/*
* Copyright 2005 Werner Guttmann
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* $Id: ManyToManyRelationResolver.java 7126 2007-08-03 21:47:55Z rjoachim $
*/
package org.castor.persist.resolver;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import org.castor.persist.ProposedEntity;
import org.castor.persist.TransactionContext;
import org.castor.persist.UpdateFlags;
import org.castor.persist.proxy.RelationCollection;
import org.exolab.castor.jdo.PersistenceException;
import org.exolab.castor.mapping.AccessMode;
import org.exolab.castor.persist.ClassMolder;
import org.exolab.castor.persist.ClassMolderHelper;
import org.exolab.castor.persist.FieldMolder;
import org.exolab.castor.persist.Lazy;
import org.exolab.castor.persist.OID;
import org.exolab.castor.persist.spi.Identity;
/**
* Implementation of {@link org.castor.persist.resolver.ResolverStrategy} for M:N relations.
*
* @author <a href="mailto:werner DOT guttmann AT gmx DOT net">Werner Guttmann</a>
* @since 0.9.9
*/
public final class ManyToManyRelationResolver extends ManyRelationResolver {
/**
* Creates an instance of ManyToManyRelationResolver.
*
* @param classMolder Associated ClassMolder.
* @param fieldMolder Associated FieldMolder.
* @param fieldIndex Field index within all fields of parent class molder.
* @param debug ???
*/
public ManyToManyRelationResolver(final ClassMolder classMolder,
final FieldMolder fieldMolder,
final int fieldIndex,
final boolean debug) {
super(classMolder, fieldMolder, fieldIndex, debug);
}
/**
* @see org.castor.persist.resolver.ResolverStrategy
* #markCreate(org.castor.persist.TransactionContext,
* org.exolab.castor.persist.OID, java.lang.Object)
*/
public boolean markCreate(final TransactionContext tx, final OID oid,
final Object object)
throws PersistenceException {
boolean updateCache = false;
// create relation if the relation table
ClassMolder fieldClassMolder = _fieldMolder.getFieldClassMolder();
Object o = _fieldMolder.getValue(object, tx.getClassLoader());
if (o != null) {
Iterator itor = ClassMolderHelper.getIterator(o);
// many-to-many relation is never dependent relation
while (itor.hasNext()) {
Object oo = itor.next();
if (tx.isAutoStore() && !tx.isRecorded(oo)) {
tx.markCreate(fieldClassMolder, oo, null);
updateCache = true;
}
}
}
return updateCache;
}
/**
* @see org.castor.persist.resolver.ResolverStrategy
* #markDelete(org.castor.persist.TransactionContext, java.lang.Object,
* java.lang.Object)
*/
public void markDelete(final TransactionContext tx, final Object object,
final Object field)
throws PersistenceException {
// delete the relation in relation table too
/*
* _fhs[i].getRelationLoader().deleteRelation(
* tx.getConnection(oid.getLockEngine()), oid.getIdentity() );
*/
ClassMolder fieldClassMolder = _fieldMolder.getFieldClassMolder();
// markDelete mix with prestore
// so, store is not yet called, and only the loaded (or created)
// relation have to be deleted.
// not really. cus, the other created relation, may already
// has reference to this object. so, how to deal with that?
