org.glowroot.shaded.h2.index.ViewCursor Maven / Gradle / Ivy
/*
* Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.glowroot.shaded.h2.index;
import org.glowroot.shaded.h2.message.DbException;
import org.glowroot.shaded.h2.result.ResultInterface;
import org.glowroot.shaded.h2.result.Row;
import org.glowroot.shaded.h2.result.SearchRow;
import org.glowroot.shaded.h2.table.Table;
import org.glowroot.shaded.h2.value.Value;
import org.glowroot.shaded.h2.value.ValueNull;
/**
* The cursor implementation of a view index.
*/
public class ViewCursor implements Cursor {
private final Table table;
private final Index index;
private final ResultInterface result;
private final SearchRow first, last;
private Row current;
ViewCursor(Index index, ResultInterface result, SearchRow first,
SearchRow last) {
this.table = index.getTable();
this.index = index;
this.result = result;
this.first = first;
this.last = last;
}
@Override
public Row get() {
return current;
}
@Override
public SearchRow getSearchRow() {
return current;
}
@Override
public boolean next() {
while (true) {
boolean res = result.next();
if (!res) {
result.close();
current = null;
return false;
}
current = table.getTemplateRow();
Value[] values = result.currentRow();
for (int i = 0, len = current.getColumnCount(); i < len; i++) {
Value v = i < values.length ? values[i] : ValueNull.INSTANCE;
current.setValue(i, v);
}
int comp;
if (first != null) {
comp = index.compareRows(current, first);
if (comp < 0) {
continue;
}
}
if (last != null) {
comp = index.compareRows(current, last);
if (comp > 0) {
continue;
}
}
return true;
}
}
@Override
public boolean previous() {
throw DbException.throwInternalError();
}
}