boxtec
/
yacy_search_server
mirror of https://github.com/yacy/yacy_search_server
4
1
Fork 0
Code Issues Projects Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from 'e004da48d3'
${ noResults }
yacy_search_server/source/de/anomic/plasma/plasmaSnippetCache.java

970 lines
46 KiB
Raw Blame History

// plasmaSnippetCache.java
// -----------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2005
// last major change: 09.10.2006
//
// contributions by Marc Nause [MN]
//
// 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.plasma;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import de.anomic.htmlFilter.htmlFilterCharacterCoding;
import de.anomic.htmlFilter.htmlFilterImageEntry;
import de.anomic.http.HttpClient;
import de.anomic.http.httpResponseHeader;
import de.anomic.index.indexDocumentMetadata;
import de.anomic.index.indexURLReference;
import de.anomic.index.indexWord;
import de.anomic.kelondro.kelondroMScoreCluster;
import de.anomic.kelondro.kelondroMSetTools;
import de.anomic.plasma.parser.ParserException;
import de.anomic.server.logging.serverLog;
import de.anomic.yacy.yacySearch;
import de.anomic.yacy.yacyURL;
public class plasmaSnippetCache {
private static final int maxCache = 500;
public static final int SOURCE_CACHE = 0;
public static final int SOURCE_FILE = 1;
public static final int SOURCE_WEB = 2;
public static final int SOURCE_METADATA = 3;
public static final int ERROR_NO_HASH_GIVEN = 11;
public static final int ERROR_SOURCE_LOADING = 12;
public static final int ERROR_RESOURCE_LOADING = 13;
public static final int ERROR_PARSER_FAILED = 14;
public static final int ERROR_PARSER_NO_LINES = 15;
public static final int ERROR_NO_MATCH = 16;
private static int snippetsScoreCounter = 0;
private static kelondroMScoreCluster<String> snippetsScore = null;
private static final HashMap<String, String> snippetsCache = new HashMap<String, String>();
/**
* a cache holding URLs to favicons specified by the page content, e.g. by using the html link-tag. e.g.
* <pre>
* &lt;link rel="shortcut icon" type="image/x-icon" href="../src/favicon.ico"&gt;
* </pre>
*/
private static final HashMap<String, yacyURL> faviconCache = new HashMap<String, yacyURL>();
private static plasmaParser parser = null;
private static serverLog log = null;
private static plasmaSwitchboard sb = null;
public static void init(
final plasmaParser parserx,
final serverLog logx,
final plasmaSwitchboard switchboard
) {
parser = parserx;
log = logx;
sb = switchboard;
snippetsScoreCounter = 0;
snippetsScore = new kelondroMScoreCluster<String>();
snippetsCache.clear();
faviconCache.clear();
}
public static class TextSnippet {
private final yacyURL url;
private String line;
private final String error;
private final int errorCode;
Set<String> remaingHashes;
private final yacyURL favicon;
/**
* <code>\\A[^\\p{L}\\p{N}].+</code>
*/
private final static Pattern p1 = Pattern.compile("\\A[^\\p{L}\\p{N}].+");
/**
* <code>.+[^\\p{L}\\p{N}]\\Z</code>
*/
private final static Pattern p2 = Pattern.compile(".+[^\\p{L}\\p{N}]\\Z");
/**
* <code>\\A[\\p{L}\\p{N}]+[^\\p{L}\\p{N}].+\\Z</code>
*/
private final static Pattern p3 = Pattern.compile("\\A[\\p{L}\\p{N}]+[^\\p{L}\\p{N}].+\\Z");
/**
* <code>[^\\p{L}\\p{N}]</code>
*/
private final static Pattern p4 = Pattern.compile("[^\\p{L}\\p{N}]");
/**
* <code>(.*?)(\\&lt;b\\&gt;.+?\\&lt;/b\\&gt;)(.*)</code>
*/
private final static Pattern p01 = Pattern.compile("(.*?)(\\<b\\>.+?\\</b\\>)(.*)"); // marked words are in <b>-tags
public TextSnippet(final yacyURL url, final String line, final int errorCode, final Set<String> remaingHashes, final String errortext) {
this(url,line,errorCode,remaingHashes,errortext,null);
}
public TextSnippet(final yacyURL url, final String line, final int errorCode, final Set<String> remaingHashes, final String errortext, final yacyURL favicon) {
this.url = url;
this.line = line;
this.errorCode = errorCode;
this.error = errortext;
this.remaingHashes = remaingHashes;
this.favicon = favicon;
}
public yacyURL getUrl() {
return this.url;
}
public yacyURL getFavicon() {
return this.favicon;
}
public boolean exists() {
return line != null;
}
public String toString() {
return (line == null) ? "" : line;
}
public String getLineRaw() {
return (line == null) ? "" : line;
}
public String getError() {
