scanmetadata.java

MG4J (Managing Gigabytes for Java) is a free full-text search engine for large document collections

package it.unimi.dsi.mg4j.tool;

/*		 
 * MG4J: Managing Gigabytes for Java
 *
 * Copyright (C) 2006-2007 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 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 program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 */

import it.unimi.dsi.fastutil.io.FastBufferedOutputStream;
import it.unimi.dsi.mg4j.document.Document;
import it.unimi.dsi.mg4j.document.DocumentCollection;
import it.unimi.dsi.mg4j.document.DocumentIterator;
import it.unimi.dsi.mg4j.document.DocumentSequence;
import it.unimi.dsi.mg4j.document.IdentityDocumentFactory;
import it.unimi.dsi.Util;
import it.unimi.dsi.mg4j.util.MG4JClassParser;
import it.unimi.dsi.lang.MutableString;
import it.unimi.dsi.logging.ProgressLogger;

import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;

import org.apache.log4j.Logger;

import com.martiansoftware.jsap.FlaggedOption;
import com.martiansoftware.jsap.JSAP;
import com.martiansoftware.jsap.JSAPException;
import com.martiansoftware.jsap.JSAPResult;
import com.martiansoftware.jsap.Parameter;
import com.martiansoftware.jsap.SimpleJSAP;


/** Scans a document sequence and prints on standard output the corresponding URIs.
 * 
 * <p>This tool is a necessary intermediate step for the construction of an index with
 * virtual fields.
 * 
 * @author Sebastiano Vigna
 * @since 1.1
 */

public class ScanMetadata {
	private final static Logger LOGGER = Util.getLogger( ScanMetadata.class );

	private static final char[] LINE_TERMINATORS = new char[] { '\n', '\r' };
	private static final char[] SPACES = new char[] { ' ', ' ' };
	
	public static void main( final String[] arg ) throws JSAPException, InvocationTargetException, NoSuchMethodException, ClassNotFoundException, IOException, IllegalAccessException, InstantiationException {

		SimpleJSAP jsap = new SimpleJSAP( ScanMetadata.class.getName(), "Scans and prints to standard output metadata of a collection. All line terminators in the metadata will be substituted with spaces.",
			new Parameter[] {
				new FlaggedOption( "sequence", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.NOT_REQUIRED, 'S', "sequence", "A serialised document sequence that will be used instead of stdin." ),
				new FlaggedOption( "delimiter", JSAP.INTEGER_PARSER, Integer.toString( Scan.DEFAULT_DELIMITER ), JSAP.NOT_REQUIRED, 'd', "delimiter", "The document delimiter." ),
				new FlaggedOption( "factory", MG4JClassParser.getParser(), IdentityDocumentFactory.class.getName(), JSAP.NOT_REQUIRED, 'f', "factory", "A document factory with a standard constructor." ),
				new FlaggedOption( "property", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.NOT_REQUIRED, 'p', "property", "A 'key=value' specification, or the name of a property file" ).setAllowMultipleDeclarations( true ),
				new FlaggedOption( "renumber", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.NOT_REQUIRED, 'r', "renumber", "The filename of a document renumbering." ),
				new FlaggedOption( "logInterval", JSAP.LONG_PARSER, Long.toString( ProgressLogger.DEFAULT_LOG_INTERVAL ), JSAP.NOT_REQUIRED, 'l', "log-interval", "The minimum time interval between activity logs in milliseconds." ),
				new FlaggedOption( "titles", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.NOT_REQUIRED, 't', "titles", "The resulting document titles." ),
				new FlaggedOption( "uris", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.NOT_REQUIRED, 'u', "uris", "The resulting document URIs." ),
		});

		JSAPResult jsapResult = jsap.parse( arg );
		if ( jsap.messagePrinted() ) return;

		DocumentSequence documentSequence = Scan.getSequence( jsapResult.getString( "sequence" ), jsapResult.getClass( "factory" ), jsapResult.getStringArray( "property" ), jsapResult.getInt( "delimiter" ), LOGGER );

		if ( ! jsapResult.userSpecified( "uris" ) && ! jsapResult.userSpecified( "titles" ) ) 
			throw new IllegalArgumentException( "You specify either a title or a URI output file" );
		
		Util.ensureLog4JIsConfigured();

		final DocumentIterator documentIterator = documentSequence.iterator();

		Document document;
		FastBufferedOutputStream uriStream = null, titleStream = null;
		
		if ( jsapResult.userSpecified( "uris" ) ) uriStream = new FastBufferedOutputStream( new FileOutputStream( jsapResult.getString( "uris" ) ) );
		if ( jsapResult.userSpecified( "titles" ) ) titleStream = new FastBufferedOutputStream( new FileOutputStream( jsapResult.getString( "titles" ) ) );
		
		MutableString s = new MutableString();

		ProgressLogger progressLogger = new ProgressLogger( LOGGER, jsapResult.getLong( "logInterval" ), "documents" );
		if ( documentSequence instanceof DocumentCollection ) progressLogger.expectedUpdates = ((DocumentCollection)documentSequence).size();
		progressLogger.start( "Scanning..." );
		
		while( ( document = documentIterator.nextDocument() ) != null ) {
			if ( uriStream != null ) {
				s.replace( document.uri() );
				s.replace( LINE_TERMINATORS, SPACES );
				s.writeUTF8( uriStream );
				uriStream.write( '\n' );
			}
			if ( titleStream != null ) {
				s.replace( document.title() );
				s.replace( LINE_TERMINATORS, SPACES );
				s.writeUTF8( titleStream );
				titleStream.write( '\n' );
			}
			progressLogger.lightUpdate();
		}
		
		progressLogger.done();
		if ( uriStream != null ) uriStream.close();
		if ( titleStream != null ) titleStream.close();
	}
}