/// <summary>
/// 确定当前路径下文件是否被其他下载 Socket 占用
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
private bool IsFileOccupying(string path)
{
lock (this.ServerFileSet)
{
List <int> ids = new List <int>(ServerFileSet.Keys);
for (int i = 0; i < ids.Count; ++i)
{
ServerFileInfoClass p = ServerFileSet[ids[i]];
if (p.ServerPath == path)
{
// 若该 FileStream 不在使用中 (60s空闲) 则释放
if ((DateTime.Now - p.LastTime).Seconds > 60)
{
p.FStream.Close();
ServerFileSet.Remove(ids[i]);
return(false);
}
else
{
return(true);
}
}
}
return(false);
}
}
/// <summary>
///
/// </summary>
/// <param name="client"></param>
/// <param name="header"></param>
/// <param name="bytes"></param>
/// <param name="isUpload"></param>
private void ResponseFileStreamId(Socket client, HB32Header header, byte[] bytes, bool isUpload)
{
SocketDataFlag mask = (SocketDataFlag)((isUpload ? 1 : 0) << 8);
string path;
/// 验证 key
if (isUpload)
{
int keyLength = Config.KeyLength;
byte[] key = new byte[keyLength];
Array.Copy(bytes, 0, key, 0, keyLength);
path = BytesParser.ParseString(bytes, ref keyLength);
if (!CheckKey(key))
{
SendBytes(client, new HB32Header {
Flag = SocketDataFlag.DownloadDenied ^ mask
}, "key error");
return;
}
}
else
{
path = Encoding.UTF8.GetString(bytes);
}
/// 验证文件是否被占用
if (IsFileOccupying(path))
{
SendBytes(client, new HB32Header {
Flag = SocketDataFlag.DownloadDenied ^ mask
}, "file occupied");
return;
}
/// 生成 FileStreamId 并记录
try
{
FileInfo fif = new FileInfo(path);
FileStream fs = new FileStream(path, FileMode.OpenOrCreate, isUpload ? FileAccess.Write : FileAccess.Read);
ServerFileInfoClass record = new ServerFileInfoClass
{
FStream = fs,
ServerPath = path,
Length = fif.Length,
};
int id = GenerateRandomFileStreamId(1 << 16);
ServerFileSet.Add(id, record);
SendBytes(client, new HB32Header {
Flag = SocketDataFlag.DownloadAllowed ^ mask
}, id.ToString());
}
catch (Exception ex)
{
SendBytes(client, new HB32Header {
Flag = SocketDataFlag.DownloadDenied ^ mask
}, ex.Message);
}
}
/// <summary>
///
/// </summary>
/// <param name="client"></param>
/// <param name="header"></param>
/// <param name="bytes"></param>
/// <param name="isUpload"></param>
private void ResponseTransferPacket(Socket client, HB32Header header, byte[] bytes, bool isUpload)
{
ServerFileInfoClass sfc = ServerFileSet[header.I1];
FileStream fs = sfc.FStream;
/// I2 == -1 则关闭 FileStream
if (header.I2 == -1)
{
fs.Close();
ServerFileSet.Remove(header.I1);
Display.TimeWriteLine("Released file id : " + header.I1.ToString());
return;
}
/// 确定有效 byte 长度
long begin = (long)header.I2 * HB32Encoding.DataSize;
int length = HB32Encoding.DataSize; // 有效byte长度
if (begin + HB32Encoding.DataSize > sfc.Length)
{
length = (int)(sfc.Length - begin);
}
byte[] responseBytes = new byte[0];
/// 定位 FileStream 读取/写入 bytes
lock (fs)
{
fs.Seek(begin, SeekOrigin.Begin);
if (isUpload)
{
fs.Write(bytes, 0, header.ValidByteLength);
//Display.TimeWriteLine(header.I2.ToString());
}
else
{
responseBytes = new byte[length];
fs.Read(responseBytes, 0, length);
}
}
sfc.LastTime = DateTime.Now;
/// response
if (isUpload)
{
SendHeader(client, new HB32Header {
Flag = SocketDataFlag.UploadPacketResponse
});
}
else
{
SendBytes(client, new HB32Header {
Flag = SocketDataFlag.DownloadPacketResponse
}, responseBytes);
}
}