001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006     * See the AUTHORS.txt file in the distribution for a full listing of 
007     * individual contributors. 
008     *
009     * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010     * is licensed to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     *
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.connector.store.jpa.model.basic;
025    
026    import java.io.Serializable;
027    import javax.persistence.Column;
028    import javax.persistence.Embeddable;
029    import net.jcip.annotations.Immutable;
030    
031    /**
032     * A unique identifer for a large value, which is the 160-bit SHA-1 hash of this value, in hex form (40-bytes). The SHA-1
033     * algorithm is fast and has not yet proven to have any duplicates. Even if SHA-2 and SHA-3 are better for cryptographically
034     * secure purposes, it is doubtful whether a repository needs more than SHA-1 for identity purposes.
035     * 
036     * @author Randall Hauch
037     */
038    @Embeddable
039    @Immutable
040    @org.hibernate.annotations.Immutable
041    public class LargeValueId implements Serializable {
042    
043        /**
044         * Version {@value}
045         */
046        private static final long serialVersionUID = 1L;
047    
048        @Column( name = "SHA1", nullable = false, length = 40 )
049        private String hash;
050    
051        public LargeValueId() {
052        }
053    
054        public LargeValueId( String hash ) {
055            this.hash = hash;
056        }
057    
058        /**
059         * @return hash
060         */
061        public String getHash() {
062            return hash;
063        }
064    
065        /**
066         * {@inheritDoc}
067         * 
068         * @see java.lang.Object#hashCode()
069         */
070        @Override
071        public int hashCode() {
072            return hash.hashCode();
073        }
074    
075        /**
076         * {@inheritDoc}
077         * 
078         * @see java.lang.Object#equals(java.lang.Object)
079         */
080        @Override
081        public boolean equals( Object obj ) {
082            if (obj == this) return true;
083            if (obj instanceof LargeValueId) {
084                LargeValueId that = (LargeValueId)obj;
085                return this.hash.equals(that.hash);
086            }
087            return false;
088        }
089    
090        /**
091         * {@inheritDoc}
092         * 
093         * @see java.lang.Object#toString()
094         */
095        @Override
096        public String toString() {
097            return "Large value " + hash;
098        }
099    
100    }