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yacy_search_server/source/de/anomic/search/ResultFetcher.java

401 lines
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// SearchEvent.java
// (C) 2005 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 10.10.2005 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// LICENSE
//
// 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
package de.anomic.search;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import net.yacy.cora.document.MultiProtocolURI;
import net.yacy.document.Condenser;
import net.yacy.kelondro.data.meta.URIMetadataRow;
import net.yacy.kelondro.data.word.Word;
import net.yacy.kelondro.index.HandleSet;
import net.yacy.kelondro.index.RowSpaceExceededException;
import net.yacy.kelondro.logging.Log;
import net.yacy.kelondro.util.EventTracker;
import net.yacy.kelondro.util.SortStack;
import net.yacy.kelondro.util.SortStore;
import net.yacy.repository.LoaderDispatcher;
import de.anomic.crawler.CrawlProfile;
import de.anomic.search.MediaSnippet;
import de.anomic.yacy.yacySeedDB;
import de.anomic.yacy.graphics.ProfilingGraph;
public class ResultFetcher {
// input values
final RankingProcess rankedCache; // ordered search results, grows dynamically as all the query threads enrich this container
QueryParams query;
private final yacySeedDB peers;
// result values
protected final LoaderDispatcher loader;
protected Worker[] workerThreads;
protected final SortStore<ResultEntry> result;
protected final SortStore<MediaSnippet> images; // container to sort images by size
protected final HandleSet failedURLs; // a set of urlhashes that could not been verified during search
protected final HandleSet snippetFetchWordHashes; // a set of word hashes that are used to match with the snippets
long urlRetrievalAllTime;
long snippetComputationAllTime;
int taketimeout;
public ResultFetcher(
final LoaderDispatcher loader,
RankingProcess rankedCache,
final QueryParams query,
final yacySeedDB peers,
final int taketimeout) {
this.loader = loader;
this.rankedCache = rankedCache;
this.query = query;
this.peers = peers;
this.taketimeout = taketimeout;
this.urlRetrievalAllTime = 0;
this.snippetComputationAllTime = 0;
this.result = new SortStore<ResultEntry>(-1, true); // this is the result, enriched with snippets, ranked and ordered by ranking
this.images = new SortStore<MediaSnippet>(-1, true);
this.failedURLs = new HandleSet(URIMetadataRow.rowdef.primaryKeyLength, URIMetadataRow.rowdef.objectOrder, 0); // a set of url hashes where a worker thread tried to work on, but failed.
// snippets do not need to match with the complete query hashes,
// only with the query minus the stopwords which had not been used for the search
HandleSet filtered;
try {
filtered = HandleSet.joinConstructive(query.queryHashes, Switchboard.stopwordHashes);
} catch (RowSpaceExceededException e) {
Log.logException(e);
filtered = new HandleSet(query.queryHashes.row().primaryKeyLength, query.queryHashes.comparator(), 0);
}
this.snippetFetchWordHashes = query.queryHashes.clone();
if (filtered != null && !filtered.isEmpty()) {
this.snippetFetchWordHashes.excludeDestructive(Switchboard.stopwordHashes);
}
// start worker threads to fetch urls and snippets
this.workerThreads = null;
deployWorker(Math.min(10, query.itemsPerPage), query.neededResults());
EventTracker.update("SEARCH", new ProfilingGraph.searchEvent(query.id(true), this.workerThreads.length + " online snippet fetch threads started", 0, 0), false, 30000, ProfilingGraph.maxTime);
}
public void deployWorker(int deployCount, int neededResults) {
if (anyWorkerAlive()) return;
this.workerThreads = new Worker[(query.snippetCacheStrategy.isAllowedToFetchOnline()) ? deployCount : 1];
for (int i = 0; i < workerThreads.length; i++) {
