/*
* 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.sparql.graph;
import com.hp.hpl.jena.graph.* ;
import com.hp.hpl.jena.graph.impl.AllCapabilities ;
import com.hp.hpl.jena.graph.impl.GraphBase ;
import com.hp.hpl.jena.graph.impl.GraphMatcher ;
import com.hp.hpl.jena.graph.impl.GraphWithPerform ;
import com.hp.hpl.jena.graph.impl.SimpleBulkUpdateHandler ;
import com.hp.hpl.jena.graph.impl.SimpleEventManager ;
import com.hp.hpl.jena.graph.impl.SimpleTransactionHandler ;
import com.hp.hpl.jena.graph.query.QueryHandler ;
import com.hp.hpl.jena.shared.AddDeniedException ;
import com.hp.hpl.jena.shared.ClosedException ;
import com.hp.hpl.jena.shared.DeleteDeniedException ;
import com.hp.hpl.jena.shared.PrefixMapping ;
import com.hp.hpl.jena.util.iterator.ClosableIterator ;
import com.hp.hpl.jena.util.iterator.ExtendedIterator ;
public abstract class GraphBase2 implements GraphWithPerform
{
// Like GraphBase but no reificiation handling in normal operations.
// AKA Hard coded ReificationStyle.Standard
/**
Whether or not this graph has been closed - used to report ClosedExceptions
when an operation is attempted on a closed graph.
*/
protected boolean closed = false;
/**
Initialise this graph
*/
public GraphBase2() {}
/**
Utility method: throw a ClosedException if this graph has been closed.
*/
protected void checkOpen()
{ if (closed) throw new ClosedException( "already closed", this ); }
/**
Close this graph. Subgraphs may extend to discard resources.
*/
@Override
public void close()
{
closed = true;
if (reifier != null) reifier.close();
}
@Override
public boolean isClosed()
{ return closed; }
/**
Default implementation answers <code>true</code> iff this graph is the
same graph as the argument graph.
*/
@Override
public boolean dependsOn( Graph other )
{ return this == other; }
/**
Answer a QueryHandler bound to this graph. The default implementation
returns the same SimpleQueryHandler each time it is called; sub-classes
may override if they need specialised query handlers.
*/
@Override
public abstract QueryHandler queryHandler() ;
// {
// if (queryHandler == null) queryHandler = new SimpleQueryHandler(this);
// return queryHandler;
// }
/**
The query handler for this graph, or null if queryHandler() has not been
called yet.
*/
protected QueryHandler queryHandler;
@Override
public GraphStatisticsHandler getStatisticsHandler()
{
if (statisticsHandler == null) statisticsHandler = createStatisticsHandler();
return statisticsHandler;
}
protected GraphStatisticsHandler statisticsHandler;
protected GraphStatisticsHandler createStatisticsHandler()
{ return null; }
/**
Answer the event manager for this graph; allocate a new one if required.
Subclasses may override if they have a more specialised event handler.
The default is a SimpleEventManager.
*/
@Override
public GraphEventManager getEventManager()
{
if (gem == null) gem = new SimpleEventManager( this );
return gem;
}
/**
The event manager that this Graph uses to, well, manage events; allocated on
demand.
*/
protected GraphEventManager gem;
/**
Tell the event manager that the triple <code>t</code> has been added to the graph.
*/
public void notifyAdd( Triple t )
{ getEventManager().notifyAddTriple( this, t ); }
/**
Tell the event manager that the triple <code>t</code> has been deleted from the
graph.
*/
public void notifyDelete( Triple t )
{ getEventManager().notifyDeleteTriple( this, t ); }
/**
Answer a transaction handler bound to this graph. The default is
SimpleTransactionHandler, which handles <i>no</i> transactions.
*/
@Override
public TransactionHandler getTransactionHandler()
{ return new SimpleTransactionHandler(); }
/**
Answer a BulkUpdateHandler bound to this graph. The default is a
SimpleBulkUpdateHandler, which does bulk update by repeated simple
(add/delete) updates; the same handler is returned on each call. Subclasses
may override if they have specialised implementations.
