src/net/pterodactylus/arachne/core/Core.java

   1 /*
   2  * © 2009 David ‘Bombe’ Roden
   3  */
   4 package net.pterodactylus.arachne.core;
   5
   6 import java.net.MalformedURLException;
   7 import java.net.URL;
   8 import java.util.ArrayList;
   9 import java.util.List;
  10 import java.util.concurrent.Executor;
  11 import java.util.concurrent.Executors;
  12 import java.util.logging.Level;
  13 import java.util.logging.Logger;
  14
  15 import de.ina.util.service.AbstractService;
  16 import de.ina.util.thread.DumpingThreadFactory;
  17 import de.ina.util.validation.Validation;
  18
  19 /**
  20  * Arachne’s core.
  21  *
  22  * @author David ‘Bombe’ Roden <bombe@pterodactylus.net>
  23  */
  24 public class Core extends AbstractService {
  25
  26         /** The logger. */
  27         private static final Logger logger = Logger.getLogger(Core.class.getName());
  28
  29         //
  30         // PROPERTIES
  31         //
  32
  33         /** The host of the freenet node. */
  34         private String nodeHost = "localhost";
  35
  36         /** The port of the freenet node. */
  37         private int nodePort = 8888;
  38
  39         //
  40         // INTERNAL MEMBERS
  41         //
  42
  43         /** Thread pool for the URL fetches. */
  44         private Executor urlFetcherExecutor = Executors.newFixedThreadPool(1, new DumpingThreadFactory("URLFetcher-"));
  45
  46         /** The current list of URLs to crawl. */
  47         private final List<Page> pages = new ArrayList<Page>();
  48
  49         //
  50         // ACTIONS
  51         //
  52
  53         /**
  54          * Adds the given URL to the list of pages to crawl.
  55          *
  56          * @param url
  57          *            The URL to add
  58          */
  59         public void addPage(URL url) {
  60                 Validation.begin().isNotNull("url", url).check().isEqual("url.getHost()", url.getHost(), (Object) nodeHost).isEqual("url.getPort()", url.getPort(), nodePort).check();
  61                 String path = url.getPath();
  62                 if (path.length() == 0) {
  63                         path = "/";
  64                 }
  65                 String[] pathComponents = path.split("/");
  66                 if (pathComponents.length < 2) {
  67                         throw new IllegalArgumentException("URL “" + url + "” is not a valid freenet page.");
  68                 }
  69                 String siteName = pathComponents[1];
  70                 String[] siteComponents = siteName.split("@");
  71                 if (siteComponents.length != 2) {
  72                         throw new IllegalArgumentException("siteName “" + siteName + "” is not a valid freenet page.");
  73                 }
  74                 if (!"USK".equals(siteComponents[0]) && !"SSK".equals(siteComponents[0]) && !"CHK".equals(siteComponents[0])) {
  75                         throw new IllegalArgumentException("siteName “" + siteName + "” is not a valid freenet page.");
  76                 }
  77                 if ("USK".equals(siteComponents[0])) {
  78                         Site site = new Site(siteComponents[1], pathComponents[2]);
  79                         Edition edition = new Edition(site, Integer.parseInt(pathComponents[3]));
  80                         Page page = new Page(edition, createPath(pathComponents, 4));
  81                         addPage(page);
  82                 }
  83                 if ("SSK".equals(siteComponents[0])) {
  84                         int lastDash = pathComponents[2].lastIndexOf('-');
  85                         String basename = pathComponents[2].substring(0, lastDash);
  86                         int editionNumber = Integer.parseInt(pathComponents[2].substring(lastDash + 1));
  87                         Site site = new Site(siteComponents[1], basename);
  88                         Edition edition = new Edition(site, editionNumber);
  89                         Page page = new Page(edition, createPath(pathComponents, 3));
  90                         addPage(page);
  91                 }
  92                 /* TODO: handle CHK */
  93         }
  94
  95         /**
  96          * Adds the given URL to the list of pages to crawl.
  97          *
  98          * @param url
  99          *            The URL of the page to crawl
 100          * @throws MalformedURLException
 101          *             if the URL is not a valid URL
 102          */
 103         public void addPage(String url) throws MalformedURLException {
 104                 Validation.begin().isNotNull("url", (Object) url).check();
 105                 addPage(new URL(url));
 106         }
 107
 108         /**
 109          * Adds the given page to the list of pages to crawl.
 110          *
 111          * @param page
 112          *            The page to add
 113          */
 114         public void addPage(Page page) {
 115                 Validation.begin().isNotNull("page", page).check();
 116                 pages.add(page);
 117                 notifySyncObject();
 118         }
 119
 120         //
 121         // SERVICE METHODS
 122         //
 123
 124         /**
 125          * {@inheritdoc}
 126          *
 127          * @see de.ina.util.service.AbstractService#serviceRun()
 128          */
 129         @Override
 130         protected void serviceRun() {
 131                 while (!shouldStop()) {
 132                         Page nextPage = null;
 133                         synchronized (syncObject) {
 134                                 while (!shouldStop() && pages.isEmpty()) {
 135                                         try {
 136                                                 syncObject.wait();
 137                                         } catch (InterruptedException ie1) {
 138                                                 /* ignore. */
 139                                         }
 140                                 }
 141                                 if (!shouldStop()) {
 142                                         nextPage = pages.remove(0);
 143                                 }
 144                         }
 145                         if (shouldStop()) {
 146                                 break;
 147                         }
 148                         URL nextURL = createURL(nextPage);
 149                         if (nextURL == null) {
 150                                 logger.log(Level.INFO, "Skipping “" + nextPage + "”.");
 151                                 continue;
 152                         }
 153                         URLFetcher urlFetcher = new URLFetcher(this, nextURL);
 154                         urlFetcherExecutor.execute(urlFetcher);
 155                 }
 156         }
 157
 158         //
 159         // PRIVATE METHODS
 160         //
 161
 162         /**
 163          * Creates a path from the given String array, starting at the given index.
 164          * The path is created by joining all Strings from the array, separating
 165          * them with a slash (‘/’).
 166          *
 167          * @param pathComponents
 168          *            The array of path components
 169          * @param index
 170          *            The index of the first path components
 171          * @return The joined path
 172          */
 173         private String createPath(String[] pathComponents, int index) {
 174                 Validation.begin().isNotNull("pathComponents", pathComponents).check().isLess("index", index, pathComponents.length).check();
 175                 StringBuilder path = new StringBuilder();
 176                 for (int pathComponentIndex = index; pathComponentIndex < pathComponents.length; pathComponentIndex++) {
 177                         if (path.length() > 0) {
 178                                 path.append('/');
 179                         }
 180                         path.append(pathComponents[pathComponentIndex]);
 181                 }
 182                 return path.toString();
 183         }
 184
 185         /**
 186          * Creates a URL from the given page.
 187          *
 188          * @param page
 189          *            The page to create a URL from
 190          * @return The created URL, or <code>null</code> if the URL could not be
 191          *         created
 192          */
 193         private URL createURL(Page page) {
 194                 try {
 195                         return new URL("http://" + nodeHost + ":" + nodePort + "/");
 196                 } catch (MalformedURLException mue1) {
 197                         /* nearly impossible. */
 198                 }
 199                 return null;
 200         }
 201
 202 }