using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Sockets;
using System.Text;

namespace HuizhongLibrary.Network
{
    #region 缓存管理BufferPool
    public class BufferPool
    {
        int m_numBytes;                 // 未知
        byte[] m_buffer;                // 
        Stack<int> m_freeIndexPool;     // 
        int m_currentIndex;　　　　　　 //未知　　　
        int m_bufferSize;  //缓存大小

        public BufferPool(int totalBytes, int bufferSize)
        {
            m_numBytes = totalBytes;
            m_currentIndex = 0;
            m_bufferSize = bufferSize;
            m_freeIndexPool = new Stack<int>();
        }

        public void InitBuffer()
        {
            m_buffer = new byte[m_numBytes];
        }

        public bool SetBuffer(SocketAsyncEventArgs args)
        {

            if (m_freeIndexPool.Count > 0)
            {
                args.SetBuffer(m_buffer, m_freeIndexPool.Pop(), m_bufferSize);
            }
            else
            {
                if ((m_numBytes - m_bufferSize) < m_currentIndex)
                {
                    return false;
                }
                args.SetBuffer(m_buffer, m_currentIndex, m_bufferSize);
                m_currentIndex += m_bufferSize;
            }
            return true;
        }

        public void FreeBuffer(SocketAsyncEventArgs args)
        {
            m_freeIndexPool.Push(args.Offset);
            args.SetBuffer(null, 0, 0);
        }

    }
    #endregion
}