oracle.toplink.essentials.sequencing.DefaultSequence Maven / Gradle / Ivy
/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the "License"). You may not use this file except
* in compliance with the License.
*
* You can obtain a copy of the license at
* glassfish/bootstrap/legal/CDDLv1.0.txt or
* https://glassfish.dev.java.net/public/CDDLv1.0.html.
* See the License for the specific language governing
* permissions and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* HEADER in each file and include the License file at
* glassfish/bootstrap/legal/CDDLv1.0.txt. If applicable,
* add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your
* own identifying information: Portions Copyright [yyyy]
* [name of copyright owner]
*/
// Copyright (c) 1998, 2007, Oracle. All rights reserved.
package oracle.toplink.essentials.sequencing;
import java.util.Vector;
import oracle.toplink.essentials.internal.sessions.AbstractSession;
import oracle.toplink.essentials.internal.databaseaccess.Accessor;
/**
*
* Purpose: Reference to the default sequence
*
*/
public class DefaultSequence extends Sequence {
protected Sequence defaultSequence;
public DefaultSequence() {
super();
}
// Created with this constructor,
// DefaultSequence uses preallocation size of defaultSequence.
public DefaultSequence(String name) {
super(name, 0);
}
public DefaultSequence(String name, int size) {
super(name, size);
}
public DefaultSequence(String name, int size, int initialValue) {
super(name, size, initialValue);
}
public Sequence getDefaultSequence() {
return getDatasourcePlatform().getDefaultSequence();
}
public boolean hasPreallocationSize() {
return size != 0;
}
public int getPreallocationSize() {
if ((size != 0) || (getDefaultSequence() == null)) {
return size;
} else {
return getDefaultSequence().getPreallocationSize();
}
}
public int getInitialValue() {
if ((initialValue != 0) || (getDefaultSequence() == null)) {
return initialValue;
} else {
return getDefaultSequence().getInitialValue();
}
}
public boolean equals(Object obj) {
if (obj instanceof DefaultSequence) {
return equalNameAndSize(this, (DefaultSequence)obj);
} else {
return false;
}
}
/**
* INTERNAL:
* Indicates whether sequencing value should be acquired after INSERT.
* Note that preallocation could be used only in case sequencing values
* should be acquired before insert (this method returns false).
* In default implementation, it is true for table sequencing and native
* sequencing on Oracle platform, false for native sequencing on other platforms.
*/
public boolean shouldAcquireValueAfterInsert() {
return getDefaultSequence().shouldAcquireValueAfterInsert();
}
/**
* INTERNAL:
* Indicates whether TopLink should internally call beginTransaction() before
* getGeneratedValue/Vector, and commitTransaction after.
* In default implementation, it is true for table sequencing and
* false for native sequencing.
*/
public boolean shouldUseTransaction() {
return getDefaultSequence().shouldUseTransaction();
}
/**
* INTERNAL:
* Indicates whether existing attribute value should be overridden.
* This method is called in case an attribute mapped to PK of sequencing-using
* descriptor contains non-null value.
* @param seqName String is sequencing number field name
* @param existingValue Object is a non-null value of PK-mapped attribute.
*/
public boolean shouldOverrideExistingValue(String seqName, Object existingValue) {
return getDefaultSequence().shouldOverrideExistingValue(seqName, existingValue);
}
/**
* INTERNAL:
* Return the newly-generated sequencing value.
* Used only in case preallocation is not used (shouldUsePreallocation()==false).
* Accessor may be non-null only in case shouldUseSeparateConnection()==true.
* Even in this case accessor could be null - if SequencingControl().shouldUseSeparateConnection()==false;
* Therefore in case shouldUseSeparateConnection()==true, implementation should handle
* both cases: use a separate connection if provided (accessor != null), or get by
* without it (accessor == null).
* @param accessor Accessor is a separate sequencing accessor (may be null);
* @param writeSession Session is a Session used for writing (either ClientSession or DatabaseSession);
* @param seqName String is sequencing number field name
*/
public Object getGeneratedValue(Accessor accessor, AbstractSession writeSession, String seqName) {
return getDefaultSequence().getGeneratedValue(accessor, writeSession, seqName);
}
/**
* INTERNAL:
* Return a Vector of newly-generated sequencing values.
* Used only in case preallocation is used (shouldUsePreallocation()==true).
* Accessor may be non-null only in case shouldUseSeparateConnection()==true.
* Even in this case accessor could be null - if SequencingControl().shouldUseSeparateConnection()==false;
* Therefore in case shouldUseSeparateConnection()==true, implementation should handle
* both cases: use a separate connection if provided (accessor != null), or get by
* without it (accessor == null).
* @param accessor Accessor is a separate sequencing accessor (may be null);
* @param writeSession Session is a Session used for writing (either ClientSession or DatabaseSession);
* @param seqName String is sequencing number field name
* @param size int number of values to preallocate (output Vector size).
*/
public Vector getGeneratedVector(Accessor accessor, AbstractSession writeSession, String name, int size) {
return getDefaultSequence().getGeneratedVector(accessor, writeSession, name, size);
}
/**
* INTERNAL:
* This method is called when Sequencing object is created.
* It's a chance to do initialization.
* @param ownerSession DatabaseSession
*/
protected void onConnect() {
// nothing to do
}
/**
* INTERNAL:
* This method is called when Sequencing object is destroyed..
* It's a chance to do deinitialization.
*/
public void onDisconnect() {
// nothing to do
}
}