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670 lines
29 KiB
670 lines
29 KiB
// plasmaSnippetCache.java
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// -----------------------
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// part of YaCy
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// (C) by Michael Peter Christen; mc@anomic.de
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// first published on http://www.anomic.de
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// Frankfurt, Germany, 2005
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// last major change: 09.10.2006
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//
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// contributions by Marc Nause [MN]
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//
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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//
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// Using this software in any meaning (reading, learning, copying, compiling,
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// running) means that you agree that the Author(s) is (are) not responsible
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// for cost, loss of data or any harm that may be caused directly or indirectly
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// by usage of this softare or this documentation. The usage of this software
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// is on your own risk. The installation and usage (starting/running) of this
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// software may allow other people or application to access your computer and
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// any attached devices and is highly dependent on the configuration of the
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// software which must be done by the user of the software; the author(s) is
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// (are) also not responsible for proper configuration and usage of the
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// software, even if provoked by documentation provided together with
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// the software.
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//
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// Any changes to this file according to the GPL as documented in the file
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// gpl.txt aside this file in the shipment you received can be done to the
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// lines that follows this copyright notice here, but changes must not be
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// done inside the copyright notive above. A re-distribution must contain
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// the intact and unchanged copyright notice.
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// Contributions and changes to the program code must be marked as such.
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package de.anomic.plasma;
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import java.io.ByteArrayInputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.util.ArrayList;
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import java.util.Enumeration;
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import java.util.HashMap;
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import java.util.HashSet;
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import java.util.Iterator;
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import java.util.Set;
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import de.anomic.http.httpHeader;
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import de.anomic.http.httpc;
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import de.anomic.plasma.plasmaURL;
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import de.anomic.index.indexURLEntry;
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import de.anomic.kelondro.kelondroMScoreCluster;
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import de.anomic.net.URL;
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import de.anomic.plasma.cache.IResourceInfo;
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import de.anomic.plasma.crawler.plasmaCrawlerException;
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import de.anomic.plasma.parser.ParserException;
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import de.anomic.server.logging.serverLog;
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import de.anomic.yacy.yacySearch;
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import de.anomic.yacy.yacyCore;
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public class plasmaSnippetCache {
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private static final int maxCache = 500;
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public static final int SOURCE_CACHE = 0;
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public static final int SOURCE_FILE = 1;
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public static final int SOURCE_WEB = 2;
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public static final int ERROR_NO_HASH_GIVEN = 11;
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public static final int ERROR_SOURCE_LOADING = 12;
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public static final int ERROR_RESOURCE_LOADING = 13;
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public static final int ERROR_PARSER_FAILED = 14;
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public static final int ERROR_PARSER_NO_LINES = 15;
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public static final int ERROR_NO_MATCH = 16;
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private int snippetsScoreCounter;
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private kelondroMScoreCluster snippetsScore;
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private HashMap snippetsCache;
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private plasmaHTCache cacheManager;
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private plasmaParser parser;
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private serverLog log;
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private plasmaSwitchboard sb;
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public plasmaSnippetCache(
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plasmaSwitchboard theSb,
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plasmaHTCache cacheManager,
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plasmaParser parser,
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serverLog log
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) {
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this.cacheManager = cacheManager;
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this.parser = parser;
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this.log = log;
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this.sb = theSb;
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this.snippetsScoreCounter = 0;
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this.snippetsScore = new kelondroMScoreCluster();
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this.snippetsCache = new HashMap();
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}
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public class Snippet {
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private String line;
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private String error;
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private int source;
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public Snippet(String line, int source, String errortext) {
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this.line = line;
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this.source = source;
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this.error = errortext;
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}
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public boolean exists() {
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return line != null;
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}
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public String toString() {
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return (line == null) ? "" : line;
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}
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public String getLineRaw() {
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return (line == null) ? "" : line;
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}
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public String getError() {
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return (error == null) ? "" : error.trim();
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}
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public String getLineMarked(Set queryHashes) {
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if (line == null) return "";
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if ((queryHashes == null) || (queryHashes.size() == 0)) return line.trim();
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if (line.endsWith(".")) line = line.substring(0, line.length() - 1);
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Iterator i = queryHashes.iterator();
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String h;
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String[] w = line.split(" ");
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String prefix = "";
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String postfix = "";
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int len = 0;
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while (i.hasNext()) {
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h = (String) i.next();
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for (int j = 0; j < w.length; j++) {
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//ignore punctuation marks (contrib [MN])
