jellyfin/MediaBrowser.Common/Extensions/ShuffleExtensions.cs

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#nullable enable
using System;
using System.Collections.Generic;
namespace MediaBrowser.Common.Extensions
{
/// <summary>
/// Provides <c>Shuffle</c> extensions methods for <see cref="IList{T}" />.
/// </summary>
public static class ShuffleExtensions
{
private static readonly Random _rng = new Random();
/// <summary>
/// Shuffles the items in a list.
/// </summary>
/// <param name="list">The list that should get shuffled.</param>
/// <typeparam name="T">The type.</typeparam>
public static void Shuffle<T>(this IList<T> list)
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{
list.Shuffle(_rng);
}
/// <summary>
/// Shuffles the items in a list.
/// </summary>
/// <param name="list">The list that should get shuffled.</param>
/// <param name="rng">The random number generator to use.</param>
/// <typeparam name="T">The type.</typeparam>
public static void Shuffle<T>(this IList<T> list, Random rng)
{
int n = list.Count;
while (n > 1)
{
n--;
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int k = rng.Next(n + 1);
T value = list[k];
list[k] = list[n];
list[n] = value;
}
}
}
}