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.net.UnknownHostException;
  29 import java.util.ArrayList;
  30 import java.util.Collections;
  31 import java.util.HashMap;
  32 import java.util.HashSet;
  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.ConnectResult;
  41 import net.pterodactylus.fcp.highlevel.HighLevelCallback;
  42 import net.pterodactylus.fcp.highlevel.HighLevelClient;
  43 import net.pterodactylus.util.io.Closer;
  44
  45 /**
  46  * TODO
  47  *
  48  * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
  49  * @version $Id$
  50  */
  51 public class NodeManager {
  52
  53         /** Logger. */
  54         private static final Logger logger = Logger.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         /** All nodes. */
  66         private List<Node> nodes = Collections.synchronizedList(new ArrayList<Node>());
  67
  68         /** All FCP connections. */
  69         private Map<Node, HighLevelClient> nodeConnections = Collections.synchronizedMap(new HashMap<Node, HighLevelClient>());
  70
  71         /** Keeps track of which connection is in use right now. */
  72         private Set<HighLevelClient> usedConnections = Collections.synchronizedSet(new HashSet<HighLevelClient>());
  73
  74         /** Maps nodes to high-level clients. */
  75         private Map<HighLevelClient, Node> clientNodes = Collections.synchronizedMap(new HashMap<HighLevelClient, Node>());
  76
  77         /**
  78          * Creates a new FCP collector.
  79          *
  80          * @param clientName
  81          *            The name of the FCP client
  82          * @param directory
  83          *            The directory in which to store the nodes
  84          */
  85         public NodeManager(String clientName, String directory) {
  86                 this.clientName = clientName;
  87                 this.directory = directory;
  88         }
  89
  90         //
  91         // ACCESSORS
  92         //
  93
  94         /**
  95          * Returns the directory in which the nodes are stored.
  96          *
  97          * @return The directory the nodes are stored in
  98          */
  99         public String getDirectory() {
 100                 return directory;
 101         }
 102
 103         /**
 104          * Checks whether the given node is already connected.
 105          *
 106          * @param node
 107          *            The node to check
 108          * @return <code>true</code> if the node is already connected,
 109          *         <code>false</code> otherwise
 110          */
 111         public boolean hasNode(Node node) {
 112                 return nodes.contains(node);
 113         }
 114
 115         //
 116         // ACTIONS
 117         //
 118
 119         /**
 120          * Loads nodes.
 121          *
 122          * @throws IOException
 123          *             if an I/O error occurs loading the nodes
 124          */
 125         public void load() throws IOException {
 126                 File directoryFile = new File(directory);
 127                 File nodeFile = new File(directoryFile, "nodes.properties");
 128                 if (!nodeFile.exists() || !nodeFile.isFile() || !nodeFile.canRead()) {
 129                         return;
 130                 }
 131                 Properties nodeProperties = new Properties();
 132                 InputStream nodeInputStream = null;
 133                 try {
 134                         nodeInputStream = new FileInputStream(nodeFile);
 135                         nodeProperties.load(nodeInputStream);
 136                 } finally {
 137                         Closer.close(nodeInputStream);
 138                 }
 139                 int nodeIndex = -1;
 140                 List<Node> loadedNodes = new ArrayList<Node>();
 141                 while (nodeProperties.containsKey("nodes." + ++nodeIndex + ".name")) {
 142                         String nodePrefix = "nodes." + nodeIndex;
 143                         String nodeName = nodeProperties.getProperty(nodePrefix + ".name");
 144                         if (!Verifier.verifyNodeName(nodeName)) {
 145                                 logger.log(Level.WARNING, "invalid node name “" + nodeName + "”, skipping…");
 146                                 continue;
 147                         }
 148                         String nodeHostname = nodeProperties.getProperty(nodePrefix + ".hostname");
 149                         if (!Verifier.verifyHostname(nodeHostname)) {
 150                                 logger.log(Level.WARNING, "invalid host name “" + nodeHostname + "”");
 151                                 /* not fatal, might be valid later on. */
 152                         }
 153                         String nodePortString = nodeProperties.getProperty(nodePrefix + ".port");
 154                         if (!Verifier.verifyPort(nodePortString)) {
 155                                 logger.log(Level.WARNING, "invalid port number “" + nodePortString + "”, skipping…");
 156                                 continue;
 157                         }
 158                         int nodePort = -1;
 159                         try {
 160                                 nodePort = Integer.valueOf(nodePortString);
 161                         } catch (NumberFormatException nfe1) {
 162                                 /* shouldn't happen, port number was checked before. */
 163                                 logger.log(Level.SEVERE, "invalid port number “" + nodePortString + "”, check failed! skipping…");
 164                                 continue;
 165                         }
 166                         Node newNode = new Node();
 167                         newNode.setName(nodeName);
 168                         newNode.setHostname(nodeHostname);
 169                         newNode.setPort(nodePort);
 170                         loadedNodes.add(newNode);
 171                 }
 172                 synchronized (syncObject) {
 173                         nodes.clear();
 174                         nodes.addAll(loadedNodes);
 175                 }
 176         }
 177
 178         /**
 179          * Saves all configured nodes.