return (error == null) ? "" : error.trim();
}
public int getErrorCode() {
return errorCode;
}
public Set<String> getRemainingHashes() {
return this.remaingHashes;
}
public String getLineMarked(final Set<String> queryHashes) {
if (line == null) return "";
if ((queryHashes == null) || (queryHashes.size() == 0)) return line.trim();
if (line.endsWith(".")) line = line.substring(0, line.length() - 1);
final Iterator<String> i = queryHashes.iterator();
String h;
final String[] w = line.split(" ");
while (i.hasNext()) {
h = i.next();
for (int j = 0; j < w.length; j++) {
final ArrayList<String> al = markedWordArrayList(w[j]); // mark special character separated words correctly if more than 1 word has to be marked
w[j] = "";
for (int k = 0; k < al.size(); k++) {
if(k % 2 == 0){ // word has not been marked
w[j] += getWordMarked(al.get(k), h);
} else { // word has been marked, do not encode again
w[j] += al.get(k);
}
}
}
}
final StringBuilder l = new StringBuilder(line.length() + queryHashes.size() * 8);
for (int j = 0; j < w.length; j++) {
l.append(w[j]);
l.append(' ');
}
return l.toString().trim();
}
/**
* mark words with &lt;b&gt;-tags
* @param word the word to mark
* @param h the hash of the word to mark
* @return the marked word if hash matches, else the unmarked word
* @see #getLineMarked(Set)
*/
private static String getWordMarked(String word, String h){
//ignore punctuation marks (contrib [MN])
//note to myself:
//For details on regex see "Mastering regular expressions" by J.E.F. Friedl
//especially p. 123 and p. 390/391 (in the German version of the 2nd edition)
String prefix = "";
String postfix = "";
int len = 0;
// cut off prefix if it contains of non-characters or non-numbers
while(p1.matcher(word).find()) {
prefix = prefix + word.substring(0,1);
word = word.substring(1);
}
// cut off postfix if it contains of non-characters or non-numbers
while(p2.matcher(word).find()) {
len = word.length();
postfix = word.substring(len-1,len) + postfix;
word = word.substring(0,len-1);
}
//special treatment if there is a special character in the word
if(p3.matcher(word).find()) {
String out = "";
String temp = "";
for(int k=0; k < word.length(); k++) {
//is character a special character?
if(p4.matcher(word.substring(k,k+1)).find()) {
if (indexWord.word2hash(temp).equals(h)) temp = "<b>" + htmlFilterCharacterCoding.unicode2html(temp, false) + "</b>";
out = out + temp + htmlFilterCharacterCoding.unicode2html(word.substring(k,k+1), false);
temp = "";
}
//last character
else if(k == (word.length()-1)) {
temp = temp + word.substring(k,k+1);
if (indexWord.word2hash(temp).equals(h)) temp = "<b>" + htmlFilterCharacterCoding.unicode2html(temp, false) + "</b>";
out = out + temp;
temp = "";
}
else temp = temp + word.substring(k,k+1);
}
word = out;
}
//end contrib [MN]
else if (indexWord.word2hash(word).equals(h)) word = "<b>" + htmlFilterCharacterCoding.unicode2html(word, false) + "</b>";
word = htmlFilterCharacterCoding.unicode2html(prefix, false)
+ word
+ htmlFilterCharacterCoding.unicode2html(postfix, false);
return word;
}
/**
* words that already has been marked has index <code>(i % 2 == 1)</code>
* words that has not yet been marked has index <code>(i % 2 == 0)</code>
* @param string the String to be processed
* @return words that already has and has not yet been marked
* @author [DW], 08.11.2008
*/
private static ArrayList<String> markedWordArrayList(String string){
ArrayList<String> al = new java.util.ArrayList<String>(1);
Matcher m = p01.matcher(string);
while (m.find()) {
al.add(m.group(1));
al.add(m.group(2));
string = m.group(3); // the postfix
m = p01.matcher(string);
}
al.add(string);
return al;
}
}
public static class MediaSnippet {
public int type;
public yacyURL href, source;
public String name, attr;
public int ranking;
public MediaSnippet(final int type, final yacyURL href, final String name, final String attr, final int ranking, final yacyURL source) {
this.type = type;
this.href = href;
this.source = source; // the web page where the media resource appeared
this.name = name;
this.attr = attr;
this.ranking = ranking; // the smaller the better! small values should be shown first
if ((this.name == null) || (this.name.length() == 0)) this.name = "_";
if ((this.attr == null) || (this.attr.length() == 0)) this.attr = "_";
}
public int hashCode() {
