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Blazegraph Modifications to the DSI utils. This are forked from version 1.10.0 under LGPLv2.1.

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package it.unimi.dsi.util;

/*		 
 * Sux4J: Succinct data structures for Java
 *
 * Copyright (C) 2009 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.Util;
import it.unimi.dsi.fastutil.io.BinIO;
import it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction;
import it.unimi.dsi.fastutil.objects.Object2LongFunction;
import it.unimi.dsi.fastutil.objects.ObjectList;
import it.unimi.dsi.io.FileLinesCollection;
import it.unimi.dsi.lang.MutableString;

import java.io.IOException;
import java.io.Serializable;
import java.nio.charset.Charset;

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;
import com.martiansoftware.jsap.Switch;
import com.martiansoftware.jsap.UnflaggedOption;
import com.martiansoftware.jsap.stringparsers.ForNameStringParser;

/** A string map based on a function signed using the original list of strings. 
 * 
 * 

A minimal perfect hash function maps a set of string to an initial segment of the natural * numbers, but will actually map any string to that segment. We can check that * a string is part of the key set by hashing it to a value h, and checking that the h-th * string of the original list does coincide. Since, moreover, this class implements {@link StringMap}, * and thus {@linkplain #list() exposes the original list}, we have a two-way * dictionary. In other words, this is a full {@link StringMap} implementation. * *

Note that some care must be exercised: {@link CharSequence}'s contract does not * prescribe equality by content, so if your function behaves badly on some implementations of * {@link CharSequence} you might make the checks fail. To avoid difficulties, the * constructor checks that every string in the list is hashed correctly. * *

For the same reason, this class implements StringMap<MutableString>, and * requires that the list of strings provided at construction time is actually a list of * {@linkplain MutableString mutable strings}. * *

A typical usage of this class pairs a {@link FrontCodedStringList} with some kind * of succinct structure from Sux4J. * * @author Sebastiano Vigna * @since 1.0.8 */ public class LiterallySignedStringMap extends AbstractObject2LongFunction implements StringMap, Serializable { private static final long serialVersionUID = 0L; private static final Logger LOGGER = Util.getLogger( LiterallySignedStringMap.class ); /** The underlying map. */ protected final Object2LongFunction function; /** The underlying list. */ protected final ObjectList list; /** The size of {@link #list}. */ protected final int size; /** Creates a new shift-add-xor signed string map using a given hash map. * * @param function a function mapping each string in list to its ordinal position. * @param list a list of strings. */ public LiterallySignedStringMap( final Object2LongFunction function, final ObjectList list ) { this.function = function; this.list = list; size = list.size(); for( int i = 0; i < size; i++ ) if ( function.getLong( list.get( i ) ) != i ) throw new IllegalArgumentException( "Function and list do not agree" ); defRetValue = -1; } @SuppressWarnings("unchecked") public long getLong( final Object o ) { final CharSequence s = (CharSequence)o; final long index = function.getLong( s ); return index >= 0 && index < size && list.get( (int)index ).equals( s ) ? index : defRetValue; } @SuppressWarnings("unchecked") public Long get( final Object o ) { final CharSequence s = (CharSequence)o; final long index = function.getLong( s ); return index >= 0 && index < size && list.get( (int)index ).equals( s ) ? Long.valueOf( index ) : null; } public int size() { return function.size(); } public boolean containsKey( final Object o ) { return getLong( o ) != -1; } public ObjectList list() { return list; } @SuppressWarnings("unchecked") public static void main( final String[] arg ) throws IOException, JSAPException, ClassNotFoundException, SecurityException, NoSuchMethodException { final SimpleJSAP jsap = new SimpleJSAP( LiterallySignedStringMap.class.getName(), "Builds a shift-add-xor signed string map by reading a newline-separated list of strings and a function built on the same list of strings.", new Parameter[] { new FlaggedOption( "encoding", ForNameStringParser.getParser( Charset.class ), "UTF-8", JSAP.NOT_REQUIRED, 'e', "encoding", "The string file encoding." ), new Switch( "zipped", 'z', "zipped", "The string list is compressed in gzip format." ), new Switch( "text", 't', "text", "The string list actually a text file, with one string per line." ), new UnflaggedOption( "function", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.REQUIRED, JSAP.NOT_GREEDY, "The filename of the function to be signed." ), new UnflaggedOption( "list", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.REQUIRED, JSAP.NOT_GREEDY, "The filename of the serialised list of strings, or of a text file containing a list of strings, if -t is specified." ), new UnflaggedOption( "map", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.REQUIRED, JSAP.NOT_GREEDY, "The filename of the resulting map." ), }); JSAPResult jsapResult = jsap.parse( arg ); if ( jsap.messagePrinted() ) return; final String functionName = jsapResult.getString( "function" ); final String listName = jsapResult.getString( "list" ); final String mapName = jsapResult.getString( "map" ); final Charset encoding = (Charset)jsapResult.getObject( "encoding" ); final boolean zipped = jsapResult.getBoolean( "zipped" ); final boolean text = jsapResult.getBoolean( "text" ); ObjectList list = text ? new FileLinesCollection( listName, encoding.toString(), zipped ).allLines() : (ObjectList)BinIO.loadObject( listName ); LOGGER.info( "Signing..." ); BinIO.storeObject( new LiterallySignedStringMap( (Object2LongFunction)BinIO.loadObject( functionName ), list ), mapName ); LOGGER.info( "Completed." ); } }





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