this.workerThreads[i] = new Worker(i, 10000, query.snippetCacheStrategy, neededResults);
this.workerThreads[i].start();
}
}
boolean anyWorkerAlive() {
if (this.workerThreads == null) return false;
for (int i = 0; i < this.workerThreads.length; i++) {
if ((this.workerThreads[i] != null) &&
(this.workerThreads[i].isAlive()) &&
(this.workerThreads[i].busytime() < 3000)) return true;
}
return false;
}
public long getURLRetrievalTime() {
return this.urlRetrievalAllTime;
}
public long getSnippetComputationTime() {
return this.snippetComputationAllTime;
}
protected class Worker extends Thread {
private final long timeout; // the date until this thread should try to work
private long lastLifeSign; // when the last time the run()-loop was executed
private final int id;
private final CrawlProfile.CacheStrategy cacheStrategy;
private final int neededResults;
public Worker(final int id, final long maxlifetime, CrawlProfile.CacheStrategy cacheStrategy, int neededResults) {
this.id = id;
this.cacheStrategy = cacheStrategy;
this.lastLifeSign = System.currentTimeMillis();
this.timeout = System.currentTimeMillis() + Math.max(1000, maxlifetime);
this.neededResults = neededResults;
}
public void run() {
// start fetching urls and snippets
URIMetadataRow page;
//final int fetchAhead = snippetMode == 0 ? 0 : 10;
boolean nav_topics = query.navigators.equals("all") || query.navigators.indexOf("topics") >= 0;
try {
while (System.currentTimeMillis() < this.timeout) {
if (result.size() > neededResults) break;
this.lastLifeSign = System.currentTimeMillis();
// check if we have enough
if ((query.contentdom == ContentDomain.IMAGE) && (images.size() >= query.neededResults() + 50)) break;
if ((query.contentdom != ContentDomain.IMAGE) && (result.size() >= query.neededResults() + 10)) break;
// get next entry
page = rankedCache.takeURL(true, taketimeout);
if (page == null) break;
if (failedURLs.has(page.hash())) continue;
final ResultEntry resultEntry = fetchSnippet(page, cacheStrategy); // does not fetch snippets if snippetMode == 0
if (resultEntry == null) continue; // the entry had some problems, cannot be used
if (result.exists(resultEntry)) continue;
urlRetrievalAllTime += resultEntry.dbRetrievalTime;
snippetComputationAllTime += resultEntry.snippetComputationTime;
//System.out.println("+++DEBUG-resultWorker+++ fetched " + resultEntry.urlstring());
// place the result to the result vector
// apply post-ranking
long ranking = Long.valueOf(rankedCache.getOrder().cardinal(resultEntry.word()));
ranking += postRanking(resultEntry, rankedCache.getTopics());
//System.out.println("*** resultEntry.hash = " + resultEntry.hash());
result.push(resultEntry, ranking);
if (nav_topics) rankedCache.addTopics(resultEntry);
//System.out.println("DEBUG SNIPPET_LOADING: thread " + id + " got " + resultEntry.url());
}
} catch (final Exception e) {
Log.logException(e);
}
Log.logInfo("SEARCH", "resultWorker thread " + id + " terminated");
}
public long busytime() {
return System.currentTimeMillis() - this.lastLifeSign;
}
}
protected ResultEntry fetchSnippet(final URIMetadataRow page, CrawlProfile.CacheStrategy cacheStrategy) {
// Snippet Fetching can has 3 modes:
// 0 - do not fetch snippets
// 1 - fetch snippets offline only
// 2 - online snippet fetch
// load only urls if there was not yet a root url of that hash
// find the url entry
long startTime = System.currentTimeMillis();
final URIMetadataRow.Components metadata = page.metadata();
if (metadata == null) return null;
final long dbRetrievalTime = System.currentTimeMillis() - startTime;
if (cacheStrategy == null) {
return new ResultEntry(page, query.getSegment(), peers, null, null, dbRetrievalTime, 0); // result without snippet
}
// load snippet
if (query.contentdom == ContentDomain.TEXT) {
