/// <summary>
/// 对块进行切片
/// </summary>
/// <param name="buffer">块数据</param>
/// <param name="identity">文件标识</param>
/// <returns></returns>
public List <byte[]> BlockSlice(byte[] buffer, ushort identity)
{
List <byte[]> result = new List <byte[]>();
ushort sliceCount = (ushort)(buffer.Length / SlicePackageSize);
if (buffer.Length % SlicePackageSize > 0)
{
sliceCount++;
}
for (ushort i = 1; i <= sliceCount; i++)
{
var tmp = buffer.Length - (i - 1) * SlicePackageSize;
var blockSlicePackage = new UdpPackage()
{
PackageIdentity = identity,
PackageOpCode = (byte)OpCode.Message,
PackageBlockSerial = BlockSerial,
PackageSliceSerial = i,
PackageSliceCount = sliceCount,
PackageBody = buffer.Skip((i - 1) * SlicePackageSize)
.Take(tmp < SlicePackageSize ? tmp : SlicePackageSize).ToArray()
};
result.Add(blockSlicePackage.ToBytes());
}
NextBlock();
return(result);
}
/// <summary>
/// 收集块切片
/// </summary>
/// <param name="buffer">切片</param>
/// <param name="lostSlices">丢失的切片序号</param>
/// <returns>切片组装状态</returns>
public bool SlicePackageConcat(byte[] buffer, out ushort[] lostSlices, out bool isEnd)
{
isEnd = false;
lostSlices = null;
if (buffer.Length == 0)
{
return(false);
}
var package = new UdpPackage().BytesToUdpPackage(buffer);
switch ((OpCode)package.PackageOpCode)
{
case OpCode.Start:
FileName = Encoding.UTF8.GetString(package.PackageBody);
return(false);
case OpCode.End:
return(IntegrityChecks(Convert.ToUInt16(Encoding.UTF8.GetString(package.PackageBody)), out lostSlices, out isEnd));
case OpCode.Notice:
BlockNum = Convert.ToInt32(Encoding.UTF8.GetString(package.PackageBody));
return(false);
}
BlockSlicePackages.Add(package);
// 块完整性检查
if (package.PackageSliceCount ==
BlockSlicePackages.Count(x => x.PackageBlockSerial == package.PackageBlockSerial))
{
return(true);
}
return(false);
}