using System.Collections.Generic;

internal class SafeDictionary<TKey, TValue>
{
	private readonly object _Padlock = new object();

	private readonly Dictionary<TKey, TValue> _Dictionary;

	public TValue this[TKey key]
	{
		get
		{
			lock (_Padlock)
			{
				return _Dictionary[key];
			}
		}
		set
		{
			lock (_Padlock)
			{
				_Dictionary[key] = value;
			}
		}
	}

	public SafeDictionary(int capacity)
	{
		_Dictionary = new Dictionary<TKey, TValue>(capacity);
	}

	public SafeDictionary()
	{
		_Dictionary = new Dictionary<TKey, TValue>();
	}

	public bool TryGetValue(TKey key, out TValue value)
	{
		lock (_Padlock)
		{
			return _Dictionary.TryGetValue(key, out value);
		}
	}

	public void Add(TKey key, TValue value)
	{
		lock (_Padlock)
		{
			if (!_Dictionary.ContainsKey(key))
			{
				_Dictionary.Add(key, value);
			}
		}
	}
}