/*
* JBoss, Home of Professional Open Source.
* Copyright 2009, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.system.server.profileservice.repository.clustered.local.file;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.jboss.logging.Logger;
import org.jboss.system.server.profileservice.repository.clustered.sync.AbstractSynchronizationAction;
import org.jboss.system.server.profileservice.repository.clustered.sync.ByteChunk;
import org.jboss.system.server.profileservice.repository.clustered.sync.ContentModification;
import org.jboss.system.server.profileservice.repository.clustered.sync.SynchronizationReadAction;
/**
* {@link SynchronizationReadAction} that reads from a {@link File}.
*
* @author Brian Stansberry
*
* @version $Revision: $
*/
public class FileReadAction extends AbstractSynchronizationAction<FileBasedSynchronizationActionContext>
implements SynchronizationReadAction<FileBasedSynchronizationActionContext>
{
private static final Logger log = Logger.getLogger(FileReadAction.class);
/**
* Max file transfer buffer size that we read at a time.
* This influences the number of times that we will invoke disk read/write file
* operations versus how much memory we will consume for a file transfer.
*/
public static final int MAX_CHUNK_BUFFER_SIZE = 512 * 1024;
private final File file;
private InputStream stream;
/**
* Create a new FileReadAction.
*
* @param file the file to read
* @param context the overall context of the modification
* @param modification the modification
*/
public FileReadAction(File file, FileBasedSynchronizationActionContext context,
ContentModification modification)
{
super(context, modification);
if (file == null)
{
throw new IllegalArgumentException("Null file");
}
this.file = file;
}
// ------------------------------------ RepositorySynchronizationReadAction
public ByteChunk getNextBytes() throws IOException
{
InputStream is = getInputStream();
byte[] b = null;
int read = -1;
synchronized (is)
{
b = new byte[MAX_CHUNK_BUFFER_SIZE];
read = is.read(b);
}
return new ByteChunk(b, read);
}
// -------------------------------------------------------------- Protected
@Override
protected void doCancel()
{
safeCloseStream();
}
@Override
protected void doCommit()
{
safeCloseStream();
}
@Override
protected void doComplete() throws Exception
{
safeCloseStream();
if (log.isTraceEnabled())
{
ContentModification mod = getRepositoryContentModification();
log.trace("doComplete(): " + mod.getType() + " for " + mod.getItem().getRelativePath());
}
}
@Override
protected boolean doPrepare()
{
safeCloseStream();
return true;
}
@Override
protected void doRollbackFromCancelled()
{
safeCloseStream();
}
@Override
protected void doRollbackFromComplete()
{
safeCloseStream();
}
@Override
protected void doRollbackFromOpen()
{
safeCloseStream();
}
@Override
protected void doRollbackFromPrepared()
{
safeCloseStream();
}
@Override
protected void doRollbackFromRollbackOnly()
{
safeCloseStream();
}
private synchronized InputStream getInputStream() throws IOException
{
State s = getState();
if (s != State.OPEN && s != State.CANCELLED)
{
throw new IllegalStateException("Cannot read when state is " + s);
}
if (stream == null)
{
FileInputStream fis = new FileInputStream(file);
stream = new BufferedInputStream(fis);
}
return stream;
}
private synchronized void safeCloseStream()
{
if (stream != null)
{
synchronized (stream)
{
try
{
stream.close();
}
catch (IOException e)
{
ContentModification mod = getRepositoryContentModification();
log.debug("Caught exception closing stream for " + mod.getRootName() +
" " + mod.getItem().getRelativePath(), e);
}
finally
{
stream = null;
}
}
}
}
}