refactor: factor out dynamic worker creation
[poolifier.git] / src / pools / selection-strategies / abstract-worker-choice-strategy.ts
index aa370fe433e74065e4155d8612499abef5ec59fb..d9a573417ec2f96c0cbf68bc88a6931aeb68de29 100644 (file)
@@ -1,9 +1,11 @@
-import type { IPoolInternal } from '../pool-internal'
-import { PoolType } from '../pool-internal'
-import type { IPoolWorker } from '../pool-worker'
+import { cpus } from 'node:os'
+import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import type { IPool } from '../pool'
+import type { IWorker } from '../worker'
 import type {
   IWorkerChoiceStrategy,
-  RequiredStatistics
+  TaskStatisticsRequirements,
+  WorkerChoiceStrategyOptions
 } from './selection-strategies-types'
 
 /**
@@ -11,39 +13,226 @@ import type {
  *
  * @typeParam Worker - Type of worker which manages the strategy.
  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
- * @typeParam Response - Type of response of execution. This can only be serializable data.
+ * @typeParam Response - Type of execution response. This can only be serializable data.
  */
 export abstract class AbstractWorkerChoiceStrategy<
-  Worker extends IPoolWorker,
-  Data,
-  Response
+  Worker extends IWorker,
+  Data = unknown,
+  Response = unknown
 > implements IWorkerChoiceStrategy {
-  /** {@inheritDoc} */
-  public readonly isDynamicPool: boolean
-  /** {@inheritDoc} */
-  public requiredStatistics: RequiredStatistics = {
-    runTime: false,
-    avgRunTime: false
+  /**
+   * Toggles finding the last free worker node key.
+   */
+  private toggleFindLastFreeWorkerNodeKey: boolean = false
+  /** @inheritDoc */
+  public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
+    runTime: {
+      aggregate: false,
+      average: false,
+      median: false
+    },
+    waitTime: {
+      aggregate: false,
+      average: false,
+      median: false
+    },
+    elu: {
+      aggregate: false,
+      average: false,
+      median: false
+    }
   }
 
   /**
-   * Constructs a worker choice strategy attached to the pool.
+   * Constructs a worker choice strategy bound to the pool.
    *
    * @param pool - The pool instance.
+   * @param opts - The worker choice strategy options.
    */
   public constructor (
-    protected readonly pool: IPoolInternal<Worker, Data, Response>
+    protected readonly pool: IPool<Worker, Data, Response>,
+    protected opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
   ) {
-    this.isDynamicPool = this.pool.type === PoolType.DYNAMIC
-    this.choose.bind(this)
+    this.choose = this.choose.bind(this)
+  }
+
+  protected setTaskStatisticsRequirements (
+    opts: WorkerChoiceStrategyOptions
+  ): void {
+    if (
+      this.taskStatisticsRequirements.runTime.average &&
+      opts.runTime?.median === true
+    ) {
+      this.taskStatisticsRequirements.runTime.average = false
+      this.taskStatisticsRequirements.runTime.median = opts.runTime
+        .median as boolean
+    }
+    if (
+      this.taskStatisticsRequirements.runTime.median &&
+      opts.runTime?.median === false
+    ) {
+      this.taskStatisticsRequirements.runTime.average = true
+      this.taskStatisticsRequirements.runTime.median = opts.runTime
+        .median as boolean
+    }
+    if (
+      this.taskStatisticsRequirements.waitTime.average &&
+      opts.waitTime?.median === true
+    ) {
+      this.taskStatisticsRequirements.waitTime.average = false
+      this.taskStatisticsRequirements.waitTime.median = opts.waitTime
+        .median as boolean
+    }
+    if (
+      this.taskStatisticsRequirements.waitTime.median &&
+      opts.waitTime?.median === false
+    ) {
+      this.taskStatisticsRequirements.waitTime.average = true
+      this.taskStatisticsRequirements.waitTime.median = opts.waitTime
+        .median as boolean
+    }
+    if (
+      this.taskStatisticsRequirements.elu.average &&
+      opts.elu?.median === true
+    ) {
+      this.taskStatisticsRequirements.elu.average = false
+      this.taskStatisticsRequirements.elu.median = opts.elu.median as boolean
+    }
+    if (
+      this.taskStatisticsRequirements.elu.median &&
+      opts.elu?.median === false
+    ) {
+      this.taskStatisticsRequirements.elu.average = true
+      this.taskStatisticsRequirements.elu.median = opts.elu.median as boolean
+    }
   }
 
-  /** {@inheritDoc} */
+  /** @inheritDoc */
   public abstract reset (): boolean
 