// attach text snippet
startTime = System.currentTimeMillis();
final TextSnippet snippet = TextSnippet.retrieveTextSnippet(
this.loader,
metadata,
snippetFetchWordHashes,
cacheStrategy,
((query.constraint != null) && (query.constraint.get(Condenser.flag_cat_indexof))),
180,
Integer.MAX_VALUE,
query.isGlobal());
final long snippetComputationTime = System.currentTimeMillis() - startTime;
Log.logInfo("SEARCH", "text snippet load time for " + metadata.url() + ": " + snippetComputationTime + ", " + ((snippet.getErrorCode() < 11) ? "snippet found" : ("no snippet found (" + snippet.getError() + ")")));
if (snippet.getErrorCode() < 11) {
// we loaded the file and found the snippet
return new ResultEntry(page, query.getSegment(), peers, snippet, null, dbRetrievalTime, snippetComputationTime); // result with snippet attached
} else if (cacheStrategy.mustBeOffline()) {
// we did not demand online loading, therefore a failure does not mean that the missing snippet causes a rejection of this result
// this may happen during a remote search, because snippet loading is omitted to retrieve results faster
return new ResultEntry(page, query.getSegment(), peers, null, null, dbRetrievalTime, snippetComputationTime); // result without snippet
} else {
// problems with snippet fetch
registerFailure(page.hash(), "no text snippet for URL " + metadata.url() + "; errorCode = " + snippet.getErrorCode());
return null;
}
} else {
// attach media information
startTime = System.currentTimeMillis();
final ArrayList<MediaSnippet> mediaSnippets = MediaSnippet.retrieveMediaSnippets(metadata.url(), snippetFetchWordHashes, query.contentdom, cacheStrategy, 6000, query.isGlobal());
final long snippetComputationTime = System.currentTimeMillis() - startTime;
Log.logInfo("SEARCH", "media snippet load time for " + metadata.url() + ": " + snippetComputationTime);
if (mediaSnippets != null && !mediaSnippets.isEmpty()) {
// found media snippets, return entry
return new ResultEntry(page, query.getSegment(), peers, null, mediaSnippets, dbRetrievalTime, snippetComputationTime);
} else if (cacheStrategy.mustBeOffline()) {
return new ResultEntry(page, query.getSegment(), peers, null, null, dbRetrievalTime, snippetComputationTime);
} else {
// problems with snippet fetch
registerFailure(page.hash(), "no media snippet for URL " + metadata.url());
return null;
}
}
// finished, no more actions possible here
}
private void registerFailure(final byte[] urlhash, final String reason) {
try {
this.failedURLs.put(urlhash);
} catch (RowSpaceExceededException e) {
Log.logException(e);
}
Log.logInfo("SEARCH", "sorted out urlhash " + new String(urlhash) + " during search: " + reason);
}
public int resultCount() {
return this.result.size();
}
public ResultEntry oneResult(final int item) {
// check if we already retrieved this item
// (happens if a search pages is accessed a second time)
EventTracker.update("SEARCH", new ProfilingGraph.searchEvent(query.id(true), "obtain one result entry - start", 0, 0), false, 30000, ProfilingGraph.maxTime);
if (this.result.sizeStore() > item) {
// we have the wanted result already in the result array .. return that
return this.result.element(item).element;
}
/*
System.out.println("rankedCache.size() = " + this.rankedCache.size());
System.out.println("result.size() = " + this.result.size());
System.out.println("query.neededResults() = " + query.neededResults());
*/
if ((!anyWorkerAlive()) &&
(((query.contentdom == ContentDomain.IMAGE) && (images.size() + 30 < query.neededResults())) ||
(this.result.size() < query.neededResults())) &&
//(event.query.onlineSnippetFetch) &&
(this.rankedCache.size() > this.result.size())
) {
// start worker threads to fetch urls and snippets
deployWorker(Math.min(10, query.itemsPerPage), query.neededResults());
