src/main/java/net/pterodactylus/irc/Connection.java

   1 /*
   2  * XdccDownloader - Connection.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.irc;
  19
  20 import static com.google.common.base.Preconditions.checkState;
  21 import static java.util.concurrent.TimeUnit.SECONDS;
  22
  23 import java.io.BufferedReader;
  24 import java.io.Closeable;
  25 import java.io.EOFException;
  26 import java.io.IOException;
  27 import java.io.InputStream;
  28 import java.io.InputStreamReader;
  29 import java.io.OutputStream;
  30 import java.io.UnsupportedEncodingException;
  31 import java.net.InetAddress;
  32 import java.net.Socket;
  33 import java.net.UnknownHostException;
  34 import java.util.ArrayList;
  35 import java.util.List;
  36 import java.util.Map;
  37 import java.util.Set;
  38 import java.util.concurrent.TimeUnit;
  39 import javax.net.SocketFactory;
  40
  41 import net.pterodactylus.irc.event.ChannelJoined;
  42 import net.pterodactylus.irc.event.ChannelLeft;
  43 import net.pterodactylus.irc.event.ChannelMessageReceived;
  44 import net.pterodactylus.irc.event.ChannelNicknames;
  45 import net.pterodactylus.irc.event.ChannelNotJoined;
  46 import net.pterodactylus.irc.event.ChannelNotJoined.Reason;
  47 import net.pterodactylus.irc.event.ChannelNoticeReceived;
  48 import net.pterodactylus.irc.event.ChannelTopic;
  49 import net.pterodactylus.irc.event.ClientQuit;
  50 import net.pterodactylus.irc.event.ConnectionClosed;
  51 import net.pterodactylus.irc.event.ConnectionEstablished;
  52 import net.pterodactylus.irc.event.ConnectionFailed;
  53 import net.pterodactylus.irc.event.DccAcceptReceived;
  54 import net.pterodactylus.irc.event.DccSendReceived;
  55 import net.pterodactylus.irc.event.MotdReceived;
  56 import net.pterodactylus.irc.event.NicknameChanged;
  57 import net.pterodactylus.irc.event.NicknameInUseReceived;
  58 import net.pterodactylus.irc.event.NoNicknameGivenReceived;
  59 import net.pterodactylus.irc.event.PrivateMessageReceived;
  60 import net.pterodactylus.irc.event.PrivateNoticeReceived;
  61 import net.pterodactylus.irc.event.ReplyReceived;
  62 import net.pterodactylus.irc.event.UnknownReplyReceived;
  63 import net.pterodactylus.irc.util.RandomNickname;
  64 import net.pterodactylus.xdcc.util.io.BandwidthCountingInputStream;
  65 import net.pterodactylus.xdcc.util.io.BandwidthCountingOutputStream;
  66
  67 import com.google.common.base.Optional;
  68 import com.google.common.collect.Maps;
  69 import com.google.common.collect.Sets;
  70 import com.google.common.eventbus.EventBus;
  71 import com.google.common.io.Closeables;
  72 import com.google.common.primitives.Ints;
  73 import com.google.common.primitives.Longs;
  74 import com.google.common.util.concurrent.AbstractExecutionThreadService;
  75 import com.google.common.util.concurrent.Service;
  76 import org.apache.log4j.Logger;
  77
  78 /**
  79  * A connection to an IRC server.
  80  *
  81  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  82  */
  83 public class Connection extends AbstractExecutionThreadService implements Service {
  84
  85         /* The logger. */
  86         private static final Logger logger = Logger.getLogger(Connection.class.getName());
  87
  88         /** The event bus. */
  89         private final EventBus eventBus;
  90
  91         /** The socket factory. */
  92         private final SocketFactory socketFactory;
  93
  94         /** The hostname to connect to. */
  95         private final String hostname;
  96
  97         /** The port to connect to. */
  98         private final int port;
  99
 100         /** The nickname chooser. */
 101         private NicknameChooser nicknameChooser = new NicknameChooser() {
 102
 103                 @Override
 104                 public String getNickname() {
 105                         return RandomNickname.get();
 106                 }
 107         };
 108
 109         /** The nickname. */
 110         private String nickname = null;
 111
 112         /** The username. */
 113         private Optional<String> username = Optional.absent();
 114
 115         /** The real name. */
 116         private Optional<String> realName = Optional.absent();
 117
 118         /** The optional password for the connection. */
 119         private Optional<String> password = Optional.absent();
 120
 121         /** The connection handler. */
 122         private ConnectionHandler connectionHandler;
 123
 124         /** Whether the connection has already been established. */
 125         private boolean established;
 126
 127         /**
 128          * Creates a new connection.
