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