return href.hashCode();
}
}
public static boolean existsInCache(final yacyURL url, final Set<String> queryhashes) {
final String hashes = yacySearch.set2string(queryhashes);
return retrieveFromCache(hashes, url.hash()) != null;
}
@SuppressWarnings("unchecked")
public static TextSnippet retrieveTextSnippet(final indexURLReference.Components comp, final Set<String> queryhashes, final boolean fetchOnline, final boolean pre, final int snippetMaxLength, final int timeout, final int maxDocLen, final boolean reindexing) {
// heise = "0OQUNU3JSs05"
final yacyURL url = comp.url();
if (queryhashes.size() == 0) {
//System.out.println("found no queryhashes for URL retrieve " + url);
return new TextSnippet(url, null, ERROR_NO_HASH_GIVEN, queryhashes, "no query hashes given");
}
// try to get snippet from snippetCache
int source = SOURCE_CACHE;
final String wordhashes = yacySearch.set2string(queryhashes);
String line = retrieveFromCache(wordhashes, url.hash());
if (line != null) {
// found the snippet
return new TextSnippet(url, line, source, null, null, faviconCache.get(url.hash()));
}
/* ===========================================================================
* LOADING RESOURCE DATA
* =========================================================================== */
// if the snippet is not in the cache, we can try to get it from the htcache
long resContentLength = 0;
InputStream resContent = null;
httpResponseHeader responseHeader = null;
try {
// trying to load the resource from the cache
resContent = plasmaHTCache.getResourceContentStream(url);
responseHeader = plasmaHTCache.loadResponseHeader(url);
if (resContent != null) {
// if the content was found
resContentLength = plasmaHTCache.getResourceContentLength(url);
if ((resContentLength > maxDocLen) && (!fetchOnline)) {
// content may be too large to be parsed here. To be fast, we omit calculation of snippet here
return new TextSnippet(url, null, ERROR_SOURCE_LOADING, queryhashes, "resource available, but too large: " + resContentLength + " bytes");
}
} else if (containsAllHashes(comp.dc_title(), queryhashes)) {
// try to create the snippet from information given in the url itself
return new TextSnippet(url, (comp.dc_subject().length() > 0) ? comp.dc_creator() : comp.dc_subject(), SOURCE_METADATA, null, null, faviconCache.get(url.hash()));
} else if (containsAllHashes(comp.dc_creator(), queryhashes)) {
// try to create the snippet from information given in the creator metadata
return new TextSnippet(url, comp.dc_creator(), SOURCE_METADATA, null, null, faviconCache.get(url.hash()));
} else if (containsAllHashes(comp.dc_subject(), queryhashes)) {
// try to create the snippet from information given in the subject metadata
return new TextSnippet(url, (comp.dc_creator().length() > 0) ? comp.dc_creator() : comp.dc_subject(), SOURCE_METADATA, null, null, faviconCache.get(url.hash()));
} else if (containsAllHashes(comp.url().toNormalform(true, true), queryhashes)) {
// try to create the snippet from information given in the subject metadata
return new TextSnippet(url, (comp.dc_creator().length() > 0) ? comp.dc_creator() : comp.dc_subject(), SOURCE_METADATA, null, null, faviconCache.get(url.hash()));
} else if (fetchOnline) {
// if not found try to download it
// download resource using the crawler and keep resource in memory if possible
final indexDocumentMetadata entry = plasmaSwitchboard.getSwitchboard().crawlQueues.loadResourceFromWeb(url, timeout, true, true, reindexing);
// getting resource metadata (e.g. the http headers for http resources)
if (entry != null) {
// place entry on crawl queue
sb.htEntryStoreProcess(entry);
// read resource body (if it is there)
final byte []resourceArray = entry.cacheArray();
if (resourceArray != null) {
resContent = new ByteArrayInputStream(resourceArray);
resContentLength = resourceArray.length;
} else {
resContent = plasmaHTCache.getResourceContentStream(url);
resContentLength = plasmaHTCache.getResourceContentLength(url);
}
}
// if it is still not available, report an error
if (resContent == null) return new TextSnippet(url, null, ERROR_RESOURCE_LOADING, queryhashes, "error loading resource, plasmaHTCache.Entry cache is NULL");
source = SOURCE_WEB;
} else {
return new TextSnippet(url, null, ERROR_SOURCE_LOADING, queryhashes, "no resource available");
}
