org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy Maven / Gradle / Ivy
/*
* Copyright (c) 1998, 2024 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.descriptors;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.expressions.ExpressionBuilder;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.identitymaps.CacheKey;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
import org.eclipse.persistence.queries.DeleteObjectQuery;
import org.eclipse.persistence.queries.ObjectLevelModifyQuery;
import org.eclipse.persistence.queries.WriteObjectQuery;
import java.io.Serializable;
public interface OptimisticLockingPolicy extends Cloneable, Serializable {
/**
* INTERNAL:
* Add update fields for template row.
* These are any unmapped fields required to write in an update.
*
* #see this method in VersionLockingPolicy
*/
void addLockFieldsToUpdateRow(AbstractRecord databaseRow, AbstractSession session);
/**
* INTERNAL:
* The method should update the translation row with the
* correct write lock values. This method is called on a delete.
*
* #see this method in VersionLockingPolicy
*/
void addLockValuesToTranslationRow(ObjectLevelModifyQuery query);
/**
* INTERNAL:
* When given an expression, this method will return a new expression with
* the optimistic locking values included. This expression will be used
* in a delete call.
*
* #see this method in VersionLockingPolicy
*/
Expression buildDeleteExpression(org.eclipse.persistence.internal.helper.DatabaseTable table, Expression mainExpression, AbstractRecord row);
/**
* INTERNAL:
* When given an expression, this method will return a new expression with
* the optimistic locking values included. This expression will be used in
* an update call.
*
* #see this method in VersionLockingPolicy
*/
Expression buildUpdateExpression(org.eclipse.persistence.internal.helper.DatabaseTable table, Expression mainExpression, AbstractRecord translationRow, AbstractRecord modifyRow);
Object clone();
/**
* INTERNAL:
* Indicates whether compareWriteLockValues method is supported by the policy.
* Numeric or timestamp lock values could be compared:
* for every pair of values v1 and v2 - either v1 lessthan v2; or v1==v2; or v1 greaterthan v2.
* However it's impossible to compare values for FieldsLockingPolicy for two reasons:
* 1. there is no "linear order": v1 lessthan v2 and v greaterthan v2 is not defined: either v1==v2 or v1!=v2;
* 2. locking value is not a single field which is not part of mapped object value
* but rather a set of object's mapped fields. That means any object's mapped attribute change
* is potentially a change of the locking value.
* For ChangedFieldsLockingPolicy every mapped attribute's change is a change of locking value.
* The pattern used by versioning: "if the original locking value is unchanged
* then the object hasn't been changed outside of the application", which allows
* to distinguish between the change made inside and outside the application,
* doesn't work for fields locking.
* It degenerates into useless pattern: "if the original locking value is unchanged
* then the object hasn't been changed".
*
* Use compareWriteLockValues method only if this method returns true.
*/
boolean supportsWriteLockValuesComparison();
/**
* INTERNAL:
* This method shouldn't be called if supportsWriteLockValuesComparison() returns false.
* This method compares two writeLockValues.
* The writeLockValues should be non-null and of the correct type.
* Returns:
* -1 if value1 is less (older) than value2;
* 0 if value1 equals value2;
* 1 if value1 is greater (newer) than value2.
* Throws:
* NullPointerException if the passed value is null;
* ClassCastException if the passed value is of a wrong type.
*/
int compareWriteLockValues(Object value1, Object value2);
/**
* INTERNAL:
* This is the base value that is older than all other values, it is used in the place of
* null in some situations.
*/
T getBaseValue();
/**
* ADVANCED:
* returns the LockOnChange mode for this policy. This mode specifies if a
* Optimistic Write lock should be enforced on this entity when a set of mappings are changed.
*/
LockOnChange getLockOnChangeMode();
/**
* INTERNAL:
* Return the value that should be stored in the identity map.
* If the value is not stored in the cache, then return a null.
*
* #see this method in VersionLockingPolicy
*/
T getValueToPutInCache(AbstractRecord row, AbstractSession session);
/**
* PUBLIC:
* Return the number of versions different between these objects.
