001/** 002 * Copyright 2015 DuraSpace, Inc. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016package org.fcrepo.kernel.modeshape.utils; 017 018import org.fcrepo.kernel.api.exception.RepositoryRuntimeException; 019import org.fcrepo.kernel.api.utils.CacheEntry; 020import org.fcrepo.kernel.api.utils.ContentDigest; 021import org.fcrepo.kernel.api.utils.FixityResult; 022 023import org.slf4j.Logger; 024 025import javax.jcr.RepositoryException; 026 027import java.io.IOException; 028import java.net.URI; 029import java.security.MessageDigest; 030import java.security.NoSuchAlgorithmException; 031import java.util.Collection; 032 033import static java.util.Arrays.asList; 034import static org.slf4j.LoggerFactory.getLogger; 035 036/** 037 * Cache entry that wraps a binary stream and provides 038 * fixity methods against it 039 * 040 * @author fasseg 041 */ 042public abstract class BasicCacheEntry implements CacheEntry { 043 044 public static final int DEV_NULL_BUFFER_SIZE = 4096; 045 046 private static final byte[] devNull = new byte[DEV_NULL_BUFFER_SIZE]; 047 048 private static final Logger LOGGER = getLogger(BasicCacheEntry.class); 049 050 /** 051 * Calculate the fixity of a CacheEntry by piping it through 052 * a simple fixity-calculating InputStream 053 * 054 * @param digest the digest 055 * @return the fixity of this cache entry 056 * @throws RepositoryException if repository exception occurred 057 */ 058 @Override 059 public Collection<FixityResult> checkFixity(final String digest) 060 throws RepositoryException { 061 062 try (FixityInputStream fixityInputStream = new FixityInputStream(this.getInputStream(), 063 MessageDigest.getInstance(digest))) { 064 // exhaust our source 065 while (fixityInputStream.read(devNull) != -1) { } 066 067 final URI calculatedChecksum = ContentDigest.asURI(digest, 068 fixityInputStream.getMessageDigest().digest()); 069 final FixityResult result = 070 new FixityResultImpl(this, 071 fixityInputStream.getByteCount(), 072 calculatedChecksum); 073 074 LOGGER.debug("Got {}", result.toString()); 075 076 return asList(result); 077 } catch (final IOException e) { 078 LOGGER.debug("Got error closing input stream: {}", e); 079 throw new RepositoryRuntimeException(e); 080 } catch (final NoSuchAlgorithmException e1) { 081 throw new RepositoryRuntimeException(e1); 082 } 083 084 } 085}