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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.apache.openjpa.kernel;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.datacache.DataCache;
import org.apache.openjpa.datacache.DataCacheManager;
import org.apache.openjpa.lib.conf.Configurable;
import org.apache.openjpa.lib.conf.Configuration;
import org.apache.openjpa.lib.log.Log;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.meta.FieldMetaData;
import org.apache.openjpa.meta.JavaTypes;
import org.apache.openjpa.meta.ValueMetaData;
import org.apache.openjpa.util.InvalidStateException;
/**
* Class which manages inverse relations before flushing
* to the datastore. Ensures that inverse fields are set.
* Currently limited to managing PC and Collection-type relations.
*
* @author Steve Kim
*/
public class InverseManager implements Configurable {
private static final Localizer _loc = Localizer.forPackage(InverseManager.class);
protected static final Object NONE = new Object();
protected DataCacheManager _mgr;
/**
* Constant representing the {@link #ACTION_MANAGE} action
*/
public static final int ACTION_MANAGE = 0;
/**
* Constant representing the {@link #ACTION_WARN} action
*/
public static final int ACTION_WARN = 1;
/**
* Constant representing the {@link #ACTION_EXCEPTION} action
*/
public static final int ACTION_EXCEPTION = 2;
private boolean _manageLRS = false;
private int _action = ACTION_MANAGE;
private Log _log;
/**
* Return whether to manage LRS fields.
*/
public boolean getManageLRS() {
return _manageLRS;
}
/**
* Set whether to false LRS relations. Defaults to false.
*/
public void setManageLRS(boolean manage) {
_manageLRS = manage;
}
/**
* Return the action constant to use during relationship checking.
* Defaults to {@link #ACTION_MANAGE}.
*/
public int getAction() {
return _action;
}
/**
* Set the action constant to use during relationship checking.
* Defaults to {@link #ACTION_MANAGE}.
*/
public void setAction(int action) {
_action = action;
}
/**
* Set the action string to use during relationship checking.
* Options include manage, exception, warn.
* This method is primarily for string-based automated configuration.
*/
public void setAction(String action) {
if ("exception".equals(action))
_action = ACTION_EXCEPTION;
else if ("warn".equals(action))
_action = ACTION_WARN;
else if ("manage".equals(action))
_action = ACTION_MANAGE;
else
throw new IllegalArgumentException(action);
}
public void startConfiguration() {
}
public void endConfiguration() {
}
public void setConfiguration(Configuration conf) {
_log = conf.getLog(OpenJPAConfiguration.LOG_RUNTIME);
_mgr = ((OpenJPAConfiguration)conf).getDataCacheManagerInstance();
}
/**
* Correct relations from the given dirty field to inverse instances.
* Field fmd of the instance managed by sm has
* value value. Ensure that all inverses relations from
* value are consistent with this.
*/
public void correctRelations(OpenJPAStateManager sm, FieldMetaData fmd,
Object value) {
if (fmd.getDeclaredTypeCode() != JavaTypes.PC &&
((fmd.getDeclaredTypeCode() != JavaTypes.COLLECTION &&
fmd.getDeclaredTypeCode() != JavaTypes.MAP) ||
fmd.getElement().getDeclaredTypeCode() != JavaTypes.PC))
return;
// ignore LRS fields
if (!getManageLRS() && fmd.isLRS())
return;
FieldMetaData[] inverses = fmd.getInverseMetaDatas();
if (inverses.length == 0)
return;
// clear any restorable relations
clearInverseRelations(sm, fmd, inverses, value);
if (value != null) {
StoreContext ctx = sm.getContext();
switch (fmd.getDeclaredTypeCode()) {
case JavaTypes.PC:
createInverseRelations(ctx, sm.getManagedInstance(),
value, fmd, inverses);
break;
case JavaTypes.COLLECTION:
for (Iterator itr = ((Collection) value).iterator();
itr.hasNext();)
createInverseRelations(ctx, sm.getManagedInstance(),
itr.next(), fmd, inverses);
break;
}
}
}
/**
* Create the inverse relations for all the given inverse fields.
