using System;
using System.Runtime.CompilerServices;

/*https://github.com/sidristij/memory-pools*/

namespace MemoryPools.Memory.Pooling
{
    /// <summary>
    ///     This pool returns NEW instance if pool is empty and old if non-empty.
    ///     When got, user can return instance back to pool. If not returned, GC will collect it
    ///     This means, that if you want to detect 'leaks', you should:
    ///     1) add [CallerFilePath], [CallerLineNumber] to your Init() method parameters
    ///     2) make finalizer in your type and log saved fileName and lineNumber from (1).
    /// </summary>
    /// <code>
    ///  MyType Init(int arg0, string arg1 
    /// 		#if DEBUG
    ///  	, [CallerFilePath] string fileName = default, [CallerLineNumber] int lineNumber = default
    /// 		#endif
    ///   )
    ///  {
    /// 		#if DEBUG
    ///  	_fileName = fileName;
    ///  	_lineNumber = lineNumber;
    /// 		#endif
    ///  }
    /// 	#if DEBUG
    ///  ~MyType()
    ///  {
    ///  	Console.WriteLine($" - {_fileName}:{_lineNumber}");
    ///  }
    /// 	#endif
    ///  </code>
    public sealed class BucketsBasedCrossThreadsMemoryPool<T>
	{
		private BucketsBasedCrossThreadsArrayPool<T> _pool;

		[ThreadStatic]
		private static BucketsBasedCrossThreadsMemoryPool<T> _mempool;

		internal BucketsBasedCrossThreadsArrayPool<T> _arraysPool => _pool ??= new BucketsBasedCrossThreadsArrayPool<T>();

		public static BucketsBasedCrossThreadsMemoryPool<T> Shared => _mempool ??= new BucketsBasedCrossThreadsMemoryPool<T>();

		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public CountdownMemoryOwner<T> Rent(int minBufferSize = -1)
		{
			return Pool<CountdownMemoryOwner<T>>.Get().Init(_arraysPool.Rent(minBufferSize), minBufferSize);
		}
	}
}