 129          *
 130          * @param eventBus
 131          *              The event bus
 132          * @param socketFactory
 133          *              The socket factory
 134          * @param hostname
 135          *              The hostname of the IRC server
 136          * @param port
 137          *              The port number of the IRC server
 138          */
 139         public Connection(EventBus eventBus, SocketFactory socketFactory, String hostname, int port) {
 140                 this.eventBus = eventBus;
 141                 this.socketFactory = socketFactory;
 142                 this.hostname = hostname;
 143                 this.port = port;
 144         }
 145
 146         //
 147         // ACCESSORS
 148         //
 149
 150         /**
 151          * Returns the hostname of the remote end of the connection.
 152          *
 153          * @return The remote’s hostname
 154          */
 155         public String hostname() {
 156                 return hostname;
 157         }
 158
 159         /**
 160          * Returns the port number of the remote end of the connection.
 161          *
 162          * @return The remote’s port number
 163          */
 164         public int port() {
 165                 return port;
 166         }
 167
 168         /**
 169          * Returns whether this connection has already been established.
 170          *
 171          * @return {@code true} as long as this connection is established, {@code
 172          *         false} otherwise
 173          */
 174         public boolean established() {
 175                 return established;
 176         }
 177
 178         /**
 179          * Returns the nickname that is currently in use by this connection. The
 180          * nickname is only available once the connection has been {@link #start()}ed.
 181          *
 182          * @return The current nickname
 183          */
 184         public String nickname() {
 185                 return nickname;
 186         }
 187
 188         //
 189         // MUTATORS
 190         //
 191
 192         /**
 193          * Sets the nickname chooser. The nickname chooser is only used during the
 194          * creation of the connection.
 195          *
 196          * @param nicknameChooser
 197          *              The nickname chooser
 198          * @return This connection
 199          */
 200         public Connection nicknameChooser(NicknameChooser nicknameChooser) {
 201                 this.nicknameChooser = nicknameChooser;
 202                 return this;
 203         }
 204
 205         /**
 206          * Sets the username to use.
 207          *
 208          * @param username
 209          *              The username to use
 210          * @return This connection
 211          */
 212         public Connection username(String username) {
 213                 this.username = Optional.fromNullable(username);
 214                 return this;
 215         }
 216
 217         /**
 218          * Sets the real name to use.
 219          *
 220          * @param realName
 221          *              The real name to use
 222          * @return This connection
 223          */
 224         public Connection realName(String realName) {
 225                 this.realName = Optional.fromNullable(realName);
 226                 return this;
 227         }
 228
 229         /**
 230          * Sets the optional password for the connection.
 231          *
 232          * @param password
 233          *              The password for the connection
 234          * @return This connection
 235          */
 236         public Connection password(String password) {
 237                 this.password = Optional.fromNullable(password);
 238                 return this;
 239         }
 240
 241         //
 242         // ACTIONS
 243         //
 244
 245         /**
 246          * Returns the current rate of the connection’s incoming side.
 247          *
 248          * @return The current input rate (in bytes per second)
 249          */
 250         public long getInputRate() {
 251                 return (connectionHandler != null) ? connectionHandler.getInputRate() : 0;
 252         }
 253
 254         /**
 255          * Returns the current rate of the connection’s outgoing side.
 256          *
 257          * @return The current output rate (in bytes per second)
 258          */
 259         public long getOutputRate() {
 260                 return (connectionHandler != null) ? connectionHandler.getOutputRate() : 0;
 261         }
 262
 263         /**
 264          * Checks whether the given source is the client represented by this
 265          * connection.
