///////////////////////////////////////////////////////////////////////////////
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//

using System;
using Microsoft.SingSharp;
using Microsoft.Singularity;
using Microsoft.Singularity.Channels;

namespace Smb.Shared
{
	class BufferPool : IDisposable
	{
		public BufferPool(int maxcount, int size)
		{
			_maxcount = maxcount;
			_buffersize = size;
		}
		
		readonly int _maxcount;
		readonly int _buffersize;
		readonly VContainer<byte>[]! _pool = new VContainer<byte>[0x10];
		
		int _readycount = 0;
		
		public void Recycle([Claims]byte[]! in ExHeap buffer)
		{
			if (_readycount < _pool.Length) {
				VContainer<byte> container = _pool[_readycount];
				if (container != null) {
					container.Release(buffer);				
				} else {
					_pool[_readycount] = new VContainer<byte>(buffer);
				}
				_readycount++;				
			} else {
				delete buffer;
			}
		}
		
		public byte[]! in ExHeap Allocate()
		{
			if (_readycount> 0) {
				byte[] in ExHeap buf = ((!)_pool[--_readycount]).Acquire();
				return buf;
			} else {
				byte[]! in ExHeap buf = new[ExHeap] byte[_buffersize];
				return buf;			
			}
		}
		
		public void Dispose()
		{
			for (int i = 0; i < _readycount; i++) {
				byte[] in ExHeap! buf = ((!)_pool[i]).Acquire();
				delete buf;
			}
			_readycount = 0;
		}
	}
}