playcanvas/build/playcanvas.dbg/src/core/object-pool.js

PlayCanvas WebGL game engine

/**
 * A pool of reusable objects of the same type. Designed to promote reuse of objects to reduce
 * garbage collection.
 *
 * @template {new (...args: any[]) => any} T
 * @ignore
 */ class ObjectPool {
    /**
     * @param {T} constructorFunc - The constructor function for the
     * objects in the pool.
     * @param {number} size - The initial number of object instances to allocate.
     */ constructor(constructorFunc, size){
        /**
     * Array of object instances.
     *
     * @type {InstanceType<T>[]}
     * @private
     */ this._pool = [];
        /**
     * The number of object instances that are currently allocated.
     *
     * @type {number}
     * @private
     */ this._count = 0;
        this._constructor = constructorFunc;
        this._resize(size);
    }
    /**
     * @param {number} size - The number of object instances to allocate.
     * @private
     */ _resize(size) {
        if (size > this._pool.length) {
            for(let i = this._pool.length; i < size; i++){
                this._pool[i] = new this._constructor();
            }
        }
    }
    /**
     * Returns an object instance from the pool. If no instances are available, the pool will be
     * doubled in size and a new instance will be returned.
     *
     * @returns {InstanceType<T>} An object instance from the pool.
     */ allocate() {
        if (this._count >= this._pool.length) {
            this._resize(this._pool.length * 2);
        }
        return this._pool[this._count++];
    }
    /**
     * All object instances in the pool will be available again. The pool itself will not be
     * resized.
     */ freeAll() {
        this._count = 0;
    }
}

export { ObjectPool };