* A relation exists from fromRef to toRef; this
* method creates the inverses.
*/
protected void createInverseRelations(StoreContext ctx,
Object fromRef, Object toRef, FieldMetaData fmd,
FieldMetaData[] inverses) {
OpenJPAStateManager other = ctx.getStateManager(toRef);
if (other == null || other.isDeleted())
return;
boolean owned;
for (int i = 0; i < inverses.length; i++) {
if (!getManageLRS() && inverses[i].isLRS())
continue;
// if this is the owned side of the relation and has not yet been
// loaded, no point in setting it now, cause it'll have the correct
// value the next time it is loaded after the flush
owned = fmd == inverses[i].getMappedByMetaData()
&& _action == ACTION_MANAGE
&& !isLoaded(other, inverses[i].getIndex());
switch (inverses[i].getDeclaredTypeCode()) {
case JavaTypes.PC:
if (!owned || inverses[i].getCascadeDelete()
== ValueMetaData.CASCADE_AUTO)
storeField(other, inverses[i], NONE, fromRef);
break;
case JavaTypes.COLLECTION:
if (!owned || inverses[i].getElement().getCascadeDelete()
== ValueMetaData.CASCADE_AUTO)
addToCollection(other, inverses[i], fromRef);
break;
}
}
}
/**
* Return whether the given field is loaded for the given instance.
*/
private boolean isLoaded(OpenJPAStateManager sm, int field) {
if (sm.getLoaded().get(field))
return true;
// if the field isn't loaded in the state manager, it still might be
// loaded in the data cache, in which case we still have to correct
// it to keep the cache in sync
DataCache cache = _mgr.selectCache(sm);
if (cache == null)
return false;
// can't retrieve an embedded object directly, so always assume the
// field is loaded and needs to be corrected
if (sm.isEmbedded())
return true;
PCData pc = cache.get(sm.getObjectId());
if (pc == null)
return false;
return pc.isLoaded(field);
}
/**
* Remove all relations between the initial value of fmd for
* the instance managed by sm and its inverses. Relations
* shared with newValue can be left intact.
*/
protected void clearInverseRelations(OpenJPAStateManager sm,
FieldMetaData fmd, FieldMetaData[] inverses, Object newValue) {
// don't bother clearing unflushed new instances
if (sm.isNew() && !sm.getFlushed().get(fmd.getIndex()))
return;
if (fmd.getDeclaredTypeCode() == JavaTypes.PC) {
Object initial = sm.fetchInitialField(fmd.getIndex());
clearInverseRelations(sm, initial, fmd, inverses);
} else {
Object obj = sm.fetchInitialField(fmd.getIndex());
Collection initial = null;
if (obj instanceof Collection)
initial = (Collection) obj;
else if (obj instanceof Map)
initial = ((Map)obj).values();
if (initial == null)
return;
// clear all relations not also in the new value
Collection coll = null;
if (newValue instanceof Collection)
coll = (Collection) newValue;
else if (newValue instanceof Map)
coll = ((Map)newValue).values();
Object elem;
for (Iterator itr = initial.iterator(); itr.hasNext();) {
elem = itr.next();
if (coll == null || !coll.contains(elem))
clearInverseRelations(sm, elem, fmd, inverses);
}
}
}
/**
* Clear all inverse the relations from val to the instance
* managed by sm.
