之前写过一篇关于c#udp分包发送的文章
这篇文章里面介绍的方法是一种实现，但是存在一个缺点就是一个对象序列化后会增大很多，不利于在网络中的传输。
我们在网络中的传输是需要尽可能的减小传送的数据包的大小，于是我参考了网上一些资料和一些开源的项目（http://www.fishlee.net/）这个上面的那个开源的飞鸽传输的框架，
其实也就是把要传送的数据按照某种规定放在一个byte数组中，然后接收到后按照相应的格式把数据解析出来，为了减小数据还使用了GZipStream的压缩，之前出的问题就是在解压缩时，不过现在已经解决了。
首先我们要定义一种能表示我们传送数据的包的格式
public class PacketNetWorkMsg : IComparable<PacketNetWorkMsg>
{
/// <summary>
/// 封包版本
/// </summary>
public int Version { get; set; }
/// <summary>
/// 要发送的数据包
/// </summary>
public byte[] Data { get; set; }
/// <summary>
/// 数据包所含数据长度
/// </summary>
public int DataLength { get; set; }
/// <summary>
/// 分包后最后一个剩余长度
/// </summary>
public int Remainder { get; set; }
/// <summary>
/// 远程地址
/// </summary>
public IPEndPoint RemoteIP { get; set; }
/// <summary>
/// 发送次数
/// </summary>
public int SendTimes { get; set; }
/// <summary>
/// 包编号
/// </summary>
public long PackageNo { get; set; }
/// <summary>
/// 分包索引
/// </summary>
public int PackageIndex { get; set; }
/// <summary>
/// 分包总数
/// </summary>
public int PackageCount { get; set; }
/// <summary>
/// 获得或设置是否需要返回已收到标志
/// </summary>
public bool IsRequireReceiveCheck { get; set; }
public PacketNetWorkMsg()
{
Version = 1;
CreationTime = DateTime.Now;
}
public PacketNetWorkMsg(long packageNo, int Count, int index, byte[] data, int dataLength, int remainder, IPEndPoint desip, bool IsRequireReceive)
{
this.PackageNo = packageNo;
this.PackageCount = Count;
this.PackageIndex = index;
this.Data = data;
this.DataLength = dataLength;
this.Remainder = remainder;
this.IsRequireReceiveCheck = IsRequireReceive;//默认都需要确认包
this.RemoteIP = desip;
}
#region IComparable<PackedNetworkMessage> 成员
public int CompareTo(PacketNetWorkMsg other)
{
return PackageIndex < other.PackageIndex ? -1 : 1;
}
#endregion
/// <summary>
/// 获得生成数据包的时间
/// </summary>
public DateTime CreationTime { get; private set; }
}这个类是我们在网络中需要传输的具体最小的包
然后还有一个就是我们用来表示我们传输的数据的格式类Msg类，一个Msg类可能被分为多个PacketNetWorkMsg 来传送，分包的方法是为了突破udp方式传输数据的限制（64k）,，能够使用udp传输大数据，很多人就在问，为什么不用TCP，虽然TCP是非常好的方式，但是我也不想说出个所以然来，我就喜欢这么干。
public class Msg
{
/// <summary>
/// 是否已经被处理.在挂钩过程中,如果为true,则底层代码不会再对信息进行处理
/// </summary>
public bool Handled { get; set; }
/// <summary>
/// 获得或设置当前的消息编号
/// </summary>
/// <value></value>
/// <remarks></remarks>
public long PackageNo { get; set; }
/// <summary>
/// 获得或设置当前的消息所属的主机名
/// </summary>
public string HostName { get; set; }
/// <summary>
/// 获得或设置当前的消息所属的用户名
/// </summary>
public string UserName { get; set; }
/// <summary>
/// 获得或设置当前的命令代码
/// </summary>
//命令的名称
public Commands Command { get; set; }
/// <summary>
/// 获得或设置当前的消息的类型 文本消息，或者二进制消息
/// </summary>
public Consts Type { get; set; }
/// <summary>
/// 获得或设置当前的命令消息文本
/// </summary>
public string NormalMsg { get; set; }
/// <summary>
/// 消息文本字节
/// </summary>
public byte[] NormalMsgBytes { get; set; }
/// <summary>
/// 扩展消息文本字节
/// </summary>
public byte[] ExtendMessageBytes { get; set; }
/// <summary>
/// 获得或设置当前命令的扩展文本
/// </summary>
public string ExtendMessage { get; set; }
/// <summary>
/// 远程地址
/// </summary>
public IPEndPoint RemoteAddr { get; set; }
/// <summary>
/// 主机地址
/// </summary>
public IPEndPoint HostAddr { get; set; }
/// <summary>
/// 获得或设置是否需要返回已收到标志
/// </summary>
public bool IsRequireReceive { get; set; }
public Msg(IPEndPoint Addr)
{
RemoteAddr = Addr;
Handled = false;
Type = Consts.MESSAGE_TEXT;
}
public Msg(IPEndPoint hostIP,IPEndPoint remoteIP,Commands cmd)
