checkin logging

apps/i2psnark/java/src/org/klomp/snark/web/XI2PTorrentLocationFilter.java

@@ -0,0 +1,183 @@
+package org.klomp.snark.web;
+
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.handler.HandlerWrapper;
+
+import net.i2p.I2PAppContext;
+import net.i2p.util.Log;
+
+import org.klomp.snark.Storage;
+//import org.klomp.snark.Snark;
+//import org.klomp.snark.SnarkManager;
+import org.klomp.snark.I2PSnarkUtil;
+import org.klomp.snark.MetaInfo;
+import org.eclipse.jetty.server.Handler;
+
+/**
+ * Adds a header, X-I2P-TorrentLocation, to requests for files which contains
+ * a magnet link. The magnet link contains:
+ * - The infohash of the file to download
+ * - At least one open tracker
+ * - A web seed corresponding to the URL of the file
+ *
+ * @since 0.9.51
+ */
+public class XI2PTorrentLocationFilter extends HandlerWrapper implements Handler {
+    private static final String encodeUTF = StandardCharsets.UTF_8.toString();
+    private final Log _log = I2PAppContext.getGlobalContext().logManager().getLog(XI2PTorrentLocationFilter.class);
+    private final I2PSnarkUtil _util;
+
+    public XI2PTorrentLocationFilter() {
+        // get the I2PAppContext
+        I2PAppContext ctx = I2PAppContext.getGlobalContext();
+        _util = new I2PSnarkUtil(ctx);
+    }
+
+    public XI2PTorrentLocationFilter(I2PSnarkUtil util) {
+        _util = util;
+    }
+
+    private synchronized File shouldRecheck(final HttpServletRequest httpRequest) {
+        File recheck = null;
+        if (_log.shouldLog(_log.DEBUG)) {
+            _log.debug("shouldRecheck: " + httpRequest.getRequestURI());
+        }
+        // get the request URI path only
+        String path = httpRequest.getRequestURI();
+        if (path != null && !path.endsWith("/")) {
+            // get the docroot
+            String docroot = httpRequest.getContextPath();
+            // combine the docroot with the path
+            File filepath = new File(docroot, path);
+            // exist?
+            if (filepath.exists()) {
+                if (_log.shouldLog(_log.DEBUG)) {
+                    _log.debug("shouldRecheck: exists");
+                }
+                // is *not* it a torrent file?
+                if (!filepath.getName().endsWith(".torrent")) {
+                    if (_log.shouldLog(_log.DEBUG)) {
+                        _log.debug("shouldRecheck: not a torrent file");
+                    }
+                    // is it a directory?
+                    if (!filepath.isDirectory()) {
+                        if (_log.shouldLog(_log.DEBUG)) {
+                            _log.debug("shouldRecheck: not a directory");
+                        }
+                        File precheck = filepath.getAbsoluteFile();
+                        File torrentcheck = new File(precheck.getParentFile(), precheck.getName() + ".torrent");
+                        if (torrentcheck.exists()) {
+                            if (_log.shouldLog(_log.DEBUG)) {
+                                _log.debug("shouldRecheck: torrent exists");
+                            }
+                            // get the last modified fime of precheck
+                            long lastModified = precheck.lastModified();
+                            // get the last modified time of torrentcheck
+                            long lastModified2 = torrentcheck.lastModified();
+                            // if the last modified time of torrentcheck is less than the last modified
+                            // time of precheck
+                            if (lastModified2 < lastModified) {
+                                // set the recheck to the precheck
+                                recheck = precheck;
+                            }
+                        } else {
+                            if (_log.shouldLog(_log.DEBUG)) {
+                                _log.debug("shouldRecheck: torrent does not exist");
+                            }
+                            // set the recheck to the precheck
+                            recheck = precheck;
+                        }
+                    }
+                }
+            }
+        }
+        return recheck;
+    }
+
+    private synchronized String headerContents(final HttpServletRequest httpRequest) {
+        File recheck = shouldRecheck(httpRequest);
+        if (recheck != null) {
+            // return null;
+            List<String> openTrackers = _util.getOpenTrackers();
+            List<List<String>> announce_list = null;
+            if (openTrackers != null) {
+                if (_log.shouldLog(_log.DEBUG)) {
+                    _log.debug("headerContents: has opentrackers");
+                }
+                if (openTrackers.size() > 1) {
+                    announce_list = new ArrayList<List<String>>();
+                    // for (String tracker : openTrackers) {
+                    for (int i = 1; i < openTrackers.size(); i++) {
+                        String tracker = openTrackers.get(i);
+                        List<String> announce = new ArrayList<String>();
+                        announce.add(tracker);
+                        announce_list.add(announce);
+                    }
+                }
+                String announce = openTrackers.get(0);
+                List<String> url_list = new ArrayList<String>();
+                String url = httpRequest.getRequestURL().toString();
+                url_list.add(url);
+                try {
+                    Storage torrentData = new Storage(_util,
+                            recheck,
+                            announce,
+                            announce_list,
+                            null,
+                            false,
+                            url_list,
+                            null,
+                            null);
+                    String torrentString = torrentData.toString();
+                    MetaInfo metaInfo = torrentData.getMetaInfo();
+                    String magnet = "magnet:?xt=urn:btih:" + metaInfo.getInfoHash() +
+                            "&dn=" + metaInfo.getName() +
+                            "&tr=" + announce +
+                            "&ws=" + url;
+                    // write torrentString to file recheck.torrent
+                    File torrentFile = new File(recheck.getParentFile(), recheck.getName() + ".torrent");
+                    if (torrentFile.exists()) {
+                        torrentFile.delete();
+                    }
+                    BufferedWriter writer = new BufferedWriter(new FileWriter(torrentFile));
+                    writer.write(torrentString);
+                    writer.close();
+                    torrentData.close();
+                    return magnet;
+
+                } catch (IOException e) {
+                    _log.error("Error creating torrent", e);
+                }
+            }
+        }
+        if (_log.shouldLog(_log.DEBUG)) {
+            _log.debug("headerContents: unable to create torrent");
+        }
+        return "";
+    }
+
+    @Override
+    public void handle(final String target, final Request request, final HttpServletRequest httpRequest,
+            HttpServletResponse httpResponse)
+            throws IOException, ServletException {
+
+        String header = headerContents(httpRequest);
+        if (header != null && !header.equals("")) {
+            httpResponse.setHeader("X-I2P-TorrentLocation", header);
+        }
+
+        _handler.handle(target, request, httpRequest, httpResponse);
+    }
+}