 180          *
 181          * @throws IOException
 182          *             if an I/O error occurs saving the nodes
 183          */
 184         public void save() throws IOException {
 185                 File directoryFile = new File(directory);
 186                 if (!directoryFile.exists()) {
 187                         if (!directoryFile.mkdirs()) {
 188                                 throw new IOException("could not create directory: " + directory);
 189                         }
 190                 }
 191                 Properties nodeProperties = new Properties();
 192                 int nodeIndex = -1;
 193                 for (Node node: nodes) {
 194                         String nodePrefix = "nodes." + ++nodeIndex;
 195                         nodeProperties.setProperty(nodePrefix + ".name", node.getName());
 196                         nodeProperties.setProperty(nodePrefix + ".hostname", node.getHostname());
 197                         nodeProperties.setProperty(nodePrefix + ".port", String.valueOf(node.getPort()));
 198                 }
 199                 File projectFile = new File(directoryFile, "nodes.properties");
 200                 OutputStream nodeOutputStream = null;
 201                 try {
 202                         nodeOutputStream = new FileOutputStream(projectFile);
 203                         nodeProperties.store(nodeOutputStream, "jSite nodes");
 204                 } finally {
 205                         Closer.close(nodeOutputStream);
 206                 }
 207         }
 208
 209         /**
 210          * Adds a connection to the given node. The connection is made instantly so
 211          * this method may block. If the node can not be connected, it will not be
 212          * added to the list of nodes.
 213          *
 214          * @param node
 215          *            The node to connect to
 216          * @return <code>true</code> if the connection to the node could be
 217          *         established
 218          * @throws UnknownHostException
 219          *             if the hostname of the node can not be resolved
 220          * @throws IOException
 221          *             if an I/O error occurs connecting to the node
 222          */
 223         public boolean addNode(Node node) throws UnknownHostException, IOException {
 224                 if (nodes.contains(node)) {
 225                         return true;
 226                 }
 227                 HighLevelClient highLevelClient = new HighLevelClient(clientName, node.getHostname(), node.getPort());
 228                 HighLevelCallback<ConnectResult> connectCallback = highLevelClient.connect();
 229                 ConnectResult connectResult = null;
 230                 while (connectResult == null) {
 231                         try {
 232                                 connectResult = connectCallback.getResult();
 233                         } catch (InterruptedException e) {
 234                                 /* ignore. */
 235                         }
 236                 }
 237                 if (connectResult.isConnected()) {
 238                         synchronized (syncObject) {
 239                                 nodes.add(node);
 240                                 nodeConnections.put(node, highLevelClient);
 241                                 clientNodes.put(highLevelClient, node);
 242                         }
 243                 }
 244                 return connectResult.isConnected();
 245         }
 246
 247         /**
 248          * Returns a list of all nodes.
 249          *
 250          * @return A list of all nodes
 251          */
 252         public List<Node> getNodes() {
 253                 return new ArrayList<Node>(clientNodes.values());
 254         }
 255
 256         //
 257         // PRIVATE METHODS
 258         //
 259
 260         /**
 261          * Finds a currently unused high-level client, optionally waiting until a
 262          * client is free and marking it used.
 263          *
 264          * @param wait
 265          *            <code>true</code> to wait for a free connection,
 266          *            <code>false</code> to return <code>null</code>
 267          * @param markAsUsed
 268          *            <code>true</code> to mark the connection as used before
 269          *            returning it, <code>false</code> not to mark it
 270          * @return An unused FCP connection, or <code>null</code> if no connection
 271          *         could be found
 272          */
 273         @SuppressWarnings("unused")
 274         private HighLevelClient findUnusedClient(boolean wait, boolean markAsUsed) {
 275                 synchronized (syncObject) {
 276                         HighLevelClient freeHighLevelClient = null;
 277                         while (freeHighLevelClient == null) {
 278                                 for (HighLevelClient highLevelClient: nodeConnections.values()) {
 279                                         if (!usedConnections.contains(highLevelClient)) {
 280                                                 freeHighLevelClient = highLevelClient;
 281                                                 break;
 282                                         }
 283                                 }
 284                                 if (freeHighLevelClient != null) {
 285                                         if (markAsUsed) {
 286                                                 usedConnections.add(freeHighLevelClient);
 287                                         }
 288                                         return freeHighLevelClient;
 289                                 }
 290                                 if (!wait) {
 291                                         return null;
 292                                 }
 293                         }
 294                         /* we never get here, but the compiler doesn't realize. */
 295                         return null;
 296                 }
 297         }
 298
 299 }