| 1 | {"version":3,"file":"pixi-object-pool.js","sources":["../src/AverageProvider.ts","../src/ObjectPool.ts","../src/ObjectPoolFactory.ts"],"sourcesContent":["/**\n * Provides the exponential moving average of a sequence.\n *\n * Ignored because not directly exposed.\n *\n * @internal\n * @ignore\n * @class\n */\nexport class AverageProvider\n{\n private _history: number[];\n private _decayRatio: number;\n\n private _currentIndex: number;\n private _average: number;\n\n /**\n * @ignore\n * @param {number} windowSize - no. of inputs used to calculate window\n * @param {number} decayRatio - quantifies the weight of previous values (b/w 0 and 1)\n */\n constructor(windowSize: number, decayRatio: number)\n {\n this._history = new Array(windowSize);\n this._decayRatio = decayRatio;\n\n this._currentIndex = 0;\n\n for (let i = 0; i < windowSize; i++)\n {\n this._history[i] = 0;\n }\n }\n\n /**\n * @ignore\n * @param {number} input - the next value in the sequence\n * @returns {number} - the moving average\n */\n next(input: number): number\n {\n const { _history: history, _decayRatio: decayRatio } = this;\n const historyLength = history.length;\n\n this._currentIndex = this._currentIndex < historyLength - 1 ? this._currentIndex + 1 : 0;\n history[this._currentIndex] = input;\n\n let weightedSum = 0;\n let weight = 0;\n\n for (let i = this._currentIndex + 1; i < historyLength; i++)\n {\n weightedSum = (weightedSum + history[i]) * decayRatio;\n weight = (weight + 1) * decayRatio;\n }\n for (let i = 0; i <= this._currentIndex; i++)\n {\n weightedSum = (weightedSum + history[i]) * decayRatio;\n weight = (weight + 1) * decayRatio;\n }\n\n this._average = weightedSum / weight;\n\n return this._average;\n }\n\n absDev(): number\n {\n let errSum = 0;\n\n for (let i = 0, j = this._history.length; i < j; i++)\n {\n errSum += Math.abs(this._history[i] - this._average);\n }\n\n return errSum / this._history.length;\n }\n}\n","import { Ticker, UPDATE_PRIORITY } from '@pixi/ticker';\nimport { AverageProvider } from './AverageProvider';\n\n/**\n * @interface\n * @public\n */\nexport interface IObjectPoolOptions\n{\n capacityRatio?: number;\n decayRatio?: number;\n reserve?: number;\n}\n\n/**\n * `ObjectPool` provides the framework necessary for pooling minus the object instantiation\n * method. You can use `ObjectPoolFactory` for objects that can be created using a default\n * constructor.\n *\n * @template T\n * @class\n * @public\n */\nexport abstract class ObjectPool<T>\n{\n protected _freeList: Array<T>;\n protected _freeCount: number;\n protected _reserveCount: number;\n\n protected _borrowRate: number;\n protected _returnRate: number;\n protected _flowRate: number;\n protected _borrowRateAverage: number;\n protected _marginAverage: number;\n\n private _capacityRatio: number;\n private _decayRatio: number;\n private _borrowRateAverageProvider: AverageProvider;\n private _marginAverageProvider: AverageProvider;\n\n /**\n * @param {IObjectPoolOptions} options\n */\n constructor(options: IObjectPoolOptions = {})\n {\n /**\n * Supply pool of objects that can be used to immediately lend.\n *\n * @member {Array<T>}\n * @protected\n */\n this._freeList = [];\n\n /**\n * Number of objects in the pool. This is less than or equal to `_pool.length`.\n *\n * @member {number}\n * @protected\n */\n this._freeCount = 0;\n\n this._borrowRate = 0;\n this._returnRate = 0;\n this._flowRate = 0;\n this._borrowRateAverage = 0;\n\n this._reserveCount = options.reserve || 0;\n this._capacityRatio = options.capacityRatio || 1.2;\n this._decayRatio = options.decayRatio || 0.67;\n this._marginAverage = 0;\n this._borrowRateAverageProvider = new AverageProvider(128, this._decayRatio);\n this._marginAverageProvider = new AverageProvider(128, this._decayRatio);\n }\n\n /**\n * Instantiates a new object of type `T`.