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.graph.property; 025 026 import java.io.InputStream; 027 import java.io.Serializable; 028 import java.security.MessageDigest; 029 import net.jcip.annotations.Immutable; 030 031 /** 032 * Value holder for binary data. Binary instances are not mutable. 033 * 034 * @author Randall Hauch 035 */ 036 @Immutable 037 public interface Binary extends Comparable<Binary>, Serializable { 038 039 /** 040 * Get the length of this binary data. 041 * 042 * @return the number of bytes in this binary data 043 * @see #acquire() 044 */ 045 public long getSize(); 046 047 /** 048 * Get the SHA-1 hash of the contents. This hash can be used to determine whether two Binary instances contain the same 049 * content. 050 * <p> 051 * Repeatedly calling this method should generally be efficient, as it most implementations will compute the hash only once. 052 * </p> 053 * 054 * @return the hash of the contents as a byte array, or an empty array if the hash could not be computed. 055 * @see #acquire() 056 * @see MessageDigest#digest(byte[]) 057 * @see MessageDigest#getInstance(String) 058 */ 059 public byte[] getHash(); 060 061 /** 062 * Get the contents of this data as a stream. 063 * 064 * @return the stream to this data's contents 065 * @see #acquire() 066 * @throws IoException if there is a problem returning the stream 067 */ 068 public InputStream getStream(); 069 070 /** 071 * Get the contents of this data as a byte array. 072 * 073 * @return the data as an array 074 * @see #acquire() 075 * @throws IoException if there is a problem returning the bytes 076 */ 077 public byte[] getBytes(); 078 079 /** 080 * Acquire any resources for this data. This method must be called before any other method on this object. 081 * 082 * @see #release() 083 */ 084 public void acquire(); 085 086 /** 087 * Release any acquired resources. This method must be called after a client is finished with this value. 088 * 089 * @see #acquire() 090 */ 091 public void release(); 092 093 }