{
HostAddr = hostIP;
RemoteAddr = remoteIP;
Command = cmd;
Handled = false;
Type = Consts.MESSAGE_TEXT;
}
public Msg(IPEndPoint addr, string hostName, string userName,Commands command, string message, string extendMessage)
{
RemoteAddr = addr;
Handled = false;
HostName = hostName;
UserName = userName;
Command = command;
NormalMsg = message;
ExtendMessage = extendMessage;
Type = Consts.MESSAGE_TEXT;
}
/// <summary>
/// 直接创建一个新的Message对象
/// </summary>
/// <param name="host">主机对象</param>
/// <param name="addr">远程地址</param>
/// <param name="hostName">主机名</param>
/// <param name="userName">用户名</param>
/// <param name="command">命令</param>
/// <param name="options">选项</param>
/// <param name="message">信息</param>
/// <param name="extendMessage">扩展信息</param>
/// <returns></returns>
public static Msg Create(Host host, IPEndPoint addr, string hostName, string userName, Commands command, string message, string extendMessage)
{
return new Msg(addr,hostName, userName, command,message, extendMessage);
}
}然后接下来是我们主要的类，分包和组包的一个类了
/// <summary>
/// 消息封包类
/// </summary>
public class MessagePacker
{
Timer _timer;
public MessagePacker()
{
_timer = new Timer(_ => CheckForOutdateMessage(), null, new TimeSpan(0, 5, 0), new TimeSpan(0, 0, 5, 0));
}
/*
* 消息包注意：
* 1.第一位始终是2(ASCII码50)
* 2.第二位到第九位是一个long类型的整数，代表消息编号
* 3.第十位到第十三位是一个int类型的整数，代表消息内容总长度
* 4.第十四位到第十七位是一个int类型的整数，代表分包的总数
* 5.第十八位到第二十一位是一个int类型的整数，代表当前的分包编号
* 6.第二十二位表示是否需要返回一个确认标识(1/0)
* 7.第二十三到第三十一位是保留的(Reserved)
* 8.第三十二字节以后是数据包
* */
/// <summary>
/// 消息版本号
/// </summary>
public static byte VersionHeader { get { return 50; } }
/// <summary>
/// 返回当前消息封包的头字节数
/// </summary>
public static int PackageHeaderLength { get { return 32; } }
/// <summary>
/// 获得消息包的字节流
/// </summary>
/// <param name="message">要打包的消息对象</param>
/// <returns></returns>
public static PacketNetWorkMsg[] BuildNetworkMessage(Msg message)
{
if (message.ExtendMessageBytes != null)
{
return BuildNetworkMessage(
message.RemoteAddr,
message.PackageNo,
message.Command,
message.UserName,
message.HostName,
message.Type,
message.NormalMsgBytes,
message.ExtendMessageBytes,
message.IsRequireReceive
);
}
else
{
return BuildNetworkMessage(
message.RemoteAddr,
message.PackageNo,
message.Command,
message.UserName,
message.HostName,
message.Type,
System.Text.Encoding.Unicode.GetBytes(message.NormalMsg),
System.Text.Encoding.Unicode.GetBytes(message.ExtendMessage),
message.IsRequireReceive
);
}
}
/// <summary>
/// 获得消息包的字节流
/// </summary>
/// <param name="remoteIp">远程主机地址</param>
/// <param name="packageNo">包编号</param>
/// <param name="command">命令</param>
/// <param name="options">参数</param>
/// <param name="userName">用户名</param>
/// <param name="hostName">主机名</param>
/// <param name="content">正文消息</param>
/// <param name="extendContents">扩展消息</param>
/// <returns></returns>
public static PacketNetWorkMsg[] BuildNetworkMessage(IPEndPoint remoteIp, long packageNo, Commands command, string userName, string hostName,Consts type ,byte[] content, byte[] extendContents, bool RequireReceiveCheck)
{
//每次发送所能容下的数据量
int maxBytesPerPackage = (int)Consts.MAX_UDP_PACKAGE_LENGTH - PackageHeaderLength;
//压缩数据流
var ms = new MemoryStream();
//var dest = new MemoryStream();
//var zip = new GZipStream(dest, CompressionMode.Compress);
var bw = new BinaryWriter(ms, System.Text.Encoding.Unicode);
//写入头部数据
bw.Write(packageNo); //包编号
