// NavigationReferenceRow.java
// (C) 2009 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 19.05.2009 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.data.navigation;
import java.util.Collection;
import net.yacy.cora.document.encoding.ASCII;
import net.yacy.cora.order.Base64Order;
import net.yacy.kelondro.data.word.Word;
import net.yacy.kelondro.index.Column;
import net.yacy.kelondro.index.Row;
import net.yacy.kelondro.index.Row.Entry;
import net.yacy.kelondro.rwi.AbstractReference;
import net.yacy.kelondro.rwi.Reference;
public final class NavigationReferenceRow extends AbstractReference implements NavigationReference, Cloneable {
/*
* A Navigation Reference is a index that stores the occurrences of Words from a specific Domain
* (when words in documents occur in spcial categories or in a dictionary) in relation to a normal
* word index of documents. The navigation index is like a property addition to the word index.
* Example: Navigation for Author name Occurrences. The dictionary for the navigation index contains
* names of Authors. Consider that a document is indexed, and the Word 'Goethe' appears in a author field.
* Then an reference entry in the Author Navigation index is made. The reference entry must contain the following
* entities:
* - reference to document (like in the RWI; this is the primary key of the reference entry)
* - matching word (in this case: term hash of 'Goethe')
* - flag to see where the tag appeared (in a qualified field for authors or anywhere in the text)
* - number of occurrences
*/
public static final Row navEntryRow = new Row(new Column[]{
new Column("n", Column.celltype_string, Column.encoder_bytes, Word.commonHashLength * 2, "navhash"), // hash of the navigation term plus document reference hash
new Column("c", Column.celltype_cardinal, Column.encoder_b256, 1, "hitcount"), // number of occurrences of navigation term
new Column("p", Column.celltype_cardinal, Column.encoder_b256, 2, "posintext"), // position of navigation term in document
new Column("f", Column.celltype_cardinal, Column.encoder_b256, 1, "reserve") // reserve for flags etc
},
Base64Order.enhancedCoder
);
// static properties
private static final int col_navhash = 0; // n 24 the navigation hash and reference hash b64-encoded
private static final int col_count = 1; // c the number of occurences
private static final int col_pos = 2; // p the position of the first occurence
private static final int col_flags = 3; // f reserve, may be used for flags
private final Row.Entry entry;
public NavigationReferenceRow(
final byte[] termhash,
final byte[] refhash,
final int count,
final int pos,
final byte flags
) {
assert (termhash.length == 12) : "termhash = " + ASCII.String(termhash);
assert (refhash.length == 12) : "refhash = " + ASCII.String(refhash);
this.entry = navEntryRow.newEntry();
this.entry.setCol(col_navhash, ASCII.String(termhash) + ASCII.String(refhash));
this.entry.setCol(col_count, count);
this.entry.setCol(col_pos, pos);
this.entry.setCol(col_flags, flags);
}
private NavigationReferenceRow(final byte[] row) {
this.entry = navEntryRow.newEntry(row);
}
public NavigationReferenceRow(final Row.Entry entry) {
this.entry = entry;
}
@Override
public NavigationReferenceRow clone() {
final byte[] b = new byte[navEntryRow.objectsize];
System.arraycopy(this.entry.bytes(), 0, b, 0, navEntryRow.objectsize);
return new NavigationReferenceRow(b);
}
@Override
public String toPropertyForm() {
return this.entry.toPropertyForm('=', true, true, false, false);
}
@Override
public Entry toKelondroEntry() {
return this.entry;
}
@Override
public String navigationHash() {
return this.entry.getColASCII(col_navhash);
}
@Override
public byte[] urlhash() {
return ASCII.getBytes(navigationHash().substring(12));
}
@Override
public byte[] termHash() {
return ASCII.getBytes(navigationHash().substring(0, 12));
}
@Override
public int hitcount() {
return (int) this.entry.getColLong(col_count);
}
@Override
public int position(final int p) {
assert p == 0 : "p = " + p;
return (int) this.entry.getColLong(col_pos);
}
@Override
public byte flags() {
return (byte) this.entry.getColLong(col_flags);
}
@Override
public String toString() {
return toPropertyForm();
}
@Override
public int hashCode() {
return navigationHash().hashCode();
}
@Override
public boolean equals(final Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (!(obj instanceof NavigationReferenceRow)) return false;
final NavigationReferenceRow other = (NavigationReferenceRow) obj;
return navigationHash().equals(other.navigationHash());
}
@Override
public boolean isOlder(final Reference other) {
return false;
}
// unsupported operations:
@Override
public void join(final Reference oe) {
throw new UnsupportedOperationException();
}
@Override
public long lastModified() {
throw new UnsupportedOperationException();
}
@Override
public Collection<Integer> positions() {
throw new UnsupportedOperationException();
}
@Override
public int posintext() {
throw new UnsupportedOperationException();
}
}