yacy_search_server/htroot/yacy/search.java

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// search.java
// -----------------------
// part of the AnomicHTTPD caching proxy
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
// You must compile this file with
// javac -classpath .:../../Classes search.java
// if the shell's current path is htroot/yacy
import java.util.HashSet;
import de.anomic.http.httpHeader;
import de.anomic.plasma.plasmaCrawlLURL;
import de.anomic.plasma.plasmaSearchEvent;
import de.anomic.plasma.plasmaSearchRankingProfile;
import de.anomic.plasma.plasmaSearchResult;
import de.anomic.plasma.plasmaSearchTimingProfile;
import de.anomic.plasma.plasmaSnippetCache;
import de.anomic.plasma.plasmaSwitchboard;
import de.anomic.plasma.plasmaWordIndexEntry;
import de.anomic.plasma.plasmaSearchQuery;
import de.anomic.server.serverCore;
import de.anomic.server.serverObjects;
import de.anomic.server.serverSwitch;
import de.anomic.yacy.yacyCore;
import de.anomic.yacy.yacySeed;
*) Asynchronous queuing of crawl job URLs (stackCrawl) various checks like the blacklist check or the robots.txt disallow check are now done by a separate thread to unburden the indexer thread(s) TODO: maybe we have to introduce a threadpool here if it turn out that this single thread is a bottleneck because of the time consuming robots.txt downloads *) improved index transfer The index selection and transmission is done in parallel now to improve index transfer performance. TODO: maybe we could speed up performance by unsing multiple transmission threads in parallel instead of only a single one. *) gzip encoded post requests it is now configureable if a gzip encoded post request should be send on intex transfer/distribution *) storage Peer (very experimentell and not optimized yet) Now it's possible to send the result of the yacy indexer thread to a remote peer istead of storing the indexed words locally. This could be done by setting the property "storagePeerHash" in the yacy config file - Please note that if the index transfer fails, the index ist stored locally. - TODO: currently this index transfer is done by the indexer thread. To seedup the indexer a) this transmission should be done in parallel and b) multiple chunks should be bundled and transfered together *) general performance improvements - better memory cleanup after http request processing has finished - replacing some string concatenations with stringBuffers - replacing BufferedInputStreams with serverByteBuffer - replacing vectors with arraylists wherever possible - replacing hashtables with hashmaps wherever possible This was done because function calls to verctor or hashtable functions take 3 time longer than calls to functions of arraylists or hashmaps. TODO: we should take a look on the class serverObject which is inherited from hashmap Do we realy need a synchronization for this class? TODO: replace arraylists with linkedLists if random access to the list elements is not needed *) Robots Parser supports if-modified-since downloads now If the downloaded robots.txt file is older than 7 days the robots parser tries to download the robots.txt with the if-modified-since header to avoid unnecessary downloads if the file was not changed. Additionally the ETag header is used to detect changes. *) Crawler: better handling of unsupported mimeTypes + FileExtension *) Bugfix: plasmaWordIndexEntity was not closed correctly in - query.java - plasmaswitchboard.java *) function minimizeUrlDB added to yacy.java this function tests the current urlHashDB for unused urls ATTENTION: please don't use this function at the moment because it causes the wordIndexDB to flush all words into the word directory! git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@853 6c8d7289-2bf4-0310-a012-ef5d649a1542
2005-10-05 12:45:33 +02:00
public final class search {
public static serverObjects respond(httpHeader header, serverObjects post, serverSwitch ss) {
if (post == null || ss == null) { return null; }
// return variable that accumulates replacements
final plasmaSwitchboard sb = (plasmaSwitchboard) ss;
//System.out.println("yacy: search received request = " + post.toString());
final String oseed = post.get("myseed", ""); // complete seed of the requesting peer
// final String youare = post.get("youare", ""); // seed hash of the target peer, used for testing network stability
final String key = post.get("key", ""); // transmission key for response
final String query = post.get("query", ""); // a string of word hashes
