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Neo4j kernel is a lightweight, embedded Java database designed to
store data structured as graphs rather than tables. For more
information, see http://neo4j.org.
/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [http://neo4j.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see
{
static final long SHALLOW_SIZE = shallowSizeOfInstance( RelationshipEntityWrappingValue.class ) + RelationshipEntity.SHALLOW_SIZE;
private final Relationship relationship;
private volatile TextValue type;
private volatile MapValue properties;
private volatile VirtualNodeValue startNode;
private volatile VirtualNodeValue endNode;
/**
* Wraps a {@link Relationship}, reading out its meta data lazily, i.e. on first access of e.g. {@link #startNodeId()}.
*/
static RelationshipEntityWrappingValue wrapLazy( Relationship relationship )
{
return new RelationshipEntityWrappingValue( relationship, NO_ID, NO_ID );
}
private RelationshipEntityWrappingValue( Relationship relationship, long startNodeId, long endNodeId )
{
super( relationship.getId(), startNodeId, endNodeId );
this.relationship = relationship;
}
public Relationship relationshipEntity()
{
return relationship;
}
@Override
public void writeTo( AnyValueWriter writer ) throws E
{
if ( writer.entityMode() == REFERENCE )
{
writer.writeRelationshipReference( id() );
}
else
{
boolean isDeleted = false;
if ( relationship instanceof RelationshipEntity )
{
RelationshipEntity proxy = (RelationshipEntity) relationship;
if ( !proxy.initializeData() )
{
// If the relationship has been deleted since it was found by the query,
// then we'll have to tell the client that their transaction conflicted,
// and that they need to retry it.
throw new ReadAndDeleteTransactionConflictException( RelationshipEntity.isDeletedInCurrentTransaction( relationship ) );
}
}
MapValue p;
try
{
p = properties();
}
catch ( ReadAndDeleteTransactionConflictException e )
{
if ( !e.wasDeletedInThisTransaction() )
{
throw e;
}
// If it isn't a transient error then the relationship was deleted in the current transaction and we should write an 'empty' relationship.
p = VirtualValues.EMPTY_MAP;
isDeleted = true;
}
if ( id() < 0 )
{
writer.writeVirtualRelationshipHack( relationship );
}
writer.writeRelationship( id(), startNode().id(), endNode().id(), type(), p, isDeleted );
}
}
@Override
public long estimatedHeapUsage()
{
long size = SHALLOW_SIZE;
if ( type != null )
{
size += type.estimatedHeapUsage();
}
if ( properties != null )
{
size += properties.estimatedHeapUsage();
}
if ( startNode != null )
{
size += startNode.estimatedHeapUsage();
}
if ( endNode != null )
{
size += endNode.estimatedHeapUsage();
}
return size;
}
public void populate( RelationshipScanCursor relCursor, PropertyCursor propertyCursor )
{
try
{
if ( relationship instanceof RelationshipEntity )
{
RelationshipEntity proxy = (RelationshipEntity) relationship;
if ( !proxy.initializeData( relCursor ) )
{
// When this happens to relationship proxies, we have most likely observed our relationship being deleted by an overlapping committed
// transaction.
return;
}
}
// type, startNode and endNode will have counted their DB hits as part of initializeData.
type();
properties( propertyCursor );
startNode();
endNode();
}
catch ( NotFoundException | ReadAndDeleteTransactionConflictException e )
{
// best effort, cannot do more
}
}
public void populate()
{
try
{
if ( relationship instanceof RelationshipEntity )
{
RelationshipEntity proxy = (RelationshipEntity) relationship;
if ( !proxy.initializeData() )
{
// When this happens to relationship proxies, we have most likely observed our relationship being deleted by an overlapping committed
// transaction.
return;
}
}
type();
properties();
startNode();
endNode();
}
catch ( NotFoundException | ReadAndDeleteTransactionConflictException e )
{
// best effort, cannot do more
}
}
public boolean isPopulated()
{
return type != null && properties != null && startNode != null && endNode != null;
}
@Override
public long startNodeId()
{
// Often a RelationshipEntityWrappingValue is initialized with the start/end node ids given, but if that's not the case
// Then use the other route of looking up the start node the slow way and getting its ID.
long startNodeId = super.startNodeId();
return startNodeId != NO_ID ? startNodeId : startNode().id();
}
@Override
public long endNodeId()
{
// Often a RelationshipEntityWrappingValue is initialized with the start/end node ids given, but if that's not the case
// Then use the other route of looking up the end node the slow way and getting its ID.
long endNodeId = super.endNodeId();
return endNodeId != NO_ID ? endNodeId : endNode().id();
}
@Override
public VirtualNodeValue startNode()
{
VirtualNodeValue start = startNode;
if ( start == null )
{
synchronized ( this )
{
start = startNode;
if ( start == null )
{
start = startNode = ValueUtils.fromNodeEntity( relationship.getStartNode() );
}
}
}
return start;
}
@Override
public VirtualNodeValue endNode()
{
VirtualNodeValue end = endNode;
if ( end == null )
{
synchronized ( this )
{
end = endNode;
if ( end == null )
{
end = endNode = ValueUtils.fromNodeEntity( relationship.getEndNode() );
}
}
}
return end;
}
@Override
public VirtualNodeValue otherNode( VirtualNodeValue node )
{
if ( node instanceof NodeEntityWrappingNodeValue )
{
Node proxy = ((NodeEntityWrappingNodeValue) node).getEntity();
return ValueUtils.fromNodeEntity( relationship.getOtherNode( proxy ) );
}
else
{
return super.otherNode( node );
}
}
@Override
public long otherNodeId( long node )
{
return relationship.getOtherNodeId( node );
}
@Override
public TextValue type()
{
TextValue t = type;
if ( t == null )
{
try
{
synchronized ( this )
{
t = type;
if ( t == null )
{
t = type = Values.utf8Value( relationship.getType().name() );
}
}
}
catch ( IllegalStateException e )
{
throw new ReadAndDeleteTransactionConflictException( RelationshipEntity.isDeletedInCurrentTransaction( relationship ), e );
}
}
return t;
}
@Override
public MapValue properties()
{
MapValue m = properties;
if ( m == null )
{
try
{
synchronized ( this )
{
m = properties;
if ( m == null )
{
m = properties = ValueUtils.asMapValue( relationship.getAllProperties() );
}
}
}
catch ( NotFoundException | IllegalStateException e )
{
throw new ReadAndDeleteTransactionConflictException( RelationshipEntity.isDeletedInCurrentTransaction( relationship ), e );
}
}
return m;
}
@Override
public Relationship getEntity()
{
return relationship;
}
public MapValue properties( PropertyCursor propertyCursor )
{
MapValue m = properties;
if ( m == null )
{
try
{
synchronized ( this )
{
m = properties;
if ( m == null )
{
var relProperties = relationship instanceof RelationshipEntity ?
((RelationshipEntity) relationship).getAllProperties( propertyCursor ) : relationship.getAllProperties();
m = properties = ValueUtils.asMapValue( relProperties );
}
}
}
catch ( NotFoundException | IllegalStateException e )
{
throw new ReadAndDeleteTransactionConflictException( RelationshipEntity.isDeletedInCurrentTransaction( relationship ), e );
}
}
return m;
}
}