/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* JBoss, Home of Professional Open Source
* Copyright 2010-2012 Red Hat Inc. and/or its affiliates and other contributors
* as indicated by the @authors tag. All rights reserved.
* See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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, v. 2.1.
* This program is distributed in the hope that it will be useful, but WITHOUT A
* 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,
* v.2.1 along with this distribution; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
package org.hibernate.ogm.dialect.mongodb;
import java.util.Collections;
import java.util.List;
import java.util.regex.Pattern;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.annotations.common.AssertionFailure;
import org.hibernate.dialect.lock.LockingStrategy;
import org.hibernate.id.IntegralDataTypeHolder;
import org.hibernate.ogm.datastore.impl.EmptyTupleSnapshot;
import org.hibernate.ogm.datastore.mongodb.Environment;
import org.hibernate.ogm.datastore.mongodb.impl.MongoDBDatastoreProvider;
import org.hibernate.ogm.datastore.spi.Association;
import org.hibernate.ogm.datastore.spi.AssociationContext;
import org.hibernate.ogm.datastore.spi.AssociationOperation;
import org.hibernate.ogm.datastore.spi.Tuple;
import org.hibernate.ogm.datastore.spi.TupleContext;
import org.hibernate.ogm.datastore.spi.TupleOperation;
import org.hibernate.ogm.dialect.GridDialect;
import org.hibernate.ogm.grid.AssociationKey;
import org.hibernate.ogm.grid.EntityKey;
import org.hibernate.ogm.grid.RowKey;
import org.hibernate.ogm.logging.mongodb.impl.Log;
import org.hibernate.ogm.logging.mongodb.impl.LoggerFactory;
import org.hibernate.ogm.type.GridType;
import org.hibernate.ogm.type.StringCalendarDateType;
import org.hibernate.persister.entity.Lockable;
import org.hibernate.ogm.type.ByteStringType;
import org.hibernate.type.StandardBasicTypes;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import org.hibernate.type.Type;
import static org.hibernate.ogm.dialect.mongodb.MongoHelpers.addEmptyAssociationField;
import static org.hibernate.ogm.dialect.mongodb.MongoHelpers.isEmbeddedInEntity;
/**
* Each Tuple entry is stored as a property in a MongoDB document.
*
* Each association is stored in an association document containing three properties:
* - the association table name (optionally)
* - the RowKey column names and values
* - the tuples as an array of elements
*
* Associations can be stored as:
* - one MongoDB collection per association class. The collection name is prefixed.
* - one MongoDB collection for all associations (the association table name property in then used)
* - embed the collection info in the owning entity document is planned but not supported at the moment (OGM-177)
*
* Collection of embeddable are stored within the owning entity document under the
* unqualified collection role
*
* @author Guillaume Scheibel <guillaume.scheibel@gmail.com>
* @author Alan Fitton <alan at eth0.org.uk>
* @author Emmanuel Bernard <emmanuel@hibernate.org>
*/
public class MongoDBDialect implements GridDialect {
private static final Log log = LoggerFactory.getLogger();
private static final Integer ONE = Integer.valueOf( 1 );
private static final Pattern DOT_SEPARATOR_PATTERN = Pattern.compile( "\\." );
public static final String ID_FIELDNAME = "_id";
public static final String PROPERTY_SEPARATOR = ".";
public static final String SEQUENCE_VALUE = "sequence_value";
public static final String ROWS_FIELDNAME = "rows";
public static final String TABLE_FIELDNAME = "table";
public static final String ASSOCIATIONS_COLLECTION_PREFIX = "associations_";
private static final List<String> ROWS_FIELDNAME_LIST = Collections.singletonList( ROWS_FIELDNAME );
private final MongoDBDatastoreProvider provider;
private final DB currentDB;
public MongoDBDialect(MongoDBDatastoreProvider provider) {
this.provider = provider;
this.currentDB = this.provider.getDatabase();
}
@Override
public LockingStrategy getLockingStrategy(Lockable lockable, LockMode lockMode) {
throw new UnsupportedOperationException( "The MongoDB GridDialect does not support locking" );
}
@Override
public Tuple getTuple(EntityKey key, TupleContext tupleContext){
DBObject found = this.getObject( key, tupleContext );
return found != null ? new Tuple( new MongoDBTupleSnapshot( found, key ) ) : null;
}
@Override
public Tuple createTuple(EntityKey key) {
DBObject toSave = this.prepareIdObject( key );
return new Tuple( new MongoDBTupleSnapshot( toSave, key ) );
}
private DBObject getObjectAsEmbeddedAssociation(AssociationKey key) {
DBCollection collection = this.getCollection( key.getEntityKey() );
DBObject searchObject = this.prepareIdObject( key.getEntityKey() );
DBObject restrictionObject = this.getSearchObject( key, true );
return collection.findOne( searchObject, restrictionObject );
}
private DBObject getObject(EntityKey key, TupleContext tupleContext) {
DBCollection collection = this.getCollection( key );
DBObject searchObject = this.prepareIdObject( key );
BasicDBObject restrictionObject = this.getSearchObject( tupleContext );
return collection.findOne( searchObject, restrictionObject );
}
private BasicDBObject getSearchObject(TupleContext tupleContext){
return this.getSearchObject( tupleContext.getSelectableColumns() );
}
private BasicDBObject getSearchObject(List<String> selectedColumns){
BasicDBObject searchObject = new BasicDBObject();
for ( String column : selectedColumns ) {
searchObject.append( column, 1 );
}
return searchObject;
}
/**
* Create a DBObject which represents the _id field.
