/// <summary>
/// 从一个报文中获取到具体的报文实例
/// </summary>
/// <param name="data">接收到的byte数据</param>
/// <returns></returns>
public static MessageContent InitMessageFromData(ref byte[] data, out byte[] leftMessage)
{
var textContent = Encoding.UTF8.GetString(data);
leftMessage = null;
MessageContent message = new MessageContent();
StringReader stringReader = new StringReader(textContent);
string line = "";
string headerline = "";
// 因为这个函数主要是为了验证头部的完整性，从而读取出报文的总长度，数据部分长度
// 定义三个变量，分别代表报头是否开始，是否有效，是否结束，三个条件缺一不可
// 否则将报文归纳为剩余报文，放到之后的报文前面一起处理
bool headerBegin = false;
bool headerValid = false;
bool headerEnd = false;
MessageType messageType = MessageType.None;
string gid = "";
int contentLength = 0;
string ipAddress = "";
string encoding = "";
// 开始解析头部
while (line != null)
{
// 读到当前行
line = stringReader.ReadLine();
if (line != null)
{
if (headerBegin == false)
{
// 如果还没检测到固定头，则通过这个函数检查并给消息种类赋值
headerBegin = CheakIfHeaderLineAndGetType(line, ref messageType);
if (messageType == MessageType.None)
{
break;
}
if (messageType == MessageType.HeartBeat)
{
headerValid = true;
headerline += line + "\r\n";
headerEnd = true;
break;
}
}
else
{
// 请求头读完，退出循环
if (headerValid && line == "")
{
headerline += line + "\r\n";
headerEnd = true;
break;
}
var lineSplit = line.Split(':');
if (lineSplit.Length >= 2)
{
headerValid = true;
// 如果是GID
if (gid == "" && lineSplit[0].ToUpper() == "GID")
{
gid = lineSplit[1].Trim();
}
if (encoding == "" && lineSplit[0].ToUpper() == "TRANSFER-ENCODING")
{
encoding = lineSplit[1].Trim();
// 如果是分包报文
if (encoding.ToUpper().Trim() == "CHUNKED")
{
message.IsChunked = true;
}
}
if (contentLength == 0 && lineSplit[0].ToUpper() == "CONTENT-LENGTH")
{
int.TryParse(lineSplit[1].Trim(), out contentLength);
}
if (ipAddress == "" && lineSplit[0].ToUpper() == "IP")
{
ipAddress = lineSplit[1].Trim() + (lineSplit.Length > 2 ? ":" + lineSplit[2].Trim() : "");
}
}
else
{
contentLength = 0;
gid = "";
ipAddress = "";
headerValid = false;
headerBegin = false;
encoding = "";
}
}
if (headerBegin)
{
headerline += line + "\r\n";
}
else
{
headerline = "";
}
}
}
// 当前数据是错的，舍弃掉所有数据，等待之后的数据
if (messageType == MessageType.None)
{
leftMessage = null;
return(null);
}
// 头还没读完，用之后的数据来处理
if (headerBegin && !headerEnd)
{
leftMessage = data;
return(null);
}
line = stringReader.ReadLine();
if (headerEnd == true && line == null && data.Last() != 10)
{
leftMessage = data;
return(null);
}
// 如果当前是分包数据，一直读到最后一个包，若包完整，给Content-Length赋值
if (message.IsChunked)
{
var readLength = Encoding.UTF8.GetBytes(headerline).Length;
var readFinish = false;
while (readFinish == false)
{
var dataleft = data.Skip(readLength).ToArray();
StringReader reader = new StringReader(Encoding.UTF8.GetString(dataleft));
line = reader.ReadLine();
if (line != null)
{
var lengthIsValid = int.TryParse(line, System.Globalization.NumberStyles.HexNumber, null, out var result);
// 如果长度有效，
if (lengthIsValid)
{
if (result != 0)
{
readLength += Encoding.UTF8.GetBytes(line + "\r\n").Length + result + Encoding.UTF8.GetBytes("\r\n").Length;
if (data.Length <= readLength)
{
leftMessage = data;
return(null);
}
}
else
{
readLength += Encoding.UTF8.GetBytes(line + "\r\n\r\n").Length;
if (data.Length >= readLength)
{
readFinish = true;
}
}
}
else
{
leftMessage = null;
return(null);
}
}
else
{
leftMessage = data;
return(null);
}
}
contentLength = readLength - Encoding.UTF8.GetBytes(headerline).Length;
}
// 当头完整时，根据这个头的信息，获取报文实体
if (headerBegin && headerValid && headerEnd)
{
message = GetMessageByInfo(messageType, ref data, headerline,
contentLength, gid, ipAddress, ref leftMessage);
}
return(message);
}
/// <summary>
/// 根据报文的各种信息初始化一个报文实例
/// </summary>
/// <param name="messageType">报文种类</param>
/// <param name="data">从报头开始的数据</param>
/// <param name="headerline">请求头文本内容</param>
/// <param name="contentLength">请求行中标注的数据长度</param>
/// <param name="gid">项目号</param>
/// <param name="ipAddress">IP地址(包含Port)</param>
/// <param name="leftMessage">剩余的数据</param>
/// <returns>报文实例，如果当前报文格式不正确，则返回null</returns>
private static MessageContent GetMessageByInfo(MessageType messageType, ref byte[] data, string headerline, int contentLength, string gid, string ipAddress, ref byte[] leftMessage)
{
var message = new MessageContent();
message.Type = messageType;
// 算出报头长度
var headerLength = Encoding.UTF8.GetBytes(headerline).Length;
message.MessageLength = headerLength + contentLength;
// 如果不是HTTP报文，还会在报文最后加上回车换行两个符号，所以总长度要加2
if (messageType != MessageType.Http && messageType != MessageType.HeartBeat && contentLength != 0)
{
message.MessageLength += 2;
}
// 当前数据长度不够
if (message.MessageLength > data.Length)
{
leftMessage = data;
return(null);
}
byte[] contentData = null;
// 对于具体的报文种类，要具体处理
switch (messageType)
{
case MessageType.Login:
if (gid == "")
{
message = null;
}
else
{
message.GID = gid;
}
break;
case MessageType.Client:
case MessageType.Server:
// 必须携带IP地址和端口号
var destIPAndPort = GetEndPointFromString(ipAddress);
if (destIPAndPort.Invalid)
{
message = null;
}
else
{
message.IPAndPort = destIPAndPort;
}
break;
case MessageType.HeartBeat:
case MessageType.Http:
message.GID = gid;
break;
default:
message = null;
break;
}
if (message != null)
{
if (messageType == MessageType.Http)
{
message.DataLength = message.MessageLength;
// 添加要转发的报文内容
contentData = new byte[message.MessageLength];
Array.Copy(data, contentData, message.MessageLength);
message.Data = contentData;
}
else
{
message.DataLength = contentLength;
// 添加要转发的报文内容
contentData = new byte[contentLength];
Array.Copy(data, headerLength, contentData, 0, contentLength);
message.Data = contentData;
}
// 剩的数据里面可能含有效的报文也可能没有，
data = data.Skip(message.MessageLength).ToArray();
}
return(message);
}