} catch (final Exception e) {
e.printStackTrace();
return new TextSnippet(url, null, ERROR_SOURCE_LOADING, queryhashes, "error loading resource: " + e.getMessage());
}
/* ===========================================================================
* PARSING RESOURCE
* =========================================================================== */
plasmaParserDocument document = null;
try {
document = parseDocument(url, resContentLength, resContent, responseHeader);
} catch (final ParserException e) {
return new TextSnippet(url, null, ERROR_PARSER_FAILED, queryhashes, e.getMessage()); // cannot be parsed
} finally {
try { resContent.close(); } catch (final Exception e) {/* ignore this */}
}
if (document == null) return new TextSnippet(url, null, ERROR_PARSER_FAILED, queryhashes, "parser error/failed"); // cannot be parsed
/* ===========================================================================
* COMPUTE SNIPPET
* =========================================================================== */
final yacyURL resFavicon = document.getFavicon();
if (resFavicon != null) faviconCache.put(url.hash(), resFavicon);
// we have found a parseable non-empty file: use the lines
// compute snippet from text
final Iterator<StringBuilder> sentences = document.getSentences(pre);
if (sentences == null) return new TextSnippet(url, null, ERROR_PARSER_NO_LINES, queryhashes, "parser returned no sentences",resFavicon);
final Object[] tsr = computeTextSnippet(sentences, queryhashes, snippetMaxLength);
final String textline = (tsr == null) ? null : (String) tsr[0];
final Set<String> remainingHashes = (tsr == null) ? queryhashes : (Set<String>) tsr[1];
// compute snippet from media
//String audioline = computeMediaSnippet(document.getAudiolinks(), queryhashes);
//String videoline = computeMediaSnippet(document.getVideolinks(), queryhashes);
//String appline = computeMediaSnippet(document.getApplinks(), queryhashes);
//String hrefline = computeMediaSnippet(document.getAnchors(), queryhashes);
//String imageline = computeMediaSnippet(document.getAudiolinks(), queryhashes);
line = "";
//if (audioline != null) line += (line.length() == 0) ? audioline : "<br />" + audioline;
//if (videoline != null) line += (line.length() == 0) ? videoline : "<br />" + videoline;
//if (appline != null) line += (line.length() == 0) ? appline : "<br />" + appline;
//if (hrefline != null) line += (line.length() == 0) ? hrefline : "<br />" + hrefline;
if (textline != null) line += (line.length() == 0) ? textline : "<br />" + textline;
if ((line == null) || (remainingHashes.size() > 0)) return new TextSnippet(url, null, ERROR_NO_MATCH, remainingHashes, "no matching snippet found",resFavicon);
if (line.length() > snippetMaxLength) line = line.substring(0, snippetMaxLength);
// finally store this snippet in our own cache
storeToCache(wordhashes, url.hash(), line);
document.close();
return new TextSnippet(url, line, source, null, null, resFavicon);
}
/**
* Tries to load and parse a resource specified by it's URL.
* If the resource is not stored in cache and if fetchOnline is set the
* this function tries to download the resource from web.
*
* @param url the URL of the resource
* @param fetchOnline specifies if the resource should be loaded from web if it'as not available in the cache
* @param timeout
* @param forText
* @param global the domain of the search. If global == true then the content is re-indexed
* @return the parsed document as {@link plasmaParserDocument}
*/
public static plasmaParserDocument retrieveDocument(final yacyURL url, final boolean fetchOnline, final int timeout, final boolean forText, final boolean global) {
// load resource
long resContentLength = 0;
InputStream resContent = null;
httpResponseHeader responseHeader = null;
try {
// trying to load the resource from the cache
resContent = plasmaHTCache.getResourceContentStream(url);
responseHeader = plasmaHTCache.loadResponseHeader(url);
if (resContent != null) {
// if the content was found
resContentLength = plasmaHTCache.getResourceContentLength(url);
} else if (fetchOnline) {
// if not found try to download it
// download resource using the crawler and keep resource in memory if possible
final indexDocumentMetadata entry = plasmaSwitchboard.getSwitchboard().crawlQueues.loadResourceFromWeb(url, timeout, true, forText, global);
