src/net/pterodactylus/jsite/core/NodeManager.java

   1 /*
   2  * jSite2 - FcpCollector.java -
   3  * Copyright © 2008 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.jsite.core;
  21
  22 import java.io.File;
  23 import java.io.FileInputStream;
  24 import java.io.FileOutputStream;
  25 import java.io.IOException;
  26 import java.io.InputStream;
  27 import java.io.OutputStream;
  28 import java.util.ArrayList;
  29 import java.util.Collections;
  30 import java.util.HashMap;
  31 import java.util.HashSet;
  32 import java.util.Iterator;
  33 import java.util.List;
  34 import java.util.Map;
  35 import java.util.Properties;
  36 import java.util.Set;
  37 import java.util.logging.Level;
  38 import java.util.logging.Logger;
  39
  40 import net.pterodactylus.fcp.highlevel.HighLevelClient;
  41 import net.pterodactylus.fcp.highlevel.HighLevelClientListener;
  42 import net.pterodactylus.util.io.Closer;
  43 import net.pterodactylus.util.logging.Logging;
  44
  45 /**
  46  * TODO
  47  *
  48  * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
  49  * @version $Id$
  50  */
  51 public class NodeManager implements Iterable<Node>, HighLevelClientListener {
  52
  53         /** Logger. */
  54         private static final Logger logger = Logging.getLogger(NodeManager.class.getName());
  55
  56         /** The FCP client name. */
  57         private final String clientName;
  58
  59         /** The directory for the configuration. */
  60         private final String directory;
  61
  62         /** Object used for synchronization. */
  63         private final Object syncObject = new Object();
  64
  65         /** Node listeners. */
  66         private List<NodeListener> nodeListeners = Collections.synchronizedList(new ArrayList<NodeListener>());
  67
  68         /** All nodes. */
  69         private List<Node> nodes = Collections.synchronizedList(new ArrayList<Node>());
  70
  71         /** All FCP connections. */
  72         private Map<Node, HighLevelClient> nodeClients = Collections.synchronizedMap(new HashMap<Node, HighLevelClient>());
  73
  74         /** Keeps track of which connection is in use right now. */
  75         private Set<HighLevelClient> usedConnections = Collections.synchronizedSet(new HashSet<HighLevelClient>());
  76
  77         /** Maps nodes to high-level clients. */
  78         private Map<HighLevelClient, Node> clientNodes = Collections.synchronizedMap(new HashMap<HighLevelClient, Node>());
  79
  80         /**
  81          * Creates a new FCP collector.
  82          *
  83          * @param clientName
  84          *            The name of the FCP client
  85          * @param directory
  86          *            The directory in which to store the nodes
  87          */
  88         public NodeManager(String clientName, String directory) {
  89                 this.clientName = clientName;
  90                 this.directory = directory;
  91         }
  92
  93         //
  94         // EVENT MANAGEMENT
  95         //
  96
  97         /**
  98          * Adds the given listener to the list of listeners.
  99          *
 100          * @param nodeListener
 101          *            The listener to add
 102          */
 103         public void addNodeListener(NodeListener nodeListener) {
 104                 nodeListeners.add(nodeListener);
 105         }
 106
 107         /**
 108          * Removes the given listener from the list of listeners.
 109          *
 110          * @param nodeListener
 111          *            The listener to remove
 112          */
 113         public void removeNodeListener(NodeListener nodeListener) {
 114                 nodeListeners.remove(nodeListener);
 115         }
 116
 117         /**
 118          * Notifies all listeners that a node was added.
 119          *
 120          * @param node
 121          *            The node that was added.
 122          */
 123         private void fireNodeAdded(Node node) {
 124                 for (NodeListener nodeListener: nodeListeners) {
 125                         nodeListener.nodeAdded(node);
 126                 }
 127         }
 128
 129         /**
 130          * Notifies all listeners that a node was removed.
 131          *
 132          * @param node
 133          *            The node that was removed
 134          */
 135         private void fireNodeRemoved(Node node) {
 136                 for (NodeListener nodeListener: nodeListeners) {
 137                         nodeListener.nodeRemoved(node);
 138                 }
 139         }
 140
 141         /**
 142          * Notifies all listeners that the given node was connected.