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//note to myself:
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//For details on regex see "Mastering regular expressions" by J.E.F. Friedl
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//especially p. 123 and p. 390/391 (in the German version of the 2nd edition)
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prefix = "";
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postfix = "";
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while((w[j].matches("\\A[^\\p{L}\\p{N}].+"))) {
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prefix = w[j].substring(0,1) + prefix;
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w[j] = w[j].substring(1);
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}
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while((w[j].matches(".+[^\\p{L}\\p{N}]\\Z"))) {
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len = w[j].length();
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postfix = w[j].substring(len-1,len) + postfix;
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w[j] = w[j].substring(0,len-1);
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}
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//end contrib [MN]
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if (plasmaCondenser.word2hash(w[j]).equals(h)) w[j] = "<b>" + w[j] + "</b>";
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w[j] = prefix + w[j] + postfix;
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}
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}
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StringBuffer l = new StringBuffer(line.length() + queryHashes.size() * 8);
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for (int j = 0; j < w.length; j++) {
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l.append(w[j]);
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l.append(' ');
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}
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return l.toString().trim();
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}
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public int getSource() {
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return source;
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}
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}
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public boolean existsInCache(URL url, Set queryhashes) {
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String hashes = yacySearch.set2string(queryhashes);
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return retrieveFromCache(hashes, plasmaURL.urlHash(url)) != null;
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}
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public Snippet retrieveSnippet(URL url, Set queryhashes, boolean fetchOnline, int snippetMaxLength, int timeout) {
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// heise = "0OQUNU3JSs05"
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if (queryhashes.size() == 0) {
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//System.out.println("found no queryhashes for URL retrieve " + url);
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return new Snippet(null, ERROR_NO_HASH_GIVEN, "no query hashes given");
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}
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String urlhash = plasmaURL.urlHash(url);
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// try to get snippet from snippetCache
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int source = SOURCE_CACHE;
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String wordhashes = yacySearch.set2string(queryhashes);
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String line = retrieveFromCache(wordhashes, urlhash);
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if (line != null) {
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//System.out.println("found snippet for URL " + url + " in cache: " + line);
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return new Snippet(line, source, null);
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}
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/* ===========================================================================
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* LOADING RESOURCE DATA
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* =========================================================================== */
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// if the snippet is not in the cache, we can try to get it from the htcache
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long resContentLength = 0;
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InputStream resContent = null;
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IResourceInfo resInfo = null;
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try {
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// trying to load the resource from the cache
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resContent = this.cacheManager.getResourceContentStream(url);
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if (resContent != null) {
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// if the content was found
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resContentLength = this.cacheManager.getResourceContentLength(url);
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} else if (fetchOnline) {
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// if not found try to download it
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// download resource using the crawler and keep resource in memory if possible
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plasmaHTCache.Entry entry = loadResourceFromWeb(url, timeout, true);
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// getting resource metadata (e.g. the http headers for http resources)
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if (entry != null) {
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resInfo = entry.getDocumentInfo();
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// read resource body (if it is there)
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byte []resourceArray = entry.cacheArray();
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if (resourceArray != null) {
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resContent = new ByteArrayInputStream(resourceArray);
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resContentLength = resourceArray.length;
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} else {
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resContent = this.cacheManager.getResourceContentStream(url);
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resContentLength = this.cacheManager.getResourceContentLength(url);
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}
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}
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// if it is still not available, report an error
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if (resContent == null) return new Snippet(null, ERROR_RESOURCE_LOADING, "error loading resource, plasmaHTCache.Entry cache is NULL");
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source = SOURCE_WEB;
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} else {
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return new Snippet(null, ERROR_SOURCE_LOADING, "no resource available");
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}
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} catch (Exception e) {
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if (!(e instanceof plasmaCrawlerException)) e.printStackTrace();
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return new Snippet(null, ERROR_SOURCE_LOADING, "error loading resource: " + e.getMessage());
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}
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/* ===========================================================================
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* PARSING RESOURCE
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* =========================================================================== */
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plasmaParserDocument document = null;
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try {
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document = parseDocument(url, resContentLength, resContent, resInfo);
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} catch (ParserException e) {
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return new Snippet(null, ERROR_PARSER_FAILED, e.getMessage()); // cannot be parsed
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} finally {
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try { resContent.close(); } catch (Exception e) {/* ignore this */}
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}
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if (document == null) return new Snippet(null, ERROR_PARSER_FAILED, "parser error/failed"); // cannot be parsed
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//System.out.println("loaded document for URL " + url);
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final Enumeration sentences = document.getSentences(null); // FIXME: apply correct charset
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document.close();
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//System.out.println("----" + url.toString()); for (int l = 0; l < sentences.length; l++) System.out.println(sentences[l]);
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if (sentences == null) {
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//System.out.println("found no sentences in url " + url);
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return new Snippet(null, ERROR_PARSER_NO_LINES, "parser returned no sentences");
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}
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/* ===========================================================================
