/*
* 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.lealone.dbobject.table;
import java.util.ArrayList;
import org.lealone.dbobject.Schema;
import org.lealone.dbobject.index.Index;
import org.lealone.dbobject.index.IndexType;
import org.lealone.dbobject.index.RangeIndex;
import org.lealone.engine.Session;
import org.lealone.expression.Expression;
import org.lealone.message.DbException;
import org.lealone.result.Row;
import org.lealone.value.Value;
/**
* The table SYSTEM_RANGE is a virtual table that generates incrementing numbers
* with a given start end end point.
*/
public class RangeTable extends Table {
/**
* The name of the range table.
*/
public static final String NAME = "SYSTEM_RANGE";
private Expression min, max;
private boolean optimized;
/**
* Create a new range with the given start and end expressions.
*
* @param schema the schema (always the main schema)
* @param min the start expression
* @param max the end expression
* @param noColumns whether this table has no columns
*/
public RangeTable(Schema schema, Expression min, Expression max, boolean noColumns) {
super(schema, 0, NAME, true, true);
Column[] cols = noColumns ? new Column[0] : new Column[] { new Column("X", Value.LONG) };
this.min = min;
this.max = max;
setColumns(cols);
}
public String getDropSQL() {
return null;
}
public String getCreateSQL() {
return null;
}
public String getSQL() {
return NAME + "(" + min.getSQL() + ", " + max.getSQL() + ")";
}
public void lock(Session session, boolean exclusive, boolean force) {
// nothing to do
}
public void close(Session session) {
// nothing to do
}
public void unlock(Session s) {
// nothing to do
}
public boolean isLockedExclusively() {
return false;
}
public Index addIndex(Session session, String indexName, int indexId, IndexColumn[] cols, IndexType indexType,
boolean create, String indexComment) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
public void removeRow(Session session, Row row) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
public void addRow(Session session, Row row) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
public void checkSupportAlter() {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
public void checkRename() {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
public boolean canGetRowCount() {
return true;
}
public boolean canDrop() {
return false;
}
public long getRowCount(Session session) {
return Math.max(0, getMax(session) - getMin(session) + 1);
}
public String getTableType() {
throw DbException.throwInternalError();
}
public Index getScanIndex(Session session) {
return new RangeIndex(this, IndexColumn.wrap(columns));
}
/**
* Calculate and get the start value of this range.
*
* @param session the session
* @return the start value
*/
public long getMin(Session session) {
optimize(session);
return min.getValue(session).getLong();
}
/**
* Calculate and get the end value of this range.
*
* @param session the session
* @return the end value
*/
public long getMax(Session session) {
optimize(session);
return max.getValue(session).getLong();
}
private void optimize(Session s) {
if (!optimized) {
min = min.optimize(s);
max = max.optimize(s);
optimized = true;
}
}
public ArrayList<Index> getIndexes() {
return null;
}
public void truncate(Session session) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
public long getMaxDataModificationId() {
return 0;
}
public Index getUniqueIndex() {
return null;
}
public long getRowCountApproximation() {
return 100;
}
public long getDiskSpaceUsed() {
return 0;
}
public boolean isDeterministic() {
return true;
}
public boolean canReference() {
return false;
}
}