// getting resource metadata (e.g. the http headers for http resources)
if (entry != null) {
// read resource body (if it is there)
final byte[] resourceArray = entry.cacheArray();
if (resourceArray != null) {
resContent = new ByteArrayInputStream(resourceArray);
resContentLength = resourceArray.length;
} else {
resContent = plasmaHTCache.getResourceContentStream(url);
resContentLength = plasmaHTCache.getResourceContentLength(url);
}
}
// if it is still not available, report an error
if (resContent == null) {
serverLog.logFine("snippet fetch", "plasmaHTCache.Entry cache is NULL for url " + url);
return null;
}
} else {
serverLog.logFine("snippet fetch", "no resource available for url " + url);
return null;
}
} catch (final Exception e) {
serverLog.logFine("snippet fetch", "error loading resource: " + e.getMessage() + " for url " + url);
return null;
}
// parse resource
plasmaParserDocument document = null;
try {
document = parseDocument(url, resContentLength, resContent, responseHeader);
} catch (final ParserException e) {
serverLog.logFine("snippet fetch", "parser error " + e.getMessage() + " for url " + url);
return null;
} finally {
try { resContent.close(); } catch (final Exception e) {}
}
return document;
}
public static void storeToCache(final String wordhashes, final String urlhash, final String snippet) {
// generate key
String key = urlhash + wordhashes;
// do nothing if snippet is known
if (snippetsCache.containsKey(key)) return;
// learn new snippet
snippetsScore.addScore(key, snippetsScoreCounter++);
snippetsCache.put(key, snippet);
// care for counter
if (snippetsScoreCounter == java.lang.Integer.MAX_VALUE) {
snippetsScoreCounter = 0;
snippetsScore = new kelondroMScoreCluster<String>();
snippetsCache.clear();
}
// flush cache if cache is full
while (snippetsCache.size() > maxCache) {
key = snippetsScore.getMinObject();
snippetsScore.deleteScore(key);
snippetsCache.remove(key);
}
}
private static String retrieveFromCache(final String wordhashes, final String urlhash) {
// generate key
final String key = urlhash + wordhashes;
return snippetsCache.get(key);
}
/*
private static String computeMediaSnippet(Map<yacyURL, String> media, Set<String> queryhashes) {
Iterator<Map.Entry<yacyURL, String>> i = media.entrySet().iterator();
Map.Entry<yacyURL, String> entry;
yacyURL url;
String desc;
Set<String> s;
String result = "";
while (i.hasNext()) {
entry = i.next();
url = entry.getKey();
desc = entry.getValue();
s = removeAppearanceHashes(url.toNormalform(false, false), queryhashes);
if (s.size() == 0) {
result += "<br /><a href=\"" + url + "\">" + ((desc.length() == 0) ? url : desc) + "</a>";
continue;
}
s = removeAppearanceHashes(desc, s);
if (s.size() == 0) {
result += "<br /><a href=\"" + url + "\">" + ((desc.length() == 0) ? url : desc) + "</a>";
continue;
}
}
if (result.length() == 0) return null;
return result.substring(6);
}
*/
@SuppressWarnings("unchecked")
private static Object[] /*{String - the snippet, Set - remaining hashes}*/
computeTextSnippet(final Iterator<StringBuilder> sentences, final Set<String> queryhashes, int maxLength) {
try {
if (sentences == null) return null;
if ((queryhashes == null) || (queryhashes.size() == 0)) return null;
Iterator<String> j;
HashMap<String, Integer> hs;
StringBuilder sentence;
final TreeMap<Integer, StringBuilder> os = new TreeMap<Integer, StringBuilder>();
int uniqCounter = 9999;
int score;
while (sentences.hasNext()) {
sentence = sentences.next();
hs = hashSentence(sentence.toString());
j = queryhashes.iterator();
score = 0;
while (j.hasNext()) {if (hs.containsKey(j.next())) score++;}
if (score > 0) {
os.put(Integer.valueOf(1000000 * score - sentence.length() * 10000 + uniqCounter--), sentence);
}
}
String result;
Set<String> remaininghashes;
while (os.size() > 0) {
sentence = os.remove(os.lastKey()); // sentence with the biggest score
Object[] tsr = computeTextSnippet(sentence.toString(), queryhashes, maxLength);
if (tsr == null) continue;
result = (String) tsr[0];
if ((result != null) && (result.length() > 0)) {
remaininghashes = (Set<String>) tsr[1];
if (remaininghashes.size() == 0) {
// we have found the snippet
return new Object[]{result, remaininghashes};
} else if (remaininghashes.size() < queryhashes.size()) {
// the result has not all words in it.