*/
@Override
public BulkUpdateHandler getBulkUpdateHandler()
{
if (bulkHandler == null) bulkHandler = new SimpleBulkUpdateHandler( this );
return bulkHandler;
}
/**
The allocated BulkUpdateHandler, or null if no handler has been allocated yet.
*/
protected BulkUpdateHandler bulkHandler;
/**
Answer the capabilities of this graph; the default is an AllCapabilities object
(the same one each time, not that it matters - Capabilities should be
immutable).
*/
@Override
public Capabilities getCapabilities()
{
if (capabilities == null) capabilities = new AllCapabilities();
return capabilities;
}
/**
The allocated Capabilities object, or null if unallocated.
*/
protected Capabilities capabilities = null;
/**
Answer the PrefixMapping object for this graph, the same one each time.
Subclasses are unlikely to want to modify this.
*/
@Override
public PrefixMapping getPrefixMapping()
{
if ( pm == null )
pm = createPrefixMapping() ;
return pm;
}
private PrefixMapping pm = null ;
protected abstract PrefixMapping createPrefixMapping() ;
/**
Add a triple, and notify the event manager. Subclasses should not need to
override this - we might make it final. The triple is added using performAdd,
and notification done by notifyAdd.
*/
@Override
public void add( Triple t )
{
checkOpen();
performAdd( t );
notifyAdd( t );
}
/**
Add a triple to the triple store. The default implementation throws an
AddDeniedException; subclasses must override if they want to be able to
add triples.
*/
@Override
public void performAdd( Triple t )
{ throw new AddDeniedException( "GraphBase::performAdd" ); }
/**
Delete a triple, and notify the event manager. Subclasses should not need to
override this - we might make it final. The triple is added using performDelete,
and notification done by notifyDelete.
*/
@Override
public final void delete( Triple t )
{
checkOpen();
performDelete( t );
notifyDelete( t );
}
/**
Remove a triple from the triple store. The default implementation throws
a DeleteDeniedException; subclasses must override if they want to be able
to remove triples.
*/
@Override
public void performDelete( Triple t )
{ throw new DeleteDeniedException( "GraphBase::delete" ); }
/**
Answer an (extended) iterator over all the triples in this Graph matching
<code>m</code>. Subclasses cannot over-ride this, because it implements
the appending of reification quadlets; instead they must implement
graphBaseFind(TripleMatch).
*/
@Override
public final ExtendedIterator<Triple> find( TripleMatch m )
{
checkOpen();
//return reifierTriples( m ) .andThen( graphBaseFind( m ) );
return graphBaseFind( m ) ;
}
/**
Answer an iterator over all the triples held in this graph's non-reified triple store
that match <code>m</code>. Subclasses <i>must</i> override; it is the core
implementation for <code>find(TripleMatch)</code>.
*/
protected abstract ExtendedIterator<Triple> graphBaseFind( TripleMatch m );
public ExtendedIterator<Triple> forTestingOnly_graphBaseFind( TripleMatch tm )
{ return graphBaseFind( tm ); }
@Override
public final ExtendedIterator<Triple> find(Node s, Node p, Node o)
{
checkOpen() ;
return graphBaseFind(s, p, o) ;
}
protected ExtendedIterator<Triple> graphBaseFind( Node s, Node p, Node o )
{ return find( Triple.createMatch( s, p, o ) ); }
/**
Answer <code>true</code> iff <code>t</code> is in the graph as revealed by
<code>find(t)</code> being non-empty. <code>t</code> may contain ANY
wildcards. Sub-classes may over-ride reifierContains and graphBaseContains
for efficiency.
*/
@Override
public final boolean contains( Triple t )
{
checkOpen();
//return reifierContains( t ) || graphBaseContains( t ); }
return graphBaseContains( t ) ;
}
// /**
// Answer true if the reifier contains a quad matching <code>t</code>. The
// default implementation uses the reifier's <code>findExposed</code> method.
// Subclasses probably don't need to override (if they're interested, they
// probably have specialised reifiers).
// */
// protected boolean reifierContains( Triple t )
// { ClosableIterator it = getReifier().findExposed( t );
// try { return it.hasNext(); } finally { it.close(); } }
/**
Answer true if the graph contains any triple matching <code>t</code>.
