/*
* Copyright (c) 1998-2010 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source 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.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.db.table;
import com.caucho.db.index.BTree;
import com.caucho.db.sql.QueryContext;
import com.caucho.db.xa.Transaction;
import com.caucho.inject.Module;
import com.caucho.sql.SQLExceptionWrapper;
import com.caucho.util.L10N;
import java.io.IOException;
import java.sql.SQLException;
/**
* Validity constraints.
*/
@Module
public class UniqueIndexColumnConstraint extends Constraint {
private final static L10N L = new L10N(UniqueIndexColumnConstraint.class);
private final Column _column;
/**
* Creates a uniqueness constraint.
*/
public UniqueIndexColumnConstraint(Column column)
{
_column = column;
}
/**
* validate the constraint.
*/
@Override
public void validate(TableIterator []sourceRows,
QueryContext context, Transaction xa)
throws SQLException
{
try {
TableIterator sourceRow = sourceRows[0];
byte []sourceBuffer = sourceRow.getBuffer();
int sourceOffset = sourceRow.getRowOffset();
byte []buffer = context.getBuffer();
int length = _column.getLength();
if (length <= 0)
return;
BTree index = _column.getIndex();
long value = index.lookup(buffer, 0, length);
if (value != 0) {
Table table = sourceRow.getTable();
long blockId = sourceRow.getBlockId();
throw new SQLException(L.l("`{0}' in {1}.{2} fails uniqueness constraint.",
_column.getString(blockId, sourceBuffer,
sourceOffset),
table.getName(),
_column.getName()));
}
} catch (IOException e) {
throw new SQLExceptionWrapper(e);
}
}
}