| 150 | */ |
| 151 | protected abstract sendToMainWorker (message: MessageValue<Response>): void |
| 152 | |
| 153 | /** |
| 154 | * Checks if the worker should be terminated, because its living too long. |
| 155 | */ |
| 156 | protected checkAlive (): void { |
| 157 | if ( |
| 158 | performance.now() - this.lastTaskTimestamp > |
| 159 | (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) |
| 160 | ) { |
| 161 | this.sendToMainWorker({ kill: this.opts.killBehavior }) |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * Handles an error and convert it to a string so it can be sent back to the main worker. |
| 167 | * |
| 168 | * @param e - The error raised by the worker. |
| 169 | * @returns Message of the error. |
| 170 | */ |
| 171 | protected handleError (e: Error | string): string { |
| 172 | return e as string |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * Runs the given function synchronously. |
| 177 | * |
| 178 | * @param fn - Function that will be executed. |
| 179 | * @param message - Input data for the given function. |
| 180 | */ |
| 181 | protected run ( |
| 182 | fn: WorkerSyncFunction<Data, Response>, |
| 183 | message: MessageValue<Data> |
| 184 | ): void { |
| 185 | try { |
| 186 | const startTimestamp = performance.now() |
| 187 | const res = fn(message.data) |
| 188 | const runTime = performance.now() - startTimestamp |
| 189 | this.sendToMainWorker({ |
| 190 | data: res, |
| 191 | id: message.id, |
| 192 | runTime |
| 193 | }) |
| 194 | } catch (e) { |
| 195 | const err = this.handleError(e as Error) |
| 196 | this.sendToMainWorker({ error: err, id: message.id }) |
| 197 | } finally { |
| 198 | !this.isMain && (this.lastTaskTimestamp = performance.now()) |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | /** |
| 203 | * Runs the given function asynchronously. |
| 204 | * |
| 205 | * @param fn - Function that will be executed. |
| 206 | * @param message - Input data for the given function. |
| 207 | */ |
| 208 | protected runAsync ( |
| 209 | fn: WorkerAsyncFunction<Data, Response>, |
| 210 | message: MessageValue<Data> |
| 211 | ): void { |
| 212 | const startTimestamp = performance.now() |
| 213 | fn(message.data) |
| 214 | .then(res => { |
| 215 | const runTime = performance.now() - startTimestamp |
| 216 | this.sendToMainWorker({ |
| 217 | data: res, |
| 218 | id: message.id, |
| 219 | runTime |
| 220 | }) |
| 221 | return null |
| 222 | }) |
| 223 | .catch(e => { |
| 224 | const err = this.handleError(e as Error) |
| 225 | this.sendToMainWorker({ error: err, id: message.id }) |
| 226 | }) |
| 227 | .finally(() => { |
| 228 | !this.isMain && (this.lastTaskTimestamp = performance.now()) |
| 229 | }) |
| 230 | .catch(EMPTY_FUNCTION) |
| 231 | } |
| 232 | } |