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.
69 lines
2.4 KiB
69 lines
2.4 KiB
// AbstractReference.java
|
|
// (C) 2009 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
|
|
// first published 14.04.2009 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 net.yacy.kelondro.rwi;
|
|
|
|
import java.util.Iterator;
|
|
import net.yacy.cora.util.ConcurrentLog;
|
|
|
|
|
|
public abstract class AbstractReference implements Reference {
|
|
|
|
/**
|
|
* The average distance (in words) between search query terms for multi word searches.
|
|
* @return word distance
|
|
*/
|
|
@Override
|
|
public int distance() {
|
|
// check if positions have been joined
|
|
if (positions() == null || positions().isEmpty()) return 0;
|
|
int d = 0;
|
|
Iterator<Integer> i = positions().iterator();
|
|
int s0 = posintext(); // init with own positon
|
|
int s1;
|
|
while (i.hasNext()) {
|
|
s1 = i.next();
|
|
if (s0 > 0) d += Math.abs(s0 - s1);
|
|
s0 = s1;
|
|
}
|
|
// despite first line checks for size < 2 Arithmetic exception div by zero occured (1.91/9278 2016-10-19)
|
|
// added d == 0 condition as protection for this (which was in all above tests the case)
|
|
try {
|
|
return d == 0 ? 0 : d / positions().size();
|
|
} catch (ArithmeticException ex) {
|
|
ConcurrentLog.fine("AbstractReference", "word distance calculation:" + ex.getMessage());
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public boolean isOlder(final Reference other) {
|
|
if (other == null) return false;
|
|
if (this.lastModified() < other.lastModified()) return true;
|
|
return false;
|
|
}
|
|
}
|