异步tcp通信——APM.Core 解包

TCP通信解包

　　虽说这是一个老生长谈的问题，不过网上基本很少见完整业务；或多或少都没有写完或者存在bug。接收到的数据包可以简单分成：小包、大包、跨包三种情况，根据这三种情况作相对应的拆包处理，示例如下：

/*****************************************************************************************************
 * 本代码版权归@wenli所有，All Rights Reserved (C) 2015-2016
 *****************************************************************************************************
 * CLR版本：4.0.30319.42000
 * 唯一标识：7a846c42-665d-4628-b91f-9d58b670437d
 * 机器名称：WENLI-PC
 * 联系人邮箱：wenguoli_520@qq.com
 *****************************************************************************************************
 * 项目名称：$projectname$
 * 命名空间：APM.Core
 * 类名称：UserToken
 * 创建时间：2016/11/30 16:56:29
 * 创建人：wenli
 * 创建说明：
 *****************************************************************************************************/
using System;
using System.Net.Sockets;

namespace APM.Core
{
    /// <summary>
    /// tcp用户信息
    /// </summary>
    public class UserToken
    {
        private int offset, count = 0;

        private byte[] _myBuffer;

        private byte[] _myLenBuffer;

        public int MaxBufferSize
        {
            get; private set;
        }

        /// <summary>
        /// 用户标识
        /// </summary>
        public string ID
        {
            get; set;
        }
        /// <summary>
        /// 连接的客户
        /// </summary>
        public Socket Client
        {
            get; set;
        }

        /// <summary>
        /// 会话验证码
        /// </summary>
        public int Auth
        {
            get; set;
        }



        public UserToken(int maxBufferSize = 10 * 1024)
        {
            this.MaxBufferSize = maxBufferSize;
            this.ReceiveBuffer = new byte[this.MaxBufferSize];
        }



        /// <summary>
        /// 处理收取数据
        /// 解包
        /// </summary>
        /// <param name="receiveData"></param>
        /// <param name="action"></param>
        internal void UnPackage(byte[] receiveData, Action<TcpPackage> action)
        {
            //当前包取内容的
            if (offset == 0)
            {
                var packageLength = 0;
                if (this._myLenBuffer != null) //长度不完整的（包头不完整的）
                {
                    //调整receiveData包内容
                    var nData = new byte[this._myLenBuffer.Length + receiveData.Length];
                    Buffer.BlockCopy(this._myLenBuffer, 0, nData, 0, this._myLenBuffer.Length);
                    Buffer.BlockCopy(receiveData, 0, nData, this._myLenBuffer.Length, receiveData.Length);
                    receiveData = nData;
                    nData = null;
                    this._myLenBuffer = null;
                }
                else //全新包（包头完整的）
                {
                    packageLength = TcpPackage.GetLength(receiveData);
                    if (packageLength == 0)
                        return;
                }
                if (packageLength < receiveData.Length)
                {
                    var package = TcpPackage.Parse(receiveData);
                    if (action != null && package != null)
                    {
                        action(package);
                    }

                    var slen = TcpPackage.GetLength(receiveData, package.Length);
                    if (slen >= 9)
                    {
                        var next = new byte[receiveData.Length - package.Length];
                        Buffer.BlockCopy(receiveData, package.Length, next, 0, next.Length);
                        this.UnPackage(next, action);
                    }
                }
                else if (packageLength == receiveData.Length)
                {
                    var package = TcpPackage.Parse(receiveData);
                    if (action != null && package != null)
                    {
                        action(package);
                    }
                }
                else if (packageLength > receiveData.Length)
                {
                    this.count = packageLength;
                    this._myBuffer = new byte[packageLength];
                    Buffer.BlockCopy(receiveData, 0, this._myBuffer, 0, receiveData.Length);
                    this.offset = receiveData.Length;
                }
                receiveData = null;

            }
            else //跨包取内容的
            {
                if (receiveData.Length + offset < count) //包内容超出
                {
                    Buffer.BlockCopy(receiveData, 0, this._myBuffer, offset, receiveData.Length);
                    offset += receiveData.Length;
                }
                else if (receiveData.Length + offset >= count) //包内容短的
                {
                    var packageLast = count - offset;
                    Buffer.BlockCopy(receiveData, 0, this._myBuffer, offset, packageLast);
                    var package = TcpPackage.Parse(this._myBuffer);
                    if (action != null && package != null)
                    {
                        action(package);
                    }
                    this._myBuffer = null;
                    count = offset = 0;
                    var receiveLast = receiveData.Length - packageLast;
                    if (receiveLast >= 4)//包含包头长度
                    {
                        var packageLength = TcpPackage.GetLength(receiveData, packageLast);
                        if (packageLength > 0)
                        {
                            if (receiveLast > packageLength)
                            {
                                var nextData = new byte[receiveLast];
                                Buffer.BlockCopy(receiveData, packageLast, nextData, 0, receiveLast);
                                this.UnPackage(nextData, action);
                            }
                            else
                            {
                                this._myBuffer = new byte[packageLength];
                                Buffer.BlockCopy(receiveData, packageLast, this._myBuffer, 0, receiveLast);
                                offset = receiveLast;
                                count = packageLength;
                            }
                        }
                        else
                        {
                            this._myBuffer = null;
                            count = offset = 0;
                            this._myLenBuffer = null;
                        }
                    }
                    else if (receiveLast > 0)//不包含包头长度
                    {
                        this._myLenBuffer = new byte[receiveLast];
                        Buffer.BlockCopy(receiveData, packageLast, this._myLenBuffer, 0, receiveLast);
                        if (TcpPackage.GetLength(this._myLenBuffer) == 0)
                        {
                            this._myLenBuffer = null;
                        }
                        this._myBuffer = null;
                        count = offset = 0;
                    }
                }
                receiveData = null;
            }
        }

        public byte[] ReceiveBuffer
        {
            get; set;
        }

        public void ClearReceiveBuffer()
        {
            for (int i = 0; i < this.ReceiveBuffer.Length; i++)
            {
                this.ReceiveBuffer[i] = 0;
            }
        }
    }
}

 　　有了解包就可以发超长消息、文件等

异步tcp通信——APM.Core 服务端概述

异步tcp通信——APM.Core 解包

异步tcp通信——APM.Server 消息推送服务的实现

异步tcp通信——APM.ConsoleDemo

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更多内容欢迎star作者的github：https://github.com/yswenli/APM
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