/// <summary>
/// 创建分片
/// </summary>
/// <param name="filesize">文件的大小</param>
/// <param name="sliceSize">分片的字节大小</param>
/// <returns>返回分片列表</returns>
public static List<Slice> CreateSliceList(long filesize, int sliceSize)
{
List<Slice> slicelist = new List<Slice>();
#region 开始分片
long slice_count = 0; //分片数量
// 先按照最小分片计算分片数量
long slice_size = sliceSize;
slice_count = (int)(filesize / slice_size);
if ((filesize % slice_size) != 0)
slice_count++;
long offset = 0;
for (int i = 0; i < slice_count; i++)
{
Slice ts = new Slice()
{
index = i,
start = offset,
totalSize = slice_size
};
if (ts.start + ts.totalSize > filesize) ts.totalSize = filesize - ts.start;
offset += slice_size;
slicelist.Add(ts);
}
#endregion
return slicelist;
}
/// <summary>
/// 读入一个分片
/// </summary>
/// <param name="br">用于读入数据的流</param>
/// <returns></returns>
public static Slice ReadSlice(BinaryReader br)
{
byte[] bs;
Slice slice = new Slice();
slice.index = br.ReadInt32();
slice.start = br.ReadInt64();
slice.totalSize = br.ReadInt64();
slice.doneSize = br.ReadInt64();
slice.status = (SliceStatus)br.ReadInt32();
int len = br.ReadInt32();
if (len > 0)
{
bs = br.ReadBytes(len);
slice.md5 = Encoding.UTF8.GetString(bs).Trim('\0').Trim();
}
return slice;
}
/// <summary>
/// 写入一个分片
/// </summary>
/// <param name="br">用于写入数据的流</param>
/// <param name="slice">待写入的分片</param>
public static void WriteSlice(BinaryWriter br, Slice slice)
{
byte[] bs;
br.Write(slice.index);
br.Write(slice.start);
br.Write(slice.totalSize);
br.Write(slice.doneSize);
br.Write((int)slice.status);
if (!string.IsNullOrEmpty(slice.md5))
{
bs = Encoding.UTF8.GetBytes(slice.md5);
br.Write(bs.Length);
br.Write(bs);
}
else
{
br.Write((int)0);
}
}
