/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sdb.layout2;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.slf4j.LoggerFactory;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.sdb.SDBException;
/** Operations associated with nodes and layout 2 (the Triples+Nodes layout)
*/
public class NodeLayout2
{
// Turn into the lexcial form
public static String nodeToLex(Node node)
{
if ( node.isURI() ) return node.getURI() ;
if ( node.isLiteral() ) return node.getLiteralLexicalForm() ;
if ( node.isBlank() ) return node.getBlankNodeId().getLabelString() ;
throw new SDBException("Can't create lexical representation for "+node) ;
}
public static String nodeToLexTruncate(Node node, int length)
{ return nodeToLexTruncate(node, length, null) ; }
public static String nodeToLexTruncate(Node node, int length, String logPrefix)
{
String lex = nodeToLex(node) ;
if ( length < 0 )
return lex ;
if ( lex.length() > length )
{
String tmp = "Too long ("+length+"/"+lex.length()+"): "+lex.substring(0,20)+"..." ;
if ( logPrefix != null )
tmp = logPrefix+": "+tmp ;
LoggerFactory.getLogger(NodeLayout2.class).warn(tmp) ;
lex = lex.substring(0, length) ;
}
return lex ;
}
public static int nodeToType(Node node)
{
return ValueType.lookup(node).getTypeId() ;
// ValueType vType = ValueType.lookup(node) ;
// if ( vType == ValueType.OTHER )
// throw new SDBException("Can't find node type for "+node) ;
// return vType.getTypeId() ;
}
public static String nodeToLang(Node node)
{
if ( !node.isLiteral() ) return "" ;
String lang = node.getLiteralLanguage() ;
if ( lang == null ) return "" ;
return lang ;
}
public static long hash(Node n)
{
// Get the bits and pieces for a value
String lexForm = null ;
if ( n.isURI() ) lexForm = n.getURI() ;
else if ( n.isLiteral() ) lexForm = n.getLiteralLexicalForm() ;
else if ( n.isBlank() ) lexForm = n.getBlankNodeLabel() ;
else throw new SDBException("Attempt to hash a variable") ;
String datatypeStr = "" ;
if ( n.isLiteral() )
datatypeStr = n.getLiteralDatatypeURI() ;
String langStr = "" ;
if ( n.isLiteral() )
langStr = n.getLiteralLanguage() ;
ValueType vType = ValueType.lookup(n) ;
return hash(lexForm,langStr,datatypeStr,vType.getTypeId());
}
public static long hash(String lex, String lang, String datatype, int type)
{
if ( datatype == null )
datatype = "" ;
if ( lang == null )
lang = "" ;
String toHash = lex + "|" + lang + "|" + datatype;
MessageDigest digest;
try
{
digest = MessageDigest.getInstance("MD5");
digest.update(toHash.getBytes("UTF8"));
digest.update((byte) type);
byte[] hash = digest.digest();
BigInteger bigInt = new BigInteger(hash);
return bigInt.longValue();
}
catch (NoSuchAlgorithmException e)
{
e.printStackTrace();
}
catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
return -1;
}
}