 266          *
 267          * @param source
 268          *              The source to check
 269          * @return {@code true} if this connection represents the given source, {@code
 270          *         false} otherwise
 271          */
 272         public boolean isSource(Source source) {
 273                 return source.nick().isPresent() && source.nick().get().equals(nickname);
 274         }
 275
 276         /**
 277          * Joins the given channel.
 278          *
 279          * @param channel
 280          *              The channel to join
 281          * @throws IOException
 282          *              if an I/O error occurs
 283          */
 284         public void joinChannel(final String channel) throws IOException {
 285                 connectionHandler.sendCommand("JOIN", channel);
 286         }
 287
 288         /**
 289          * Sends a message to the given recipient, which may be a channel or another
 290          * nickname.
 291          *
 292          * @param recipient
 293          *              The recipient of the message
 294          * @param message
 295          *              The message
 296          * @throws IOException
 297          *              if an I/O error occurs
 298          */
 299         public void sendMessage(String recipient, String message) throws IOException {
 300                 connectionHandler.sendCommand("PRIVMSG", recipient, message);
 301         }
 302
 303         /**
 304          * Sends a DCC RESUME request to the given recipient.
 305          *
 306          * @param recipient
 307          *              The recipient of the request
 308          * @param filename
 309          *              The name of the file to resume
 310          * @param port
 311          *              The port number from the original DCC SEND request
 312          * @param position
 313          *              The position at which to resume the transfer
 314          * @throws IOException
 315          *              if an I/O error occurs
 316          */
 317         public void sendDccResume(String recipient, String filename, int port, long position) throws IOException {
 318                 connectionHandler.sendCommand("PRIVMSG", recipient, String.format("\u0001DCC RESUME %s %d %d\u0001", filename, port, position));
 319         }
 320
 321         /**
 322          * Closes this connection.
 323          *
 324          * @throws IOException
 325          *              if an I/O error occurs
 326          */
 327         public void close() throws IOException {
 328                 if (connectionHandler != null) {
 329                         connectionHandler.close();
 330                 }
 331         }
 332
 333         //
 334         // ABSTRACTEXECUTIONTHREADSERVICE METHODS
 335         //
 336
 337         @Override
 338         protected void startUp() throws IllegalStateException {
 339                 checkState(username.isPresent(), "username must be set");
 340                 checkState(realName.isPresent(), "realName must be set");
 341         }
 342
 343         @Override
 344         protected void run() {
 345
 346                 /* connect to remote socket. */
 347                 try {
 348                         Socket socket = socketFactory.createSocket(hostname, port);
 349                         socket.setSoTimeout((int) TimeUnit.MINUTES.toMillis(3));
 350                         connectionHandler = new ConnectionHandler(socket.getInputStream(), socket.getOutputStream());
 351
 352                         /* register connection. */
 353                         if (password.isPresent()) {
 354                                 connectionHandler.sendCommand("PASSWORD", password.get());
 355                         }
 356                         connectionHandler.sendCommand("USER", username.get(), "8", "*", realName.get());
 357                         nickname = nicknameChooser.getNickname();
 358                         connectionHandler.sendCommand("NICK", nickname);
 359
 360                 } catch (IOException ioe1) {
 361                         eventBus.post(new ConnectionFailed(this, ioe1));
 362                         return;
 363                 }
 364
 365                 /* now read replies and react. */
 366                 try {
 367                         /* some status variables. */
 368                         int oldConnectionStatus = 0;
 369                         int connectionStatus = 0;
 370                         boolean connected = true;
 371                         StringBuilder motd = new StringBuilder();
 372                         Set<Nickname> nicks = Sets.newHashSet();
 373
 374                         /* server modes. */
 375                         Map<String, String> nickPrefixes = Maps.newHashMap();
 376                         Set<Character> channelTypes = Sets.newHashSet();
 377
 378                         while (connected) {
 379                                 Reply reply = connectionHandler.readReply();
 380                                 eventBus.post(new ReplyReceived(this, reply));
 381                                 logger.trace(String.format("<< %s", reply));
 382                                 String command = reply.command();
 383                                 List<String> parameters = reply.parameters();
 384
 385                                 /* most common events. */
 386                                 if (command.equalsIgnoreCase("PRIVMSG")) {
 387                                         String recipient = parameters.get(0);
 388                                         String message = parameters.get(1);
