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package it.unimi.dsi.big.mg4j.document;
/*
* MG4J: Managing Gigabytes for Java (big)
*
* Copyright (C) 2005-2011 Paolo Boldi
*
* 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 Each instance of this class has an associated zip file. Each Zip entry corresponds to a document:
* the title is recorded in the comment field, whereas the
* URI is written with {@link MutableString#writeSelfDelimUTF8(java.io.OutputStream)}
* directly to the zipped output stream. When building an exact
* {@linkplain it.unimi.dsi.big.mg4j.document.ZipDocumentCollection}
* subsequent word/nonword pairs are written in the same way, and
* delimited by two empty strings. If the collection is not exact, just words are written,
* and delimited by an empty string. Non-text fields are written directly to the zipped output stream
* as serialised objects.
*
*
The collection will produce the same documents as the original sequence whence it
* was produced, in the following sense:
*
*
* - the resulting collection has as many document as the original sequence, in the same order, with
* the same titles and URI;
*
- every document has the same number of fields, with the same names and types;
*
- non-textual non-virtual fields will be written out as objects, so they need to be serializable;
*
- virtual fields will be written as a sequence of {@linkplain MutableString#writeSelfDelimUTF8(java.io.DataOutput) self-delimiting UTF-8 mutable strings}
* starting with the number of fragments (converted into a string with {@link String#valueOf(int)}),
* followed by a pair of strings for each fragment (the first string being the document specifier,
* and the second being the associated text);
*
- textual fields will be written out in such a way that, when reading them, the same sequence
* of words and non-words will be produced; alternatively, one may produce a collection that only
* copies words (non-words are not copied).
*
*
* The collection will be, as any other collection, serialized on a file, but it will refer to another
* zip file that is going to contain the documents themselves. Please use {@link AbstractDocumentSequence#load(CharSequence)}
* to load instances of this collection.
*
*
Note that the zip format is not designed for a large number of files. This class is mainly a useful example,
* and a handy way to build quickly a collection containing all fields at indexing time. For a more efficient
* kind of collection, see {@link SimpleCompressedDocumentCollection}.
*
*
Warning: the {@link java.io.Reader} returned by {@link it.unimi.dsi.big.mg4j.document.Document#content(int)}
* for documents produced by this factory is just obtained as the concatenation of words and non-words returned by
* the word reader for that field. In case the collection is not exact, nonwords are substituted by a space.
*/
public class ZipDocumentCollection extends AbstractDocumentCollection implements Serializable {
private static final long serialVersionUID = 2L;
public final static String ZIP_EXTENSION = ".zip";
/** Symbolic names for common properties of a {@link it.unimi.dsi.big.mg4j.document.DocumentCollection}. */
public static enum PropertyKeys {
/** The serialised collection. */
COLLECTION,
}
private static final Logger LOGGER = Util.getLogger( ZipDocumentCollection.class );
private static final boolean DEBUG = false;
/** The name of the zip collection file. */
private String zipFilename;
/** The zip collection file. */
private transient ZipFile zipFile;
/** The factory used for the original document sequence. */
private final DocumentFactory underlyingFactory;
/** The factory used for this document collection. */
private final DocumentFactory factory;
/** The number of documents. */
private final long numberOfDocuments;
/** true iff this is an exact reproduction of the original sequence (i.e., if also non-words are preserved). */
private final boolean exact;
/** A factory tightly coupled to a {@link ZipDocumentCollection}. */
protected static class ZipFactory extends AbstractDocumentFactory {
private static final long serialVersionUID = 1L;
private final boolean exact;
private final DocumentFactory underlyingFactory;
protected ZipFactory( final DocumentFactory underlyingFactory, final boolean exact ) {
this.underlyingFactory = underlyingFactory;
this.exact = exact;
}
public ZipFactory copy() {
return this;
}
public int numberOfFields() {
return underlyingFactory.numberOfFields();
}
public String fieldName( final int field ) {
ensureFieldIndex( field );
return underlyingFactory.fieldName( field );
}
public int fieldIndex( final String fieldName ) {
return underlyingFactory.fieldIndex( fieldName );
}
public FieldType fieldType( final int field ) {
ensureFieldIndex( field );
return underlyingFactory.fieldType( field );
}
public Document getDocument( final InputStream rawContent, final Reference2ObjectMap,Object> metadata ) throws IOException {
return new AbstractDocument() {
final DataInputStream rawContentDataInputStream = new DataInputStream( rawContent );
int nextFieldToRead = 0;
final MutableString uri = new MutableString();
{
uri.readSelfDelimUTF8( rawContent ).compact();
}
@Override
public void close() throws IOException {
super.close();
rawContent.close();
}
public CharSequence title() {
return (CharSequence)metadata.get( MetadataKeys.TITLE );
}
public String toString() {
return title().toString();
}
public CharSequence uri() {
return uri.length() == 0 ? null : uri;
}
/** Skips until the end of the current field, and increments nextFieldToRead.
