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;
import it.unimi.dsi.fastutil.objects.AbstractObject2ObjectFunction;
import it.unimi.dsi.fastutil.objects.Object2ObjectFunction;
import it.unimi.dsi.lang.MutableString;
import it.unimi.dsi.util.Interval;
import it.unimi.dsi.util.Intervals;
import it.unimi.dsi.util.PrefixMap;
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 prefix map.
*
* @author Alessandro Arrabito
* @author Sebastiano Vigna
*/
public class RemotePrefixMap extends RemoteTermMap implements PrefixMap<MutableString>, Serializable {
public final static byte GET_INTERVAL = 3;
public final static byte GET_PREFIX = 4;
public final static byte HAS_PREFIXES = 5;
static final long serialVersionUID = 1;
/** Whether the remote map implements {@link PrefixMap#prefixMap()}. */
private boolean hasPrefixes;
private AbstractObject2ObjectFunction<Interval, MutableString> prefixMap;
private Object2ObjectFunction<CharSequence, Interval> rangeMap;
public RemotePrefixMap( final SocketAddress address, final int size ) {
super( address, size );
hasPrefixes = hasPrefixes();
}
private void ensureConnection() throws IOException {
if ( remoteConnection == null ) remoteConnection = new RemoteIndexServerConnection( address, IndexServer.GET_PREFIX_MAP );
}
private boolean hasPrefixes() {
try {
ensureConnection();
remoteConnection.outputStream.writeByte( RemotePrefixMap.HAS_PREFIXES );
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 PrefixMap<? extends CharSequence> prefixMap;
public ServerThread( final Socket socket, final PrefixMap<? extends CharSequence> prefixMap ) throws IOException {
super( socket );
this.prefixMap = prefixMap;
}
public void run() {
try {
final MutableString s = new MutableString();
int command;
Interval interval;
for ( ;; ) {
command = inputStream.readByte();
if ( DEBUG ) LOGGER.debug( "Received remote command: " + command );
switch ( command ) {
case RemoteTermMap.GET_NUMBER:
outputStream.writeLong( prefixMap.getLong( s.readSelfDelimUTF8( (InputStream)inputStream ) ) );
outputStream.flush();
break;
case RemoteTermMap.GET_TERM:
new MutableString( prefixMap.list().get( inputStream.readInt() ) ).writeSelfDelimUTF8( (OutputStream)outputStream );
outputStream.flush();
break;
case RemoteTermMap.HAS_TERMS:
outputStream.writeBoolean( prefixMap.list() != null );
outputStream.flush();
break;
case RemotePrefixMap.GET_INTERVAL:
interval = prefixMap.rangeMap().get( s.readSelfDelimUTF8( (InputStream)inputStream ) );
outputStream.writeInt( interval.left );
outputStream.writeInt( interval.right );
outputStream.flush();
break;
case RemotePrefixMap.GET_PREFIX:
new MutableString( prefixMap.prefixMap().get( Interval.valueOf( inputStream.readInt(), inputStream.readInt() ) ) ).writeSelfDelimUTF8( (OutputStream)outputStream );
outputStream.flush();
break;
case RemotePrefixMap.HAS_PREFIXES:
outputStream.writeBoolean( prefixMap.prefixMap() != 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 Object2ObjectFunction<Interval, MutableString> prefixMap() {
if ( hasPrefixes && prefixMap == null ) prefixMap = new AbstractObject2ObjectFunction<Interval, MutableString>() {
private static final long serialVersionUID = 1L;
public boolean containsKey( Object o ) {
Interval interval = (Interval)o;
return interval != Intervals.EMPTY_INTERVAL && interval.left >= 0 && interval.right < RemotePrefixMap.this.size();
}
public MutableString get( Object o ) {
final Interval interval = (Interval)o;
try {
ensureConnection();
remoteConnection.outputStream.writeByte( RemotePrefixMap.GET_PREFIX );
remoteConnection.outputStream.writeInt( interval.left );
remoteConnection.outputStream.writeInt( interval.right );
remoteConnection.outputStream.flush();
return new MutableString().readSelfDelimUTF8( (InputStream)remoteConnection.inputStream );
}
catch ( Exception e ) {
throw new RuntimeException( e );
}
}
public int size() {
return -1;
}
};
return prefixMap;
}
public Object2ObjectFunction<CharSequence, Interval> rangeMap() {
if ( rangeMap == null ) rangeMap = new AbstractObject2ObjectFunction<CharSequence, Interval>() {
private static final long serialVersionUID = 1L;
public boolean containsKey( Object o ) {
return get( o ) != Intervals.EMPTY_INTERVAL;
}
public Interval get( Object o ) {
CharSequence prefix = (CharSequence)o;
try {
ensureConnection();
remoteConnection.outputStream.writeByte( RemotePrefixMap.GET_INTERVAL );
new MutableString( prefix ).writeSelfDelimUTF8( (OutputStream)remoteConnection.outputStream );
remoteConnection.outputStream.flush();
return Interval.valueOf( remoteConnection.inputStream.readInt(), remoteConnection.inputStream.readInt() );
}
catch ( Exception e ) {
throw new RuntimeException( e );
}
}
public int size() {
return -1;
}
};
return rangeMap;
}
}