public int Serialize(ref byte[] bytes, int offset, JT809Package value)
{
// 1. 先序列化数据体，根据数据体的长度赋值给头部，在序列化头部。
int messageBodyOffset = 0;
JT809BodiesTypeAttribute jT809BodiesTypeAttribute = value.Header.BusinessType.GetAttribute <JT809BodiesTypeAttribute>();
if (jT809BodiesTypeAttribute != null)
{
if (value.Bodies != null)
{
// 1.1 处理数据体
messageBodyOffset = JT809FormatterResolverExtensions.JT809DynamicSerialize(JT809FormatterExtensions.GetFormatter(jT809BodiesTypeAttribute.JT809BodiesType), ref bytes, messageBodyOffset, value.Bodies);
}
}
byte[] messageBodyData = null;
if (messageBodyOffset != 0)
{
messageBodyData = bytes.AsSpan(0, messageBodyOffset).ToArray();
// 1.2 数据加密
switch (value.Header.EncryptFlag)
{
case JT809Header_Encrypt.None:
break;
case JT809Header_Encrypt.Common:
messageBodyData = JT809GlobalConfig.Instance.Encrypt.Encrypt(messageBodyData, value.Header.EncryptKey);
break;
}
}
// ------------------------------------开始组包
// 1.起始符
offset += JT809BinaryExtensions.WriteByteLittle(bytes, offset, value.BeginFlag);
// 2.赋值头数据长度
if (messageBodyOffset != 0)
{
value.Header.MsgLength = (uint)(JT809Package.FixedByteLength + messageBodyData.Length);
}
else
{
value.Header.MsgLength = JT809Package.FixedByteLength;
}
// 2.1写入头部数据
offset = JT809FormatterExtensions.GetFormatter <JT809Header>().Serialize(ref bytes, offset, value.Header);
if (messageBodyOffset != 0)
{
// 3. 写入数据体
Array.Copy(messageBodyData, 0, bytes, offset, messageBodyData.Length);
offset += messageBodyData.Length;
messageBodyData = null;
}
// 4.校验码
offset += JT809BinaryExtensions.WriteUInt16Little(bytes, offset, bytes.ToCRC16_CCITT(1, offset));
// 5.终止符
offset += JT809BinaryExtensions.WriteByteLittle(bytes, offset, value.EndFlag);
// 6.转义
return(JT809Util.JT809Escape(ref bytes, offset));
}
public JT809HeaderPackage Deserialize(ReadOnlySpan <byte> bytes, out int readSize)
{
int offset = 0;
JT809HeaderPackage jT809HeaderPackage = new JT809HeaderPackage();
// 转义还原——>验证校验码——>解析消息
// 1. 解码（转义还原）
ReadOnlySpan <byte> buffer = JT809Util.JT809DeEscape(bytes);
// 2. 验证校验码
// 2.1. 获取校验位索引
int checkIndex = buffer.Length - 3;
// 2.2. 获取校验码
int crcCodeOffset = 0;
jT809HeaderPackage.CRCCode = JT809BinaryExtensions.ReadUInt16Little(buffer.Slice(checkIndex, 2), ref crcCodeOffset);
if (!JT809GlobalConfig.Instance.SkipCRCCode)
{
// 2.3. 从消息头到校验码前一个字节
ushort checkCode = buffer.ToCRC16_CCITT(1, checkIndex);
// 2.4. 验证校验码
if (jT809HeaderPackage.CRCCode != checkCode)
{
throw new JT809Exception(JT809ErrorCode.CRC16CheckInvalid, $"{jT809HeaderPackage.CRCCode.ToString()}!={checkCode.ToString()}");
}
}
jT809HeaderPackage.BeginFlag = JT809BinaryExtensions.ReadByteLittle(buffer, ref offset);
// 3.初始化消息头
try
{
jT809HeaderPackage.Header = JT809FormatterExtensions.GetFormatter <JT809Header>().Deserialize(buffer.Slice(offset, JT809Header.FixedByteLength), out readSize);
}
catch (Exception ex)
{
throw new JT809Exception(JT809ErrorCode.HeaderParseError, $"offset>{offset.ToString()}", ex);
}
offset += readSize;
// 5.数据体处理
// 5.1 判断是否有数据体（总长度-固定长度）> 0
if ((jT809HeaderPackage.Header.MsgLength - JT809Package.FixedByteLength) > 0)
{
//JT809.Protocol.Enums.JT809BusinessType 映射对应消息特性
JT809BodiesTypeAttribute jT809BodiesTypeAttribute = jT809HeaderPackage.Header.BusinessType.GetAttribute <JT809BodiesTypeAttribute>();
if (jT809BodiesTypeAttribute != null)
{
try
{
// 5.2 是否加密
switch (jT809HeaderPackage.Header.EncryptFlag)
{
case JT809Header_Encrypt.None:
//5.3 处理消息体
jT809HeaderPackage.Bodies = buffer.Slice(offset, checkIndex - offset).ToArray();
break;
case JT809Header_Encrypt.Common:
byte[] bodiesData = JT809GlobalConfig.Instance.Encrypt.Decrypt(buffer.Slice(offset, checkIndex - offset).ToArray(), jT809HeaderPackage.Header.EncryptKey);
jT809HeaderPackage.Bodies = bodiesData;
break;
}
}
catch (Exception ex)
{
throw new JT809Exception(JT809ErrorCode.BodiesParseError, $"offset>{offset.ToString()}", ex);
}
}
}
jT809HeaderPackage.EndFlag = buffer[buffer.Length - 1];
readSize = buffer.Length;
return(jT809HeaderPackage);
}