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* COMPUTE SNIPPET
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* =========================================================================== */
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// we have found a parseable non-empty file: use the lines
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line = computeSnippet(sentences, queryhashes, 3 * queryhashes.size(), snippetMaxLength);
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//System.out.println("loaded snippet for URL " + url + ": " + line);
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if (line == null) return new Snippet(null, ERROR_NO_MATCH, "no matching snippet found");
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if (line.length() > snippetMaxLength) line = line.substring(0, snippetMaxLength);
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// finally store this snippet in our own cache
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storeToCache(wordhashes, urlhash, line);
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return new Snippet(line, source, null);
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}
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/**
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* Tries to load and parse a resource specified by it's URL.
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* If the resource is not stored in cache and if fetchOnline is set the
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* this function tries to download the resource from web.
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*
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* @param url the URL of the resource
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* @param fetchOnline specifies if the resource should be loaded from web if it'as not available in the cache
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* @return the parsed document as {@link plasmaParserDocument}
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*/
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public plasmaParserDocument retrieveDocument(URL url, boolean fetchOnline) {
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if (url == null) return null;
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IResourceInfo docInfo = null;
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try {
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// trying to load the resource body from cache
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InputStream content = this.cacheManager.getResourceContentStream(url);
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long resourceLength = this.cacheManager.getResourceContentLength(url);
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// if not available try to load resource from web
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if ((fetchOnline) && (content == null)) {
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// download resource using crawler
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plasmaHTCache.Entry entry = loadResourceFromWeb(url, 5000, true);
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// fetching metadata of the resource (e.g. http headers for http resource)
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if (entry != null) {
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docInfo = entry.getDocumentInfo();
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byte[] resourceArray = entry.cacheArray();
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if (resourceArray != null) {
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// read resource body (if it is there)
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content = new ByteArrayInputStream(resourceArray);
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resourceLength = resourceArray.length;
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} else {
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// in case that the reosurce was not in ram, read it from disk
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content = this.cacheManager.getResourceContentStream(url);
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resourceLength = this.cacheManager.getResourceContentLength(url);
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}
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}
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} else {
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// trying to load resource metadata
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docInfo = this.cacheManager.loadResourceInfo(url);
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}
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// parsing document
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if (content == null) return null;
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return parseDocument(url, resourceLength, content, docInfo);
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} catch (ParserException e) {
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this.log.logWarning("Unable to parse resource. " + e.getMessage());
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return null;
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} catch (Exception e) {
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this.log.logWarning("Unexpected error while retrieving document. " + e.getMessage(),e);
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return null;
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}
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}
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public void storeToCache(String wordhashes, String urlhash, String snippet) {
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// generate key
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String key = urlhash + wordhashes;
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// do nothing if snippet is known
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if (snippetsCache.containsKey(key)) return;
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// learn new snippet
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snippetsScore.addScore(key, snippetsScoreCounter++);
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snippetsCache.put(key, snippet);
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// care for counter
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if (snippetsScoreCounter == java.lang.Integer.MAX_VALUE) {
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snippetsScoreCounter = 0;
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snippetsScore = new kelondroMScoreCluster();
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snippetsCache = new HashMap();
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}
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// flush cache if cache is full
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while (snippetsCache.size() > maxCache) {
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key = (String) snippetsScore.getMinObject();
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snippetsScore.deleteScore(key);
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snippetsCache.remove(key);
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}
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}
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private String retrieveFromCache(String wordhashes, String urlhash) {
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// generate key
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String key = urlhash + wordhashes;
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return (String) snippetsCache.get(key);
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}
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private String computeSnippet(Enumeration sentences, Set queryhashes, int minLength, int maxLength) {
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try {
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if (sentences == null) return null;
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if ((queryhashes == null) || (queryhashes.size() == 0)) return null;
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kelondroMScoreCluster hitTable = new kelondroMScoreCluster();
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Iterator j;
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HashMap hs;
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String hash;
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ArrayList sb = new ArrayList();
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String sentence;
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while (sentences.hasMoreElements()) {
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sentence = (String) sentences.nextElement();
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//System.out.println("Snippet-Sentence :" + sentence); // DEBUG
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if (sentence.length() > minLength) {
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hs = hashSentence(sentence);
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j = queryhashes.iterator();
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while (j.hasNext()) {
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hash = (String) j.next();
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if (hs.containsKey(hash)) {
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//System.out.println("hash " + hash + " appears in line " + i);
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hitTable.incScore(new Integer(sb.size()));
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}
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}
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sb.add(sentence);
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}
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}
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int score = hitTable.getMaxScore(); // best number of hits
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if (score <= 0) return null;
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// we found (a) line(s) that have <score> hits.