 389                                         if (message.startsWith("\u0001") && message.endsWith("\u0001")) {
 390                                                 /* CTCP! */
 391                                                 handleCtcp(reply.source().get(), message);
 392                                         } else if (!channelTypes.contains(recipient.charAt(0))) {
 393                                                 eventBus.post(new PrivateMessageReceived(this, reply.source().get(), message));
 394                                         } else {
 395                                                 eventBus.post(new ChannelMessageReceived(this, recipient, reply.source().get(), message));
 396                                         }
 397
 398                                 } else if (command.equalsIgnoreCase("NOTICE")) {
 399                                         String recipient = parameters.get(0);
 400                                         String message = parameters.get(1);
 401                                         if (message.startsWith("\u0001") && message.endsWith("\u0001")) {
 402                                                 /* CTCP! */
 403                                                 handleCtcp(reply.source().get(), message);
 404                                         } else if (!channelTypes.contains(recipient.charAt(0))) {
 405                                                 eventBus.post(new PrivateNoticeReceived(this, reply));
 406                                         } else {
 407                                                 eventBus.post(new ChannelNoticeReceived(this, reply.source().get(), recipient, message));
 408                                         }
 409
 410                                 /* 43x replies are for nick change errors. */
 411                                 } else if (command.equals("431")) {
 412                                         eventBus.post(new NoNicknameGivenReceived(this, reply));
 413                                 } else if (command.equals("433")) {
 414                                         if (connectionStatus == 0) {
 415                                                 nickname = nicknameChooser.getNickname();
 416                                                 connectionHandler.sendCommand("NICK", nickname);
 417                                         } else {
 418                                                 eventBus.post(new NicknameInUseReceived(this, reply));
 419                                         }
 420
 421                                 /* client stuff. */
 422                                 } else if (command.equalsIgnoreCase("NICK")) {
 423                                         eventBus.post(new NicknameChanged(this, reply.source().get(), parameters.get(0)));
 424
 425                                 /* channel stuff. */
 426                                 } else if (command.equalsIgnoreCase("JOIN")) {
 427                                         eventBus.post(new ChannelJoined(this, parameters.get(0), reply.source().get()));
 428                                 } else if (command.equals("331")) {
 429                                         /* no topic is set. */
 430                                 } else if (command.equals("332")) {
 431                                         eventBus.post(new ChannelTopic(this, parameters.get(1), parameters.get(2)));
 432                                 } else if (command.equals("353")) {
 433                                         for (String nickname : parameters.get(3).split(" ")) {
 434                                                 if (nickPrefixes.containsKey(nickname.substring(0, 1))) {
 435                                                         nicks.add(new Nickname(nickname.substring(1), nickname.substring(0, 1)));
 436                                                 } else {
 437                                                         nicks.add(new Nickname(nickname, ""));
 438                                                 }
 439                                         }
 440                                 } else if (command.equals("366")) {
 441                                         eventBus.post(new ChannelNicknames(this, parameters.get(1), nicks));
 442                                         nicks.clear();
 443                                 } else if (command.equalsIgnoreCase("PART")) {
 444                                         eventBus.post(new ChannelLeft(this, parameters.get(0), reply.source().get(), getOptional(parameters, 1)));
 445                                 } else if (command.equalsIgnoreCase("QUIT")) {
 446                                         eventBus.post(new ClientQuit(this, reply.source().get(), parameters.get(0)));
 447
 448                                 /* common channel join errors. */
 449                                 } else if (command.equals("474")) {
 450                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.banned));
 451                                 } else if (command.equals("473")) {
 452                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.inviteOnly));
 453                                 } else if (command.equals("475")) {
 454                                         eventBus.post(new ChannelNotJoined(this, parameters.get(1), Reason.badChannelKey));
 455
 456                                 /* basic connection housekeeping. */
 457                                 } else if (command.equalsIgnoreCase("PING")) {
