Unity.Pooling

Dependencies

• org.nuget.system.runtime.compilerservices.unsafe@6.0.0
• com.cysharp.unitask
• com.laicasaane.collections.pooled

Addressables support

The related modules will be enabled automatically when the com.unity.addressables package is installed.

Installation

Install via Open UPM

You can install this package from the Open UPM registry.

More details here.

openupm add com.zbase.foundation.pooling

Install via Package Manager

1. Open the Poject Settings window
2. Navigate to the Package Manager section
3. Add a new Scoped Registry

"name": "Unity NuGet",
"url": "https://unitynuget-registry.azurewebsites.net",
"scopes": [
    "org.nuget"
]

4. Open the Package Manager window
5. Select the Add package from git URL option from the + dropdown
6. Enter this git url:

https://github.com/Zitga-Tech/ZBase.Foundation.Pooling.git?path=Packages/ZBase.Foundation.Pooling

ZBase.Foundation.Pooling

Foundation

The entire package is built upon these 2 interfaces:

• IPool<T> defines synchronous APIs, mostly for pooling C# objects.
• IAsyncPool<T> defines asynchronous APIs, mostly for pooling Unity objects.

Pools

These are the basic pools that implement the most generic functions for pooling C# objects:

• Pool<T, TInstantiator>
• AsyncPool<T, T Instantiator>
• Pool<T>
• AsyncPool<T>

For basic pooling, Pool<T> and AsyncPool<T> are ready-to-use.

Instantiators

It should be noted that Pool<T> and AsyncPool<T> will create instances of T through Activator.CreateInstance by using these instantiators:

• ActivatorInstantiator<T>
• AsyncActivatorInstantiator<T>

This module also provides instantiators that use default constructor:

• DefaultConstructorInstantiator<T>
• AsyncDefaultConstructorInstantiator<T>

However the type T must satisfy this constraint on the instantiators

where T : class, new()

• T must be a reference type
• T must have a public parameterless constructor (ie. default constructor)

Example usage

public class MyClass { }
...
var pool = new Pool<MyClass, DefaultConstructorInstantiator<MyClass>>(); // Works
...
var pool = new Pool<string, DefaultConstructorInstantiator<string>>(); // Error!

User-defined instantiators

Alternately, users can define custom instantiators for specific types by implementing IInstantiable<T>:

public struct MyClassInstantiator : IInstantiable<MyClass>
{
    public MyClass Instantiate() => new MyClass();
}
...
var pool = new Pool<MyClass, MyClassInstantiator>();

Shared pools

SharedPool.Of<T> will return a shared instance (aka singleton) of any type that satisfy this constraint:

where T : IPool, IShareable, new()

• T must implement IPool and IShareable
• T must have a public parameterless constructor (ie. default constructor)

Example usage

var myClassPool = SharedPool.Of< Pool<MyClass> >();
var listPool    = SharedPool.Of< ListPool<int> >();

Disposable context

Leverage IDisposable interface to automatically return instances to the pool at the end of their usage.

1. Get the context by calling .DisposableContext() (extension method) on the pool.
2. Apply using when renting from the context so the disposing mechanism can be automated.

Example usage

var pool           = SharedPool.Of< ListPool<int> >();
var disposablePool = pool.DisposableContext();         // Get the context
using var instance = disposablePool.Rent();            // Rent from the context with `using`

using (var otherInstance = disposablePool.Rent())     // Explicit `using` scope
{
    // work with `otherInstance`

} // `otherInstance` will be returned to the pool automatically

// End of the Method
// `instance` will be returned to the pool automatically

Collection Pools

Are the pools for collection instances (such as List, Dictionary and so on).

• ListPool<T>
• HashSetPool<T>
• QueuePool<T>
• StackPool<T>
• DictionaryPool<TKey, TValue>

They are implemented the same in these 2 modules:

• System.Collections.Generic.Pooling
• Collections.Pooled.Generic.Pooling

var listInst    = SharedPool.Of< ListPool<int> >().Rent();
var myClassInst = SharedPool.Of< Pool<MyClass> >().Rent();

var dictPool = new DictionaryPool<int, string>();
var dictInst = dictPool.Rent();

ZBase.Foundation.Pooling.UnityPools

This module provides basic facility to pooling Unity objects, especially GameObject and Component:

• UnityPool<T, TPrefab> is the base for Unity object pools.
• IPrefab to implement custom Unity object instantiators.
• IPrepooler<T, TPrefab, TPool> to implement custom prepooling mechanism.
• UnityPoolBehaviour<T, ...> is the base for pooling components attached on a GameObject.

Pools

All the pools implemented in this module are ready-to-use.

• UnityPool<T, TPrefab>
• GameObjectPool<TPrefab>
• GameObjectPool
• ComponentPool<T, TPrefab>
• ComponentPool<T>

var goPool       = new GameObjectPool();
var colliderPool = new ComponentPool<BoxCollider>();

Prefabs

Prefab is a way to change how pools would instantiate or release their objects.

• UnityPrefab<T, TSource>
• GameObjectPrefab
• ComponentPrefab<T>

If customization is needed, a subtype of UnityPrefab<T, TSource> must be implemented then passed to the generic pool that accept TPrefab.

public class CustomGameObjectPrefab : UnityPrefab<GameObject, GameObject>
{
    protected override async UniTask<GameObject> Instantiate(GameObject source, Transform parent)
    {
        // implement Instiatate method
    }

    public override void Release(GameObject instance)
    {
        // implement Release method
    }
}
...
var poolA = new GameObjectPool<CustomGameObjectPrefab>();
var poolB = new UnityPool<GameObject, CustomGameObjectPrefab>()

Alternately any type implements IPrefab<T> works the same way.

public class SimpleGameObjectPrefab : IPrefab<GameObject>
{
    public async UniTask<GameObject> Instantiate()
    {
        // implement Instiatate method
    }

    public void Release(GameObject instance)
    {
        // implement Release method
    }
}
...
var poolA = new GameObjectPool<SimpleGameObjectPrefab>();
var poolB = new UnityPool<GameObject, SimpleGameObjectPrefab>()

Behaviours

These are wrappers of the pools, derived from MonoBehaviour:

• PoolBehaviour<T, TPool>
• UnityPoolBehaviour<T, TPrefab, TPool>
• GameObjectPoolBehaviour
• ComponentPoolBehaviour<T>

Only GameObjectPoolBehaviour is ready-to-use.

Others require declaring non-generic subtypes:

public class BoxColliderPoolBehaviour
    : ComponentPoolBehaviour<BoxCollider>
{ }

public class SpritePoolBehaviour
    : UnityPoolBehaviour<SpriteRenderer, SpritePrefab, ComponentPool<SpriteRenderer>>
{ }

ZBase.Foundation.Pooling.Addressables

This module offers 2 ways to work with Addressables:

• Address* requires a string address to load the asset
• AssetRef* requires an AssetReference

Pools

All the pools implemented in this module are ready-to-use.

String Address	AssetReference
AddressComponentPool<T, TPrefab>	AssetRefComponentPool<T>
AddressComponentPool<T>	AssetRefGameObjectPool
AddressGameObjectPool<TPrefab>
AddressGameObjectPool

Prefabs

String Address	AssetReference
AddressPrefab<T>	AssetRefPrefab<T, TAssetRef>
AddressComponentPrefab<T>	AssetRefComponentPrefab<T>
AddressGameObjectPrefab	AssetRefGameObjectPrefab

⚠️ Notes that the prefabs are using Addressables and AssetReference to instantiate objects. But this behaviour can be changed by declaring subtypes and overriding the Instantiate method.