\n *\n * @abstract\n * @returns {T}\n */\n abstract create(): T;\n\n // TODO: Support object destruction. It might not be so good for perf tho.\n // /**\n // * Destroys the object before discarding it.\n // *\n // * @param {T} object\n // */\n // abstract destroyObject(object: T): void;\n\n /**\n * The number of objects that can be stored in the pool without allocating more space.\n *\n * @member {number}\n */\n protected get capacity(): number\n {\n return this._freeList.length;\n }\n protected set capacity(cp: number)\n {\n this._freeList.length = Math.ceil(cp);\n }\n\n /**\n * Obtains an instance from this pool.\n *\n * @returns {T}\n */\n allocate(): T\n {\n ++this._borrowRate;\n\n ++this._flowRate;\n\n if (this._freeCount > 0)\n {\n return this._freeList[--this._freeCount];\n }\n\n return this.create();\n }\n\n /**\n * Obtains an array of instances from this pool. This is faster than allocating multiple objects\n * separately from this pool.\n *\n * @param {number | T[]} lengthOrArray - no. of objects to allocate OR the array itself into which\n * objects are inserted. The amount to allocate is inferred from the array's length.\n * @returns {T[]} array of allocated objects\n */\n allocateArray(lengthOrArray: number | T[]): T[]\n {\n let array: T[];\n let length: number;\n\n if (Array.isArray(lengthOrArray))\n {\n array = lengthOrArray;\n length = lengthOrArray.length;\n }\n else\n {\n length = lengthOrArray;\n array = new Array(length);\n }\n\n this._borrowRate += length;\n this._flowRate += length;\n\n let filled = 0;\n\n // Allocate as many objects from the existing pool\n if (this._freeCount > 0)\n {\n const pool = this._freeList;\n const poolFilled = Math.min(this._freeCount, length);\n let poolSize = this._freeCount;\n\n for (let i = 0; i < poolFilled; i++)\n {\n array[filled] = pool[poolSize - 1];\n ++filled;\n --poolSize;\n }\n\n this._freeCount = poolSize;\n }\n\n // Construct the rest of the allocation\n while (filled < length)\n {\n array[filled] = this.create();\n ++filled;\n }\n\n return array;\n }\n\n /**\n * Returns the object to the pool.\n *\n * @param {T} object\n */\n release(object: T): void\n {\n ++this._returnRate;\n --this._flowRate;\n\n if (this._freeCount === this.capacity)\n {\n this.capacity *= this._capacityRatio;\n }\n\n this._freeList[this._freeCount] = object;\n ++this._freeCount;\n }\n\n /**\n * Releases all of the objects in the passed array. These need not be allocated using `allocateArray`, however.\n *\n * @param {T[]} array\n */\n releaseArray(array: T[]): void\n {\n this._returnRate += array.length;\n this._flowRate -= array.length;\n\n if (this._freeCount + array.length > this.capacity)\n {\n // Ensure we have enough capacity to insert the release objects\n this.capacity = Math.max(this.capacity * this._capacityRatio, this._freeCount + array.length);\n }\n\n // Place objects into pool list\n for (let i = 0, j = array.length; i < j; i++)\n {\n this._freeList[this._freeCount] = array[i];\n ++this._freeCount;\n }\n }\n\n /**\n * Preallocates objects so that the pool size is at least `count`.\n *\n * @param {number} count\n */\n reserve(count: number): void\n {\n this._reserveCount = count;\n\n if (this._freeCount < count)\n {\n const diff = this._freeCount - count;\n\n for (let i = 0; i < diff; i++)\n {\n this._freeList[this._freeCount] = this.create();\n ++this._freeCount;\n }\n }\n }\n\n /**\n * Dereferences objects for the GC to collect and brings the pool size down to `count`.