 458                                         connectionHandler.sendCommand("PONG", getOptional(parameters, 0), getOptional(parameters, 1));
 459
 460                                 /* replies 001-004 don’t hold information but they have to be sent on a successful connection. */
 461                                 } else if (command.equals("001")) {
 462                                         connectionStatus |= 0x01;
 463                                 } else if (command.equals("002")) {
 464                                         connectionStatus |= 0x02;
 465                                 } else if (command.equals("003")) {
 466                                         connectionStatus |= 0x04;
 467                                 } else if (command.equals("004")) {
 468                                         connectionStatus |= 0x08;
 469
 470                                 /* 005 originally was a bounce message, now used to transmit useful information about the server. */
 471                                 } else if (command.equals("005")) {
 472                                         for (String parameter : parameters) {
 473                                                 if (parameter.startsWith("PREFIX=")) {
 474                                                         int openParen = parameter.indexOf('(');
 475                                                         int closeParen = parameter.indexOf(')');
 476                                                         if ((openParen != -1) && (closeParen != -1)) {
 477                                                                 for (int modeCharacterIndex = 1; modeCharacterIndex < (closeParen - openParen); ++modeCharacterIndex) {
 478                                                                         char modeCharacter = parameter.charAt(openParen + modeCharacterIndex);
 479                                                                         char modeSymbol = parameter.charAt(closeParen + modeCharacterIndex);
 480                                                                         nickPrefixes.put(String.valueOf(modeSymbol), String.valueOf(modeCharacter));
 481                                                                 }
 482                                                                 logger.debug(String.format("Parsed Prefixes: %s", nickPrefixes));
 483                                                         }
 484                                                 } else if (parameter.startsWith("CHANTYPES=")) {
 485                                                         for (int typeIndex = 10; typeIndex < parameter.length(); ++typeIndex) {
 486                                                                 channelTypes.add(parameter.charAt(typeIndex));
 487                                                         }
 488                                                         logger.debug(String.format("Parsed Channel Types: %s", channelTypes));
 489                                                 }
 490                                         }
 491
 492                                 /* 375, 372, and 376 handle the server’s MOTD. */
 493                                 } else if (command.equals("375")) {
 494                                         /* MOTD starts. */
 495                                         motd.append(parameters.get(1)).append('\n');
 496                                 } else if (command.equals("372")) {
 497                                         motd.append(parameters.get(1)).append('\n');
 498                                 } else if (command.equals("376")) {
 499                                         motd.append(parameters.get(1)).append('\n');
 500                                         eventBus.post(new MotdReceived(this, motd.toString()));
 501                                         motd.setLength(0);
 502
 503                                 /* okay, everything else. */
 504                                 } else {
 505                                         eventBus.post(new UnknownReplyReceived(this, reply));
 506                                 }
 507
 508                                 if ((connectionStatus == 0x0f) && (connectionStatus != oldConnectionStatus)) {
 509                                         /* connection succeeded! */
 510                                         established = true;
 511                                         eventBus.post(new ConnectionEstablished(this));
 512                                 }
 513                                 oldConnectionStatus = connectionStatus;
 514                         }
 515                         eventBus.post(new ConnectionClosed(this));
 516                 } catch (IOException ioe1) {
 517                         logger.warn("I/O error", ioe1);
 518                         eventBus.post(new ConnectionClosed(this, ioe1));
 519                 } catch (RuntimeException re1) {
 520                         logger.error("Runtime error", re1);
 521                         eventBus.post(new ConnectionClosed(this, re1));
 522                 } finally {
 523                         established = false;
 524                         logger.info("Closing Connection.");
 525                         try {
 526                                 Closeables.close(connectionHandler, true);
 527                         } catch (IOException ioe1) {
 528                                 /* will not be thrown. */
 529                         }
 530                 }
 531
 532         }
 533
 534         //
 535         // PRIVATE METHODS
 536         //
 537
 538         /**
 539          * Handles a CTCP message.
