/*
 * Copyright 2004-2019 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.List;
import org.h2.command.dml.AllColumnsForPlan;
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.
/** * 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) { super(table, id, name, IndexColumn.wrap(new Column[] { table.getColumn(mainIndex.getMainIndexColumn()) }), indexType); this.mainIndex = mainIndex; if (id < 0) { throw DbException.throwInternalError(name); } } @Override public void addRowsToBuffer(List<Row> rows, String bufferName) { throw DbException.throwInternalError(); } @Override public void addBufferedRows(List<String> bufferNames) { throw DbException.throwInternalError(); } @Override public void add(Session session, Row row) { // nothing to do } @Override public Row getRow(Session session, long key) { return mainIndex.getRow(session, key); } @Override public boolean isRowIdIndex() { return true; } @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, ValueLong.MIN, ValueLong.MIN); // ifNull is MIN as well, because the column is never NULL // so avoid returning all rows (returning one row is OK) ValueLong max = mainIndex.getKey(last, ValueLong.MAX, ValueLong.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 boolean isFirstColumn(Column column) { return getColumnIndex(column) == 0; } @Override public double getCost(Session session, int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder, AllColumnsForPlan 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 update(Session session, Row oldRow, Row newRow) { // nothing to do } @Override public void remove(Session session) { mainIndex.setMainIndexColumn(SearchRow.ROWID_INDEX); } @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; } }