\n *\n * @param {number} count\n */\n limit(count: number): void\n {\n if (this._freeCount > count)\n {\n const oldCapacity = this.capacity;\n\n if (oldCapacity > count * this._capacityRatio)\n {\n this.capacity = count * this._capacityRatio;\n }\n\n const excessBound = Math.min(this._freeCount, this.capacity);\n\n for (let i = count; i < excessBound; i++)\n {\n this._freeList[i] = null;\n }\n }\n }\n\n /**\n * Install the GC on the shared ticker.\n *\n * @param {Ticker}[ticker=Ticker.shared]\n */\n startGC(ticker: Ticker = Ticker.shared): void\n {\n ticker.add(this._gcTick, null, UPDATE_PRIORITY.UTILITY);\n }\n\n /**\n * Stops running the GC on the pool.\n *\n * @param {Ticker}[ticker=Ticker.shared]\n */\n stopGC(ticker: Ticker = Ticker.shared): void\n {\n ticker.remove(this._gcTick);\n }\n\n private _gcTick = (): void =>\n {\n this._borrowRateAverage = this._borrowRateAverageProvider.next(this._borrowRate);\n this._marginAverage = this._marginAverageProvider.next(this._freeCount - this._borrowRate);\n\n const absDev = this._borrowRateAverageProvider.absDev();\n\n this._flowRate = 0;\n this._borrowRate = 0;\n this._returnRate = 0;\n\n const poolSize = this._freeCount;\n const poolCapacity = this._freeList.length;\n\n // If the pool is small enough, it shouldn't really matter\n if (poolSize < 128 && this._borrowRateAverage < 128 && poolCapacity < 128)\n {\n return;\n }\n\n // If pool is say, 2x, larger than borrowing rate on average (adjusted for variance/abs-dev), then downsize.\n const threshold = Math.max(this._borrowRateAverage * (this._capacityRatio - 1), this._reserveCount);\n\n if (this._freeCount > threshold + absDev)\n {\n const newCap = threshold + absDev;\n\n this.capacity = Math.min(this._freeList.length, Math.ceil(newCap));\n this._freeCount = this._freeList.length;\n }\n };\n}\n","import { ObjectPool } from './ObjectPool';\n\n/**\n * This stores existing object pools created for class-constructed objects.\n *\n * @ignore\n */\nconst poolMap: Map<{ new(): any }, ObjectPool<any>> = new Map();\n\n/**\n * Factory for creating pools of objects with default constructors. It will store the pool of\n * a given type and reuse it on further builds.\n *\n * @class\n * @public\n * @example\n * ```js\n * import { ObjectPool, ObjectPoolFactory } from '@pixi-essentials/object-pool';\n *\n * class AABB {}\n *\n * const opool: ObjectPool<AABB> = ObjectPoolFactory.build(AABB) as ObjectPool<AABB>;\n *\n * const temp = opool.borrowObject();\n * // do something\n * opool.returnObject(temp);\n * ```\n */\nexport class ObjectPoolFactory\n{\n /**\n * Builds an object-pool for objects constructed from the given class with a default constructor. If an\n * object pool for that class was already created, an existing instance is returned.\n *\n * @param classConstructor\n */\n static build<T>(Type: { new(): T }): ObjectPool<T>\n {\n let pool = poolMap.get(Type);\n\n if (pool)\n {\n return pool;\n }\n\n pool = new (class DefaultObjectPool extends ObjectPool<any>\n {\n create(): any\n {\n return new Type();\n }\n })();\n\n poolMap.set(Type, pool);\n\n return pool;\n }\n\n /**\n * Builds an object-pool for objects built using a factory function. The factory function's context will be the\n * object-pool.\n *\n * These types of pools are not cached and should only be used on internal data structures.\n *\n * @param factoryFunction\n */\n static buildFunctional<T>(factoryFunction: () => T): ObjectPool<T>\n {\n return new (class DefaultObjectPool extends ObjectPool<T>\n {\n create = factoryFunction;\n })();\n }\n}\n"],"names":[],"mappings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eC9TA;IACA;IACA;IACA;IACA;IACA;IACA;AACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;;IAEA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;AACA;IACA;IACA;IACA;IACA;AACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;AACA;IACA;AACA;IACA;IACA;AACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;IACA;;;;;;;;;;;;;;;;"} |