org.jactr.tools.async.message.ast.BaseASTMessage.java Source code

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Here is the source code for org.jactr.tools.async.message.ast.BaseASTMessage.java

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/*
 * Created on Feb 22, 2007 Copyright (C) 2001-6, Anthony Harrison anh23@pitt.edu
 * (jactr.org) This library 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 library 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
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA 02111-1307 USA
 */
package org.jactr.tools.async.message.ast;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.Serializable;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.antlr.runtime.tree.CommonTree;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jactr.io.antlr3.serialization.Serializer;
import org.jactr.tools.async.message.BaseMessage;

/**
 * @author developer
 */
public class BaseASTMessage extends BaseMessage implements Serializable, IASTMessage {
    /**
     * 
     */
    private static final long serialVersionUID = -7905429360085152901L;

    /**
     * logger definition
     */
    static private final Log LOGGER = LogFactory.getLog(BaseASTMessage.class);

    private transient CommonTree _ast;

    private transient boolean _compress;

    static private transient ThreadLocal<ByteArrayOutputStream> _localBAOS = new ThreadLocal<ByteArrayOutputStream>();

    static private transient ThreadLocal<byte[]> _localInput = new ThreadLocal<byte[]>();

    public BaseASTMessage(CommonTree ast) {
        _ast = ast;
    }

    public void compressAST() {
        _compress = true;
    }

    public CommonTree getAST() {
        return _ast;
    }

    protected void setAST(CommonTree ast) {
        _ast = ast;
    }

    private void writeObject(java.io.ObjectOutputStream out) throws IOException {
        out.defaultWriteObject();
        if (_ast != null) {
            out.writeBoolean(true);
            out.writeBoolean(_compress);

            if (_compress) {
                /*
                 * go to a GZIPOutputStream
                 */
                ByteArrayOutputStream baos = _localBAOS.get();
                if (baos == null) {
                    baos = new ByteArrayOutputStream();
                    _localBAOS.set(baos);
                }
                baos.reset();

                DataOutputStream zip = new DataOutputStream(new GZIPOutputStream(baos));
                Serializer.write(_ast, zip);
                zip.flush();
                zip.close();
                // byte[] bytes = baos.toByteArray();

                if (LOGGER.isDebugEnabled())
                    LOGGER.debug(String.format("Writing %d compressed bytes", baos.size()));

                out.writeInt(baos.size());
                baos.writeTo(out);

                // if (LOGGER.isDebugEnabled())
                // LOGGER.debug("Compressed AST to "+bytes.length);
                // out.writeInt(bytes.length);
                // out.write(bytes);
            } else
                Serializer.write(_ast, out);
        } else
            out.writeBoolean(false);
    }

    private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
        in.defaultReadObject();
        boolean astIsNotNull = in.readBoolean();
        if (astIsNotNull) {
            boolean wasCompressed = in.readBoolean();

            if (wasCompressed) {
                /*
                 * pull through GZIPInputStream. this can be done more effeciently..
                 */
                int len = in.readInt();

                byte[] bytes = _localInput.get();
                if (bytes == null || bytes.length < len) {
                    bytes = new byte[len];
                    _localInput.set(bytes);
                }

                if (LOGGER.isDebugEnabled())
                    LOGGER.debug("Reading " + len + " bytes to decompress");

                in.read(bytes, 0, len);

                // in.readFully(bytes);

                ByteArrayInputStream bais = new ByteArrayInputStream(bytes, 0, len);
                DataInputStream zip = new DataInputStream(new GZIPInputStream(bais));
                _ast = Serializer.read(zip);
            } else
                _ast = Serializer.read(in);
        }
    }
}