src/net/pterodactylus/fcp/highlevel/FcpClient.java

   1 /*
   2  * jFCPlib - FcpClient.java -
   3  * Copyright © 2009 David Roden
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 package net.pterodactylus.fcp.highlevel;
  21
  22 import java.io.IOException;
  23 import java.net.InetAddress;
  24 import java.net.UnknownHostException;
  25 import java.util.HashSet;
  26 import java.util.Set;
  27 import java.util.concurrent.CountDownLatch;
  28
  29 import net.pterodactylus.fcp.ClientHello;
  30 import net.pterodactylus.fcp.CloseConnectionDuplicateClientName;
  31 import net.pterodactylus.fcp.EndListPeers;
  32 import net.pterodactylus.fcp.FcpAdapter;
  33 import net.pterodactylus.fcp.FcpConnection;
  34 import net.pterodactylus.fcp.FcpListener;
  35 import net.pterodactylus.fcp.ListPeers;
  36 import net.pterodactylus.fcp.NodeHello;
  37 import net.pterodactylus.fcp.Peer;
  38 import net.pterodactylus.fcp.ProtocolError;
  39
  40 /**
  41  * High-level FCP client that hides the details of the underlying FCP
  42  * implementation.
  43  *
  44  * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
  45  */
  46 public class FcpClient {
  47
  48         /** Object used for synchronization. */
  49         private final Object syncObject = new Object();
  50
  51         /** The name of this client. */
  52         private final String name;
  53
  54         /** The underlying FCP connection. */
  55         private final FcpConnection fcpConnection;
  56
  57         /**
  58          * Creates an FCP client with the given name.
  59          *
  60          * @param name
  61          *            The name of the FCP client
  62          * @throws UnknownHostException
  63          *             if the hostname “localhost” is unknown
  64          */
  65         public FcpClient(String name) throws UnknownHostException {
  66                 this(name, "localhost");
  67         }
  68
  69         /**
  70          * Creates an FCP client.
  71          *
  72          * @param name
  73          *            The name of the FCP client
  74          * @param hostname
  75          *            The hostname of the Freenet node
  76          * @throws UnknownHostException
  77          *             if the given hostname can not be resolved
  78          */
  79         public FcpClient(String name, String hostname) throws UnknownHostException {
  80                 this(name, hostname, FcpConnection.DEFAULT_PORT);
  81         }
  82
  83         /**
  84          * Creates an FCP client.
  85          *
  86          * @param name
  87          *            The name of the FCP client
  88          * @param hostname
  89          *            The hostname of the Freenet node
  90          * @param port
  91          *            The Freenet node’s FCP port
  92          * @throws UnknownHostException
  93          *             if the given hostname can not be resolved
  94          */
  95         public FcpClient(String name, String hostname, int port) throws UnknownHostException {
  96                 this(name, InetAddress.getByName(hostname), port);
  97         }
  98
  99         /**
 100          * Creates an FCP client.
 101          *
 102          * @param name
 103          *            The name of the FCP client
 104          * @param host
 105          *            The host address of the Freenet node
 106          */
 107         public FcpClient(String name, InetAddress host) {
 108                 this(name, host, FcpConnection.DEFAULT_PORT);
 109         }
 110
 111         /**
 112          * Creates an FCP client.
 113          *
 114          * @param name
 115          *            The name of the FCP client
 116          * @param host
 117          *            The host address of the Freenet node
 118          * @param port
 119          *            The Freenet node’s FCP port
 120          */
 121         public FcpClient(String name, InetAddress host, int port) {
 122                 this.name = name;
 123                 fcpConnection = new FcpConnection(host, port);
 124         }
 125
 126         //
 127         // ACTIONS
 128         //
 129
 130         /**
 131          * Connects the FCP client.
 132          *
 133          * @throws IOException
 134          *             if an I/O error occurs
 135          * @throws FcpException
 136          *             if an FCP error occurs
 137          */
 138         public void connect() throws IOException, FcpException {
 139                 ExtendedFcpAdapter fcpListener = new ExtendedFcpAdapter() {
 140
 141                         /**
 142                          * {@inheritDoc}
 143                          */
 144                         @Override
 145                         public void receivedNodeHello(FcpConnection fcpConnection, NodeHello nodeHello) {
 146                                 completionLatch.countDown();
 147                         }
 148                 };
 149                 fcpConnection.addFcpListener(fcpListener);
 150                 try {
 151                         fcpConnection.connect();
 152                         ClientHello clientHello = new ClientHello(name);
 153                         fcpConnection.sendMessage(clientHello);
 154                         while (true) {
 155                                 try {
 156                                         fcpListener.complete();
 157                                         break;
 158                                 } catch (InterruptedException e) {
 159                                         /* ignore, we’ll loop. */
 160                                 }
 161                         }
 162                 } finally {
 163                         fcpConnection.removeFcpListener(fcpListener);
 164                 }
 165                 if (fcpListener.getFcpException() != null) {
 166                         throw fcpListener.getFcpException();
 167                 }
 168         }
 169
 170         /**
 171          * Disconnects the FCP client.