The default implementation uses <code>find</code> and checks to see
if the iterator is non-empty.
*/
protected boolean graphBaseContains( Triple t )
{ return containsByFind( t ); }
/**
Answer <code>true</code> if this graph contains <code>(s, p, o)</code>;
this canonical implementation cannot be over-ridden.
*/
@Override
public final boolean contains( Node s, Node p, Node o ) {
checkOpen();
return contains( Triple.create( s, p, o ) );
}
/**
Utility method: answer true iff we can find at least one instantiation of
the triple in this graph using find(TripleMatch).
@param t Triple that is the pattern to match
@return true iff find(t) returns at least one result
*/
final protected boolean containsByFind( Triple t )
{
ClosableIterator<Triple> it = find( t );
try { return it.hasNext(); } finally { it.close(); }
}
// /**
// Answer an iterator over all the triples exposed in this graph's reifier that
// match <code>m</code>. The default implementation delegates this to
// the reifier; subclasses probably don't need to override this.
// */
// protected ExtendedIterator reifierTriples( TripleMatch m )
// { return getReifier().findExposed( m ); }
/**
Answer this graph's reifier. The reifier may be lazily constructed, and it
must be the same reifier on each call. The default implementation is a
SimpleReifier. Generally DO NOT override this method: override
<code>constructReifier</code> instead.
*/
@Override
public Reifier getReifier()
{
if (reifier == null) reifier = constructReifier();
return reifier;
}
/**
Answer a reifier appropriate to this graph. Subclasses override if
they need non-SimpleReifiers.
*/
protected Reifier constructReifier()
{ return new Reifier2(this) ; }
/**
The cache variable for the allocated Reifier.
*/
protected Reifier reifier = null;
/**
Answer the size of this graph (ie the number of exposed triples). Defined as
the size of the triple store plus the size of the reification store. Subclasses
must override graphBaseSize() to reimplement (and reifierSize if they have
some special reason for redefined that).
*/
@Override
public final int size()
{
checkOpen() ;
return graphBaseSize() ;
// int baseSize = graphBaseSize() ;
// int reifierSize = reifierSize() ;
// // String className = leafName( this.getClass().getName() );
// // System.err.println( ">> GB(" + className + ")::size = " + baseSize +
// // "(base) + " + reifierSize + "(reifier)" );
// return baseSize + reifierSize ;
}
// private String leafName( String name )
// {
// int dot = name.lastIndexOf( '.' );
// return name.substring( dot + 1 );
// }
// /**
// Answer the number of visible reification quads. Subclasses will not normally
// need to override this, since it just invokes the reifier's size() method, and
// they can implement their own reifier.
// */
// protected int reifierSize()
// { return getReifier().size(); }
/**
Answer the number of triples in this graph. Default implementation counts its
way through the results of a findAll. Subclasses must override if they want
size() to be efficient.
*/
protected int graphBaseSize()
{
ExtendedIterator<Triple> it = GraphUtil.findAll( this );
try
{
int tripleCount = 0;
while (it.hasNext()) { it.next(); tripleCount += 1; }
return tripleCount;
}
finally
{ it.close(); }
}
/**
Answer true iff this graph contains no triples (hidden reification quads do
not count). The default implementation is <code>size() == 0</code>, which is
fine if <code>size</code> is reasonable efficient. Subclasses may override
if necessary. This method may become final and defined in terms of other
methods.
*/
@Override
public boolean isEmpty()
{ return size() == 0; }
/**
Answer true iff this graph is isomorphic to <code>g</code> according to
the algorithm (indeed, method) in <code>GraphMatcher</code>.
*/
@Override
public boolean isIsomorphicWith( Graph g )
{ checkOpen();
return g != null && GraphMatcher.equals( this, g ); }
/**
Answer a human-consumable representation of this graph. Not advised for
big graphs, as it generates a big string: intended for debugging purposes.
*/
@Override
public String toString()
{
return GraphBase.toString("", this) ;
// Model m = ModelFactory.createModelForGraph(this) ;
// m.setNsPrefixes(PrefixMapping.Standard) ;
// StringWriter w = new StringWriter() ;
// m.write(w, "TTL") ;
// return w.toString() ;
}
}