/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program 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. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.id.enhanced;
import java.io.Serializable;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.engine.TransactionHelper;
import org.hibernate.id.IdentifierGenerationException;
import org.hibernate.jdbc.util.FormatStyle;
import org.hibernate.jdbc.util.SQLStatementLogger;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Describes a table used to mimic sequence behavior
*
* @author Steve Ebersole
*/
public class TableStructure extends TransactionHelper implements DatabaseStructure {
private static final Logger log = LoggerFactory.getLogger( TableStructure.class );
private static final SQLStatementLogger SQL_STATEMENT_LOGGER = new SQLStatementLogger( false, false );
private final String tableName;
private final String valueColumnName;
private final int initialValue;
private final int incrementSize;
private final String selectQuery;
private final String updateQuery;
private boolean applyIncrementSizeToSourceValues;
private int accessCounter;
public TableStructure(Dialect dialect, String tableName, String valueColumnName, int initialValue, int incrementSize) {
this.tableName = tableName;
this.initialValue = initialValue;
this.incrementSize = incrementSize;
this.valueColumnName = valueColumnName;
selectQuery = "select " + valueColumnName + " as id_val" +
" from " + dialect.appendLockHint( LockMode.UPGRADE, tableName ) +
dialect.getForUpdateString();
updateQuery = "update " + tableName +
" set " + valueColumnName + "= ?" +
" where " + valueColumnName + "=?";
}
/**
* {@inheritDoc}
*/
public String getName() {
return tableName;
}
/**
* {@inheritDoc}
*/
public int getIncrementSize() {
return incrementSize;
}
/**
* {@inheritDoc}
*/
public int getTimesAccessed() {
return accessCounter;
}
/**
* {@inheritDoc}
*/
public void prepare(Optimizer optimizer) {
applyIncrementSizeToSourceValues = optimizer.applyIncrementSizeToSourceValues();
}
/**
* {@inheritDoc}
*/
public AccessCallback buildCallback(final SessionImplementor session) {
return new AccessCallback() {
public long getNextValue() {
return ( ( Number ) doWorkInNewTransaction( session ) ).longValue();
}
};
}
/**
* {@inheritDoc}
*/
public String[] sqlCreateStrings(Dialect dialect) throws HibernateException {
return new String[] {
dialect.getCreateTableString() + " " + tableName + " ( " + valueColumnName + " " + dialect.getTypeName( Types.BIGINT ) + " )",
"insert into " + tableName + " values ( " + initialValue + " )"
};
}
/**
* {@inheritDoc}
*/
public String[] sqlDropStrings(Dialect dialect) throws HibernateException {
StringBuffer sqlDropString = new StringBuffer().append( "drop table " );
if ( dialect.supportsIfExistsBeforeTableName() ) {
sqlDropString.append( "if exists " );
}
sqlDropString.append( tableName ).append( dialect.getCascadeConstraintsString() );
if ( dialect.supportsIfExistsAfterTableName() ) {
sqlDropString.append( " if exists" );
}
return new String[] { sqlDropString.toString() };
}
/**
* {@inheritDoc}
*/
protected Serializable doWorkInCurrentTransaction(Connection conn, String sql) throws SQLException {
long result;
int rows;
do {
SQL_STATEMENT_LOGGER.logStatement( selectQuery, FormatStyle.BASIC );
PreparedStatement selectPS = conn.prepareStatement( selectQuery );
try {
ResultSet selectRS = selectPS.executeQuery();
if ( !selectRS.next() ) {
String err = "could not read a hi value - you need to populate the table: " + tableName;
log.error( err );
throw new IdentifierGenerationException( err );
}
result = selectRS.getLong( 1 );
selectRS.close();
}
catch ( SQLException sqle ) {
log.error( "could not read a hi value", sqle );
throw sqle;
}
finally {
selectPS.close();
}
SQL_STATEMENT_LOGGER.logStatement( updateQuery, FormatStyle.BASIC );
PreparedStatement updatePS = conn.prepareStatement( updateQuery );
try {
int increment = applyIncrementSizeToSourceValues ? incrementSize : 1;
updatePS.setLong( 1, result + increment );
updatePS.setLong( 2, result );
rows = updatePS.executeUpdate();
}
catch ( SQLException sqle ) {
log.error( "could not updateQuery hi value in: " + tableName, sqle );
throw sqle;
}
finally {
updatePS.close();
}
} while ( rows == 0 );
accessCounter++;
return new Long( result );
}
}