ArchiSteamFarm/ArchiSteamFarm/ConcurrentEnumerator.cs

//     _                _      _  ____   _                           _____
//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
// 
//  Copyright 2015-2018 Łukasz "JustArchi" Domeradzki
//  Contact: JustArchi@JustArchi.net
// 
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
// 
//  http://www.apache.org/licenses/LICENSE-2.0
//      
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading;

namespace ArchiSteamFarm {
	internal sealed class ConcurrentEnumerator<T> : IEnumerator<T> {
		public T Current => Enumerator.Current;

		private readonly IEnumerator<T> Enumerator;
		private readonly SemaphoreSlim SemaphoreSlim;

		object IEnumerator.Current => Current;

		internal ConcurrentEnumerator(IReadOnlyCollection<T> collection, SemaphoreSlim semaphoreSlim) {
			if ((collection == null) || (semaphoreSlim == null)) {
				throw new ArgumentNullException(nameof(collection) + " || " + nameof(semaphoreSlim));
			}

			SemaphoreSlim = semaphoreSlim;
			SemaphoreSlim.Wait();

			Enumerator = collection.GetEnumerator();
		}

		public void Dispose() => SemaphoreSlim.Release();
		public bool MoveNext() => Enumerator.MoveNext();
		public void Reset() => Enumerator.Reset();
	}
}