// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections.Generic;
 
namespace Microsoft.AspNetCore.Razor.PooledObjects;
 
/// <summary>
/// A pool of <see cref="HashSet{T}"/> instances that compares items using default equality.
/// </summary>
/// 
/// <remarks>
/// Instances originating from this pool are intended to be short-lived and are suitable
/// for temporary work. Do not return them as the results of methods or store them in fields.
/// </remarks>
internal sealed partial class HashSetPool<T> : CustomObjectPool<HashSet<T>>
{
    public static readonly HashSetPool<T> Default = Create();
 
    private readonly Policy _policy;
 
    private HashSetPool(Policy policy, Optional<int> poolSize)
        : base(policy, poolSize)
    {
        _policy = policy;
    }
 
    public IEqualityComparer<T> Comparer => _policy.Comparer;
 
    public static HashSetPool<T> Create(
        Optional<IEqualityComparer<T>?> comparer = default,
        Optional<int> maximumObjectSize = default,
        Optional<int> poolSize = default)
        => new(Policy.Create(comparer, maximumObjectSize), poolSize);
 
    public static PooledObject<HashSet<T>> GetPooledObject()
        => Default.GetPooledObject();
 
    public static PooledObject<HashSet<T>> GetPooledObject(out HashSet<T> set)
        => Default.GetPooledObject(out set);
}