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// now find the shortest line of these hits
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int shortLineIndex = -1;
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int shortLineLength = Integer.MAX_VALUE;
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for (int i = 0; i < sb.size(); i++) {
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if ((hitTable.getScore(new Integer(i)) == score) && (((String) sb.get(i)).length() < shortLineLength)) {
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shortLineIndex = i;
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shortLineLength = ((String) sb.get(i)).length();
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}
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}
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// find a first result
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String result = (String) sb.get(shortLineIndex);
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// remove all hashes that appear in the result
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hs = hashSentence(result);
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j = queryhashes.iterator();
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Integer pos;
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Set remaininghashes = new HashSet();
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int p, minpos = result.length(), maxpos = -1;
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while (j.hasNext()) {
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hash = (String) j.next();
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pos = (Integer) hs.get(hash);
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if (pos == null) {
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remaininghashes.add(new String(hash));
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} else {
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p = pos.intValue();
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if (p > maxpos) maxpos = p;
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if (p < minpos) minpos = p;
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}
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}
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// check result size
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maxpos = maxpos + 10;
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if (maxpos > result.length()) maxpos = result.length();
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if (minpos < 0) minpos = 0;
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// we have a result, but is it short enough?
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if (maxpos - minpos + 10 > maxLength) {
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// the string is too long, even if we cut at both ends
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// so cut here in the middle of the string
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int lenb = result.length();
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result = result.substring(0, (minpos + 20 > result.length()) ? result.length() : minpos + 20).trim() +
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" [..] " +
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result.substring((maxpos + 26 > result.length()) ? result.length() : maxpos + 26).trim();
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maxpos = maxpos + lenb - result.length() + 6;
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}
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if (maxpos > maxLength) {
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// the string is too long, even if we cut it at the end
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// so cut it here at both ends at once
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int newlen = maxpos - minpos + 10;
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int around = (maxLength - newlen) / 2;
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result = "[..] " + result.substring(minpos - around, ((maxpos + around) > result.length()) ? result.length() : (maxpos + around)).trim() + " [..]";
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minpos = around;
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maxpos = result.length() - around - 5;
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}
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if (result.length() > maxLength) {
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// trim result, 1st step (cut at right side)
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result = result.substring(0, maxpos).trim() + " [..]";
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}
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if (result.length() > maxLength) {
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// trim result, 2nd step (cut at left side)
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result = "[..] " + result.substring(minpos).trim();
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}
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if (result.length() > maxLength) {
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// trim result, 3rd step (cut in the middle)
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result = result.substring(6, 20).trim() + " [..] " + result.substring(result.length() - 26, result.length() - 6).trim();
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}
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if (queryhashes.size() == 0) return result;
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// the result has not all words in it.
