/*
* Copyright (c) 1998-2011 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.amber.idgen;
import com.caucho.amber.manager.AmberConnection;
import com.caucho.amber.manager.AmberPersistenceUnit;
import com.caucho.amber.type.GeneratorTableType;
import com.caucho.util.L10N;
import com.caucho.util.Log;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Logger;
/**
* Generator table.
*/
public class AmberTableGenerator extends IdGenerator {
private static final L10N L = new L10N(AmberTableGenerator.class);
private static final Logger log = Log.open(AmberTableGenerator.class);
private AmberPersistenceUnit _manager;
private GeneratorTableType _table;
private String _name;
private String _selectSQL;
private String _updateSQL;
private boolean _isInit;
/**
* Creates the table generator.
*/
public AmberTableGenerator(AmberPersistenceUnit manager,
GeneratorTableType table,
String name)
{
_manager = manager;
_table = table;
_name = name;
}
/**
* Allocates the next group of ids.
*/
public long allocateGroup(AmberConnection aConn)
throws SQLException
{
int groupSize = getGroupSize();
int retry = 5;
// XXX: should use non-XA
Connection conn = aConn.getConnection();
PreparedStatement selectStmt = conn.prepareStatement(_selectSQL);
PreparedStatement updateStmt = conn.prepareStatement(_updateSQL);
selectStmt.setString(1, _name);
updateStmt.setString(2, _name);
while (retry-- > 0) {
ResultSet rs = selectStmt.executeQuery();
if (rs.next()) {
long value = rs.getLong(1);
rs.close();
updateStmt.setLong(1, value + groupSize);
updateStmt.setLong(3, value);
if (updateStmt.executeUpdate() == 1)
return value;
}
rs.close();
}
throw new SQLException(L.l("Can't allocate id from table '{0}'",
_table.getTable().getName()));
}
/**
* Initialize the table.
*/
public void init(AmberPersistenceUnit amberPersistenceUnit)
throws SQLException
{
if (_isInit)
return;
_isInit = true;
_selectSQL = ("select " + _table.getValueColumn() +
" from " + _table.getTable().getName() +
" where " + _table.getKeyColumn() + "=?");
_updateSQL = ("update " + _table.getTable().getName() +
" set " + _table.getValueColumn() + "=?" +
" where " + _table.getKeyColumn() + "=? " +
" and " + _table.getValueColumn() + "=?");
DataSource ds = amberPersistenceUnit.getDataSource();
Connection conn = ds.getConnection();
try {
try {
PreparedStatement pstmt = conn.prepareStatement(_selectSQL);
pstmt.setString(1, _name);
ResultSet rs = pstmt.executeQuery();
if (rs.next()) {
rs.close();
return;
}
} catch (SQLException e) {
}
String sql = ("INSERT INTO " + _table.getTable().getName() + " (" +
_table.getKeyColumn() + "," +
_table.getValueColumn() + ") VALUES " +
"('" + _name + "', 1)");
Statement stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
} finally {
conn.close();
}
}
}