*/
protected void clearInverseRelations(OpenJPAStateManager sm, Object val,
FieldMetaData fmd, FieldMetaData[] inverses) {
if (val == null)
return;
OpenJPAStateManager other = sm.getContext().getStateManager(val);
if (other == null || other.isDeleted())
return;
boolean owned;
for (int i = 0; i < inverses.length; i++) {
if (!getManageLRS() && inverses[i].isLRS())
continue;
// if this is the owned side of the relation and has not yet been
// loaded, no point in setting it now, cause it'll have the correct
// value the next time it is loaded after the flush
owned = fmd == inverses[i].getMappedByMetaData()
&& _action == ACTION_MANAGE
&& !isLoaded(other, inverses[i].getIndex());
switch (inverses[i].getDeclaredTypeCode()) {
case JavaTypes.PC:
if (!owned || inverses[i].getCascadeDelete()
== ValueMetaData.CASCADE_AUTO)
storeNull(other, inverses[i], sm.getManagedInstance());
break;
case JavaTypes.COLLECTION:
if (!owned || inverses[i].getElement().getCascadeDelete()
== ValueMetaData.CASCADE_AUTO)
removeFromCollection(other, inverses[i],
sm.getManagedInstance());
break;
}
}
}
/**
* Store null value at the given field. Verify that the given compare
* value is the value being nulled. Pass NONE for no comparison.
*/
protected void storeNull(OpenJPAStateManager sm, FieldMetaData fmd,
Object compare) {
storeField(sm, fmd, compare, null);
}
/**
* Store a given value at the given field. Compare the given
* argument if not NONE.
*/
protected void storeField(OpenJPAStateManager sm, FieldMetaData fmd,
Object compare, Object val) {
Object oldValue = sm.fetchObjectField(fmd.getIndex());
if (oldValue == val)
return;
if (compare != NONE && oldValue != compare)
return;
switch (_action) {
case ACTION_MANAGE:
sm.settingObjectField(sm.getPersistenceCapable(),
fmd.getIndex(),
oldValue, val, OpenJPAStateManager.SET_USER);
break;
case ACTION_WARN:
warnConsistency(sm, fmd);
break;
case ACTION_EXCEPTION:
throwException(sm, fmd);
default:
throw new IllegalStateException();
}
}
/**
* Remove the given instance from the collection.
*/
protected void removeFromCollection(OpenJPAStateManager sm,
FieldMetaData fmd,
Object val) {
Collection coll = (Collection) sm.fetchObjectField(fmd.getIndex());
if (coll != null) {
switch (_action) {
case ACTION_MANAGE:
remove:
for (int i = 0; coll.remove(val); i++)
if (i == 0 && coll instanceof Set)
break remove;
break;
case ACTION_WARN:
if (coll.contains(val))
warnConsistency(sm, fmd);
break;
case ACTION_EXCEPTION:
if (coll.contains(val))
throwException(sm, fmd);
break;
default:
throw new IllegalStateException();
}
}
}
/**
* Add the given value to the collection at the selected field.
*/
protected void addToCollection(OpenJPAStateManager sm, FieldMetaData fmd,
Object val) {
Collection coll = (Collection) sm.fetchObjectField(fmd.getIndex());
if (coll == null) {
coll = (Collection) sm.newFieldProxy(fmd.getIndex());
sm.storeObjectField(fmd.getIndex(), coll);
}
if (!coll.contains(val)) {
switch (_action) {
case ACTION_MANAGE:
coll.add(val);
break;
case ACTION_WARN:
warnConsistency(sm, fmd);
break;
case ACTION_EXCEPTION:
throwException(sm, fmd);
default:
throw new IllegalStateException();
}
}
}
/**
* Log an inconsistency warning
*/
protected void warnConsistency(OpenJPAStateManager sm, FieldMetaData fmd) {
if (_log.isWarnEnabled())
_log.warn(_loc.get("inverse-consistency", fmd, sm.getId(),
sm.getContext()));
}
/**
* Throw an inconsistency exception
*/
protected void throwException(OpenJPAStateManager sm, FieldMetaData fmd) {
throw new InvalidStateException(_loc.get("inverse-consistency",
fmd, sm.getId(), sm.getContext())).setFailedObject
(sm.getManagedInstance()).setFatal(true);
}
}
