/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. 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 Inc.
*
* 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 java.util.Collections;
import java.util.Map;
import java.util.Properties;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.LockOptions;
import org.hibernate.MappingException;
import org.hibernate.cfg.Environment;
import org.hibernate.cfg.ObjectNameNormalizer;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.jdbc.internal.FormatStyle;
import org.hibernate.engine.jdbc.spi.JdbcServices;
import org.hibernate.engine.jdbc.spi.SqlStatementLogger;
import org.hibernate.engine.spi.SessionEventListenerManager;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.id.Configurable;
import org.hibernate.id.IdentifierGeneratorHelper;
import org.hibernate.id.IntegralDataTypeHolder;
import org.hibernate.id.PersistentIdentifierGenerator;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.internal.util.config.ConfigurationHelper;
import org.hibernate.jdbc.AbstractReturningWork;
import org.hibernate.mapping.Table;
import org.hibernate.type.Type;
import org.jboss.logging.Logger;
/**
* An enhanced version of table-based id generation.
* <p/>
* Unlike the simplistic legacy one (which, btw, was only ever intended for subclassing
* support) we "segment" the table into multiple values. Thus a single table can
* actually serve as the persistent storage for multiple independent generators. One
* approach would be to segment the values by the name of the entity for which we are
* performing generation, which would mean that we would have a row in the generator
* table for each entity name. Or any configuration really; the setup is very flexible.
* <p/>
* In this respect it is very similar to the legacy
* {@link org.hibernate.id.MultipleHiLoPerTableGenerator} in terms of the
* underlying storage structure (namely a single table capable of holding
* multiple generator values). The differentiator is, as with
* {@link SequenceStyleGenerator} as well, the externalized notion
* of an optimizer.
* <p/>
* <b>NOTE</b> that by default we use a single row for all generators (based
* on {@link #DEF_SEGMENT_VALUE}). The configuration parameter
* {@link #CONFIG_PREFER_SEGMENT_PER_ENTITY} can be used to change that to
* instead default to using a row for each entity name.
* <p/>
* Configuration parameters:
* <table>
* <tr>
* <td><b>NAME</b></td>
* <td><b>DEFAULT</b></td>
* <td><b>DESCRIPTION</b></td>
* </tr>
* <tr>
* <td>{@link #TABLE_PARAM}</td>
* <td>{@link #DEF_TABLE}</td>
* <td>The name of the table to use to store/retrieve values</td>
* </tr>
* <tr>
* <td>{@link #VALUE_COLUMN_PARAM}</td>
* <td>{@link #DEF_VALUE_COLUMN}</td>
* <td>The name of column which holds the sequence value for the given segment</td>
* </tr>
* <tr>
* <td>{@link #SEGMENT_COLUMN_PARAM}</td>
* <td>{@link #DEF_SEGMENT_COLUMN}</td>
* <td>The name of the column which holds the segment key</td>
* </tr>
* <tr>
* <td>{@link #SEGMENT_VALUE_PARAM}</td>
* <td>{@link #DEF_SEGMENT_VALUE}</td>
* <td>The value indicating which segment is used by this generator; refers to values in the {@link #SEGMENT_COLUMN_PARAM} column</td>
* </tr>
* <tr>
* <td>{@link #SEGMENT_LENGTH_PARAM}</td>
* <td>{@link #DEF_SEGMENT_LENGTH}</td>
* <td>The data length of the {@link #SEGMENT_COLUMN_PARAM} column; used for schema creation</td>
* </tr>
* <tr>
* <td>{@link #INITIAL_PARAM}</td>
* <td>{@link #DEFAULT_INITIAL_VALUE}</td>
* <td>The initial value to be stored for the given segment</td>
* </tr>
* <tr>
* <td>{@link #INCREMENT_PARAM}</td>
* <td>{@link #DEFAULT_INCREMENT_SIZE}</td>
* <td>The increment size for the underlying segment; see the discussion on {@link Optimizer} for more details.</td>
* </tr>
* <tr>
* <td>{@link #OPT_PARAM}</td>
* <td><i>depends on defined increment size</i></td>
* <td>Allows explicit definition of which optimization strategy to use</td>
* </tr>
* </table>
*
* @author Steve Ebersole
*/
public class TableGenerator implements PersistentIdentifierGenerator, Configurable {
private static final CoreMessageLogger LOG = Logger.getMessageLogger(
CoreMessageLogger.class,
TableGenerator.class.getName()
);
/**
* By default (in the absence of a {@link #SEGMENT_VALUE_PARAM} setting) we use a single row for all
* generators. This setting can be used to change that to instead default to using a row for each entity name.