* In case of simple id objects the json representation will look like {_id: "theIdValue"}
* In case of composite id objects the json representation will look like {_id: {author: "Guillaume", title: "What this method is used for?"}}
*
* @param key
*
* @return the DBObject which represents the id field
*/
private BasicDBObject prepareIdObject(EntityKey key) {
return this.prepareIdObject( key.getColumnNames(), key.getColumnValues() );
}
private BasicDBObject prepareIdObject(RowKey key) {
return this.prepareIdObject( key.getColumnNames(), key.getColumnValues() );
}
private BasicDBObject prepareIdObject(String[] columnNames, Object[] columnValues){
BasicDBObject object;
if ( columnNames.length == 1 ) {
object = new BasicDBObject( ID_FIELDNAME, columnValues[0] );
}
else {
object = new BasicDBObject();
DBObject idObject = new BasicDBObject();
for ( int i = 0; i < columnNames.length; i++ ) {
String columnName = columnNames[i];
Object columnValue = columnValues[i];
if ( columnName.contains( PROPERTY_SEPARATOR ) ) {
int dotIndex = columnName.indexOf( PROPERTY_SEPARATOR );
String shortColumnName = columnName.substring( dotIndex + 1 );
idObject.put( shortColumnName, columnValue );
}
else {
idObject.put( columnNames[i], columnValue );
}
}
object.put( ID_FIELDNAME, idObject );
}
return object;
}
private DBCollection getCollection(String table) {
return this.currentDB.getCollection( table );
}
private DBCollection getCollection(EntityKey key) {
return getCollection( key.getTable() );
}
private DBCollection getAssociationCollection(AssociationKey key) {
switch ( provider.getAssociationStorage() ) {
case GLOBAL_COLLECTION:
return getCollection( Environment.MONGODB_DEFAULT_ASSOCIATION_STORE );
case COLLECTION:
return getCollection( ASSOCIATIONS_COLLECTION_PREFIX + key.getTable() );
default:
throw new AssertionFailure( "Unknown AssociationStorage: " + provider.getAssociationStorage() );
}
}
private BasicDBObject getSubQuery(String operator, BasicDBObject query) {
return query.get( operator ) != null ? (BasicDBObject) query.get( operator ) : new BasicDBObject();
}
private void addSubQuery(String operator, BasicDBObject query, String column, Object value) {
BasicDBObject subQuery = this.getSubQuery( operator, query );
query.append( operator, subQuery.append( column, value ) );
}
@Override
public void updateTuple(Tuple tuple, EntityKey key) {
MongoDBTupleSnapshot snapshot = (MongoDBTupleSnapshot) tuple.getSnapshot();
BasicDBObject updater = new BasicDBObject();
for ( TupleOperation operation : tuple.getOperations() ) {
String column = operation.getColumn();
if ( !column.equals( ID_FIELDNAME ) && !column.endsWith( PROPERTY_SEPARATOR + ID_FIELDNAME ) && !snapshot.columnInIdField(
column
) ) {
switch ( operation.getType() ) {
case PUT_NULL:
case PUT:
this.addSubQuery( "$set", updater, column, operation.getValue() );
break;
case REMOVE:
this.addSubQuery( "$unset", updater, column, ONE );
break;
}
}
}
BasicDBObject idObject = this.prepareIdObject( key );
/*
* Needed because in case of object with only an ID field
* the "_id" won't be persisted properly.