// find another sentence that represents the missing other words
// and find recursively more sentences
maxLength = maxLength - result.length();
if (maxLength < 20) maxLength = 20;
tsr = computeTextSnippet(os.values().iterator(), remaininghashes, maxLength);
if (tsr == null) return null;
final String nextSnippet = (String) tsr[0];
if (nextSnippet == null) return tsr;
return new Object[]{result + (" / " + nextSnippet), tsr[1]};
} else {
// error
//assert remaininghashes.size() < queryhashes.size() : "remaininghashes.size() = " + remaininghashes.size() + ", queryhashes.size() = " + queryhashes.size() + ", sentence = '" + sentence + "', result = '" + result + "'";
continue;
}
}
}
return null;
} catch (final IndexOutOfBoundsException e) {
log.logSevere("computeSnippet: error with string generation", e);
return new Object[]{null, queryhashes};
}
}
private static Object[] /*{String - the snippet, Set - remaining hashes}*/
computeTextSnippet(String sentence, final Set<String> queryhashes, final int maxLength) {
try {
if (sentence == null) return null;
if ((queryhashes == null) || (queryhashes.size() == 0)) return null;
String hash;
// find all hashes that appear in the sentence
final HashMap<String, Integer> hs = hashSentence(sentence);
final Iterator<String> j = queryhashes.iterator();
Integer pos;
int p, minpos = sentence.length(), maxpos = -1;
final HashSet<String> remainingHashes = new HashSet<String>();
while (j.hasNext()) {
hash = j.next();
pos = hs.get(hash);
if (pos == null) {
remainingHashes.add(hash);
} else {
p = pos.intValue();
if (p > maxpos) maxpos = p;
if (p < minpos) minpos = p;
}
}
// check result size
maxpos = maxpos + 10;
if (maxpos > sentence.length()) maxpos = sentence.length();
if (minpos < 0) minpos = 0;
// we have a result, but is it short enough?
if (maxpos - minpos + 10 > maxLength) {
// the string is too long, even if we cut at both ends
// so cut here in the middle of the string
final int lenb = sentence.length();
sentence = sentence.substring(0, (minpos + 20 > sentence.length()) ? sentence.length() : minpos + 20).trim() +
" [..] " +
sentence.substring((maxpos + 26 > sentence.length()) ? sentence.length() : maxpos + 26).trim();
maxpos = maxpos + lenb - sentence.length() + 6;
}
if (maxpos > maxLength) {
// the string is too long, even if we cut it at the end
// so cut it here at both ends at once
assert maxpos >= minpos;
final int newlen = Math.max(10, maxpos - minpos + 10);
final int around = (maxLength - newlen) / 2;
assert minpos - around < sentence.length() : "maxpos = " + maxpos + ", minpos = " + minpos + ", around = " + around + ", sentence.length() = " + sentence.length();
assert ((maxpos + around) <= sentence.length()) && ((maxpos + around) <= sentence.length()) : "maxpos = " + maxpos + ", minpos = " + minpos + ", around = " + around + ", sentence.length() = " + sentence.length();
sentence = "[..] " + sentence.substring(minpos - around, ((maxpos + around) > sentence.length()) ? sentence.length() : (maxpos + around)).trim() + " [..]";
minpos = around;
maxpos = sentence.length() - around - 5;
}
if (sentence.length() > maxLength) {
// trim sentence, 1st step (cut at right side)
sentence = sentence.substring(0, maxpos).trim() + " [..]";
}
if (sentence.length() > maxLength) {
// trim sentence, 2nd step (cut at left side)
sentence = "[..] " + sentence.substring(minpos).trim();
}
if (sentence.length() > maxLength) {
// trim sentence, 3rd step (cut in the middle)
sentence = sentence.substring(6, 20).trim() + " [..] " + sentence.substring(sentence.length() - 26, sentence.length() - 6).trim();
}
return new Object[] {sentence, remainingHashes};
} catch (final IndexOutOfBoundsException e) {
log.logSevere("computeSnippet: error with string generation", e);
return null;
}
}
public static ArrayList<MediaSnippet> retrieveMediaSnippets(final yacyURL url, final Set<String> queryhashes, final int mediatype, final boolean fetchOnline, final int timeout, final boolean reindexing) {
if (queryhashes.size() == 0) {
serverLog.logFine("snippet fetch", "no query hashes given for url " + url);
return new ArrayList<MediaSnippet>();
}
final plasmaParserDocument document = retrieveDocument(url, fetchOnline, timeout, false, reindexing);
final ArrayList<MediaSnippet> a = new ArrayList<MediaSnippet>();
if (document != null) {
if ((mediatype == plasmaSearchQuery.CONTENTDOM_ALL) || (mediatype == plasmaSearchQuery.CONTENTDOM_AUDIO)) a.addAll(computeMediaSnippets(document, queryhashes, plasmaSearchQuery.CONTENTDOM_AUDIO));