 143          *
 144          * @param node
 145          *            The node that is now connected
 146          */
 147         private void fireNodeConnected(Node node) {
 148                 for (NodeListener nodeListener: nodeListeners) {
 149                         nodeListener.nodeConnected(node);
 150                 }
 151         }
 152
 153         /**
 154          * Notifies all listeners that the given node was disconnected.
 155          *
 156          * @param node
 157          *            The node that is now disconnected
 158          * @param throwable
 159          *            The exception that caused the disconnect, or <code>null</code>
 160          *            if there was no exception
 161          */
 162         private void fireNodeDisconnected(Node node, Throwable throwable) {
 163                 for (NodeListener nodeListener: nodeListeners) {
 164                         nodeListener.nodeDisconnected(node, throwable);
 165                 }
 166         }
 167
 168         //
 169         // ACCESSORS
 170         //
 171
 172         /**
 173          * Returns the directory in which the nodes are stored.
 174          *
 175          * @return The directory the nodes are stored in
 176          */
 177         public String getDirectory() {
 178                 return directory;
 179         }
 180
 181         /**
 182          * Checks whether the given node is already connected.
 183          *
 184          * @param node
 185          *            The node to check
 186          * @return <code>true</code> if the node is already connected,
 187          *         <code>false</code> otherwise
 188          */
 189         public boolean hasNode(Node node) {
 190                 return nodes.contains(node);
 191         }
 192
 193         /**
 194          * {@inheritDoc}
 195          */
 196         public Iterator<Node> iterator() {
 197                 return nodes.iterator();
 198         }
 199
 200         //
 201         // ACTIONS
 202         //
 203
 204         /**
 205          * Loads nodes.
 206          *
 207          * @throws IOException
 208          *             if an I/O error occurs loading the nodes
 209          */
 210         public void load() throws IOException {
 211                 File directoryFile = new File(directory);
 212                 File nodeFile = new File(directoryFile, "nodes.properties");
 213                 if (!nodeFile.exists() || !nodeFile.isFile() || !nodeFile.canRead()) {
 214                         return;
 215                 }
 216                 Properties nodeProperties = new Properties();
 217                 InputStream nodeInputStream = null;
 218                 try {
 219                         nodeInputStream = new FileInputStream(nodeFile);
 220                         nodeProperties.load(nodeInputStream);
 221                 } finally {
 222                         Closer.close(nodeInputStream);
 223                 }
 224                 int nodeIndex = -1;
 225                 List<Node> loadedNodes = new ArrayList<Node>();
 226                 while (nodeProperties.containsKey("nodes." + ++nodeIndex + ".name")) {
 227                         String nodePrefix = "nodes." + nodeIndex;
 228                         String nodeName = nodeProperties.getProperty(nodePrefix + ".name");
 229                         if (!Verifier.verifyNodeName(nodeName)) {
 230                                 logger.log(Level.WARNING, "invalid node name “" + nodeName + "”, skipping…");
 231                                 continue;
 232                         }
 233                         String nodeHostname = nodeProperties.getProperty(nodePrefix + ".hostname");
 234                         if (!Verifier.verifyHostname(nodeHostname)) {
 235                                 logger.log(Level.WARNING, "invalid host name “" + nodeHostname + "”");
 236                                 /* not fatal, might be valid later on. */
 237                         }
 238                         String nodePortString = nodeProperties.getProperty(nodePrefix + ".port");
 239                         if (!Verifier.verifyPort(nodePortString)) {
 240                                 logger.log(Level.WARNING, "invalid port number “" + nodePortString + "”, skipping…");
 241                                 continue;
 242                         }
 243                         int nodePort = -1;
 244                         try {
 245                                 nodePort = Integer.valueOf(nodePortString);
 246                         } catch (NumberFormatException nfe1) {
 247                                 /* shouldn't happen, port number was checked before. */
 248                                 logger.log(Level.SEVERE, "invalid port number “" + nodePortString + "”, check failed! skipping…");
 249                                 continue;
 250                         }
 251                         Node newNode = new Node();
 252                         newNode.setName(nodeName);
 253                         newNode.setHostname(nodeHostname);
 254                         newNode.setPort(nodePort);
 255                         loadedNodes.add(newNode);
 256                 }
 257                 logger.fine("loaded " + loadedNodes.size() + " nodes from config");
 258                 synchronized (syncObject) {
 259                         nodes.clear();
 260                         nodes.addAll(loadedNodes);
 261                 }
 262                 for (Node node: nodes) {
 263                         fireNodeAdded(node);
 264                 }
 265         }
 266
 267         /**
 268          * Saves all configured nodes.
