/// <summary>
/// 处理 Tracker 请求的方法。
/// </summary>
/// <param name="processor">为此请求生成的 <see cref="Kei.KTracker.HttpProcessor"/> 对象。</param>
/// <param name="ioStream"><see cref="Kei.KTracker.HttpProcessor"/> 为此请求开启的 <see cref="System.IO.Stream"/>。</param>
/// <param name="parameters">URL 请求参数。</param>
private void HandleTrackerRequest(HttpProcessor processor, Stream ioStream, string parameters)
{
// parameters 传入类似 info_hash=XXXX&port=XXXX&ipv6=XXXX 的形式
var args = Utilities.DecomposeParameterString(parameters);
Logger.Log("[Tracker]请求: " + processor.RequestUrl);
try
{
Logger.Log("[Tracker]解码收到的参数。");
// 先解码处理各种参数（注意可能会引发异常）
string infoHashString = Utilities.UnescapePartialUriEncodedString(args["info_hash"]);
InfoHash infoHash = InfoHash.FromHexString(infoHashString);
int portNo = Convert.ToInt32(args["port"]);
TaskStatus taskStatus;
if (args.ContainsKey("event"))
{
switch (args["event"])
{
case "started":
taskStatus = TaskStatus.Started;
break;
case "stopped":
taskStatus = TaskStatus.Stopped;
break;
case "paused":
taskStatus = TaskStatus.Paused;
break;
default:
taskStatus = TaskStatus.None;
break;
}
}
else
{
taskStatus = TaskStatus.None;
}
bool compact;
if (args.ContainsKey("compact"))
{
var n = Convert.ToInt32(args["compact"]);
compact = n != 0;
}
else
{
compact = false;
}
bool noPeerID;
if (args.ContainsKey("no_peer_id"))
{
var n = Convert.ToInt32(args["no_peer_id"]);
noPeerID = n != 0;
}
else
{
noPeerID = false;
}
var peerIDString = Utilities.UnescapePartialUriEncodedString(args["peer_id"]);
// 别忘了重新确认自己
IPEndPoint newMyself = new IPEndPoint(LocalEndPoint.Address, portNo);
Logger.Log("[Tracker]新的自己(BitTorrent 客户端): " + newMyself.ToString());
SetMyself(newMyself, peerIDString);
List <Peer> peers = null;
TrackerCommEventArgs eventArgs;
// 如果接入分布网络完成
if (FreeToGo)
{
// 触发事件，得到新的可用用户列表
if (Seeds.TryGetValue(infoHash, out peers))
{
peers = Seeds[infoHash];
if (peers.IndexOf(_myself) < 0)
{
// 如果之前我不在种子列表中
// TODO: 添加 myself
peers.Add(_myself);
// 而且此时确认为自己加入网络，强制设定 event=started
taskStatus = TaskStatus.Started;
}
}
else
{
// 如果之前没有相关种子
peers = new List <Peer>();
// TODO: 添加 myself
peers.Add(_myself);
Seeds.Add(infoHash, peers);
// 而且此时确认为自己加入网络，强制设定 event=started
taskStatus = TaskStatus.Started;
}
}
eventArgs = new TrackerCommEventArgs(infoHash, peers, portNo, peerIDString, compact, noPeerID, taskStatus);
EventHelper.RaiseEventAsync(TrackerComm, this, eventArgs);
//if (eventArgs.Peers == null)
//{
// throw new NullReferenceException("Peers list is null");
//}
if (eventArgs.Peers != null)
{
peers = eventArgs.Peers;
}
// 生成返回给 μTorrent 的信息
Logger.Log("[Tracker]反馈给 BitTorrent 客户端。");
if (peers != null)
{
string peersListString = "[Tracker]种子 " + infoHash.ToString() + " 的用户列表如下:";
foreach (var p in peers)
{
peersListString += Environment.NewLine + p.EndPoint.ToString();
}
Logger.Log(peersListString);
}
else
{
Logger.Log("[Tracker]种子 " + infoHash.ToString() + " 的用户列表为空。");
}
BEncodedDictionary data = new BEncodedDictionary();
data.Add("interval", 60);
if (peers != null)
{
// 如果种子列表里有种子
// 为了防止其他线程修改这个 list 导致迭代器失效，先锁定这个对象
lock (peers)
{
if (compact)
{
// 生成字节数组
byte[] peersArray = new byte[peers.Count * 6];
byte[] tmp;
int i = 0;
foreach (var peer in peers)
{
tmp = peer.ToByteArray();
Array.Copy(tmp, 0, peersArray, i * 6, 6);
i++;
}
data.Add("peers", peersArray);
}
else
{
// 生成列表
BEncodedList peersList = new BEncodedList(peers.Count);
foreach (var peer in peers)
{
BEncodedDictionary peerDict = new BEncodedDictionary();
peerDict.Add("id", peer.ID);
peerDict.Add("ip", peer.EndPoint.GetAddressString());
peerDict.Add("port", peer.EndPoint.GetPortNumber());
peersList.Add(peerDict);
}
data.Add("peers", peersList);
}
}
data.Add("complete", peers.Count);
}
else
{
// 如果没有种子，就返回空列表
data.Add("peers", string.Empty);
}
// 输出
Logger.Log("[Tracker]写入“成功”头。");
processor.WriteSuccess(null, "text/plain");
Logger.Log("[Tracker]编码返回数据。");
var dataBytes = data.Encode();
Logger.Log("[Tracker]写入返回数据。");
ioStream.Write(dataBytes, 0, dataBytes.Length);
Logger.Log("[Tracker]向 BitTorrent 客户端返回了: " + Encoding.ASCII.GetString(dataBytes));
ioStream.Flush();
}
catch (Exception ex)
{
Logger.Log(ex.Message + Environment.NewLine + ex.StackTrace);
processor.WriteFailure();
ioStream.WriteLine(ex.Message);
ioStream.WriteLine(ex.StackTrace);
}
}
