public async Task GetPeersInfo(GetPeersInfoInput input)
{
// 如果 BT 客户端没有传递 IP，则通过 Context 获得。
if (string.IsNullOrEmpty(input.Ip))
{
input.Ip = _httpContextAccessor.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString();
}
// 本机测试用。
input.Ip = "127.0.0.1";
AnnounceInputParameters inputPara = input;
var resultDict = new BDictionary();
// 如果产生了错误，则不执行其他操作，直接返回结果。
if (inputPara.Error.Count == 0)
{
_bitTorrentManager.UpdatePeer(input.Info_Hash, inputPara);
_bitTorrentManager.ClearZombiePeers(input.Info_Hash, TimeSpan.FromMinutes(10));
var peers = _bitTorrentManager.GetPeers(input.Info_Hash);
HandlePeersData(resultDict, peers, inputPara);
// 构建剩余字段信息
// 客户端等待时间
resultDict.Add(TrackerServerConsts.IntervalKey, new BNumber((int)TimeSpan.FromSeconds(30).TotalSeconds));
// 最小等待间隔
resultDict.Add(TrackerServerConsts.MinIntervalKey, new BNumber((int)TimeSpan.FromSeconds(30).TotalSeconds));
// Tracker 服务器的 Id
resultDict.Add(TrackerServerConsts.TrackerIdKey, new BString("Tracker-DEMO"));
// 已完成的 Peer 数量
resultDict.Add(TrackerServerConsts.CompleteKey, new BNumber(_bitTorrentManager.GetComplete(input.Info_Hash)));
// 非做种状态的 Peer 数量
resultDict.Add(TrackerServerConsts.IncompleteKey, new BNumber(_bitTorrentManager.GetInComplete(input.Info_Hash)));
}
else
{
resultDict = inputPara.Error;
}
// 写入响应结果。
var resultDictBytes = resultDict.EncodeAsBytes();
var response = _httpContextAccessor.HttpContext.Response;
response.ContentType = "text/plain";
response.StatusCode = 200;
response.ContentLength = resultDictBytes.Length;
await response.Body.WriteAsync(resultDictBytes);
}
/// <summary>
/// 将 Peer 集合的数据转换为 BT 协议规定的格式
/// </summary>
private void HandlePeersData(BDictionary resultDict, IReadOnlyList <Peer> peers, AnnounceInputParameters inputParameters)
{
var total = Math.Min(peers.Count, inputParameters.PeerWantCount);
//var startIndex = new Random().Next(total);
// 判断当前 BT 客户端是否需要紧凑模式的数据。
if (inputParameters.IsEnableCompact)
{
var compactResponse = new byte[total * 6];
for (int index = 0; index < total; index++)
{
var peer = peers[index];
Buffer.BlockCopy(peer.ToBytes(), 0, compactResponse, (total - 1) * 6, 6);
}
resultDict.Add(TrackerServerConsts.PeersKey, new BString(compactResponse));
}
else
{
var nonCompactResponse = new BList();
for (int index = 0; index < total; index++)
{
var peer = peers[index];
nonCompactResponse.Add(peer.ToEncodedDictionary());
}
resultDict.Add(TrackerServerConsts.PeersKey, nonCompactResponse);
}
}