*/
public static final String CONFIG_PREFER_SEGMENT_PER_ENTITY = "prefer_entity_table_as_segment_value";
/**
* Configures the name of the table to use. The default value is {@link #DEF_TABLE}
*/
public static final String TABLE_PARAM = "table_name";
/**
* The default {@link #TABLE_PARAM} value
*/
public static final String DEF_TABLE = "hibernate_sequences";
/**
* The name of column which holds the sequence value. The default value is {@link #DEF_VALUE_COLUMN}
*/
public static final String VALUE_COLUMN_PARAM = "value_column_name";
/**
* The default {@link #VALUE_COLUMN_PARAM} value
*/
public static final String DEF_VALUE_COLUMN = "next_val";
/**
* The name of the column which holds the segment key. The segment defines the different buckets (segments)
* of values currently tracked in the table. The default value is {@link #DEF_SEGMENT_COLUMN}
*/
public static final String SEGMENT_COLUMN_PARAM = "segment_column_name";
/**
* The default {@link #SEGMENT_COLUMN_PARAM} value
*/
public static final String DEF_SEGMENT_COLUMN = "sequence_name";
/**
* The value indicating which segment is used by this generator, as indicated by the actual value stored in the
* column indicated by {@link #SEGMENT_COLUMN_PARAM}. The default value for setting is {@link #DEF_SEGMENT_VALUE},
* although {@link #CONFIG_PREFER_SEGMENT_PER_ENTITY} effects the default as well.
*/
public static final String SEGMENT_VALUE_PARAM = "segment_value";
/**
* The default {@link #SEGMENT_VALUE_PARAM} value, unless {@link #CONFIG_PREFER_SEGMENT_PER_ENTITY} is specified
*/
public static final String DEF_SEGMENT_VALUE = "default";
/**
* Indicates the length of the column defined by {@link #SEGMENT_COLUMN_PARAM}. Used in schema export. The
* default value is {@link #DEF_SEGMENT_LENGTH}
*/
public static final String SEGMENT_LENGTH_PARAM = "segment_value_length";
/**
* The default {@link #SEGMENT_LENGTH_PARAM} value
*/
public static final int DEF_SEGMENT_LENGTH = 255;
/**
* Indicates the initial value to use. The default value is {@link #DEFAULT_INITIAL_VALUE}
*/
public static final String INITIAL_PARAM = "initial_value";
/**
* The default {@link #INITIAL_PARAM} value
*/
public static final int DEFAULT_INITIAL_VALUE = 1;
/**
* Indicates the increment size to use. The default value is {@link #DEFAULT_INCREMENT_SIZE}
*/
public static final String INCREMENT_PARAM = "increment_size";
/**
* The default {@link #INCREMENT_PARAM} value
*/
public static final int DEFAULT_INCREMENT_SIZE = 1;
/**
* Indicates the optimizer to use, either naming a {@link Optimizer} implementation class or by naming
* a {@link StandardOptimizerDescriptor} by name
*/
public static final String OPT_PARAM = "optimizer";
private Type identifierType;
private String tableName;
private String segmentColumnName;
private String segmentValue;
private int segmentValueLength;
private String valueColumnName;
private int initialValue;
private int incrementSize;
private String selectQuery;
private String insertQuery;
private String updateQuery;
private Optimizer optimizer;
private long accessCount;
@Override
public Object generatorKey() {
return tableName;
}
/**
* Type mapping for the identifier.
*
* @return The identifier type mapping.
*/
public final Type getIdentifierType() {
return identifierType;
}
/**
* The name of the table in which we store this generator's persistent state.
*
* @return The table name.
*/
public final String getTableName() {
return tableName;
}
/**
* The name of the column in which we store the segment to which each row
* belongs. The value here acts as PK.
*
* @return The segment column name
*/
public final String getSegmentColumnName() {
return segmentColumnName;
}
/**
* The value in {@link #getSegmentColumnName segment column} which
* corresponding to this generator instance. In other words this value
* indicates the row in which this generator instance will store values.
