/** * Add friend by retreiving certificate from DHT. * @param key the DHT key for friend's certificate. */ public void AddDhtFriend(string key) { if (key == _local_user.DhtKey || _friends.ContainsKey(key)) { if (key != _local_user.DhtKey) { _srh.PingFriend(_friends[key]); } return; } Channel q = new Channel(); q.CloseAfterEnqueue(); q.CloseEvent += delegate(Object o, EventArgs eargs) { try { DhtGetResult dgr = (DhtGetResult)q.Dequeue(); byte[] certData = dgr.value; AddCertificate(certData, key); ProtocolLog.Write(SocialLog.SVPNLog, "ADD DHT SUCCESS: " + key); } catch (Exception e) { ProtocolLog.Write(SocialLog.SVPNLog, e.Message); ProtocolLog.Write(SocialLog.SVPNLog, "ADD DHT FAILURE: " + key); } }; this.Dht.AsGet(key, q); }
/// <summary> /// Does bulk Brunet DHT gets by calling the bulk DHT operation API of its /// XML-RPC interface. /// </summary> /// <returns>Null if not all the pieces are successfully retrieved and parsed.</returns> /// <exception cref="Exception">Parsing errors.</exception> private MemBlock GetFragsInBulk(byte[] base_key, int piece_num, out int largest_age, out int smallest_ttl) { largest_age = 0; smallest_ttl = Int32.MaxValue; MemBlock fragments = new MemBlock(); byte[][] keys = new byte[piece_num][]; for (int i = 0; i < piece_num; i++) { byte[] piece_key = BuildFragmentKey(base_key, i); keys[i] = piece_key; } DhtGetResult[] dgrs = _dht.BulkGet(keys); for (int i = 0; i < dgrs.Length; i++) { DhtGetResult dgr = dgrs[i]; if (dgr == null) { Logger.WriteLineIf(LogLevel.Error, _log_props, string.Format("Piece #{0} is null. Retrying...", i)); dgr = GetWithRetries(keys[i], 2); if (dgr == null) { Logger.WriteLineIf(LogLevel.Error, _log_props, string.Format("Piece #{0} is null after retries. Skipping " + "further parsing and returning...", i)); return(null); } } FingerprintedData fpd; try { fpd = (FingerprintedData)DictionaryData.CreateDictionaryData(dgr.value); } catch (Exception ex) { Logger.WriteLineIf(LogLevel.Error, _log_props, ex); throw ex; } Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Piece #{0} retrieved and successfully parsed", i)); RegularData rd = fpd.InnerData as RegularData; fragments = MemBlock.Concat(fragments, MemBlock.Reference(rd.PayLoad)); if (smallest_ttl > dgr.ttl) { smallest_ttl = dgr.ttl; } if (largest_age < dgr.age) { largest_age = dgr.age; } //Now it's safe to say, this attempt succeeded. } return(fragments); }
/// <summary> /// Gets the first data item of the given name and possibly gets the /// indicated pieces from DHT. /// </summary> /// <param name="getPieces">Whether to get pieces if the data at the /// specified DHT name is a FragmentationInfo</param> public DhtGetResult GetOneDatum(byte[] key, bool getPieces, OneDatumMode mode) { DhtGetResult[] results = _dht.Get(key); DhtGetResult ret; if (results.Length == 0) { ret = null; } else { DhtGetResult dgr; if (mode == OneDatumMode.FirstOne) { dgr = results[0]; } else if (mode == OneDatumMode.LastOne) { dgr = results[results.Length - 1]; } else { throw new NotImplementedException( "This OneDatumMode not implemented."); } DictionaryData dd = null; try { dd = DictionaryData.CreateDictionaryData(dgr.value); } catch (Exception ex) { // Not an error in this case. Log with verbose level. Logger.WriteLineIf(LogLevel.Verbose, _log_props, ex); } if (dd != null && dd is FragmentationInfo) { FragmentationInfo frag_info = dd as FragmentationInfo; BrunetDhtEntry bde = null; try { bde = GetFragments(frag_info) as BrunetDhtEntry; RegularData rd = (RegularData)DictionaryData.CreateDictionaryData( bde.Value); //Only 1 entry (if any) in this array ret = new DhtGetResult(rd.PayLoad, bde.Age, bde.Ttl); } catch (Exception ex) { Logger.WriteLineIf(LogLevel.Error, _log_props, string.Format("Can't get fragments."), ex); ret = null; } } else { ret = dgr; } } return(ret); }
