ArchiSteamFarm/ArchiSteamFarm/ConcurrentHashSet.cs

/*
    _                _      _  ____   _                           _____
   / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
  / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
 / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
/_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|

 Copyright 2015-2017 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.Collections;
using System.Collections.Generic;
using System.Linq;
using Nito.AsyncEx;

namespace ArchiSteamFarm {
	internal sealed class ConcurrentHashSet<T> : IReadOnlyCollection<T>, ISet<T> {
		public int Count {
			get {
				using (Lock.ReaderLock()) {
					return HashSet.Count;
				}
			}
		}

		public bool IsReadOnly => false;

		private readonly HashSet<T> HashSet = new HashSet<T>();
		private readonly AsyncReaderWriterLock Lock = new AsyncReaderWriterLock();

		public bool Add(T item) {
			using (Lock.WriterLock()) {
				return HashSet.Add(item);
			}
		}

		public void Clear() {
			using (Lock.WriterLock()) {
				HashSet.Clear();
			}
		}

		public bool Contains(T item) {
			using (Lock.ReaderLock()) {
				return HashSet.Contains(item);
			}
		}

		public void CopyTo(T[] array, int arrayIndex) {
			using (Lock.ReaderLock()) {
				HashSet.CopyTo(array, arrayIndex);
			}
		}

		public void ExceptWith(IEnumerable<T> other) {
			using (Lock.WriterLock()) {
				HashSet.ExceptWith(other);
			}
		}

		public IEnumerator<T> GetEnumerator() => new ConcurrentEnumerator<T>(HashSet, Lock);

		public void IntersectWith(IEnumerable<T> other) {
			using (Lock.WriterLock()) {
				HashSet.IntersectWith(other);
			}
		}

		public bool IsProperSubsetOf(IEnumerable<T> other) {
			using (Lock.ReaderLock()) {
				return HashSet.IsProperSubsetOf(other);
			}
		}

		public bool IsProperSupersetOf(IEnumerable<T> other) {
			using (Lock.ReaderLock()) {
				return HashSet.IsProperSupersetOf(other);
			}
		}

		public bool IsSubsetOf(IEnumerable<T> other) {
			using (Lock.ReaderLock()) {
				return HashSet.IsSubsetOf(other);
			}
		}

		public bool IsSupersetOf(IEnumerable<T> other) {
			using (Lock.ReaderLock()) {
				return HashSet.IsSupersetOf(other);
			}
		}

		public bool Overlaps(IEnumerable<T> other) {
			using (Lock.ReaderLock()) {
				return HashSet.Overlaps(other);
			}
		}

		public bool Remove(T item) {
			using (Lock.WriterLock()) {
				return HashSet.Remove(item);
			}
		}

		public bool SetEquals(IEnumerable<T> other) {
			using (Lock.ReaderLock()) {
				return HashSet.SetEquals(other);
			}
		}

		public void SymmetricExceptWith(IEnumerable<T> other) {
			using (Lock.WriterLock()) {
				HashSet.SymmetricExceptWith(other);
			}
		}

		public void UnionWith(IEnumerable<T> other) {
			using (Lock.WriterLock()) {
				HashSet.UnionWith(other);
			}
		}

		void ICollection<T>.Add(T item) => Add(item);

		IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

		internal bool AddRange(IEnumerable<T> items) {
			using (Lock.WriterLock()) {
				// We use Count() and not Any() because we must ensure full loop pass
				return items.Count(item => HashSet.Add(item)) > 0;
			}
		}

		internal void ClearAndTrim() {
			using (Lock.WriterLock()) {
				HashSet.Clear();
				HashSet.TrimExcess();
			}
		}

		internal bool RemoveRange(IEnumerable<T> items) {
			using (Lock.WriterLock()) {
				// We use Count() and not Any() because we must ensure full loop pass
				return items.Count(item => HashSet.Remove(item)) > 0;
			}
		}

		internal bool ReplaceIfNeededWith(ICollection<T> items) {
			using (Lock.WriterLock()) {
				if (HashSet.SetEquals(items)) {
					return false;
				}

				HashSet.Clear();

				foreach (T item in items) {
					HashSet.Add(item);
				}

				HashSet.TrimExcess();
				return true;
			}
		}

		internal void ReplaceWith(IEnumerable<T> items) {
			using (Lock.WriterLock()) {
				HashSet.Clear();

				foreach (T item in items) {
					HashSet.Add(item);
				}

				HashSet.TrimExcess();
			}
		}
	}
}