*
* @return The segment value for this generator instance.
*/
public final String getSegmentValue() {
return segmentValue;
}
/**
* The size of the {@link #getSegmentColumnName segment column} in the
* underlying table.
* <p/>
* <b>NOTE</b> : should really have been called 'segmentColumnLength' or
* even better 'segmentColumnSize'
*
* @return the column size.
*/
public final int getSegmentValueLength() {
return segmentValueLength;
}
/**
* The name of the column in which we store our persistent generator value.
*
* @return The name of the value column.
*/
public final String getValueColumnName() {
return valueColumnName;
}
/**
* The initial value to use when we find no previous state in the
* generator table corresponding to our sequence.
*
* @return The initial value to use.
*/
public final int getInitialValue() {
return initialValue;
}
/**
* The amount of increment to use. The exact implications of this
* depends on the {@link #getOptimizer() optimizer} being used.
*
* @return The increment amount.
*/
public final int getIncrementSize() {
return incrementSize;
}
/**
* The optimizer being used by this generator.
*
* @return Out optimizer.
*/
public final Optimizer getOptimizer() {
return optimizer;
}
/**
* Getter for property 'tableAccessCount'. Only really useful for unit test
* assertions.
*
* @return Value for property 'tableAccessCount'.
*/
public final long getTableAccessCount() {
return accessCount;
}
@Override
public void configure(Type type, Properties params, Dialect dialect) throws MappingException {
identifierType = type;
tableName = determineGeneratorTableName( params, dialect );
segmentColumnName = determineSegmentColumnName( params, dialect );
valueColumnName = determineValueColumnName( params, dialect );
segmentValue = determineSegmentValue( params );
segmentValueLength = determineSegmentColumnSize( params );
initialValue = determineInitialValue( params );
incrementSize = determineIncrementSize( params );
this.selectQuery = buildSelectQuery( dialect );
this.updateQuery = buildUpdateQuery();
this.insertQuery = buildInsertQuery();
// if the increment size is greater than one, we prefer pooled optimization; but we
// need to see if the user prefers POOL or POOL_LO...
final String defaultPooledOptimizerStrategy = ConfigurationHelper.getBoolean( Environment.PREFER_POOLED_VALUES_LO, params, false )
? StandardOptimizerDescriptor.POOLED_LO.getExternalName()
: StandardOptimizerDescriptor.POOLED.getExternalName();
final String defaultOptimizerStrategy = incrementSize <= 1
? StandardOptimizerDescriptor.NONE.getExternalName()
: defaultPooledOptimizerStrategy;
final String optimizationStrategy = ConfigurationHelper.getString( OPT_PARAM, params, defaultOptimizerStrategy );
optimizer = OptimizerFactory.buildOptimizer(
optimizationStrategy,
identifierType.getReturnedClass(),
incrementSize,
ConfigurationHelper.getInt( INITIAL_PARAM, params, -1 )
);
}
/**
* Determine the table name to use for the generator values.
* <p/>
* Called during {@link #configure configuration}.
*
* @see #getTableName()
* @param params The params supplied in the generator config (plus some standard useful extras).
* @param dialect The dialect in effect
* @return The table name to use.
*/
protected String determineGeneratorTableName(Properties params, Dialect dialect) {
String name = ConfigurationHelper.getString( TABLE_PARAM, params, DEF_TABLE );
final boolean isGivenNameUnqualified = name.indexOf( '.' ) < 0;
if ( isGivenNameUnqualified ) {
final ObjectNameNormalizer normalizer = (ObjectNameNormalizer) params.get( IDENTIFIER_NORMALIZER );
name = normalizer.normalizeIdentifierQuoting( name );
// if the given name is un-qualified we may neen to qualify it
final String schemaName = normalizer.normalizeIdentifierQuoting( params.getProperty( SCHEMA ) );
final String catalogName = normalizer.normalizeIdentifierQuoting( params.getProperty( CATALOG ) );
name = Table.qualify(
dialect.quote( catalogName ),
dialect.quote( schemaName ),
dialect.quote( name)
);
}
// if already qualified there is not much we can do in a portable manner so we pass it
// through and assume the user has set up the name correctly.
return name;
}
/**
* Determine the name of the column used to indicate the segment for each
* row. This column acts as the primary key.
* <p/>
* Called during {@link #configure configuration}.