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// find another sentence that represents the missing other words
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// and find recursively more sentences
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maxLength = maxLength - result.length();
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if (maxLength < 20) maxLength = 20;
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String nextSnippet = computeSnippet(sentences, remaininghashes, minLength, maxLength);
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return result + ((nextSnippet == null) ? "" : (" / " + nextSnippet));
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} catch (IndexOutOfBoundsException e) {
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log.logSevere("computeSnippet: error with string generation", e);
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return "";
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}
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}
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|
|
private HashMap hashSentence(String sentence) {
|
|
// generates a word-wordPos mapping
|
|
HashMap map = new HashMap();
|
|
Enumeration words = plasmaCondenser.wordTokenizer(sentence, 0);
|
|
int pos = 0;
|
|
String word;
|
|
while (words.hasMoreElements()) {
|
|
word = (String) words.nextElement();
|
|
map.put(plasmaCondenser.word2hash(word), new Integer(pos));
|
|
pos += word.length() + 1;
|
|
}
|
|
return map;
|
|
}
|
|
|
|
public plasmaParserDocument parseDocument(URL url, long contentLength, InputStream resourceStream) throws ParserException {
|
|
return parseDocument(url, contentLength, resourceStream, null);
|
|
}
|
|
|
|
/**
|
|
* Parse the resource
|
|
* @param url the URL of the resource
|
|
* @param contentLength the contentLength of the resource
|
|
* @param resourceStream the resource body as stream
|
|
* @param docInfo metadata about the resource
|
|
* @return the extracted data
|
|
* @throws ParserException
|
|
*/
|
|
public plasmaParserDocument parseDocument(URL url, long contentLength, InputStream resourceStream, IResourceInfo docInfo) throws ParserException {
|
|
try {
|
|
if (resourceStream == null) return null;
|
|
|
|
// STEP 1: if no resource metadata is available, try to load it from cache
|
|
if (docInfo == null) {
|
|
// try to get the header from the htcache directory
|
|
try {
|
|
docInfo = this.cacheManager.loadResourceInfo(url);
|
|
} catch (Exception e) {
|
|
// ignore this. resource info loading failed
|
|
}
|
|
}
|
|
|
|
// STEP 2: if the metadata is still null try to download it from web
|
|
if ((docInfo == null) && (url.getProtocol().startsWith("http"))) {
|
|
// TODO: we need a better solution here
|
|
// e.g. encapsulate this in the crawlLoader class
|
|
|
|
// getting URL mimeType
|
|
try {
|
|
httpHeader header = httpc.whead(url, url.getHost(), 10000, null, null, this.sb.remoteProxyConfig);
|
|
docInfo = this.cacheManager.getResourceInfoFactory().buildResourceInfoObj(url, header);
|
|
} catch (Exception e) {
|
|
// ingore this. http header download failed
|
|
}
|
|
}
|
|
|
|
// STEP 3: if the metadata is still null try to guess the mimeType of the resource
|
|
if (docInfo == null) {
|
|
String filename = this.cacheManager.getCachePath(url).getName();
|
|
int p = filename.lastIndexOf('.');
|
|
if ( // if no extension is available
|
|
(p < 0) ||
|
|
// or the extension is supported by one of the parsers
|
|
((p >= 0) && (plasmaParser.supportedFileExtContains(filename.substring(p + 1))))
|
|
) {
|
|
String supposedMime = "text/html";
|
|
|
|
// if the mimeType Parser is installed we can set the mimeType to null to force
|
|
// a mimetype detection
|
|
if (plasmaParser.supportedMimeTypesContains("application/octet-stream")) {
|
|
supposedMime = null;
|
|
} else if (p != -1){
|
|
// otherwise we try to determine the mimeType per file Extension
|
|
supposedMime = plasmaParser.getMimeTypeByFileExt(filename.substring(p + 1));
|
|
}
|
|
|
|
