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.File;
027 import java.io.IOException;
028 import java.io.InputStream;
029 import java.io.Reader;
030
031 /**
032 * A factory for creating {@link Binary} instances. This interface extends the {@link ValueFactory} generic interface and adds
033 * specific methods for creating binary objects.
034 *
035 * @author Randall Hauch
036 */
037 public interface BinaryFactory extends ValueFactory<Binary> {
038
039 /**
040 * Create a value from the binary content given by the supplied stream, the approximate length, and the SHA-1 secure hash of
041 * the content. If the secure hash is null, then a secure hash is computed from the content. If the secure hash is not null,
042 * it is assumed to be the hash for the content and may not be checked.
043 *
044 * @param stream the stream containing the content to be used to create the value
045 * @param approximateLength the approximate length of the content (in bytes)
046 * @param secureHash the secure hash of the content in the <code>stream</code>; if null, the secure hash is computed from the
047 * content, and if not null it is assumed to be the correct secure hash (and is not checked)
048 * @return the value, or null if the supplied stream is null
049 * @throws ValueFormatException if the conversion from an input stream could not be performed
050 * @throws IoException If an unexpected problem occurs while accessing the supplied stream (such as an {@link IOException}).
051 * @throws IllegalArgumentException if the secure hash was discovered to be incorrect
052 */
053 Binary create( InputStream stream,
054 long approximateLength,
055 byte[] secureHash ) throws ValueFormatException, IoException;
056
057 /**
058 * Create a value from the binary content given by the supplied reader, the approximate length, and the SHA-1 secure hash of
059 * the content. If the secure hash is null, then a secure hash is computed from the content. If the secure hash is not null,
060 * it is assumed to be the hash for the content and may not be checked.
061 *
062 * @param reader the reader containing the content to be used to create the value
063 * @param approximateLength the approximate length of the content (in bytes)
064 * @param secureHash the secure hash of the content in the <code>stream</code>; if null, the secure hash is computed from the
065 * content, and if not null it is assumed to be the correct secure hash (and is not checked)
066 * @return the value, or null if the supplied string is null
067 * @throws ValueFormatException if the conversion from a reader could not be performed
068 * @throws IoException If an unexpected problem occurs while accessing the supplied reader (such as an {@link IOException}).
069 * @throws IllegalArgumentException if the secure hash was discovered to be incorrect
070 */
071 Binary create( Reader reader,
072 long approximateLength,
073 byte[] secureHash ) throws ValueFormatException, IoException;
074
075 /**
076 * Create a binary value from the given file.
077 *
078 * @param file the file containing the content to be used
079 * @return the binary value, or null if the file parameter was null
080 * @throws ValueFormatException if the conversion from the file could not be performed
081 * @throws IoException If an unexpected problem occurs while accessing the supplied file (such as an {@link IOException}).
082 */
083 Binary create( File file ) throws ValueFormatException, IoException;
084
085 /**
086 * Find an existing binary value given the supplied secure hash. If no such binary value exists, null is returned. This method
087 * can be used when the caller knows the secure hash (e.g., from a previously-held Binary object), and would like to reuse an
088 * existing binary value (if possible) rather than recreate the binary value by processing the stream contents. This is
089 * especially true when the size of the binary is quite large.
090 *
091 * @param secureHash the secure hash of the binary content, which was probably {@link Binary#getHash() obtained} from a
092 * previously-held {@link Binary} object; a null or empty value is allowed, but will always result in returning null
093 * @return the existing Binary value that has the same secure hash, or null if there is no such value available at this time
094 */
095 Binary find( byte[] secureHash );
096 }