Package org.teiid.transport

Source Code of org.teiid.transport.ObjectDecoder

/*
* JBoss, Home of Professional Open Source
*
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* by the @author tags. See the COPYRIGHT.txt 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.teiid.transport;

import java.io.BufferedOutputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.StreamCorruptedException;
import java.util.List;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBufferInputStream;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
import org.jboss.netty.handler.codec.serialization.CompatibleObjectDecoder;
import org.jboss.netty.handler.codec.serialization.CompatibleObjectEncoder;
import org.jboss.netty.handler.codec.serialization.ObjectEncoder;
import org.teiid.common.buffer.FileStore;
import org.teiid.common.buffer.FileStoreInputStreamFactory;
import org.teiid.common.buffer.StorageManager;
import org.teiid.core.types.Streamable;
import org.teiid.core.types.InputStreamFactory.StreamFactoryReference;
import org.teiid.core.util.ExternalizeUtil;
import org.teiid.netty.handler.codec.serialization.CompactObjectInputStream;
import org.teiid.netty.handler.codec.serialization.ObjectEncoderOutputStream;


/**
* A decoder which deserializes the received {@link ChannelBuffer}s into Java
* objects.
* <p>
* Please note that the serialized form this decoder expects is not
* compatible with the standard {@link ObjectOutputStream}.  Please use
* {@link ObjectEncoder} or {@link ObjectEncoderOutputStream} to ensure the
* interoperability with this decoder.
* <p>
* Unless there's a requirement for the interoperability with the standard
* object streams, it is recommended to use {@link ObjectEncoder} and
* {@link ObjectDecoder} rather than {@link CompatibleObjectEncoder} and
* {@link CompatibleObjectDecoder}.
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Trustin Lee (tlee@redhat.com)
*
* @version $Rev: 381 $, $Date: 2008-10-01 20:06:18 +0900 (Wed, 01 Oct 2008) $
*
* @apiviz.landmark
*/
public class ObjectDecoder extends FrameDecoder {
 
  public static final long MAX_LOB_SIZE = 1l << 32;

    private final int maxObjectSize;
    private final ClassLoader classLoader;
   
    private Object result;
    private int streamIndex;
    private OutputStream stream;
    private List<StreamFactoryReference> streams;
    private StorageManager storageManager;
    private FileStore store;

    /**
     * Creates a new decoder with the specified maximum object size.
     *
     * @param maxObjectSize  the maximum byte length of the serialized object.
     *                       if the length of the received object is greater
     *                       than this value, {@link StreamCorruptedException}
     *                       will be raised.
     * @param classLoader    the {@link ClassLoader} which will load the class
     *                       of the serialized object
     */
    public ObjectDecoder(int maxObjectSize, ClassLoader classLoader, StorageManager storageManager) {
        if (maxObjectSize <= 0) {
            throw new IllegalArgumentException("maxObjectSize: " + maxObjectSize);
        }

        this.maxObjectSize = maxObjectSize;
        this.classLoader = classLoader;
        this.storageManager = storageManager;
    }

    @Override
    protected Object decode(
            ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
      if (result == null) {
          if (buffer.readableBytes() < 4) {
              return null;
          }
 
          int dataLen = buffer.getInt(buffer.readerIndex());
          if (dataLen <= 0) {
              throw new StreamCorruptedException("invalid data length: " + dataLen);
          }
          if (dataLen > maxObjectSize) {
              throw new StreamCorruptedException(
                      "data length too big: " + dataLen + " (max: " + maxObjectSize + ')');
          }
 
          if (buffer.readableBytes() < dataLen + 4) {
              return null;
          }
 
          buffer.skipBytes(4);
          CompactObjectInputStream cois = new CompactObjectInputStream(
                  new ChannelBufferInputStream(buffer, dataLen), classLoader);
          result = cois.readObject();
          streams = ExternalizeUtil.readList(cois, StreamFactoryReference.class);
          streamIndex = 0;
      }
      while (streamIndex < streams.size()) {
        if (buffer.readableBytes() < 2) {
              return null;
          }
          int dataLen = buffer.getShort(buffer.readerIndex()) & 0xffff;
          if (buffer.readableBytes() < dataLen + 2) {
              return null;
          }
          buffer.skipBytes(2);
         
          if (stream == null) {
            store = storageManager.createFileStore("temp-stream"); //$NON-NLS-1$
            StreamFactoryReference sfr = streams.get(streamIndex);
            sfr.setStreamFactory(new FileStoreInputStreamFactory(store, Streamable.ENCODING));
            this.stream = new BufferedOutputStream(store.createOutputStream());
          }
          if (dataLen == 0) {
            stream.close();
            stream = null;
            streamIndex++;
            continue;
          }
          if (store.getLength() + dataLen > MAX_LOB_SIZE) {
            throw new StreamCorruptedException(
                      "lob too big: " + store.getLength() + dataLen + " (max: " + MAX_LOB_SIZE + ')');
          }
          buffer.readBytes(this.stream, dataLen);
      }
        Object toReturn = result;
        result = null;
        streams = null;
        stream = null;
        store = null;
        return toReturn;
    }
}
TOP

Related Classes of org.teiid.transport.ObjectDecoder

TOP
Copyright © 2015 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.