if ((mediatype == plasmaSearchQuery.CONTENTDOM_ALL) || (mediatype == plasmaSearchQuery.CONTENTDOM_VIDEO)) a.addAll(computeMediaSnippets(document, queryhashes, plasmaSearchQuery.CONTENTDOM_VIDEO));
if ((mediatype == plasmaSearchQuery.CONTENTDOM_ALL) || (mediatype == plasmaSearchQuery.CONTENTDOM_APP)) a.addAll(computeMediaSnippets(document, queryhashes, plasmaSearchQuery.CONTENTDOM_APP));
if ((mediatype == plasmaSearchQuery.CONTENTDOM_ALL) || (mediatype == plasmaSearchQuery.CONTENTDOM_IMAGE)) a.addAll(computeImageSnippets(document, queryhashes));
}
return a;
}
public static ArrayList<MediaSnippet> computeMediaSnippets(final plasmaParserDocument document, final Set<String> queryhashes, final int mediatype) {
if (document == null) return new ArrayList<MediaSnippet>();
Map<yacyURL, String> media = null;
if (mediatype == plasmaSearchQuery.CONTENTDOM_AUDIO) media = document.getAudiolinks();
else if (mediatype == plasmaSearchQuery.CONTENTDOM_VIDEO) media = document.getVideolinks();
else if (mediatype == plasmaSearchQuery.CONTENTDOM_APP) media = document.getApplinks();
if (media == null) return null;
final Iterator<Map.Entry<yacyURL, String>> i = media.entrySet().iterator();
Map.Entry<yacyURL, String> entry;
yacyURL url;
String desc;
Set<String> s;
final ArrayList<MediaSnippet> result = new ArrayList<MediaSnippet>();
while (i.hasNext()) {
entry = i.next();
url = entry.getKey();
desc = entry.getValue();
s = removeAppearanceHashes(url.toNormalform(false, false), queryhashes);
if (s.size() == 0) {
result.add(new MediaSnippet(mediatype, url, desc, null, 0, document.dc_source()));
continue;
}
s = removeAppearanceHashes(desc, s);
if (s.size() == 0) {
result.add(new MediaSnippet(mediatype, url, desc, null, 0, document.dc_source()));
continue;
}
}
return result;
}
public static ArrayList<MediaSnippet> computeImageSnippets(final plasmaParserDocument document, final Set<String> queryhashes) {
final TreeSet<htmlFilterImageEntry> images = new TreeSet<htmlFilterImageEntry>();
images.addAll(document.getImages().values()); // iterates images in descending size order!
// a measurement for the size of the images can be retrieved using the htmlFilterImageEntry.hashCode()
final Iterator<htmlFilterImageEntry> i = images.iterator();
htmlFilterImageEntry ientry;
yacyURL url;
String desc;
Set<String> s;
final ArrayList<MediaSnippet> result = new ArrayList<MediaSnippet>();
while (i.hasNext()) {
ientry = i.next();
url = ientry.url();
desc = ientry.alt();
s = removeAppearanceHashes(url.toNormalform(false, false), queryhashes);
if (s.size() == 0) {
final int ranking = ientry.hashCode();
result.add(new MediaSnippet(plasmaSearchQuery.CONTENTDOM_IMAGE, url, desc, ientry.width() + " x " + ientry.height(), ranking, document.dc_source()));
continue;
}
s = removeAppearanceHashes(desc, s);
if (s.size() == 0) {
final int ranking = ientry.hashCode();
result.add(new MediaSnippet(plasmaSearchQuery.CONTENTDOM_IMAGE, url, desc, ientry.width() + " x " + ientry.height(), ranking, document.dc_source()));
continue;
}
}
return result;
}
private static Set<String> removeAppearanceHashes(final String sentence, final Set<String> queryhashes) {
// remove all hashes that appear in the sentence
if (sentence == null) return queryhashes;
final HashMap<String, Integer> hs = hashSentence(sentence);
final Iterator<String> j = queryhashes.iterator();
String hash;
Integer pos;
final Set<String> remaininghashes = new HashSet<String>();
while (j.hasNext()) {
hash = j.next();
pos = hs.get(hash);
if (pos == null) {
remaininghashes.add(hash);
}
}
return remaininghashes;
}
private static HashMap<String, Integer> hashSentence(final String sentence) {
// generates a word-wordPos mapping
final HashMap<String, Integer> map = new HashMap<String, Integer>();
final Enumeration<StringBuilder> words = plasmaCondenser.wordTokenizer(sentence, "UTF-8");
int pos = 0;
StringBuilder word;
String hash;
while (words.hasMoreElements()) {
word = words.nextElement();
hash = indexWord.word2hash(new String(word));
if (!map.containsKey(hash)) map.put(hash, Integer.valueOf(pos)); // dont overwrite old values, that leads to too far word distances
pos += word.length() + 1;
}
return map;
}
private static boolean containsAllHashes(final String sentence, final Set<String> queryhashes) {
final HashMap<String, Integer> m = hashSentence(sentence);
final Iterator<String> i = queryhashes.iterator();
while (i.hasNext()) {
if (!(m.containsKey(i.next()))) return false;
}
return true;
