package it.unimi.dsi.mg4j.document;
/*
* MG4J: Managing Gigabytes for Java
*
* Copyright (C) 2005-2010 Paolo Boldi and 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.fastutil.io.BinIO;
import it.unimi.dsi.io.SafelyCloseable;
import it.unimi.dsi.io.WordReader;
import it.unimi.dsi.lang.MutableString;
import it.unimi.dsi.mg4j.document.DocumentFactory.FieldType;
import java.io.IOException;
import java.io.Reader;
/** An abstract, {@link it.unimi.dsi.io.SafelyCloseable safely closeable} implementation of a document collection.
*
* <p>This class provides ready-made implementation of the {@link #iterator()} method.
* Concrete subclasses are encouraged to provide optimised, reuse-oriented versions of the
* {@link #iterator()} method. Note that since this implementation
* uses {@link it.unimi.dsi.mg4j.document.DocumentCollection#document(int) document()}
* to implement the iterator, creating two iterators concurrently will usually lead
* to unpredictable results.
*
* <p>As a commodity, the {@link #ensureDocumentIndex(int)} method can be called
* whenever it is necessary to check that a document index is not
* out of range.
*/
public abstract class AbstractDocumentCollection extends AbstractDocumentSequence implements DocumentCollection, SafelyCloseable {
/** Symbolic names for common properties of a {@link it.unimi.dsi.mg4j.document.DocumentCollection}. */
public static enum PropertyKeys {
/** The number of documents in the collection. */
DOCUMENTS,
/** The number of terms in the collection. */
TERMS,
/** The number of nonterms in the collection, or -1 if this collection does not contain nonterms. */
NONTERMS,
/** The name of the {@link DocumentCollection} class. */
COLLECTIONCLASS,
}
/** Checks that the index is correct (between 0, inclusive, and {@link DocumentCollection#size()},
* exclusive), and throws an {@link IndexOutOfBoundsException} if the index is not correct.
*
* @param index the index to be checked.
*/
protected void ensureDocumentIndex( final int index ) {
if ( index < 0 || index >= size() )
throw new IndexOutOfBoundsException( Integer.toString( index ) );
}
public DocumentIterator iterator() throws IOException {
return new AbstractDocumentIterator() {
private int nextDocumentToBeReturned = 0;
private Document last;
public Document nextDocument() throws IOException {
if ( last != null ) last.close();
return last = nextDocumentToBeReturned < size() ? document( nextDocumentToBeReturned++ ) : null;
}
};
}
public String toString() {
return this.getClass().getName() + "[size: " + size() + " factory: " + factory() + "]";
}
/** Prints all documents in a given sequence.
*
* @param seq the sequence.
*/
public static void printAllDocuments( final DocumentSequence seq ) throws IOException {
DocumentIterator it = seq.iterator();
Document document;
int doc = 0;
while ( ( document = it.nextDocument() ) != null ) {
System.out.println( "**** Document # " + doc );
System.out.println( "* Title: " + document.title() );
System.out.println( "* URI: " + document.uri() );
System.out.println( "****" );
for ( int f = 0; f < seq.factory().numberOfFields(); f++ ) {
System.out.println( "** Field # " + f + ", " + seq.factory().fieldName( f ) );
Object field = document.content( f );
if ( seq.factory().fieldType( f ) == FieldType.TEXT ) {
Reader reader = (Reader)field;
WordReader wr = document.wordReader( f );
wr.setReader( reader );
MutableString word = new MutableString();
MutableString nonWord = new MutableString();
while ( wr.next( word, nonWord ) ) System.out.println( word.toString() + nonWord.toString() );
} else System.out.println( field );
}
doc++;
}
}
public static void main( final String[] arg ) throws Exception {
DocumentSequence coll = (DocumentSequence)BinIO.loadObject( arg[ 0 ] );
printAllDocuments( coll );
}
}