// final String fwdep = post.get("fwdep", ""); // forward depth. if "0" then peer may NOT ask another peer for more results
// final String fwden = post.get("fwden", ""); // forward deny, a list of seed hashes. They may NOT be target of forward hopping
final long duetime= post.getLong("duetime", 3000);
final int count = post.getInt("count", 10); // maximum number of wanted results
final int maxdist= post.getInt("maxdist", Integer.MAX_VALUE);
final String prefer = post.get("prefer", "");
final String filter = post.get("filter", ".*");
// final boolean global = ((String) post.get("resource", "global")).equals("global"); // if true, then result may consist of answers from other peers
// Date remoteTime = yacyCore.parseUniversalDate((String) post.get(yacySeed.MYTIME)); // read remote time
// tell all threads to do nothing for a specific time
sb.intermissionAllThreads(2 * duetime);
// store accessing peer
if (yacyCore.seedDB == null) {
yacyCore.log.logSevere("yacy.search: seed cache not initialized");
} else {
yacyCore.peerActions.peerArrival(yacySeed.genRemoteSeed(oseed, key, true), true);
}
// prepare search
final HashSet keyhashes = new HashSet(query.length() / plasmaWordIndexEntry.wordHashLength);
for (int i = 0; i < (query.length() / plasmaWordIndexEntry.wordHashLength); i++) {
keyhashes.add(query.substring(i * plasmaWordIndexEntry.wordHashLength, (i + 1) * plasmaWordIndexEntry.wordHashLength));
}
final long timestamp = System.currentTimeMillis();
plasmaSearchQuery squery = new plasmaSearchQuery(keyhashes, maxdist, prefer, count, duetime, filter);
squery.domType = plasmaSearchQuery.SEARCHDOM_LOCAL;
serverObjects prop = new serverObjects();
yacyCore.log.logInfo("INIT HASH SEARCH: " + squery.queryHashes + " - " + squery.wantedResults + " links");
long timestamp1 = System.currentTimeMillis();
plasmaSearchRankingProfile rankingProfile = new plasmaSearchRankingProfile(new String[]{plasmaSearchRankingProfile.ORDER_YBR, plasmaSearchRankingProfile.ORDER_DATE, plasmaSearchRankingProfile.ORDER_QUALITY});
plasmaSearchTimingProfile localTiming = new plasmaSearchTimingProfile(squery.maximumTime, squery.wantedResults);
plasmaSearchTimingProfile remoteTiming = null;
plasmaSearchEvent theSearch = new plasmaSearchEvent(squery, rankingProfile, localTiming, remoteTiming, yacyCore.log, sb.wordIndex, sb.urlPool.loadedURL, sb.snippetCache);
plasmaSearchResult acc = null;
int idxc = 0;
idxc = theSearch.localSearch();
acc = theSearch.order();
// result is a List of urlEntry elements
if ((idxc == 0) || (acc == null)) {
prop.put("totalcount", "0");
prop.put("linkcount", "0");
prop.put("references", "");
} else {
prop.put("totalcount", Integer.toString(acc.sizeOrdered()));
int i = 0;
StringBuffer links = new StringBuffer();
String resource = "";
//plasmaIndexEntry pie;
plasmaCrawlLURL.Entry urlentry;
plasmaSnippetCache.result snippet;
while ((acc.hasMoreElements()) && (i < squery.wantedResults)) {
urlentry = acc.nextElement();
snippet = sb.snippetCache.retrieve(urlentry.url(), squery.queryHashes, false, 260);
if (snippet.getSource() == plasmaSnippetCache.ERROR_NO_MATCH) {
// suppress line: there is no match in that resource
} else {
if (snippet.exists()) {
resource = urlentry.toString(snippet.getLineRaw());
} else {
resource = urlentry.toString();
}
if (resource != null) {
links.append("resource").append(i).append("=").append(resource).append(serverCore.crlfString);
i++;
}
}
}
prop.put("links", links.toString());
prop.put("linkcount", Integer.toString(i));
// prepare reference hints
Object[] ws = acc.getReferences(16);
StringBuffer refstr = new StringBuffer();
for (int j = 0; j < ws.length; j++)
refstr.append(",").append((String) ws[j]);
prop.put("references", (refstr.length() > 0) ? refstr.substring(1) : refstr.toString());
// add information about forward peers
prop.put("fwhop", ""); // hops (depth) of forwards that had been performed to construct this result
prop.put("fwsrc", ""); // peers that helped to construct this result
prop.put("fwrec", ""); // peers that would have helped to construct this result (recommendations)
}
// log
yacyCore.log.logInfo("EXIT HASH SEARCH: " + squery.queryHashes + " - " + idxc + " links found, " + prop.get("linkcount", "?") + " links selected, " + ((System.currentTimeMillis() - timestamp1) / 1000) + " seconds");
prop.put("searchtime", Long.toString(System.currentTimeMillis() - timestamp));
final int links = Integer.parseInt(prop.get("linkcount","0"));
yacyCore.seedDB.mySeed.incSI(links);
yacyCore.seedDB.mySeed.incSU(links);
return prop;
}
}