package it.unimi.dsi.mg4j.index.remote;
/*
* MG4J: Managing Gigabytes for Java
*
* Copyright (C) 2006-2010 Sebastiano Vigna
*
* 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 3 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 program; if not, see <http://www.gnu.org/licenses/>.
*
*/
import it.unimi.dsi.util.StringMap;
import it.unimi.dsi.Util;
import it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction;
import it.unimi.dsi.fastutil.objects.AbstractObjectList;
import it.unimi.dsi.fastutil.objects.ObjectList;
import it.unimi.dsi.lang.MutableString;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.net.Socket;
import java.net.SocketAddress;
import org.apache.log4j.Logger;
/** A remote term map.
*
* @author Alessandro Arrabito
* @author Sebastiano Vigna
*/
public class RemoteTermMap extends AbstractObject2LongFunction<CharSequence> implements StringMap<MutableString>, Serializable {
protected final static byte GET_NUMBER = 0;
protected final static byte GET_TERM = 1;
protected final static byte HAS_TERMS = 2;
static final long serialVersionUID = 1;
/** The address of the index server.*/
protected SocketAddress address;
/** The size of the map. */
protected final int size;
/** The remote connection to the server (initialised lazily). */
protected transient RemoteIndexServerConnection remoteConnection;
/** The cached return value of {@link StringMap#list()}. */
protected ObjectList<MutableString> list;
/** Whether the remote map implements {@link StringMap#list()}. */
private boolean hasTerms;
public RemoteTermMap( final SocketAddress address, final int size ) {
this.address = address;
this.size = size;
this.hasTerms = hasTerms();
}
public int size() {
return size;
}
private void ensureConnection() throws IOException {
if ( remoteConnection == null ) remoteConnection = new RemoteIndexServerConnection( address, IndexServer.GET_TERM_MAP );
}
public boolean hasTerms() {
try {
ensureConnection();
remoteConnection.outputStream.writeByte( RemoteTermMap.HAS_TERMS );
remoteConnection.outputStream.flush();
return remoteConnection.inputStream.readBoolean();
}
catch ( Exception e ) {
throw new RuntimeException( e );
}
}
public static class ServerThread extends it.unimi.dsi.mg4j.index.remote.ServerThread {
private static final boolean DEBUG = false;
private final static Logger LOGGER = Util.getLogger( ServerThread.class );
/** The remoted term map. */
private final StringMap<? extends CharSequence> termMap;
public ServerThread( final Socket socket, final StringMap<? extends CharSequence> termMap ) throws IOException {
super( socket );
this.termMap = termMap;
}
public void run() {
try {
final MutableString s = new MutableString();
int command;
for ( ;; ) {
command = inputStream.readByte();
if ( DEBUG ) LOGGER.debug( "Received remote command: " + command );
switch ( command ) {
case RemoteTermMap.GET_NUMBER:
outputStream.writeLong( termMap.getLong( s.readSelfDelimUTF8( (InputStream)inputStream ) ) );
outputStream.flush();
break;
case RemoteTermMap.GET_TERM:
new MutableString( termMap.list().get( inputStream.readInt() ) ).writeSelfDelimUTF8( (OutputStream)outputStream );
outputStream.flush();
break;
case RemoteTermMap.HAS_TERMS:
outputStream.writeBoolean( termMap.list() != null );
outputStream.flush();
break;
default:
LOGGER.error( "Unknown remote command: " + command );
}
}
}
catch ( EOFException e ) {
LOGGER.warn( "The socket has been closed" );
}
catch ( Exception e ) {
LOGGER.fatal( e, e );
}
}
}
public ObjectList<MutableString> list() {
if ( hasTerms && list == null ) list = new AbstractObjectList<MutableString>() {
public MutableString get( int index ) {
try {
ensureConnection();
remoteConnection.outputStream.writeByte( RemoteTermMap.GET_TERM );
remoteConnection.outputStream.writeInt( index );
remoteConnection.outputStream.flush();
return new MutableString().readSelfDelimUTF8( (InputStream)remoteConnection.inputStream );
}
catch ( Exception e ) {
throw new RuntimeException( e );
}
}
public int size() {
return size;
}
};
return list;
}
public long getLong( Object o ) {
CharSequence term = (CharSequence)o;
try {
ensureConnection();
remoteConnection.outputStream.writeByte( RemoteTermMap.GET_NUMBER );
new MutableString( term ).writeSelfDelimUTF8( (OutputStream)remoteConnection.outputStream );
remoteConnection.outputStream.flush();
return remoteConnection.inputStream.readLong();
}
catch ( Exception e ) {
throw new RuntimeException( e );
}
}
public boolean containsKey( Object o ) {
return getLong( o ) != -1;
}
}