* @throws ClassNotFoundException
* @throws IOException
*/
private void skipOneField() throws IOException, ClassNotFoundException {
switch( fieldType( nextFieldToRead ) ) {
case TEXT:
MutableString word = new MutableString();
MutableString nonWord = new MutableString();
do {
word.readSelfDelimUTF8( rawContent );
if ( exact ) nonWord.readSelfDelimUTF8( rawContent );
} while ( word.length() > 0 || ( exact && nonWord.length() > 0 ) );
break;
case VIRTUAL:
final int nfrag = rawContentDataInputStream.readInt();
for ( int i = 0; i < 2 * nfrag; i++ ) MutableString.skipSelfDelimUTF8( rawContent );
break;
default: // Non-text and non-virtual
new ObjectInputStream( rawContent ).readObject();
}
nextFieldToRead++;
}
/** Skips to the given field.
*
* @param field the field to skip to.
* @throws IOException
* @throws ClassNotFoundException
*/
private void skipToField( final int field ) throws IOException, ClassNotFoundException {
if ( nextFieldToRead > field ) throw new IllegalStateException( "Trying to skip to field " + field + " after " + nextFieldToRead );
while ( nextFieldToRead < field ) skipOneField();
}
public Object content( final int field ) {
ensureFieldIndex( field );
Object result = null;
if ( DEBUG ) LOGGER.debug( "Called content(" + field + "); nextField:" + nextFieldToRead );
try {
skipToField( field );
if ( fieldType( nextFieldToRead ) == FieldType.VIRTUAL ) {
final int nfrag = rawContentDataInputStream.readInt();
MutableString doc = new MutableString();
MutableString text = new MutableString();
VirtualDocumentFragment[] fragArray = new VirtualDocumentFragment[ nfrag ];
for ( int i = 0; i < nfrag; i++ ) {
doc.readSelfDelimUTF8( rawContent );
text.readSelfDelimUTF8( rawContent );
fragArray[ i ] = new AnchorExtractor.Anchor( doc.copy(), text.copy() );
}
result = new ObjectArrayList( fragArray );
}
else if ( fieldType( nextFieldToRead ) != FieldType.TEXT ) {
result = new ObjectInputStream( rawContent ).readObject();
if ( DEBUG ) LOGGER.debug( "Read " + result + " from field " + fieldName( nextFieldToRead ) + " of object " + title() );
nextFieldToRead++;
}
else {
if ( DEBUG ) LOGGER.debug( "Returning reader for " + field );
result = new Reader() {
FastBufferedReader fbr = null;
int f = field;
public void close() {}
public int read( final char[] cbuf, final int off, final int len ) throws IOException {
if ( fbr == null ) {
if ( DEBUG ) LOGGER.debug( "Initialising reader for content " + f );
MutableString text = new MutableString();
MutableString word = new MutableString();
MutableString nonWord = new MutableString();
do {
text.append( word.readSelfDelimUTF8( rawContent ) );
if ( exact ) text.append( nonWord.readSelfDelimUTF8( rawContent ) );
else text.append( ' ' );
} while ( word.length() > 0 || ( exact && nonWord.length() > 0 ) );
fbr = new FastBufferedReader( text );
nextFieldToRead++;
}
return fbr.read( cbuf, off, len );
}
};
}
} catch ( IOException e ) {
throw new RuntimeException( e );
} catch (ClassNotFoundException e) {
throw new RuntimeException( e );
}
return result;
}
public WordReader wordReader( final int field ) {
ensureFieldIndex( field );
if ( DEBUG ) LOGGER.debug( "Called wordReader(" + field + ")" );
try {
skipToField( field );
} catch ( Exception e ) {
throw new RuntimeException( e );
}
//logger.debug( "Asked for a new word reader for field " + fieldName( field ) );
switch ( fieldType( field ) ) {
case TEXT:
return new WordReader() {
private static final long serialVersionUID = 1L;
public boolean next( final MutableString word, final MutableString nonWord ) throws IOException {
try {
word.readSelfDelimUTF8( rawContent );
}
catch( EOFException e ) {
return false; // TODO: a bit raw
}
nonWord.length( 0 );
if ( exact ) {
try {
nonWord.readSelfDelimUTF8( rawContent );
}
catch( EOFException e ) {
return true; // TODO: a bit raw
}
}
else nonWord.append( ' ' );
final boolean goOn = word.length() != 0 || ( exact && nonWord.length() != 0 );
if ( DEBUG ) LOGGER.debug( "Got word <" + word + "|" + nonWord + "> exact=" + exact + " returning " + goOn );
if ( ! goOn ) nextFieldToRead++;
return goOn;
}
public WordReader setReader( final Reader reader ) {
return this;
}
public WordReader copy() {
throw new UnsupportedOperationException();
}
};
case VIRTUAL:
return new FastBufferedReader();
default:
return null;
}
}
};
}
}
private void initZipFile() {
try {
zipFile = new ZipFile( zipFilename );
}
// We leave the possibility for a filename() to fix the problem and load the right zipfile.