public void OnDhtGetReturns(IAsyncResult result) { AsyncResult ar = (AsyncResult)result; AsyncFragsOpState agfs = (AsyncFragsOpState)ar.AsyncState; BrunetDhtGetOp op = (BrunetDhtGetOp)ar.AsyncDelegate; AsyncGetFragsGlobalState global_state = (AsyncGetFragsGlobalState)agfs.GlobalState; AsyncOpState piece_state = agfs.PieceState; DhtGetResult[] returns = op.EndInvoke(ar); if (returns != null && returns.Length > 0) { // We only need the first one. DhtGetResult dgr = returns[0]; Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Get succeeded for piece: {0}", Encoding.UTF8.GetString(piece_state.Key))); lock (global_state.SyncRoot) { byte[] piece_key = piece_state.Key; int piece_indx = BrunetDht.GetPieceIndexFromFragmentKey(piece_key); global_state.Fragments[piece_indx] = dgr; global_state.OpSuccCount++; if ((global_state.Concurrency > 1 && global_state.OpSuccCount % global_state.Concurrency == 0) || global_state.OpSuccCount == global_state.ExpectedPositiveReturnNum) { // put concurrently and a batch finishes. global_state.BatchFinishedEvent.Set(); } if (global_state.OpSuccCount == global_state.ExpectedPositiveReturnNum) { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("All pieces of {0} successfully got. Firing GetStoppedEvent", Encoding.UTF8.GetString(global_state.BaseKey))); global_state.Returns.Enqueue(new GetFragsStoppedEventArgs(global_state.Fragments)); } } } else { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Get failed for piece: {0}. Firing GetStoppedEvent", Encoding.UTF8.GetString(piece_state.Key))); //No retry at this level currently, stop put operation. lock (global_state.SyncRoot) { global_state.Returns.Enqueue(new PutFragsStoppedEventArgs(piece_state)); } } }
/// <returns>Null if nothing got after retries</returns> private DhtGetResult GetWithRetries(byte[] key, int retries) { bool succ = false; DhtGetResult ret = null; string key_string = Encoding.UTF8.GetString(key); int retires_local = retries; for (; !succ && retires_local > 0; retires_local--) { if (retires_local < retries) { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Retrying...")); } DhtGetResult[] results = _dht.Get(key); if (results.Length > 0) { succ = true; ret = results[0]; } } if (retires_local <= 0) { Logger.WriteLineIf(LogLevel.Error, _log_props, string.Format("Retries exhausted when getting {0}", key_string)); } else { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("{0} successfully got.", key_string)); } return(ret); }
/// <returns>The memblock assembled from pieces. Null if operation failed.</returns> private MemBlock GetFragsSequentially(byte[] base_key, int piece_num, out int largest_age, out int smallest_ttl) { largest_age = 0; smallest_ttl = Int32.MaxValue; MemBlock fragments = new MemBlock(); for (int i = 0; i < piece_num; i++) { byte[] piece_key = BuildFragmentKey(base_key, i); bool succ = false; //set to false iff bad things happen int retries = 3; //After that we fail the operation for (; !succ && retries > 0; retries--) { if (retries == 3) { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Getting: {0}", piece_key)); } else { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Retrying...")); } try { DhtGetResult[] dgrs = _dht.Get(piece_key); //It should have only one entry. If not, just let the the exception caught //and retry. DhtGetResult dgr = dgrs[0]; FingerprintedData