*/
int getVersionDifference(Object currentValue, Object domainObject, Object primaryKey, AbstractSession session);
/**
* INTERNAL:
* Return the write lock field.
*
* #see this method in VersionLockingPolicy
*/
DatabaseField getWriteLockField();
/**
* INTERNAL:
* This method will return the optimistic lock value for the object
*
* #see this method in VersionLockingPolicy
*/
T getWriteLockValue(Object domainObject, Object primaryKey, AbstractSession session);
/**
* INTERNAL:
* This method will return an expression that is used to update its optimistic locking field
*
* #see this method in VersionLockingPolicy
*/
Expression getWriteLockUpdateExpression(ExpressionBuilder builder, AbstractSession session);
/**
* INTERNAL:
* It is responsible for initializing the policy.
*
* #see this method in VersionLockingPolicy
*/
void initialize(AbstractSession session);
/**
* INTERNAL:
* Responsible for pre-initializing.
*
* #see this method in VersionLockingPolicy
*/
void initializeProperties();
/**
* INTERNAL:
* Return true if the lock value is stored in the cache.
*/
boolean isStoredInCache();
/**
* INTERNAL:
* Specify if the policy cascade locks.
*/
boolean isCascaded();
/**
* INTERNAL:
* Returns true if the value stored with the domainObject is more recent
* than the value . Returns false otherwise.
*
* #see this method in VersionLockingPolicy
*/
boolean isNewerVersion(Object currentValue, Object domainObject, Object primaryKey, AbstractSession session);
/**
* INTERNAL:
* Returns true if the value stored with the domainObject is more recent
* than the value in the row. Returns false otherwise.
* NOTE: This method will only be called if the shouldOnlyRefreshCacheIfNewerVersion()
* flag is set on descriptor.
*
* #see this method in VersionLockingPolicy
*/
boolean isNewerVersion(AbstractRecord databaseRow, Object domainObject, Object primaryKey, AbstractSession session);
/**
* INTERNAL:
* This method should merge changes from the parent into the child.
*
* #see this method in VersionLockingPolicy
*/
void mergeIntoParentCache(UnitOfWorkImpl uow, Object primaryKey, Object object);
/**
* INTERNAL:
* This method should merge changes from the parent into the child.
*
* #see this method in VersionLockingPolicy
*/
void mergeIntoParentCache(CacheKey unitOfWorkCacheKey, CacheKey parentSessionCacheKey);
/**
* INTERNAL:
* provide a way to set the descriptor for this policy
*/
void setDescriptor(ClassDescriptor descriptor);
/**
* ADVANCED:
* Sets the LockOnChange mode for this policy. This mode specifies if a
* Optimistic Write lock should be enforced on this entity when set of mappings are changed.
*/
void setLockOnChangeMode(LockOnChange lockOnChangeMode);
/**
* INTERNAL:
* Add the initial right lock values to the modify
* row in the query. This method will only be called
* on insert.
*
* #see this method in VersionLockingPolicy
*/
void setupWriteFieldsForInsert(ObjectLevelModifyQuery query);
/**
* INTERNAL:
* This method should update the translation row, the modify
* row and the domain object with th lock value.
*
* #see this method in VersionLockingPolicy
*/
void updateRowAndObjectForUpdate(ObjectLevelModifyQuery query, Object object);
/**
* INTERNAL:
* Returns true if the policy has been set to set an optimistic read lock when a owning mapping changes.
*/
boolean shouldUpdateVersionOnOwnedMappingChange();
/**
* INTERNAL:
* Returns true if the policy has been set to set an optimistic read lock when any mapping changes.
*/
boolean shouldUpdateVersionOnMappingChange();
void validateDelete(int rowCount, Object object, DeleteObjectQuery query);
void validateUpdate(int rowCount, Object object, WriteObjectQuery query);
/**
* Advanced:
*
* Purpose: Provides the configuration options to force an Optimistic Write Lock
* When a set of mappings have changes. This enum defines what mappings are within that set.
* @author Gordon Yorke
* @since EclipseLink 2.0
*/
enum LockOnChange{
OWNING, // update version when an owning mapping changes
NONE,
ALL
}
}