bw.Write(userName); //用户名
bw.Write(hostName); //主机名
bw.Write((long)command); //命令
bw.Write((long)type); //数据类型
bw.Write(content == null ? 0 : content.Length);//数据长度
//写入消息数据
if (content != null)
bw.Write(content);
bw.Write(extendContents == null ? 0 : extendContents.Length);//补充数据长度
if (extendContents != null)
bw.Write(extendContents);
ms.Flush();
ms.Seek(0, System.IO.SeekOrigin.Begin);
byte[] ibuf = ms.ToArray();
var dest = new System.IO.MemoryStream();
GZipStream zipStream = new GZipStream(dest, CompressionMode.Compress, true);
byte[] buff = new byte[1024];
int offset;
ms.Seek(0, SeekOrigin.Begin);
while ((offset = ms.Read(buff, 0, buff.Length)) > 0)
{
zipStream.Write(buff, 0, offset);//先把数据用二进制写入内存，然后在把它用zip压缩，获取压缩过后的二进制流dest
}
zipStream.Close();
bw.Close();
ms.Close();
dest.Seek(0, SeekOrigin.Begin);
//打包数据总量
int dataLength = (int)dest.Length;
int packageCount = (int)Math.Ceiling(dataLength * 1.0 / maxBytesPerPackage);
PacketNetWorkMsg[] pnma = new PacketNetWorkMsg[packageCount];
for (int i = 0; i < packageCount; i++)
{
int count = i == packageCount - 1 ? dataLength - maxBytesPerPackage * (packageCount - 1) : maxBytesPerPackage;
byte[] buf = new byte[count + PackageHeaderLength];
buf[0] = VersionHeader;//版本号 第1位
BitConverter.GetBytes(packageNo).CopyTo(buf, 1);//消息编号 第2到9位 long类型的整数
BitConverter.GetBytes(dataLength).CopyTo(buf, 9);//消息内容长度 第10到13位 int类型的整数
BitConverter.GetBytes(packageCount).CopyTo(buf, 13);//分包总数 第14位到第17位 int类型的整数
BitConverter.GetBytes(i).CopyTo(buf, 17);//分包编号 第18位到第21位 int类型的整数
buf[21] = RequireReceiveCheck ? (byte)1 : (byte)0;//是否回确认包 第22位
//第23到第31位是保留的(Reserved)
dest.Read(buf, 32, buf.Length - 32);//第32字节以后是,具体的数据包
pnma[i] = new PacketNetWorkMsg()
{
Data = buf,
PackageCount = packageCount,
PackageIndex = i,
PackageNo = packageNo,
RemoteIP = remoteIp,
SendTimes = 0,
Version = 2,
IsRequireReceiveCheck = buf[21] == 1
};
}
return pnma;
}
/// <summary>
/// 检测确认是否是这个类型的消息包
/// </summary>
/// <param name="buffer"></param>
/// <returns></returns>
public static bool Test(byte[] buffer)
{
return buffer != null && buffer.Length > PackageHeaderLength && buffer[0] == VersionHeader;
}
/// <summary>
/// 缓存接收到的片段
/// </summary>
static Dictionary<long, PacketNetWorkMsg[]> packageCache = new Dictionary<long, PacketNetWorkMsg[]>();
/// <summary>
/// 分析网络数据包并进行转换为信息对象
/// </summary>
/// <param name="packs">接收到的封包对象</param>
/// <returns></returns>
/// <remarks>
/// 对于分包消息，如果收到的只是片段并且尚未接收完全，则不会进行解析
/// </remarks>
public static Msg ParseToMessage(params PacketNetWorkMsg[] packs)
{
if (packs.Length == 0 || (packs[0].PackageCount > 1 && packs.Length != packs[0].PackageCount))
return null;
var ms = DecompressMessagePacks(packs);
if (ms == null)
{
//事件
return null;
}
//构造读取流
System.IO.BinaryReader br = new System.IO.BinaryReader(ms, System.Text.Encoding.Unicode);
//开始读出数据
Msg m = new Msg(packs[0].RemoteIP);
m.PackageNo = br.ReadInt64();//包编号
m.UserName = br.ReadString();//用户名
m.HostName = br.ReadString();//主机名
m.Command = (Commands)br.ReadInt64(); //命令
m.Type = (Consts)br.ReadInt64();//数据类型
int length = br.ReadInt32(); //数据长度
m.NormalMsgBytes = new byte[length];
br.Read(m.NormalMsgBytes, 0, length);//读取内容
length = br.ReadInt32(); //附加数据长度
m.ExtendMessageBytes = new byte[length];
br.Read(m.ExtendMessageBytes, 0, length);//读取附加数据
if (m.Type == Consts.MESSAGE_TEXT)
{