fpd = (FingerprintedData)DictionaryData.CreateDictionaryData(dgr.value); Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Piece {0} retrieved and successfully parsed", piece_key)); RegularData rd = fpd.InnerData as RegularData; fragments = MemBlock.Concat(fragments, MemBlock.Reference(rd.PayLoad)); if (smallest_ttl > dgr.ttl) { smallest_ttl = dgr.ttl; } if (largest_age < dgr.age) { largest_age = dgr.age; } //Now it's safe to say, this attempt succeeded. succ = true; } catch (Exception ex) { Logger.WriteLineIf(LogLevel.Error, _log_props, ex); succ = false; } } //if succ then we are good if (retries <= 0) { //Quit because retries exhausted. throw new Exception(string.Format("Retries exhausted when retrieving " + "and deserializing piece : {0}", piece_key)); } else { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format( "Done with piece {0}", Encoding.UTF8.GetString(piece_key))); } } return(fragments); }
/// <summary> /// Concurrenly gets the fragments from DHT. /// </summary> /// <returns>The fragments</returns> private MemBlock GetFragsConcurrently(byte[] baseKey, int pieceNum, out int largestAge, out int smallestTtl) { // First set the int values to be invalid. smallestTtl = Int32.MaxValue; largestAge = 0; int max_enqueues = 1; BlockingQueue bq_result = new BlockingQueue(max_enqueues); AsyncGetFragsGlobalState global_state = new AsyncGetFragsGlobalState(pieceNum, baseKey, bq_result); int concurrency_degree = Concurrency; global_state.Concurrency = concurrency_degree; for (int i = 0; i < pieceNum; i++) { int index = i; byte[] piece_key = BuildFragmentKey(baseKey, i); string piece_key_string = Encoding.UTF8.GetString(piece_key); // piece state AsyncOpState aps = new AsyncOpState(piece_key); AsyncFragsOpState afos = new AsyncFragsOpState(global_state, aps); // async get, one instance of IDht per get because thread safty not guaranteed IDht proxy = DhtServiceClient.GetXmlRpcDhtClient(_svc_uri.Port); BrunetDhtClientOperations brdht_ops = new BrunetDhtClientOperations( proxy); lock (global_state.SyncRoot) { brdht_ops.BeginGetWithCallback(piece_key, new AsyncCallback(this.OnDhtGetReturns), afos); } Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Get piece {0} from DHT began (asynchronously)", piece_key_string)); if ((concurrency_degree > 1 && (index + 1) % concurrency_degree == 0) || index == pieceNum - 1) { // Stop to wait for batch finish or all finish global_state.BatchFinishedEvent.WaitOne(); if (concurrency_degree > 1) { Logger.WriteLineIf(LogLevel.Verbose, _log_props, string.Format("Batch {0} finished. Moving on", (int)((index + 1) / concurrency_degree))); } } } //block here until result comes GetFragsStoppedEventArgs stop_args = (GetFragsStoppedEventArgs)bq_result.Dequeue(); //All results have returned. MemBlock ret = new MemBlock(); if (stop_args.IsSuccessful) { // We successfully got everything but aren't sure whether they are // correct. Now parse them. for (int i = 0; i < global_state.Fragments.Length; i++) { try { DhtGetResult dgr = global_state.Fragments[i]; FingerprintedData fpd = (FingerprintedData)DictionaryData.CreateDictionaryData(dgr.value); RegularData rd = fpd.InnerData as RegularData; // This piece is OK. ret = MemBlock.Concat(ret, MemBlock.Reference(rd.PayLoad)); if (smallestTtl > dgr.ttl) { smallestTtl = dgr.ttl; } if (largestAge < dgr.age) { largestAge = dgr.age; } //Now it's safe to say, this attempt succeeded. } catch (Exception) { Logger.WriteLineIf(LogLevel.Error, _log_props, string.Format("Parsing Piece failed at index {0}", i)); throw; } } return(ret); } return(null); }