EntryID.java revision 407bb81fb935e713a4a1ae1b9189b81488a944d5
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
* or http://forgerock.org/license/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 legal-notices/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]
*
* CDDL HEADER END
*
*
* Copyright 2006-2008 Sun Microsystems, Inc.
* Portions Copyright 2014 ForgeRock AS
*/
package org.opends.server.backends.jeb;
import com.sleepycat.je.DatabaseEntry;
/**
* An integer identifier assigned to each entry in the JE backend.
* An entry ID is implemented by this class as a long.
* There are static methods to assign monotonically increasing entry IDs,
* starting from 1.
*/
public class EntryID implements Comparable<EntryID>
{
/** The identifier integer value. */
private final long id;
/** The value in database format, created when necessary. */
private DatabaseEntry data;
/**
* Create a new entry ID object from a given long value.
* @param id The long value of the ID.
*/
public EntryID(long id)
{
this.id = id;
}
/**
* Create a new entry ID object from a value in database format.
* @param databaseEntry The database value of the ID.
*/
public EntryID(DatabaseEntry databaseEntry)
{
data = databaseEntry;
id = JebFormat.entryIDFromDatabase(data.getData());
}
/**
* Get the value of the entry ID as a long.
* @return The entry ID.
*/
public long longValue()
{
return id;
}
/**
* Get the value of the ID in database format.
* @return The value of the ID in database format.
*/
public DatabaseEntry getDatabaseEntry()
{
if (data == null)
{
data = new DatabaseEntry();
data.setData(JebFormat.entryIDToDatabase(id));
}
return data;
}
/**
* Compares this object with the specified object for order. Returns a
* negative integer, zero, or a positive integer as this object is less
* than, equal to, or greater than the specified object.<p>
* <p/>
*
* @param that the Object to be compared.
* @return a negative integer, zero, or a positive integer as this object
* is less than, equal to, or greater than the specified object.
* @throws ClassCastException if the specified object's type prevents it
* from being compared to this Object.
*/
@Override
public int compareTo(EntryID that) throws ClassCastException
{
final long result = this.id - that.id;
if (result < 0)
{
return -1;
}
else if (result > 0)
{
return 1;
}
return 0;
}
/**
* Indicates whether some other object is "equal to" this one.
*
* @param that the reference object with which to compare.
* @return <code>true</code> if this object is the same as the obj
* argument; <code>false</code> otherwise.
* @see #hashCode()
* @see java.util.Hashtable
*/
@Override
public boolean equals(Object that)
{
if (this == that)
{
return true;
}
if (!(that instanceof EntryID))
{
return false;
}
return this.id == ((EntryID) that).id;
}
/**
* Returns a hash code value for the object. This method is
* supported for the benefit of hashtables such as those provided by
* <code>java.util.Hashtable</code>.
*
* @return a hash code value for this object.
* @see java.lang.Object#equals(java.lang.Object)
* @see java.util.Hashtable
*/
@Override
public int hashCode()
{
return (int) id;
}
/**
* Get a string representation of this object.
* @return A string representation of this object.
*/
@Override
public String toString()
{
return Long.toString(id);
}
}