return this.parser.parseSource(url, supposedMime, null, contentLength, resourceStream);
|
|
}
|
|
return null;
|
|
}
|
|
if (plasmaParser.supportedMimeTypesContains(docInfo.getMimeType())) {
|
|
return this.parser.parseSource(url, docInfo.getMimeType(), docInfo.getCharacterEncoding(), contentLength, resourceStream);
|
|
}
|
|
return null;
|
|
} catch (InterruptedException e) {
|
|
// interruption of thread detected
|
|
return null;
|
|
}
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @param url
|
|
* @param fetchOnline
|
|
* @param socketTimeout
|
|
* @return an Object array containing
|
|
* <table>
|
|
* <tr><td>[0]</td><td>the content as {@link InputStream}</td></tr>
|
|
* <tr><td>[1]</td><td>the content-length as {@link Integer}</td></tr>
|
|
* </table>
|
|
*/
|
|
public Object[] getResource(URL url, boolean fetchOnline, int socketTimeout) {
|
|
// load the url as resource from the web
|
|
try {
|
|
long contentLength = -1;
|
|
|
|
// trying to load the resource body from cache
|
|
InputStream resource = this.cacheManager.getResourceContentStream(url);
|
|
if (resource != null) {
|
|
contentLength = this.cacheManager.getResourceContentLength(url);
|
|
} else if (fetchOnline) {
|
|
// if the content is not available in cache try to download it from web
|
|
|
|
// try to download the resource using a crawler
|
|
plasmaHTCache.Entry entry = loadResourceFromWeb(url, (socketTimeout < 0) ? -1 : socketTimeout, true);
|
|
|
|
// read resource body (if it is there)
|
|
byte[] resourceArray = entry.cacheArray();
|
|
|
|
// in case that the reosurce was not in ram, read it from disk
|
|
if (resourceArray == null) {
|
|
resource = this.cacheManager.getResourceContentStream(url);
|
|
contentLength = this.cacheManager.getResourceContentLength(url);
|
|
} else {
|
|
resource = new ByteArrayInputStream(resourceArray);
|
|
contentLength = resourceArray.length;
|
|
}
|
|
} else {
|
|
return null;
|
|
}
|
|
return new Object[]{resource,new Long(contentLength)};
|
|
} catch (IOException e) {
|
|
return null;
|
|
}
|
|
}
|
|
|
|
public plasmaHTCache.Entry loadResourceFromWeb(
|
|
URL url,
|
|
int socketTimeout,
|
|
boolean keepInMemory
|
|
) throws plasmaCrawlerException {
|
|
|
|
plasmaHTCache.Entry result = this.sb.cacheLoader.loadSync(
|
|
url, // the url
|
|
"", // name of the url, from anchor tag <a>name</a>
|
|
null, // referer
|
|
yacyCore.seedDB.mySeed.hash, // initiator
|
|
0, // depth
|
|
sb.defaultSnippetProfile, // crawl profile
|
|
socketTimeout,
|
|
keepInMemory
|
|
);
|
|
|
|
return result;
|
|
}
|
|
|
|
public void fetch(plasmaSearchResult acc, Set queryhashes, String urlmask, int fetchcount, long maxTime) {
|
|
// fetch snippets
|
|
int i = 0;
|
|
indexURLEntry urlentry;
|
|
String urlstring;
|
|
long limitTime = (maxTime < 0) ? Long.MAX_VALUE : System.currentTimeMillis() + maxTime;
|
|
while ((acc.hasMoreElements()) && (i < fetchcount) && (System.currentTimeMillis() < limitTime)) {
|
|
urlentry = acc.nextElement();
|
|
indexURLEntry.Components comp = urlentry.comp();
|
|
if (comp.url().getHost().endsWith(".yacyh")) continue;
|
|
urlstring = comp.url().toNormalform();
|
|
if ((urlstring.matches(urlmask)) &&
|
|
(!(existsInCache(comp.url(), queryhashes)))) {
|
|
new Fetcher(comp.url(), queryhashes, (int) maxTime).start();
|
|
i++;
|
|
}
|
|
}
|
|
}
|
|
|
|
public class Fetcher extends Thread {
|
|
URL url;
|
|
Set queryhashes;
|
|
int timeout;
|
|
public Fetcher(URL url, Set queryhashes, int timeout) {
|
|
if (url.getHost().endsWith(".yacyh")) return;
|
|
this.url = url;
|
|
this.queryhashes = queryhashes;
|
|
this.timeout = timeout;
|
|
}
|
|
public void run() {
|
|
log.logFine("snippetFetcher: try to get URL " + url);
|
|
plasmaSnippetCache.Snippet snippet = retrieveSnippet(url, queryhashes, true, 260, timeout);
|
|
if (snippet.line == null)
|
|
log.logFine("snippetFetcher: cannot get URL " + url + ". error(" + snippet.source + "): " + snippet.error);
|
|
else
|
|
log.logFine("snippetFetcher: got URL " + url + ", the snippet is '" + snippet.line + "', source=" + snippet.source);
|
|
}
|
|
}
|
|
|
|
}
|