* With this adjustment, it will work like this:
* if the object (from snapshot) doesn't exist so create the one represented by updater
* so if at this moment the "_id" is not enforce properly an ObjectID will be crated by the server instead
* of the custom id
*/
if ( updater.size() == 0 ) {
updater = idObject;
}
this.getCollection( key ).update( idObject, updater, true, false );
}
@Override
public void removeTuple(EntityKey key) {
DBCollection collection = this.getCollection( key );
DBObject toDelete = this.prepareIdObject( key );
collection.remove( toDelete );
}
//not for embedded
private DBObject findAssociation(AssociationKey key) {
final DBObject associationKeyObject = MongoHelpers.associationKeyToObject( provider.getAssociationStorage(), key );
return this.getAssociationCollection( key ).findOne( associationKeyObject, getSearchObject( key, false ) );
}
private DBObject getSearchObject(AssociationKey key, boolean embedded) {
if ( embedded ) {
return getSearchObject( Collections.singletonList( key.getCollectionRole() ) );
}
else {
return getSearchObject( ROWS_FIELDNAME_LIST );
}
}
@Override
public Association getAssociation(AssociationKey key, AssociationContext associationContext) {
if ( isEmbeddedInEntity( key, provider.getAssociationStorage() ) ) {
DBObject entity = getObjectAsEmbeddedAssociation( key );
if ( getAssociationFieldOrNull( key, entity ) != null ) {
return new Association( new MongoDBAssociationSnapshot( entity, key, provider.getAssociationStorage() ) );
}
else {
return null;
}
}
final DBObject result = findAssociation( key );
if ( result == null ) {
return null;
} else {
return new Association( new MongoDBAssociationSnapshot( result, key, provider.getAssociationStorage() ) );
}
}
private DBObject getAssociationFieldOrNull(AssociationKey key, DBObject entity) {
String[] path = DOT_SEPARATOR_PATTERN.split( key.getCollectionRole() );
DBObject field = entity;
for ( String node : path ) {
field = field != null ? (DBObject) field.get( node ) : null;
}
return field;
}
@Override
public Association createAssociation(AssociationKey key) {
if ( isEmbeddedInEntity( key, provider.getAssociationStorage() ) ) {
DBObject entity = getObjectAsEmbeddedAssociation( key );
boolean insert = false;
if ( entity == null ) {
insert = true;
entity = this.prepareIdObject( key.getEntityKey() );
}
if ( getAssociationFieldOrNull( key, entity ) == null ) {
if ( insert ) {
//adding assoc before insert
addEmptyAssociationField( key, entity );
getCollection( key.getEntityKey() ).insert( entity );
}
else {
BasicDBObject updater = new BasicDBObject();
this.addSubQuery( "$set", updater, key.getCollectionRole(), Collections.EMPTY_LIST );
//TODO use entity filter with only the ids
this.getCollection( key.getEntityKey() ).update( entity, updater, true, false );
//adding assoc after update because the query takes the whole object today
addEmptyAssociationField( key, entity );
}
}
return new Association( new MongoDBAssociationSnapshot( entity, key, provider.getAssociationStorage() ) );
}
DBCollection associations = getAssociationCollection( key );
DBObject assoc = MongoHelpers.associationKeyToObject( provider.getAssociationStorage(), key );
assoc.put( ROWS_FIELDNAME, Collections.EMPTY_LIST );
associations.insert( assoc );
return new Association( new MongoDBAssociationSnapshot( assoc, key, provider.getAssociationStorage() ) );
}
private DBObject removeAssociationRowKey(MongoDBAssociationSnapshot snapshot, RowKey rowKey, String associationField) {
DBObject pull = new BasicDBObject( associationField, snapshot.getRowKeyDBObject( rowKey ) );
return new BasicDBObject( "$pull", pull );
}
private DBObject putAssociationRowKey(Tuple value, String associationField, AssociationKey associationKey) {
DBObject rowTupleMap = new BasicDBObject();
for ( String valueKeyName : value.getColumnNames() ) {
boolean add = true;
//exclude columns from the associationKey
for ( String assocColumn : associationKey.getColumnNames() ) {
if ( valueKeyName.equals( assocColumn ) ) {
add = false;
break;
}
}
if (add) {
rowTupleMap.put( valueKeyName, value.get( valueKeyName ) );
}
}
DBObject row = rowTupleMap;