-  /** {@inheritDoc} */
+  /** @inheritDoc */
+  public abstract update (workerNodeKey: number): boolean
+
+  /** @inheritDoc */
   public abstract choose (): number
 
-  /** {@inheritDoc} */
-  public abstract remove (workerKey: number): boolean
+  /** @inheritDoc */
+  public abstract remove (workerNodeKey: number): boolean
+
+  /** @inheritDoc */
+  public setOptions (opts: WorkerChoiceStrategyOptions): void {
+    opts = opts ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+    this.setTaskStatisticsRequirements(opts)
+    this.opts = opts
+  }
+
+  /**
+   * Finds a free worker node key.
+   *
+   * @returns The free worker node key or `-1` if there is no free worker node.
+   */
+  protected findFreeWorkerNodeKey (): number {
+    if (this.toggleFindLastFreeWorkerNodeKey) {
+      this.toggleFindLastFreeWorkerNodeKey = false
+      return this.findLastFreeWorkerNodeKey()
+    }
+    this.toggleFindLastFreeWorkerNodeKey = true
+    return this.findFirstFreeWorkerNodeKey()
+  }
+
+  /**
+   * Gets the worker task runtime.
+   * If the task statistics require the average runtime, the average runtime is returned.
+   * If the task statistics require the median runtime , the median runtime is returned.
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns The worker task runtime.
+   */
+  protected getWorkerTaskRunTime (workerNodeKey: number): number {
+    return this.taskStatisticsRequirements.runTime.median
+      ? this.pool.workerNodes[workerNodeKey].workerUsage.runTime.median
+      : this.pool.workerNodes[workerNodeKey].workerUsage.runTime.average
+  }
+
+  /**
+   * Gets the worker task wait time.
+   * If the task statistics require the average wait time, the average wait time is returned.
+   * If the task statistics require the median wait time, the median wait time is returned.
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns The worker task wait time.
+   */
+  protected getWorkerTaskWaitTime (workerNodeKey: number): number {
+    return this.taskStatisticsRequirements.waitTime.median
+      ? this.pool.workerNodes[workerNodeKey].workerUsage.runTime.median
+      : this.pool.workerNodes[workerNodeKey].workerUsage.runTime.average
+  }
+
+  /**
+   * Gets the worker task ELU.
+   * If the task statistics require the average ELU, the average ELU is returned.
+   * If the task statistics require the median ELU, the median ELU is returned.
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns The worker task ELU.
+   */
+  protected getWorkerTaskElu (workerNodeKey: number): number {
+    return this.taskStatisticsRequirements.elu.median
+      ? this.pool.workerNodes[workerNodeKey].workerUsage.elu.active.median
+      : this.pool.workerNodes[workerNodeKey].workerUsage.elu.active.average
+  }
+
+  protected computeDefaultWorkerWeight (): number {
+    let cpusCycleTimeWeight = 0
+    for (const cpu of cpus()) {
+      // CPU estimated cycle time
+      const numberOfDigits = cpu.speed.toString().length - 1
+      const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits))
+      cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits)
+    }
+    return Math.round(cpusCycleTimeWeight / cpus().length)
+  }
+
+  /**
+   * Finds the first free worker node key based on the number of tasks the worker has applied.
+   *
+   * If a worker is found with `0` executing tasks, it is detected as free and its worker node key is returned.
+   *
+   * If no free worker is found, `-1` is returned.
+   *
+   * @returns A worker node key if there is one, `-1` otherwise.
+   */
+  private findFirstFreeWorkerNodeKey (): number {
+    return this.pool.workerNodes.findIndex(workerNode => {
+      return workerNode.workerUsage.tasks.executing === 0
+    })
+  }
+
+  /**
+   * Finds the last free worker node key based on the number of tasks the worker has applied.
+   *
+   * If a worker is found with `0` executing tasks, it is detected as free and its worker node key is returned.
+   *
+   * If no free worker is found, `-1` is returned.
+   *
+   * @returns A worker node key if there is one, `-1` otherwise.
+   */
+  private findLastFreeWorkerNodeKey (): number {
+    // It requires node >= 18.0.0:
+    // return this.workerNodes.findLastIndex(workerNode => {
+    //   return workerNode.workerUsage.tasks.executing === 0
+    // })
+    for (
+      let workerNodeKey = this.pool.workerNodes.length - 1;
+      workerNodeKey >= 0;
+      workerNodeKey--
+    ) {
+      if (
+        this.pool.workerNodes[workerNodeKey].workerUsage.tasks.executing === 0
+      ) {
+        return workerNodeKey
+      }
+    }
+    return -1
+  }
 }