 172          */
 173         public void disconnect() {
 174                 synchronized (syncObject) {
 175                         fcpConnection.close();
 176                         syncObject.notifyAll();
 177                 }
 178         }
 179
 180         //
 181         // PEER MANAGEMENT
 182         //
 183
 184         /**
 185          * Returns all peers that the node has.
 186          *
 187          * @return A set containing the node’s peers
 188          * @throws IOException
 189          *             if an I/O error occurs
 190          * @throws FcpException
 191          *             if an FCP error occurs
 192          */
 193         public Set<Peer> getPeers() throws IOException, FcpException {
 194                 final Set<Peer> peers = new HashSet<Peer>();
 195                 ExtendedFcpAdapter fcpListener = new ExtendedFcpAdapter() {
 196
 197                         /**
 198                          * {@inheritDoc}
 199                          */
 200                         @Override
 201                         public void receivedPeer(FcpConnection fcpConnection, Peer peer) {
 202                                 peers.add(peer);
 203                         }
 204
 205                         /**
 206                          * {@inheritDoc}
 207                          */
 208                         @Override
 209                         public void receivedEndListPeers(FcpConnection fcpConnection, EndListPeers endListPeers) {
 210                                 completionLatch.countDown();
 211                         }
 212                 };
 213                 fcpConnection.addFcpListener(fcpListener);
 214                 fcpConnection.sendMessage(new ListPeers("list-peers"));
 215                 try {
 216                         while (true) {
 217                                 try {
 218                                         fcpListener.complete();
 219                                         break;
 220                                 } catch (InterruptedException e) {
 221                                         /* ignore, we’ll loop. */
 222                                 }
 223                         }
 224                 } finally {
 225                         fcpConnection.removeFcpListener(fcpListener);
 226                 }
 227                 if (fcpListener.getFcpException() != null) {
 228                         throw fcpListener.getFcpException();
 229                 }
 230                 return peers;
 231         }
 232
 233         /**
 234          * Implementation of an {@link FcpListener} that can store an
 235          * {@link FcpException} and wait for the arrival of a certain command.
 236          *
 237          * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
 238          */
 239         private static class ExtendedFcpAdapter extends FcpAdapter {
 240
 241                 /** The count down latch used to wait for completion. */
 242                 protected final CountDownLatch completionLatch = new CountDownLatch(1);
 243
 244                 /** The FCP exception, if any. */
 245                 protected FcpException fcpException;
 246
 247                 /**
 248                  * Creates a new extended FCP adapter.
 249                  */
 250                 public ExtendedFcpAdapter() {
 251                         /* do nothing. */
 252                 }
 253
 254                 /**
 255                  * Returns the FCP exception that occured. If no FCP exception occured,
 256                  * <code>null</code> is returned.
 257                  *
 258                  * @return The FCP exception that occured, or <code>null</code>
 259                  */
 260                 public FcpException getFcpException() {
 261                         return fcpException;
 262                 }
 263
 264                 /**
 265                  * Waits for the completion of the command.
 266                  *
 267                  * @throws InterruptedException
 268                  *             if {@link CountDownLatch#await()} is interrupted
 269                  */
 270                 public void complete() throws InterruptedException {
 271                         completionLatch.await();
 272                 }
 273
 274                 /**
 275                  * {@inheritDoc}
 276                  */
 277                 @Override
 278                 public void connectionClosed(FcpConnection fcpConnection, Throwable throwable) {
 279                         fcpException = new FcpException("Connection closed", throwable);
 280                         completionLatch.countDown();
 281                 }
 282
 283                 /**
 284                  * {@inheritDoc}
 285                  */
 286                 @Override
 287                 public void receivedCloseConnectionDuplicateClientName(FcpConnection fcpConnection, CloseConnectionDuplicateClientName closeConnectionDuplicateClientName) {
 288                         fcpException = new FcpException("Connection closed, duplicate client name");
 289                         completionLatch.countDown();
 290                 }
 291
 292                 /**
 293                  * {@inheritDoc}
 294                  */
 295                 @Override
 296                 public void receivedProtocolError(FcpConnection fcpConnection, ProtocolError protocolError) {
 297                         fcpException = new FcpException("Protocol error (" + protocolError.getCode() + ", " + protocolError.getCodeDescription());
 298                         completionLatch.countDown();
 299                 }
 300
 301         }
 302
 303 }