 540          *
 541          * @param client
 542          *              The client sending the message
 543          * @param message
 544          *              The message
 545          */
 546         private void handleCtcp(Source client, String message) {
 547                 String[] messageWords = message.substring(1, message.length() - 1).split(" +");
 548                 String ctcpCommand = messageWords[0];
 549                 if (ctcpCommand.equalsIgnoreCase("DCC")) {
 550                         if (messageWords[1].equalsIgnoreCase("SEND")) {
 551                                 Optional<InetAddress> inetAddress = parseInetAddress(messageWords[3]);
 552                                 Optional<Integer> port = Optional.fromNullable(Ints.tryParse(messageWords[4]));
 553                                 long fileSize = Optional.fromNullable(Longs.tryParse(messageWords[5])).or(-1L);
 554                                 if (inetAddress.isPresent() && port.isPresent()) {
 555                                         eventBus.post(new DccSendReceived(this, client, messageWords[2], inetAddress.get(), port.get(), fileSize));
 556                                 } else {
 557                                         logger.warn(String.format("Received malformed DCC SEND: “%s”", message));
 558                                 }
 559                         } else if (messageWords[1].equalsIgnoreCase("ACCEPT")) {
 560                                 Optional<Integer> port = Optional.fromNullable(Ints.tryParse(messageWords[3]));
 561                                 long position = (messageWords.length > 4) ? Optional.fromNullable(Longs.tryParse(messageWords[4])).or(-1L) : -1;
 562                                 if (port.isPresent()) {
 563                                         eventBus.post(new DccAcceptReceived(this, client, messageWords[2], port.get(), position));
 564                                 } else {
 565                                         logger.warn(String.format("Received malformed DCC ACCEPT: “%s”", message));
 566                                 }
 567                         }
 568                 }
 569         }
 570
 571         /**
 572          * Returns an item from the list, or {@link Optional#absent()} if the list is
 573          * shorter than required for the given index.
 574          *
 575          * @param list
 576          *              The list to get an item from
 577          * @param index
 578          *              The index of the item
 579          * @param <T>
 580          *              The type of the list items
 581          * @return This list item wrapped in an {@link Optional}, or {@link
 582          *         Optional#absent()} if the list is not long enough
 583          */
 584         private static <T> Optional<T> getOptional(List<T> list, int index) {
 585                 if (index < list.size()) {
 586                         return Optional.fromNullable(list.get(index));
 587                 }
 588                 return Optional.absent();
 589         }
 590
 591         /**
 592          * Parses the given {@code ip} and returns an {@link InetAddress} from it.
 593          *
 594          * @param ip
 595          *              The IP to parse
 596          * @return The parsed inet address, or {@link Optional#absent()} if no inet
 597          *         address could be parsed
 598          */
 599         private Optional<InetAddress> parseInetAddress(String ip) {
 600                 Long ipNumber = Longs.tryParse(ip);
 601                 if (ipNumber == null) {
 602                         return Optional.absent();
 603                 }
 604
 605                 StringBuilder hostname = new StringBuilder(15);
 606                 hostname.append((ipNumber >>> 24) & 0xff).append('.');
 607                 hostname.append((ipNumber >>> 16) & 0xff).append('.');
 608                 hostname.append((ipNumber >>> 8) & 0xff).append('.');
 609                 hostname.append(ipNumber & 0xff);
 610                 try {
 611                         return Optional.of(InetAddress.getByName(hostname.toString()));
 612                 } catch (UnknownHostException uhe1) {
 613                         return Optional.absent();
 614                 }
 615         }
 616
 617         /** Handles input and output for the connection. */
 618         private class ConnectionHandler implements Closeable {
 619
 620                 /** The output stream of the connection. */
 621                 private final BandwidthCountingOutputStream outputStream;
 622
 623                 /** The input stream. */
 624                 private final BandwidthCountingInputStream inputStream;
 625
 626                 /** The input stream of the connection. */
 627                 private final BufferedReader inputStreamReader;
 628
 629                 /**
 630                  * Creates a new connection handler for the given input stream and output
 631                  * stream.