}
public static plasmaParserDocument parseDocument(final yacyURL url, final long contentLength, final 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 static plasmaParserDocument parseDocument(final yacyURL url, final long contentLength, final InputStream resourceStream, httpResponseHeader responseHeader) throws ParserException {
try {
if (resourceStream == null) return null;
// STEP 1: if no resource metadata is available, try to load it from cache
if (responseHeader == null) {
// try to get the header from the htcache directory
try {
responseHeader = plasmaHTCache.loadResponseHeader(url);
} catch (final Exception e) {
// ignore this. resource info loading failed
}
}
// STEP 2: if the metadata is still null try to download it from web
if ((responseHeader == null) && (url.getProtocol().startsWith("http"))) {
// TODO: we need a better solution here
// e.g. encapsulate this in the crawlLoader class
// getting URL mimeType
try {
responseHeader = HttpClient.whead(url.toString());
} catch (final 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 (responseHeader == null) {
final String filename = url.getFileName();
final 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 parser.parseSource(url, supposedMime, null, contentLength, resourceStream);
}
return null;
}
if (plasmaParser.supportedMimeTypesContains(responseHeader.mime())) {
return parser.parseSource(url, responseHeader.mime(), responseHeader.getCharacterEncoding(), contentLength, resourceStream);
}
return null;
} catch (final InterruptedException e) {
// interruption of thread detected
return null;
}
}
/**
*
* @param url
* @param fetchOnline
* @param socketTimeout
* @param forText
* @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>
* @throws IOException
*/
public static Object[] getResource(final yacyURL url, final boolean fetchOnline, final int socketTimeout, final boolean forText, final boolean reindexing) throws IOException {
// load the url as resource from the web
long contentLength = -1;
// trying to load the resource body from cache
InputStream resource = plasmaHTCache.getResourceContentStream(url);
if (resource != null) {
contentLength = plasmaHTCache.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
final indexDocumentMetadata entry = plasmaSwitchboard.getSwitchboard().crawlQueues.loadResourceFromWeb(url, (socketTimeout < 0) ? -1 : socketTimeout, true, forText, reindexing);
if (entry == null) return null; // not found in web
// read resource body (if it is there)
final byte[] resourceArray = entry.cacheArray();
// in case that the resource was not in ram, read it from disk
if (resourceArray == null) {
resource = plasmaHTCache.getResourceContentStream(url);
contentLength = plasmaHTCache.getResourceContentLength(url);
} else {
resource = new ByteArrayInputStream(resourceArray);
contentLength = resourceArray.length;
}
} else {
return null;
}
return new Object[]{resource, Long.valueOf(contentLength)};
}
public static String failConsequences(final TextSnippet snippet, final String eventID) {
// problems with snippet fetch
final String urlHash = snippet.getUrl().hash();
final String querystring = kelondroMSetTools.setToString(snippet.getRemainingHashes(), ' ');
if ((snippet.getErrorCode() == ERROR_SOURCE_LOADING) ||
(snippet.getErrorCode() == ERROR_RESOURCE_LOADING) ||
(snippet.getErrorCode() == ERROR_PARSER_FAILED) ||
(snippet.getErrorCode() == ERROR_PARSER_NO_LINES)) {
log.logInfo("error: '" + snippet.getError() + "', remove url = " + snippet.getUrl().toNormalform(false, true) + ", cause: " + snippet.getError());
plasmaSwitchboard.getSwitchboard().webIndex.removeURL(urlHash);
final plasmaSearchEvent event = plasmaSearchEvent.getEvent(eventID);
assert plasmaSwitchboard.getSwitchboard() != null;
assert plasmaSwitchboard.getSwitchboard().webIndex != null;
assert event != null : "eventID = " + eventID;
assert event.getQuery() != null;
plasmaSwitchboard.getSwitchboard().webIndex.removeEntryMultiple(event.getQuery().queryHashes, urlHash);
event.remove(urlHash);
}
if (snippet.getErrorCode() == ERROR_NO_MATCH) {
log.logInfo("error: '" + snippet.getError() + "', remove words '" + querystring + "' for url = " + snippet.getUrl().toNormalform(false, true) + ", cause: " + snippet.getError());
plasmaSwitchboard.getSwitchboard().webIndex.removeEntryMultiple(snippet.remaingHashes, urlHash);
plasmaSearchEvent.getEvent(eventID).remove(urlHash);
}
return snippet.getError();
}
}
Reference in new issue View Git Blame Copy Permalink