catch( Exception e ) {}
}
private void ensureZipFile() {
if ( zipFile == null ) throw new IllegalStateException( "The .zip file used by this " + ZipDocumentCollection.class.getSimpleName() + " has not been loaded correctly; please use " + AbstractDocumentSequence.class.getName() + ".load() or call filename() after deserialising this instance" );
}
/** Constructs a document collection (for reading) corresponding to a given zip collection file.
*
* @param zipFilename the filename of the zip collection.
* @param underlyingFactory the underlying document factory.
* @param numberOfDocuments2 the number of documents.
* @param exact true iff this is an exact reproduction of the original sequence.
*/
public ZipDocumentCollection( final String zipFilename, final DocumentFactory underlyingFactory, final long numberOfDocuments2, final boolean exact ) {
this.zipFilename = zipFilename;
this.underlyingFactory = underlyingFactory;
this.numberOfDocuments = numberOfDocuments2;
this.exact = exact;
// Creates the factory
factory = new ZipFactory( underlyingFactory, exact );
initZipFile();
}
@Override
public void filename( CharSequence filename ) throws IOException {
/* If we don't have a zipFile, we try to get it relatively to the basename.
* We also store the resulting filename, so copy() should work. */
if ( zipFile == null ) {
zipFilename = new File( new File( filename.toString() ).getParentFile(), zipFilename ).toString();
zipFile = new ZipFile( zipFilename );
}
}
private void readObject( final ObjectInputStream s ) throws IOException, ClassNotFoundException {
s.defaultReadObject();
initZipFile();
}
public ZipDocumentCollection copy() {
return new ZipDocumentCollection( zipFilename, underlyingFactory, numberOfDocuments, exact );
}
public DocumentFactory factory() {
return factory;
}
public long size() {
return numberOfDocuments;
}
private ZipEntry getEntry( final int index ) {
ensureDocumentIndex( index );
ensureZipFile();
final ZipEntry entry = zipFile.getEntry( Integer.toString( index ) );
if ( entry == null ) throw new NoSuchElementException( "Failure retrieving entry " + index );
return entry;
}
public Document document( final long index ) throws IOException {
ensureDocumentIndex( index );
final ZipEntry entry = getEntry( (int)index );
final Reference2ObjectMap,Object> metadata = metadata( index, entry );
InputStream is = zipFile.getInputStream( entry );
return factory.getDocument( is, metadata );
}
private Reference2ObjectMap,Object> metadata( final long index, ZipEntry entry ) {
ensureDocumentIndex( index );
if ( entry == null ) entry = getEntry( (int)index );
final Reference2ObjectArrayMap,Object> metadata = new Reference2ObjectArrayMap,Object>( 1 );
metadata.put( MetadataKeys.TITLE, entry.getComment() );
return metadata;
}
public Reference2ObjectMap,Object> metadata( final long index ) {
return metadata( index, null );
}
public InputStream stream( final long index ) throws IOException {
ensureDocumentIndex( index );
final ZipEntry entry = getEntry ( (int)index );
entry.getComment(); // Just skip title
InputStream is = zipFile.getInputStream( entry );
return is;
}
public DocumentIterator iterator() {
try {
return new AbstractDocumentIterator() {
final Reference2ObjectArrayMap,Object> metadata = new Reference2ObjectArrayMap,Object>( new Enum[ 1 ], new Object[ 1 ] );
ZipInputStream zis = new ZipInputStream( new FileInputStream( zipFile.getName() ) );
public Document nextDocument() throws IOException {
ZipEntry entry;
String name;
do {
entry = zis.getNextEntry();
if ( entry == null ) return null;
name = entry.getName();
} while ( !Character.isDigit( name.charAt( 0 ) ) );
String title = entry.getComment();
if ( DEBUG ) LOGGER.debug( "Reading sequentially document " + title + ", name: " + entry.getName() );
InputStream is = zipFile.getInputStream( entry );
metadata.put( MetadataKeys.TITLE, title );
return factory.getDocument( is, metadata );
}
};
} catch ( FileNotFoundException e ) {
throw new RuntimeException( e );
}
}
public void close() throws IOException {
super.close();
if ( zipFile != null ) zipFile.close();
}
}