/*
* 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.tdb.lib;
import static com.hp.hpl.jena.tdb.sys.SystemTDB.LenNodeHash ;
import java.nio.ByteBuffer ;
import java.security.DigestException ;
import java.security.MessageDigest ;
import java.security.NoSuchAlgorithmException ;
import java.util.Iterator ;
import org.apache.jena.atlas.iterator.Iter ;
import org.apache.jena.atlas.iterator.Transform ;
import org.apache.jena.atlas.lib.Bytes ;
import org.apache.jena.atlas.lib.Pool ;
import org.apache.jena.atlas.lib.PoolBase ;
import org.apache.jena.atlas.lib.PoolSync ;
import org.apache.jena.atlas.logging.Log ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.tdb.TDBException ;
import com.hp.hpl.jena.tdb.base.block.Block ;
import com.hp.hpl.jena.tdb.base.objectfile.ObjectFile ;
import com.hp.hpl.jena.tdb.base.record.Record ;
import com.hp.hpl.jena.tdb.nodetable.NodeTable ;
import com.hp.hpl.jena.tdb.nodetable.Nodec ;
import com.hp.hpl.jena.tdb.nodetable.NodecSSE ;
import com.hp.hpl.jena.tdb.store.Hash ;
import com.hp.hpl.jena.tdb.store.NodeId ;
import com.hp.hpl.jena.tdb.store.NodeType ;
public class NodeLib
{
private static Nodec nodec = new NodecSSE() ;
// Characters in IRIs that are illegal and cause SSE problems, but we wish to keep.
final private static char MarkerChar = '_' ;
final private static char[] invalidIRIChars = { MarkerChar , ' ' } ;
public static long encodeStore(Node node, ObjectFile file)
{
// Buffer pool?
// Nodes can be writtern during reads.
// Make sure this operation is sync'ed.
int maxSize = nodec.maxSize(node) ;
Block block = file.allocWrite(maxSize) ;
try {
int len = nodec.encode(node, block.getByteBuffer(), null) ;
file.completeWrite(block) ;
return block.getId() ;
} catch (TDBException ex)
{
file.abortWrite(block) ;
throw ex ;
}
}
public static Node fetchDecode(long id, ObjectFile file)
{
ByteBuffer bb = file.read(id) ;
if ( bb == null )
return null ;
return decode(bb) ;
}
/** Encode a node - pref use encodeStore */
public static ByteBuffer encode(Node node)
{
int maxSize = nodec.maxSize(node) ;
ByteBuffer bb = ByteBuffer.allocate(maxSize) ;
int len = nodec.encode(node, bb, null) ;
bb.limit(len) ;
bb.position(0) ;
return bb ;
}
/** Decode a node - pref use fetchDecode */
public static Node decode(ByteBuffer bb)
{
bb.position(0) ;
Node n = nodec.decode(bb, null) ;
return n ;
}
public static Hash hash(Node n)
{
Hash h = new Hash(LenNodeHash) ;
setHash(h, n) ;
return h ;
}
public static void setHash(Hash h, Node n)
{
NodeType nt = NodeType.lookup(n) ;
switch(nt)
{
case URI:
hash(h, n.getURI(), null, null, nt) ;
return ;
case BNODE:
hash(h, n.getBlankNodeLabel(), null, null, nt) ;
return ;
case LITERAL:
hash(h,
n.getLiteralLexicalForm(),
n.getLiteralLanguage(),
n.getLiteralDatatypeURI(), nt) ;
return ;
case OTHER:
throw new TDBException("Attempt to hash something strange: "+n) ;
}
throw new TDBException("NodeType broken: "+n) ;
}
/** This pattern is common - abstract */
private static int InitialPoolSize = 5 ;
private static Pool<MessageDigest> digesters = PoolSync.create(new PoolBase<MessageDigest>()) ;
static {
try {
for ( int i = 0 ; i < InitialPoolSize ; i++ )
digesters.put(MessageDigest.getInstance("MD5"));
}
catch (NoSuchAlgorithmException e)
{ e.printStackTrace(); }
}
private static MessageDigest allocDigest()
{
try {
MessageDigest disgest = digesters.get() ;
if ( disgest == null )
disgest = MessageDigest.getInstance("MD5");
return disgest ;
}
catch (NoSuchAlgorithmException e)
{ e.printStackTrace(); return null ; }
}
private static void deallocDigest(MessageDigest digest) { digest.reset() ; digesters.put(digest) ; }
private static void hash(Hash h, String lex, String lang, String datatype, NodeType nodeType)
{
if ( datatype == null )
datatype = "" ;
if ( lang == null )
lang = "" ;
String toHash = lex + "|" + lang + "|" + datatype+"|"+nodeType.getName() ;
MessageDigest digest;
try
{
digest = allocDigest() ; //MessageDigest.getInstance("MD5");
digest.update(Bytes.string2bytes(toHash)); //digest.update(toHash.getBytes("UTF8"));
if ( h.getLen() == 16 )
// MD5 is 16 bytes.
digest.digest(h.getBytes(), 0, 16) ;
else
{
byte b[] = digest.digest(); // 16 bytes.
// Avoid the copy? If length is 16. digest.digest(bytes, 0, length) needs 16 bytes
System.arraycopy(b, 0, h.getBytes(), 0, h.getLen()) ;
}
deallocDigest(digest) ;
return ;
}
catch (DigestException ex) { Log.fatal(NodeLib.class, "DigestException", ex); }
}
public static NodeId getNodeId(Record r, int idx)
{
return NodeId.create(Bytes.getLong(r.getKey(), idx)) ;
}
public static Node termOrAny(Node node)
{
if ( node == null || node.isVariable() )
return Node.ANY ;
return node ;
}
public static String format(String sep, Node[] nodes)
{
// Sigh ...
StringBuilder b = new StringBuilder() ;
for ( int i = 0 ; i < nodes.length ; i++ )
{
if ( i != 0 )
b.append(sep) ;
b.append(NodeFmtLib.serialize(nodes[i])) ;
}
return b.toString() ;
}
public static Iterator<Node> nodes(final NodeTable nodeTable, Iterator<NodeId> iter)
{
return Iter.map(iter, new Transform<NodeId, Node>(){
@Override
public Node convert(NodeId item)
{
return nodeTable.getNodeForNodeId(item) ;
}
}) ;
}
}