// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace Microsoft.AspNetCore.Razor.PooledObjects;
 
internal abstract class ObjectPool<T>
    where T : class
{
    public abstract T Get();
 
    public abstract void Return(T obj);
}
 
internal interface IPooledObjectPolicy<T>
    where T : class
{
    T Create();
 
    bool Return(T obj);
}
 
internal class DefaultObjectPool<T> : ObjectPool<T>
    where T : class
{
    private readonly Microsoft.CodeAnalysis.PooledObjects.ObjectPool<T> _pool;
    private readonly IPooledObjectPolicy<T> _policy;
 
    public DefaultObjectPool(IPooledObjectPolicy<T> policy, int maximumRetained)
    {
        ArgHelper.ThrowIfNull(policy);
        ArgHelper.ThrowIfNegativeOrZero(maximumRetained);
 
        _policy = policy;
        _pool = new(() => _policy.Create(), maximumRetained);
    }
 
    public override T Get()
        => _pool.Allocate();
 
    public override void Return(T obj)
    {
        ArgHelper.ThrowIfNull(obj);
 
        if (_policy.Return(obj))
        {
            _pool.Free(obj);
        }
        else
        {
            _pool.ForgetTrackedObject(obj);
        }
    }
}