*
* @see #getSegmentColumnName()
* @param params The params supplied in the generator config (plus some standard useful extras).
* @param dialect The dialect in effect
* @return The name of the segment column
*/
protected String determineSegmentColumnName(Properties params, Dialect dialect) {
final ObjectNameNormalizer normalizer = (ObjectNameNormalizer) params.get( IDENTIFIER_NORMALIZER );
final String name = ConfigurationHelper.getString( SEGMENT_COLUMN_PARAM, params, DEF_SEGMENT_COLUMN );
return dialect.quote( normalizer.normalizeIdentifierQuoting( name ) );
}
/**
* Determine the name of the column in which we will store the generator persistent value.
* <p/>
* Called during {@link #configure configuration}.
*
* @see #getValueColumnName()
* @param params The params supplied in the generator config (plus some standard useful extras).
* @param dialect The dialect in effect
* @return The name of the value column
*/
protected String determineValueColumnName(Properties params, Dialect dialect) {
final ObjectNameNormalizer normalizer = (ObjectNameNormalizer) params.get( IDENTIFIER_NORMALIZER );
final String name = ConfigurationHelper.getString( VALUE_COLUMN_PARAM, params, DEF_VALUE_COLUMN );
return dialect.quote( normalizer.normalizeIdentifierQuoting( name ) );
}
/**
* Determine the segment value corresponding to this generator instance.
* <p/>
* Called during {@link #configure configuration}.
*
* @see #getSegmentValue()
* @param params The params supplied in the generator config (plus some standard useful extras).
* @return The name of the value column
*/
protected String determineSegmentValue(Properties params) {
String segmentValue = params.getProperty( SEGMENT_VALUE_PARAM );
if ( StringHelper.isEmpty( segmentValue ) ) {
segmentValue = determineDefaultSegmentValue( params );
}
return segmentValue;
}
/**
* Used in the cases where {@link #determineSegmentValue} is unable to
* determine the value to use.
*
* @param params The params supplied in the generator config (plus some standard useful extras).
* @return The default segment value to use.
*/
protected String determineDefaultSegmentValue(Properties params) {
final boolean preferSegmentPerEntity = ConfigurationHelper.getBoolean( CONFIG_PREFER_SEGMENT_PER_ENTITY, params, false );
final String defaultToUse = preferSegmentPerEntity ? params.getProperty( TABLE ) : DEF_SEGMENT_VALUE;
LOG.usingDefaultIdGeneratorSegmentValue( tableName, segmentColumnName, defaultToUse );
return defaultToUse;
}
/**
* Determine the size of the {@link #getSegmentColumnName segment column}
* <p/>
* Called during {@link #configure configuration}.
*
* @see #getSegmentValueLength()
* @param params The params supplied in the generator config (plus some standard useful extras).
* @return The size of the segment column
*/
protected int determineSegmentColumnSize(Properties params) {
return ConfigurationHelper.getInt( SEGMENT_LENGTH_PARAM, params, DEF_SEGMENT_LENGTH );
}
protected int determineInitialValue(Properties params) {
return ConfigurationHelper.getInt( INITIAL_PARAM, params, DEFAULT_INITIAL_VALUE );
}
protected int determineIncrementSize(Properties params) {
return ConfigurationHelper.getInt( INCREMENT_PARAM, params, DEFAULT_INCREMENT_SIZE );
}
protected String buildSelectQuery(Dialect dialect) {
final String alias = "tbl";
final String query = "select " + StringHelper.qualify( alias, valueColumnName ) +
" from " + tableName + ' ' + alias +
" where " + StringHelper.qualify( alias, segmentColumnName ) + "=?";
final LockOptions lockOptions = new LockOptions( LockMode.PESSIMISTIC_WRITE );
lockOptions.setAliasSpecificLockMode( alias, LockMode.PESSIMISTIC_WRITE );
final Map updateTargetColumnsMap = Collections.singletonMap( alias, new String[] { valueColumnName } );
return dialect.applyLocksToSql( query, lockOptions, updateTargetColumnsMap );
}
protected String buildUpdateQuery() {
return "update " + tableName +
" set " + valueColumnName + "=? " +
" where " + valueColumnName + "=? and " + segmentColumnName + "=?";