if (field != null) {
ArrayList alist = (ArrayList) field;
for (int j = 0; j < alist.size(); j++) {
Identity fid = (Identity) alist.get(j);
Object fetched = null;
if (fid != null) {
fetched = tx.fetch(fieldClassMolder, fid, null);
if (fetched != null) {
fieldClassMolder.removeRelation(tx, fetched,
_classMolder, object);
}
}
}
}
Iterator itor = ClassMolderHelper.getIterator(_fieldMolder.getValue(
object, tx.getClassLoader()));
while (itor.hasNext()) {
Object fobject = itor.next();
if (fobject != null && tx.isPersistent(fobject)) {
fieldClassMolder.removeRelation(tx, fobject, _classMolder,
object);
}
}
}
/**
* @see org.castor.persist.resolver.ResolverStrategy
* #preStore(org.castor.persist.TransactionContext,
* org.exolab.castor.persist.OID, java.lang.Object, int,
* java.lang.Object)
*/
public UpdateFlags preStore(final TransactionContext tx, final OID oid,
final Object object, final int timeout, final Object field)
throws PersistenceException {
UpdateFlags flags = new UpdateFlags();
ClassMolder fieldClassMolder = _fieldMolder.getFieldClassMolder();
Object value = _fieldMolder.getValue(object, tx.getClassLoader());
ArrayList orgFields = (ArrayList) field;
if (!(value instanceof Lazy)) {
Collection removed = ClassMolderHelper.getRemovedIdsList(tx,
orgFields, value, fieldClassMolder);
Iterator removedItor = removed.iterator();
if (removedItor.hasNext()) {
if (_fieldMolder.isStored() && _fieldMolder.isCheckDirty()) {
flags.setUpdatePersist(true);
}
flags.setUpdateCache(true);
}
while (removedItor.hasNext()) {
// must be loaded thur transaction, so that the related object
// is properly locked and updated before we delete it.
Identity identity = (Identity) removedItor.next();
if (!tx.isDeletedByOID(new OID(fieldClassMolder, identity))) {
ProposedEntity proposedValue = new ProposedEntity(fieldClassMolder);
Object reldel = tx.load(identity, proposedValue, null);
if (reldel != null && tx.isPersistent(reldel)) {
tx.writeLock(reldel, tx.getLockTimeout());
_fieldMolder.getRelationLoader().deleteRelation(
tx.getConnection(oid.getMolder().getLockEngine()),
oid.getIdentity(), identity);
fieldClassMolder.removeRelation(tx, reldel, _classMolder, object);
}
}
}
Collection added = ClassMolderHelper.getAddedValuesList(tx,
orgFields, value, fieldClassMolder);
Iterator addedItor = added.iterator();
if (addedItor.hasNext()) {
if (_fieldMolder.isStored() && _fieldMolder.isCheckDirty()) {
flags.setUpdatePersist(true);
}
flags.setUpdateCache(true);
}
while (addedItor.hasNext()) {
Object addedField = addedItor.next();
tx.markModified(addedField, false/* updatePersist */,
true/* updateCache */);
if (tx.isPersistent(addedField)) {
_fieldMolder.getRelationLoader().createRelation(
tx.getConnection(oid.getMolder().getLockEngine()),
oid.getIdentity(),
fieldClassMolder.getIdentity(tx, addedField));
} else {
if (tx.isAutoStore()) {
if (!tx.isDeleted(addedField)) {
tx.markCreate(fieldClassMolder, addedField, null);
}
}
}
}
} else {
RelationCollection lazy = (RelationCollection) value;
// this RelationCollection has to clean up its state at the end of
// the
// transaction
tx.addTxSynchronizable(lazy);
ArrayList deleted = lazy.getDeleted();
if (!deleted.isEmpty()) {
if (_fieldMolder.isStored() && _fieldMolder.isCheckDirty()) {
flags.setUpdatePersist(true);
}
flags.setUpdateCache(true);
Iterator itor = deleted.iterator();
while (itor.hasNext()) {
flags.setUpdateCache(true);
Identity deletedId = (Identity) itor.next();
Object toBeDeleted = lazy.find(deletedId);
if (toBeDeleted != null) {
if (tx.isPersistent(toBeDeleted)) {
tx.writeLock(toBeDeleted, 0);
_fieldMolder.getRelationLoader().deleteRelation(
tx.getConnection(oid.getMolder().getLockEngine()),
oid.getIdentity(), deletedId);
fieldClassMolder.removeRelation(tx, toBeDeleted,
this._classMolder, object);
}
// } else {
// // what to do if it happens?
