/* $HeadURL$
* $Id$
*
* Copyright (c) 2009-2010 DuraSpace
* http://duraspace.org
*
* In collaboration with Topaz Inc.
* http://www.topazproject.org
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.akubraproject.mem;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URI;
import java.util.Map;
import org.akubraproject.Blob;
import org.akubraproject.BlobStoreConnection;
import org.akubraproject.DuplicateBlobException;
import org.akubraproject.MissingBlobException;
import org.akubraproject.impl.AbstractBlob;
import org.akubraproject.impl.StreamManager;
/**
* Simple in-memory blob store.
*
* @author Ronald Tschalär
*/
class MemBlob extends AbstractBlob {
private final Map<URI, MemData> blobs;
private final StreamManager streamMgr;
/**
* Create a new in-memory blob.
*
* @param id the blob's id
* @param blobs the blob-map to use (shared, hence needs to be synchronized)
* @param streamMgr the stream-manager to use
* @param owner the blob-store connection we belong to
*/
MemBlob(URI id, Map<URI, MemData> blobs, StreamManager streamMgr, BlobStoreConnection owner) {
super(owner, id);
this.blobs = blobs;
this.streamMgr = streamMgr;
}
@Override
public URI getCanonicalId() {
return getId();
}
@Override
public boolean exists() throws IOException {
ensureOpen();
synchronized (blobs) {
return blobs.containsKey(id);
}
}
@Override
public void delete() throws IOException {
ensureOpen();
synchronized (blobs) {
blobs.remove(id);
}
}
@Override
public Blob moveTo(URI blobId, Map<String, String> hints)
throws IOException, MissingBlobException, NullPointerException, IllegalArgumentException,
DuplicateBlobException {
ensureOpen();
MemBlob dest = (MemBlob)getConnection().getBlob(blobId, hints);
synchronized (blobs) {
if (dest.exists())
throw new DuplicateBlobException(blobId, "Destination blob already exists");
MemData data = blobs.remove(id);
if (data == null)
throw new MissingBlobException(getId());
blobs.put(dest.getId(), data);
}
return dest;
}
@Override
public InputStream openInputStream() throws IOException {
ensureOpen();
return streamMgr.manageInputStream(getConnection(), getData().getInputStream());
}
@Override
public OutputStream openOutputStream(long estimatedSize, boolean overwrite) throws IOException {
ensureOpen();
MemData data;
synchronized (blobs) {
data = blobs.get(id);
if (!overwrite && data != null)
throw new DuplicateBlobException(getId(), "Blob already exists");
if (data == null || estimatedSize > data.bufferSize()) {
data = new MemData(Math.max((int) Math.min(estimatedSize, Integer.MAX_VALUE), 1024));
blobs.put(id, data);
} else {
data.reset();
}
}
return streamMgr.manageOutputStream(getConnection(), data);
}
@Override
public long getSize() throws IOException {
ensureOpen();
return getData().size();
}
private MemData getData() throws MissingBlobException {
synchronized (blobs) {
MemData data = blobs.get(id);
if (data == null)
throw new MissingBlobException(getId());
return data;
}
}
}