}
protected String buildInsertQuery() {
return "insert into " + tableName + " (" + segmentColumnName + ", " + valueColumnName + ") " + " values (?,?)";
}
private IntegralDataTypeHolder makeValue() {
return IdentifierGeneratorHelper.getIntegralDataTypeHolder( identifierType.getReturnedClass() );
}
@Override
public Serializable generate(final SessionImplementor session, final Object obj) {
final SqlStatementLogger statementLogger = session.getFactory().getServiceRegistry()
.getService( JdbcServices.class )
.getSqlStatementLogger();
final SessionEventListenerManager statsCollector = session.getEventListenerManager();
return optimizer.generate(
new AccessCallback() {
@Override
public IntegralDataTypeHolder getNextValue() {
return session.getTransactionCoordinator().getTransaction().createIsolationDelegate().delegateWork(
new AbstractReturningWork<IntegralDataTypeHolder>() {
@Override
public IntegralDataTypeHolder execute(Connection connection) throws SQLException {
final IntegralDataTypeHolder value = makeValue();
int rows;
do {
final PreparedStatement selectPS = prepareStatement( connection, selectQuery, statementLogger, statsCollector );
try {
selectPS.setString( 1, segmentValue );
final ResultSet selectRS = executeQuery( selectPS, statsCollector );
if ( !selectRS.next() ) {
value.initialize( initialValue );
final PreparedStatement insertPS = prepareStatement( connection, insertQuery, statementLogger, statsCollector );
try {
insertPS.setString( 1, segmentValue );
value.bind( insertPS, 2 );
executeUpdate( insertPS, statsCollector );
}
finally {
insertPS.close();
}
}
else {
value.initialize( selectRS, 1 );
}
selectRS.close();
}
catch (SQLException e) {
LOG.unableToReadOrInitHiValue( e );
throw e;
}
finally {
selectPS.close();
}
final PreparedStatement updatePS = prepareStatement( connection, updateQuery, statementLogger, statsCollector );
try {
final IntegralDataTypeHolder updateValue = value.copy();
if ( optimizer.applyIncrementSizeToSourceValues() ) {
updateValue.add( incrementSize );
}
else {
updateValue.increment();
}
updateValue.bind( updatePS, 1 );
value.bind( updatePS, 2 );
updatePS.setString( 3, segmentValue );
rows = executeUpdate( updatePS, statsCollector );
}
catch (SQLException e) {
LOG.unableToUpdateQueryHiValue( tableName, e );
throw e;
}
finally {
updatePS.close();
}
}
while ( rows == 0 );
accessCount++;
return value;
}
},
true
);
}
@Override
public String getTenantIdentifier() {
return session.getTenantIdentifier();
}
}
);
}
private PreparedStatement prepareStatement(
Connection connection,
String sql,
SqlStatementLogger statementLogger,
SessionEventListenerManager statsCollector) throws SQLException {
statementLogger.logStatement( sql, FormatStyle.BASIC.getFormatter() );
try {
statsCollector.jdbcPrepareStatementStart();
return connection.prepareStatement( sql );
}
finally {
statsCollector.jdbcPrepareStatementEnd();
}
}
private int executeUpdate(PreparedStatement ps, SessionEventListenerManager statsCollector) throws SQLException {
try {
statsCollector.jdbcExecuteStatementStart();
return ps.executeUpdate();
}
finally {
statsCollector.jdbcExecuteStatementEnd();
}
}
private ResultSet executeQuery(PreparedStatement ps, SessionEventListenerManager statsCollector) throws SQLException {
try {
statsCollector.jdbcExecuteStatementStart();
return ps.executeQuery();
}
finally {
statsCollector.jdbcExecuteStatementEnd();
}
}
@Override
public String[] sqlCreateStrings(Dialect dialect) throws HibernateException {
return new String[] {
dialect.getCreateTableString() + ' ' + tableName + " ( "
+ segmentColumnName + ' ' + dialect.getTypeName( Types.VARCHAR, segmentValueLength, 0, 0 ) + " not null "
+ ", " + valueColumnName + ' ' + dialect.getTypeName( Types.BIGINT )
+ ", primary key ( " + segmentColumnName + " ) )" + dialect.getTableTypeString()
};
}
@Override
public String[] sqlDropStrings(Dialect dialect) throws HibernateException {
return new String[] { dialect.getDropTableString( tableName ) };
}
}