}
}
}
ArrayList added = lazy.getAdded();
if (!added.isEmpty()) {
if (_fieldMolder.isStored() && _fieldMolder.isCheckDirty()) {
flags.setUpdatePersist(true);
}
flags.setUpdateCache(true);
Iterator itor = added.iterator();
while (itor.hasNext()) {
Identity addedId = (Identity) itor.next();
Object toBeAdded = lazy.find(addedId);
if (toBeAdded != null) {
if (tx.isPersistent(toBeAdded)) {
_fieldMolder.getRelationLoader().createRelation(
tx.getConnection(oid.getMolder().getLockEngine()),
oid.getIdentity(), addedId);
} else {
if (tx.isAutoStore()) {
if (!tx.isRecorded(toBeAdded)) {
tx.markCreate(fieldClassMolder, toBeAdded, null);
}
}
}
// } else {
// // what to do if it happens?
}
}
}
}
return flags;
}
/**
* @see org.castor.persist.resolver.ResolverStrategy
* #update(org.castor.persist.TransactionContext,
* org.exolab.castor.persist.OID, java.lang.Object,
* org.exolab.castor.mapping.AccessMode, java.lang.Object)
*/
public void update(final TransactionContext tx, final OID oid,
final Object object, final AccessMode suggestedAccessMode,
final Object field)
throws PersistenceException {
ArrayList v = (ArrayList) field;
ClassMolder fieldClassMolder = _fieldMolder.getFieldClassMolder();
if (tx.isAutoStore()) {
ArrayList newSetOfIds = new ArrayList();
// iterate the collection of this data object field
Iterator itor = ClassMolderHelper.getIterator(_fieldMolder
.getValue(object, tx.getClassLoader()));
while (itor.hasNext()) {
Object element = itor.next();
Object actualIdentity = fieldClassMolder.getActualIdentity(tx, element);
newSetOfIds.add(actualIdentity);
if (!tx.isRecorded(element)) {
tx.markUpdate(fieldClassMolder, element, null);
}
}
// load all old objects for comparison in the preStore state
if (v != null) {
for (int j = 0; j < v.size(); j++) {
if (!newSetOfIds.contains(v.get(j))) {
// load all the dependent object in cache for
// modification
// check at commit time.
ProposedEntity proposedValue = new ProposedEntity(fieldClassMolder);
tx.load((Identity) v.get(j), proposedValue, suggestedAccessMode);
}
}
}
}
}
/**
* @see org.castor.persist.resolver.ManyRelationResolver#postCreate(
* org.castor.persist.TransactionContext,
* org.exolab.castor.persist.OID, java.lang.Object, java.lang.Object,
* org.exolab.castor.persist.spi.Identity)
*/
public Object postCreate(final TransactionContext tx, final OID oid,
final Object object, final Object field, final Identity createdId)
throws PersistenceException {
ClassMolder fieldClassMolder = _fieldMolder.getFieldClassMolder();
Object o = _fieldMolder.getValue(object, tx.getClassLoader());
Object result = field;
if (o != null) {
ArrayList fids = ClassMolderHelper.extractIdentityList(tx, fieldClassMolder, o);
result = fids;
Iterator itor = ClassMolderHelper.getIterator(o);
while (itor.hasNext()) {
Object oo = itor.next();
if (tx.isPersistent(oo)) {
_fieldMolder.getRelationLoader().createRelation(
tx.getConnection(oid.getMolder().getLockEngine()), createdId,
fieldClassMolder.getIdentity(tx, oo));
}
}
}
return result;
}
/**
* @inheritDoc
*/
public boolean updateWhenNoTimestampSet(
final TransactionContext tx,
final OID oid,
final Object object,
final AccessMode suggestedAccessMode)
throws PersistenceException {
boolean updateCache = false;
// create relation if the relation table
ClassMolder fieldClassMolder = _fieldMolder.getFieldClassMolder();
Object o = _fieldMolder.getValue(object, tx.getClassLoader());
if (o != null) {
Iterator itor = ClassMolderHelper.getIterator(o);
// many-to-many relation is never dependent relation
while (itor.hasNext()) {
Object oo = itor.next();
if (tx.isAutoStore() && !tx.isRecorded(oo)) {
boolean creating = tx.markUpdate(fieldClassMolder, oo, null);
if (creating) {
updateCache = true;
}
}
}
}
return updateCache;
}
}