 632                  *
 633                  * @param inputStream
 634                  *              The input stream of the connection
 635                  * @param outputStream
 636                  *              The output stream of the connection
 637                  * @throws UnsupportedEncodingException
 638                  *              if the encoding (currently “UTF-8”) is not valid
 639                  */
 640                 private ConnectionHandler(InputStream inputStream, OutputStream outputStream) throws UnsupportedEncodingException {
 641                         this.outputStream = new BandwidthCountingOutputStream(outputStream, 5, SECONDS);
 642                         this.inputStream = new BandwidthCountingInputStream(inputStream, 5, SECONDS);
 643                         inputStreamReader = new BufferedReader(new InputStreamReader(this.inputStream, "UTF-8"));
 644                 }
 645
 646                 //
 647                 // ACTIONS
 648                 //
 649
 650                 /**
 651                  * Returns the current rate of the connection’s incoming side.
 652                  *
 653                  * @return The current input rate (in bytes per second)
 654                  */
 655                 public long getInputRate() {
 656                         return inputStream.getCurrentRate();
 657                 }
 658
 659                 /**
 660                  * Returns the current rate of the connection’s outgoing side.
 661                  *
 662                  * @return The current output rate (in bytes per second)
 663                  */
 664                 public long getOutputRate() {
 665                         return outputStream.getCurrentRate();
 666                 }
 667
 668                 /**
 669                  * Sends a command with the given parameters, skipping all {@link
 670                  * Optional#absent()} optionals.
 671                  *
 672                  * @param command
 673                  *              The command to send
 674                  * @param parameters
 675                  *              The parameters
 676                  * @throws IOException
 677                  *              if an I/O error occurs
 678                  */
 679                 public void sendCommand(String command, Optional<String>... parameters) throws IOException {
 680                         List<String> setParameters = new ArrayList<String>();
 681                         for (Optional<String> maybeSetParameter : parameters) {
 682                                 if (maybeSetParameter.isPresent()) {
 683                                         setParameters.add(maybeSetParameter.get());
 684                                 }
 685                         }
 686                         sendCommand(command, setParameters.toArray(new String[setParameters.size()]));
 687                 }
 688
 689                 /**
 690                  * Sends a command with the given parameters.
 691                  *
 692                  * @param command
 693                  *              The command to send
 694                  * @param parameters
 695                  *              The parameters of the command
 696                  * @throws IOException
 697                  *              if an I/O error occurs
 698                  * @throws IllegalArgumentException
 699                  *              if any parameter but that last contains a space character
 700                  */
 701                 public void sendCommand(String command, String... parameters) throws IOException, IllegalArgumentException {
 702                         StringBuilder commandBuilder = new StringBuilder();
 703
 704                         commandBuilder.append(command);
 705                         for (int parameterIndex = 0; parameterIndex < parameters.length; ++parameterIndex) {
 706                                 String parameter = parameters[parameterIndex];
 707                                 /* space is only allowed in the last parameter. */
 708                                 commandBuilder.append(' ');
 709                                 if (parameter.contains(" ")) {
 710                                         if (parameterIndex == (parameters.length - 1)) {
 711                                                 commandBuilder.append(':');
 712                                         } else {
 713                                                 throw new IllegalArgumentException(String.format("parameter “%s” must not contain space!", parameter));
 714                                         }
 715                                 }
 716                                 commandBuilder.append(parameter);
 717                         }
 718
 719                         logger.trace(String.format(">> %s", commandBuilder));
 720                         outputStream.write((commandBuilder.toString() + "\r\n").getBytes("UTF-8"));
 721                         outputStream.flush();
 722                 }
 723
 724                 /**
 725                  * Reads a line of reply from the connection.
 726                  *
 727                  * @return The reply
 728                  * @throws IOException
 729                  *              if an I/O error occurs
 730                  * @throws EOFException
 731                  *              if EOF was reached
 732                  */
 733                 public Reply readReply() throws IOException, EOFException {
 734                         String line = inputStreamReader.readLine();
 735                         if (line == null) {
 736                                 throw new EOFException();
 737                         }
 738
 739                         return Reply.parseLine(line);
 740                 }
 741
 742                 //
 743                 // CLOSEABLE METHODS
 744                 //
 745
 746                 @Override
 747                 public void close() throws IOException {
 748                         Closeables.close(outputStream, true);
 749                         Closeables.close(inputStreamReader, true);
 750                         Closeables.close(inputStream, true);
 751                 }
 752
 753         }
 754
 755 }