}
// finally wait until enough results are there produced from the
// snippet fetch process
while ((anyWorkerAlive()) && (result.size() <= item)) {
try {Thread.sleep((item % query.itemsPerPage) * 10L);} catch (final InterruptedException e) {}
}
// finally, if there is something, return the result
if (this.result.size() <= item) return null;
return this.result.element(item).element;
}
private int resultCounter = 0;
public ResultEntry nextResult() {
final ResultEntry re = oneResult(resultCounter);
resultCounter++;
return re;
}
public MediaSnippet oneImage(final int item) {
// check if we already retrieved this item (happens if a search pages is accessed a second time)
if (this.images.sizeStore() > item) {
// we have the wanted result already in the result array .. return that
return this.images.element(item).element;
}
// generate result object
final ResultEntry result = nextResult();
MediaSnippet ms;
if (result != null) {
// iterate over all images in the result
final ArrayList<MediaSnippet> imagemedia = result.mediaSnippets();
if (imagemedia != null) {
for (int j = 0; j < imagemedia.size(); j++) {
ms = imagemedia.get(j);
images.push(ms, Long.valueOf(ms.ranking));
//System.out.println("*** image " + ms.href.hash() + " images.size = " + images.size() + "/" + images.size());
}
}
}
// now take the specific item from the image stack
if (this.images.size() <= item) return null;
return this.images.element(item).element;
}
public ArrayList<SortStack<ResultEntry>.stackElement> completeResults(final long waitingtime) {
final long timeout = System.currentTimeMillis() + waitingtime;
while ((result.size() < query.neededResults()) && (anyWorkerAlive()) && (System.currentTimeMillis() < timeout)) {
try {Thread.sleep(100);} catch (final InterruptedException e) {}
//System.out.println("+++DEBUG-completeResults+++ sleeping " + 200);
}
return this.result.list(this.result.size());
}
public long postRanking(
final ResultEntry rentry,
final Map<String, Navigator.Item> topwords) {
long r = 0;
// for media search: prefer pages with many links
if (query.contentdom == ContentDomain.IMAGE) r += rentry.limage() << query.ranking.coeff_cathasimage;
if (query.contentdom == ContentDomain.AUDIO) r += rentry.laudio() << query.ranking.coeff_cathasaudio;
if (query.contentdom == ContentDomain.VIDEO) r += rentry.lvideo() << query.ranking.coeff_cathasvideo;
if (query.contentdom == ContentDomain.APP ) r += rentry.lapp() << query.ranking.coeff_cathasapp;
// prefer hit with 'prefer' pattern
if (query.prefer.matcher(rentry.url().toNormalform(true, true)).matches()) r += 256 << query.ranking.coeff_prefer;
if (query.prefer.matcher(rentry.title()).matches()) r += 256 << query.ranking.coeff_prefer;
// apply 'common-sense' heuristic using references
final String urlstring = rentry.url().toNormalform(true, true);
final String[] urlcomps = MultiProtocolURI.urlComps(urlstring);
final String[] descrcomps = MultiProtocolURI.splitpattern.split(rentry.title().toLowerCase());
Navigator.Item tc;
for (int j = 0; j < urlcomps.length; j++) {
tc = topwords.get(urlcomps[j]);
if (tc != null) r += Math.max(1, tc.count) << query.ranking.coeff_urlcompintoplist;
}
for (int j = 0; j < descrcomps.length; j++) {
tc = topwords.get(descrcomps[j]);
if (tc != null) r += Math.max(1, tc.count) << query.ranking.coeff_descrcompintoplist;
}
// apply query-in-result matching
final HandleSet urlcomph = Word.words2hashesHandles(urlcomps);
final HandleSet descrcomph = Word.words2hashesHandles(descrcomps);
final Iterator<byte[]> shi = query.queryHashes.iterator();
byte[] queryhash;
while (shi.hasNext()) {
queryhash = shi.next();
if (urlcomph.has(queryhash)) r += 256 << query.ranking.coeff_appurl;
if (descrcomph.has(queryhash)) r += 256 << query.ranking.coeff_app_dc_title;
}
return r;
}
}