/// <summary>
/// 写入封包头
/// </summary>
/// <param name="buff">数据缓存</param>
/// <param name="index">写入位置</param>
/// <param name="head">封包头</param>
public static unsafe void WriteHead(byte[] buff, int index, EnvelopeHead head)
{
fixed(byte *b = &buff[index])
{
*(EnvelopeHead *)b = *&head;
}
}
/// <summary>
///
/// </summary>
/// <param name="buff">源数据</param>
/// <param name="len">数据长度</param>
/// <param name="buffer">缓存数据</param>
/// <param name="remain"></param>
/// <param name="fs"></param>
/// <returns></returns>
public static List <EnvelopePart> UnpackPart(byte[] buff, int len, byte[] buffer, ref int remain, int fs)
{
fs -= EnvelopeHeadSize;
List <EnvelopePart> list = new List <EnvelopePart>();
int s = remain;
for (int i = 0; i < len; i++)
{
buffer[s] = buff[i];
s++;
}
len += remain;
int index = 0;
for (int i = 0; i < 1024; i++)
{
EnvelopeHead head = ReadHead(buffer, index);
if (head.PartLen > fs)
{
remain = 0;
break;
}
if (index + EnvelopeHeadSize + head.PartLen > len)
{
remain = len - index;
for (int j = 0; j < len; j++)
{
buffer[j] = buffer[index];
index++;
}
return(list);
}
index += EnvelopeHeadSize;
if (head.Lenth > 2)
{
EnvelopePart part = new EnvelopePart();
part.head = head;
int l = (int)head.PartLen;
var buf = new byte[l];
int a = index;
for (int j = 0; j < l; j++)
{
buf[j] = buffer[a]; a++;
}
part.data = buf;
list.Add(part);
}
index += head.PartLen;
if (index >= len)
{
remain = 0;
break;
}
}
return(list);
}
/// <summary>
/// 对数据进行分卷, 标头4字节，总长度4字节, 当前分卷2字节，总分卷2字节，当前分卷长度4字节，总计16字节
/// </summary>
/// <param name="buff">需要打包的数据</param>
/// <param name="type">数据类型</param>
/// <param name="id">数据包标志</param>
/// <param name="fs">每个分卷大小</param>
/// <returns></returns>
public static byte[][] SubVolume(byte[] buff, byte type, UInt16 id, UInt16 fs)
{
fs -= 16;
if (buff.Length < 2)
{
buff = new byte[2];
}
int len = buff.Length;
int part = len / fs;
int r = len % fs;
UInt16 allPart = (UInt16)part;
if (r > 0)
{
allPart++;
}
byte[][] buf = new byte[allPart][];
UInt16 msgId = id;
EnvelopeHead head = new EnvelopeHead();
for (int i = 0; i < part; i++)
{
head.MsgID = msgId;
head.Type = type;
head.PartID = id;
head.CurPart = (UInt16)i;
head.AllPart = allPart;
head.PartLen = fs;
head.Lenth = (UInt32)len;
byte[] tmp = new byte[fs + 16];
WriteHead(tmp, 0, head);
buf[i] = EnvelopePart(buff, tmp, i, fs, fs);
id++;
}
if (r > 0)
{
head.MsgID = msgId;
head.Type = type;
head.PartID = id;
head.CurPart = (UInt16)part;
head.AllPart = allPart;
head.PartLen = (UInt16)r;
head.Lenth = (UInt32)len;
byte[] tmp = new byte[r + 16];
WriteHead(tmp, 0, head);
buf[part] = EnvelopePart(buff, tmp, part, r, fs);
}
return(buf);
}
public static void CopyToBuff(byte[] buff, byte[] src, int start, EnvelopeHead head, int FragmentSize)
{
int index = head.CurPart * FragmentSize;
int len = (int)head.PartLen;
int all = buff.Length;
for (int i = 0; i < len; i++)
{
if (index >= all)
{
break;
}
buff[index] = src[start];
index++;
start++;
}
}
static byte[] ReadPart(byte[] data, out EnvelopeHead head)
{
head = ReadHead(data, 0);
int len = data.Length - EnvelopeHeadSize;
if (len >= head.PartLen)
{
byte[] buf = new byte[head.PartLen];
int start = EnvelopeHeadSize;
for (int i = 0; i < head.PartLen; i++)
{
buf[i] = data[start];
start++;
}
return(buf);
}
return(null);
}