 269          *
 270          * @throws IOException
 271          *             if an I/O error occurs saving the nodes
 272          */
 273         public void save() throws IOException {
 274                 File directoryFile = new File(directory);
 275                 if (!directoryFile.exists()) {
 276                         if (!directoryFile.mkdirs()) {
 277                                 throw new IOException("could not create directory: " + directory);
 278                         }
 279                 }
 280                 Properties nodeProperties = new Properties();
 281                 int nodeIndex = -1;
 282                 for (Node node: nodes) {
 283                         String nodePrefix = "nodes." + ++nodeIndex;
 284                         nodeProperties.setProperty(nodePrefix + ".name", node.getName());
 285                         nodeProperties.setProperty(nodePrefix + ".hostname", node.getHostname());
 286                         nodeProperties.setProperty(nodePrefix + ".port", String.valueOf(node.getPort()));
 287                 }
 288                 File projectFile = new File(directoryFile, "nodes.properties");
 289                 OutputStream nodeOutputStream = null;
 290                 try {
 291                         nodeOutputStream = new FileOutputStream(projectFile);
 292                         nodeProperties.store(nodeOutputStream, "jSite nodes");
 293                 } finally {
 294                         Closer.close(nodeOutputStream);
 295                 }
 296         }
 297
 298         /**
 299          * Adds the given node to this manager.
 300          *
 301          * @see #connect(Node)
 302          * @param node
 303          *            The node to connect to
 304          */
 305         public void addNode(Node node) {
 306                 synchronized (syncObject) {
 307                         if (!nodes.contains(node)) {
 308                                 nodes.add(node);
 309                                 fireNodeAdded(node);
 310                         }
 311                 }
 312         }
 313
 314         /**
 315          * Removes the given node from the node manager, disconnecting it if it is
 316          * currently connected.
 317          *
 318          * @param node
 319          *            The node to remove
 320          */
 321         public void removeNode(Node node) {
 322                 synchronized (syncObject) {
 323                         if (!nodes.contains(node)) {
 324                                 return;
 325                         }
 326                         if (nodeClients.containsKey(node)) {
 327                                 disconnect(node);
 328                         }
 329                         fireNodeRemoved(node);
 330                 }
 331         }
 332
 333         /**
 334          * Tries to establish a connection with the given node.
 335          *
 336          * @param node
 337          *            The node to connect to
 338          */
 339         public void connect(Node node) {
 340                 try {
 341                         HighLevelClient highLevelClient = new HighLevelClient(clientName, node.getHostname(), node.getPort());
 342                         synchronized (syncObject) {
 343                                 clientNodes.put(highLevelClient, node);
 344                                 nodeClients.put(node, highLevelClient);
 345                         }
 346                         highLevelClient.addHighLevelClientListener(this);
 347                         highLevelClient.connect();
 348                 } catch (IOException ioe1) {
 349                         fireNodeDisconnected(node, ioe1);
 350                 }
 351         }
 352
 353         /**
 354          * Disconnects the given node without removing it.
 355          *
 356          * @param node
 357          *            The node to disconnect
 358          */
 359         public void disconnect(Node node) {
 360                 synchronized (syncObject) {
 361                         if (!nodes.contains(node)) {
 362                                 return;
 363                         }
 364                         HighLevelClient highLevelClient = nodeClients.get(node);
 365                         highLevelClient.disconnect();
 366                 }
 367         }
 368
 369         /**
 370          * Returns a list of all nodes.
 371          *
 372          * @return A list of all nodes
 373          */
 374         public List<Node> getNodes() {
 375                 return Collections.unmodifiableList(nodes);
 376         }
 377
 378         /**
 379          * “Borrows” a high-level client for the given node. A borrowed client
 380          * <strong>has</strong> to be returned to the node manager using
 381          * {@link #returnHighLevelClient(HighLevelClient)} when it is no longer in
 382          * use, i.e. after a message has been sent! This method will block until a
 383          * high-level client for the given node is available.