m.NormalMsg = System.Text.Encoding.Unicode.GetString(m.NormalMsgBytes, 0, length); //正文
m.ExtendMessage = System.Text.Encoding.Unicode.GetString(m.ExtendMessageBytes, 0, length); //扩展消息
m.ExtendMessageBytes = null;
m.NormalMsgBytes = null;
}
return m;
}
/// <summary>
/// 组合所有的网络数据包并执行解压缩
/// </summary>
/// <param name="packs"></param>
/// <returns></returns>
static MemoryStream DecompressMessagePacks(params PacketNetWorkMsg[] packs)
{
try
{
//尝试解压缩，先排序
Array.Sort(packs);
var msout = new MemoryStream();
using (var ms = new System.IO.MemoryStream())
{
//合并写入
//Array.ForEach(packs, s => ms.Write(s.Data, 32, s.Data.Length-32));
Array.ForEach(packs, s => ms.Write(s.Data, 0, s.Data.Length));
ms.Seek(0, SeekOrigin.Begin);
//解压缩
using (var gz = new GZipStream(ms, CompressionMode.Decompress))
{
var buffer = new byte[0x400];
var count = 0;
while ((count = gz.Read(buffer, 0, buffer.Length)) > 0)
{
msout.Write(buffer, 0, count);
}
}
}
msout.Seek(0, SeekOrigin.Begin);
return msout;
}
catch (Exception)
{
return null;
}
}
/// <summary>
/// 尝试将收到的网络包解析为实体
/// </summary>
/// <param name="pack">收到的网络包</param>
/// <returns></returns>
/// <remarks>如果收到的包是分片包，且其所有子包尚未接受完全，则会返回空值</remarks>
public static Msg TryToTranslateMessage(PacketNetWorkMsg pack)
{
if (pack == null || pack.PackageIndex > pack.PackageCount - 1) return null;
else if (pack.PackageCount == 1) return ParseToMessage(pack);
else
{
lock (packageCache)
{
if (packageCache.ContainsKey(pack.PackageNo))
{
PacketNetWorkMsg[] array = packageCache[pack.PackageNo];
array[pack.PackageIndex] = pack;
//检测是否完整
if (Array.FindIndex(array, s => s == null) == -1)
{
packageCache.Remove(pack.PackageNo);
return ParseToMessage(array);
}
else
{
return null;
}
}
else
{
PacketNetWorkMsg[] array = new PacketNetWorkMsg[pack.PackageCount];
array[pack.PackageIndex] = pack;
packageCache.Add(pack.PackageNo, array);
return null;
}
}
}
}
/// <summary>
/// 将网络信息解析为封包
/// </summary>
/// <param name="buffer"></param>
/// <returns></returns>
public static PacketNetWorkMsg Parse(byte[] buffer, IPEndPoint clientAddress)
{
if (!Test(buffer)) return null;
PacketNetWorkMsg p = new PacketNetWorkMsg()
{
RemoteIP = clientAddress,
SendTimes = 0
};
p.PackageNo = BitConverter.ToInt64(buffer, 1);//包编号
p.DataLength = (int)BitConverter.ToInt64(buffer, 9); //内容长度
p.PackageCount = BitConverter.ToInt32(buffer, 13);//分包总数
p.PackageIndex = BitConverter.ToInt32(buffer, 17);//索引
p.IsRequireReceiveCheck = buffer[21] == 1;//是否需要回包
p.Data = new byte[buffer.Length - PackageHeaderLength];
Array.Copy(buffer, PackageHeaderLength, p.Data, 0, p.Data.Length);
return p;
}
void CheckForOutdateMessage()
{
lock (packageCache)
{
//TODO 这里设置最短的过期时间为5分钟，也就是说五分钟之前的消息会被干掉
var minTime = DateTime.Now.AddMinutes(5.0);
var targetList = new List<long>();
foreach (var pkgid in packageCache.Keys)
{
if (Array.TrueForAll(packageCache[pkgid], s => s == null || s.CreationTime < minTime))
{
targetList.Add(pkgid);
}
}
foreach (var pkgid in targetList)
{
packageCache.Remove(pkgid);
}
}
}
#region 事件
/// <summary>
/// 网络层数据包解压缩失败
/// </summary>
public static event EventHandler<PackageEventArgs> DecompressFailed;
/// <summary>
/// 触发解压缩失败事件
/// </summary>
/// <param name="e">事件包含的参数</param>
protected static void OnDecompressFailed(PackageEventArgs e)
{
if (DecompressFailed != null) DecompressFailed(typeof(MessagePacker),e);
}
#endregion
}
原文地址：http://blog.csdn.net/zhujunxxxxx/article/details/38864817
