org.h2.mvstore.db.MVDelegateIndex Maven / Gradle / Ivy
/*
* Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.mvstore.db;
import java.util.HashSet;
import java.util.List;
import org.h2.engine.Session;
import org.h2.index.BaseIndex;
import org.h2.index.Cursor;
import org.h2.index.IndexType;
import org.h2.message.DbException;
import org.h2.result.Row;
import org.h2.result.SearchRow;
import org.h2.result.SortOrder;
import org.h2.table.Column;
import org.h2.table.IndexColumn;
import org.h2.table.TableFilter;
import org.h2.value.ValueLong;
/**
* An index that delegates indexing to another index.
*/
public class MVDelegateIndex extends BaseIndex implements MVIndex {
private final MVPrimaryIndex mainIndex;
public MVDelegateIndex(MVTable table, int id, String name,
MVPrimaryIndex mainIndex,
IndexType indexType) {
IndexColumn[] cols = IndexColumn.wrap(new Column[] { table
.getColumn(mainIndex.getMainIndexColumn()) });
this.initBaseIndex(table, id, name, cols, indexType);
this.mainIndex = mainIndex;
if (id < 0) {
throw DbException.throwInternalError("" + name);
}
}
@Override
public void addRowsToBuffer(List rows, String bufferName) {
throw DbException.throwInternalError();
}
@Override
public void addBufferedRows(List bufferNames) {
throw DbException.throwInternalError();
}
@Override
public void add(Session session, Row row) {
// nothing to do
}
@Override
public boolean canGetFirstOrLast() {
return true;
}
@Override
public void close(Session session) {
// nothing to do
}
@Override
public Cursor find(Session session, SearchRow first, SearchRow last) {
ValueLong min = mainIndex.getKey(first,
MVPrimaryIndex.MIN, MVPrimaryIndex.MIN);
// ifNull is MIN_VALUE as well, because the column is never NULL
// so avoid returning all rows (returning one row is OK)
ValueLong max = mainIndex.getKey(last,
MVPrimaryIndex.MAX, MVPrimaryIndex.MIN);
return mainIndex.find(session, min, max);
}
@Override
public Cursor findFirstOrLast(Session session, boolean first) {
return mainIndex.findFirstOrLast(session, first);
}
@Override
public int getColumnIndex(Column col) {
if (col.getColumnId() == mainIndex.getMainIndexColumn()) {
return 0;
}
return -1;
}
@Override
public double getCost(Session session, int[] masks,
TableFilter[] filters, int filter, SortOrder sortOrder,
HashSet allColumnsSet) {
return 10 * getCostRangeIndex(masks, mainIndex.getRowCountApproximation(),
filters, filter, sortOrder, true, allColumnsSet);
}
@Override
public boolean needRebuild() {
return false;
}
@Override
public void remove(Session session, Row row) {
// nothing to do
}
@Override
public void remove(Session session) {
mainIndex.setMainIndexColumn(-1);
}
@Override
public void truncate(Session session) {
// nothing to do
}
@Override
public void checkRename() {
// ok
}
@Override
public long getRowCount(Session session) {
return mainIndex.getRowCount(session);
}
@Override
public long getRowCountApproximation() {
return mainIndex.getRowCountApproximation();
}
@Override
public long getDiskSpaceUsed() {
return 0;
}
}
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