 384          *
 385          * @param node
 386          *            The node to get a high-level client for
 387          * @return The high-level client for a node, or <code>null</code> if the
 388          *         node was disconnected or removed
 389          */
 390         public HighLevelClient borrowHighLevelClient(Node node) {
 391                 synchronized (syncObject) {
 392                         if (!nodeClients.containsKey(node)) {
 393                                 return null;
 394                         }
 395                         HighLevelClient highLevelClient = nodeClients.get(node);
 396                         while (nodeClients.containsKey(node) && usedConnections.contains(highLevelClient)) {
 397                                 try {
 398                                         syncObject.wait();
 399                                 } catch (InterruptedException ie1) {
 400                                         /* ignore. TODO - check. */
 401                                 }
 402                         }
 403                         if (!nodeClients.containsKey(node)) {
 404                                 return null;
 405                         }
 406                         usedConnections.add(highLevelClient);
 407                         return highLevelClient;
 408                 }
 409         }
 410
 411         /**
 412          * Returns a borrowed high-level client.
 413          *
 414          * @see #borrowHighLevelClient(Node)
 415          * @param highLevelClient
 416          *            The high-level client to return
 417          */
 418         public void returnHighLevelClient(HighLevelClient highLevelClient) {
 419                 synchronized (syncObject) {
 420                         if (!clientNodes.containsKey(highLevelClient)) {
 421                                 return;
 422                         }
 423                         usedConnections.remove(highLevelClient);
 424                         syncObject.notifyAll();
 425                 }
 426         }
 427
 428         //
 429         // PRIVATE METHODS
 430         //
 431
 432         /**
 433          * Finds a currently unused high-level client, optionally waiting until a
 434          * client is free and marking it used.
 435          *
 436          * @param wait
 437          *            <code>true</code> to wait for a free connection,
 438          *            <code>false</code> to return <code>null</code>
 439          * @param markAsUsed
 440          *            <code>true</code> to mark the connection as used before
 441          *            returning it, <code>false</code> not to mark it
 442          * @return An unused FCP connection, or <code>null</code> if no connection
 443          *         could be found
 444          */
 445         @SuppressWarnings("unused")
 446         private HighLevelClient findUnusedClient(boolean wait, boolean markAsUsed) {
 447                 synchronized (syncObject) {
 448                         HighLevelClient freeHighLevelClient = null;
 449                         while (freeHighLevelClient == null) {
 450                                 for (HighLevelClient highLevelClient: nodeClients.values()) {
 451                                         if (!usedConnections.contains(highLevelClient)) {
 452                                                 freeHighLevelClient = highLevelClient;
 453                                                 break;
 454                                         }
 455                                 }
 456                                 if (freeHighLevelClient != null) {
 457                                         if (markAsUsed) {
 458                                                 usedConnections.add(freeHighLevelClient);
 459                                         }
 460                                         return freeHighLevelClient;
 461                                 }
 462                                 if (!wait) {
 463                                         return null;
 464                                 }
 465                                 try {
 466                                         syncObject.wait();
 467                                 } catch (InterruptedException e) {
 468                                         /* ignore, just re-check. */
 469                                 }
 470                         }
 471                         /* we never get here, but the compiler doesn't realize. */
 472                         return null;
 473                 }
 474         }
 475
 476         //
 477         // INTERFACE HighLevelClientListener
 478         //
 479
 480         /**
 481          * {@inheritDoc}
 482          */
 483         public void clientConnected(HighLevelClient highLevelClient) {
 484                 logger.log(Level.FINER, "clientConnected(c=" + highLevelClient + ")");
 485                 Node node = clientNodes.get(highLevelClient);
 486                 if (node == null) {
 487                         logger.log(Level.WARNING, "got event for unknown client");
 488                         return;
 489                 }
 490                 fireNodeConnected(node);
 491         }
 492
 493         /**
 494          * {@inheritDoc}
 495          */
 496         public void clientDisconnected(HighLevelClient highLevelClient, Throwable throwable) {
 497                 logger.log(Level.FINER, "clientDisconnected(c=" + highLevelClient + ",t=" + throwable + ")");
 498                 synchronized (syncObject) {
 499                         Node node = clientNodes.remove(highLevelClient);
 500                         if (node == null) {
 501                                 logger.log(Level.WARNING, "got event for unknown client");
 502                                 return;
 503                         }
 504                         nodeClients.remove(node);
 505                         usedConnections.remove(highLevelClient);
 506                         fireNodeDisconnected(node, throwable);
 507                 }
 508         }
 509
 510 }