return new BasicDBObject( "$push", new BasicDBObject( associationField, row ) );
}
@Override
public void updateAssociation(Association association, AssociationKey key) {
DBCollection collection;
DBObject query;
MongoDBAssociationSnapshot assocSnapshot = (MongoDBAssociationSnapshot) association.getSnapshot();
String associationField;
if ( isEmbeddedInEntity( key, provider.getAssociationStorage() ) ) {
collection = this.getCollection( key.getEntityKey() );
query = this.prepareIdObject( key.getEntityKey() );
associationField = key.getCollectionRole();
}
else {
collection = getAssociationCollection( key );
query = assocSnapshot.getQueryObject();
associationField = ROWS_FIELDNAME;
}
for ( AssociationOperation action : association.getOperations() ) {
RowKey rowKey = action.getKey();
Tuple rowValue = action.getValue();
DBObject update = null;
switch ( action.getType() ) {
case CLEAR:
update = new BasicDBObject( "$set", new BasicDBObject (associationField, Collections.EMPTY_LIST ) );
break;
case PUT_NULL:
case PUT:
update = putAssociationRowKey( rowValue, associationField, key );
break;
case REMOVE:
update = removeAssociationRowKey( assocSnapshot, rowKey, associationField );
break;
}
if ( update != null ) {
collection.update( query, update, true, false );
}
}
}
@Override
public void removeAssociation(AssociationKey key) {
if ( isEmbeddedInEntity( key, provider.getAssociationStorage() ) ) {
DBObject entity = this.prepareIdObject( key.getEntityKey() );
if ( entity != null ) {
BasicDBObject updater = new BasicDBObject();
this.addSubQuery( "$unset", updater, key.getCollectionRole(), ONE );
this.getCollection( key.getEntityKey() ).update( entity, updater, true, false );
}
}
else {
DBCollection collection = getAssociationCollection( key );
DBObject query = MongoHelpers.associationKeyToObject( provider.getAssociationStorage(), key );
int nAffected = collection.remove( query ).getN();
log.removedAssociation( nAffected );
}
}
@Override
public Tuple createTupleAssociation(AssociationKey associationKey, RowKey rowKey) {
return new Tuple( EmptyTupleSnapshot.SINGLETON );
}
@Override
public void nextValue(RowKey key, IntegralDataTypeHolder value, int increment, int initialValue) {
DBCollection currentCollection = this.currentDB.getCollection( key.getTable() );
DBObject query = this.prepareIdObject( key );
//all columns should match to find the value
BasicDBObject update = new BasicDBObject();
//FIXME should "value" be hardcoded?
//FIXME how to set the initialValue if the document is not present? It seems the inc value is used as initial new value
Integer incrementObject = increment == 1 ? ONE : Integer.valueOf( increment );
this.addSubQuery( "$inc", update, SEQUENCE_VALUE, incrementObject );
DBObject result = currentCollection.findAndModify( query, null, null, false, update, false, true );
Object idFromDB;
idFromDB = result == null ? null : result.get( SEQUENCE_VALUE );
if ( idFromDB == null ) {
//not inserted yet so we need to add initial value to increment to have the right next value in the DB
//FIXME that means there is a small hole as when there was not value in the DB, we do add initial value in a non atomic way
BasicDBObject updateForInitial = new BasicDBObject();
this.addSubQuery( "$inc", updateForInitial, SEQUENCE_VALUE, initialValue );
currentCollection.findAndModify( query, null, null, false, updateForInitial, false, true );
idFromDB = initialValue; //first time we ask this value
}
else {
idFromDB = result.get( SEQUENCE_VALUE );
}
if ( idFromDB.getClass().equals( Integer.class ) || idFromDB.getClass().equals( Long.class ) ) {
Number id = (Number) idFromDB;
//idFromDB is the one used and the BD contains the next available value to use
value.initialize( id.longValue() );
}
else {
throw new HibernateException( "Cannot increment a non numeric field" );
}
}
@Override
public GridType overrideType(Type type) {
// Override handling of calendar types
if ( type == StandardBasicTypes.CALENDAR || type == StandardBasicTypes.CALENDAR_DATE ) {
return StringCalendarDateType.INSTANCE;
}
else if ( type == StandardBasicTypes.BYTE ) {
return ByteStringType.INSTANCE;
}
return null; // all other types handled as in hibernate-ogm-core
}
}