/*
* Copyright 2005 JBoss Inc
*
* Licensed 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 org.drools.core.reteoo;
import org.drools.core.RuleBaseConfiguration;
import org.drools.core.base.ClassObjectType;
import org.drools.core.base.DroolsQuery;
import org.drools.core.base.ValueType;
import org.drools.core.common.AbstractWorkingMemory.WorkingMemoryReteExpireAction;
import org.drools.core.common.DroolsObjectInputStream;
import org.drools.core.common.EventFactHandle;
import org.drools.core.common.InternalFactHandle;
import org.drools.core.common.InternalWorkingMemory;
import org.drools.core.common.Memory;
import org.drools.core.common.MemoryFactory;
import org.drools.core.common.UpdateContext;
import org.drools.core.util.Iterator;
import org.drools.core.util.ObjectHashSet;
import org.drools.core.util.ObjectHashSet.ObjectEntry;
import org.drools.core.marshalling.impl.MarshallerReaderContext;
import org.drools.core.marshalling.impl.MarshallerWriteContext;
import org.drools.core.marshalling.impl.PersisterEnums;
import org.drools.core.marshalling.impl.ProtobufMessages;
import org.drools.core.marshalling.impl.ProtobufMessages.Timers.ExpireTimer;
import org.drools.core.marshalling.impl.ProtobufMessages.Timers.Timer;
import org.drools.core.marshalling.impl.TimersInputMarshaller;
import org.drools.core.marshalling.impl.TimersOutputMarshaller;
import org.drools.core.reteoo.RuleRemovalContext.CleanupAdapter;
import org.drools.core.reteoo.builder.BuildContext;
import org.drools.core.reteoo.compiled.CompiledNetwork;
import org.drools.core.rule.Declaration;
import org.drools.core.rule.EntryPointId;
import org.drools.core.rule.EvalCondition;
import org.drools.core.spi.Constraint;
import org.drools.core.spi.ObjectType;
import org.drools.core.spi.PropagationContext;
import org.drools.core.time.Job;
import org.drools.core.time.JobContext;
import org.drools.core.time.JobHandle;
import org.drools.core.time.TimerService;
import org.drools.core.time.impl.DefaultJobHandle;
import org.drools.core.time.impl.PointInTimeTrigger;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.List;
/**
* <code>ObjectTypeNodes<code> are responsible for filtering and propagating the matching
* fact assertions propagated from the <code>Rete</code> node using <code>ObjectType</code> interface.
* <p/>
* The assert and retract methods do not attempt to filter as this is the role of the <code>Rete</code>
* node which builds up a cache of matching <code>ObjectTypdeNodes</code>s for each asserted object, using
* the <code>matches(Object object)</code> method. Incorrect propagation in these methods is not checked and
* will result in <code>ClassCastExpcections</code> later on in the network.
* <p/>
* Filters <code>Objects</code> coming from the <code>Rete</code> using a
* <code>ObjectType</code> semantic module.
*
* @see Rete
*/
public class ObjectTypeNode extends ObjectSource
implements
ObjectSink,
Externalizable,
MemoryFactory
{
// ------------------------------------------------------------
// Instance members
// ------------------------------------------------------------
private static final long serialVersionUID = 510l;
/**
* The <code>ObjectType</code> semantic module.
*/
protected ObjectType objectType;
private boolean objectMemoryEnabled;
private long expirationOffset = -1;
public static final transient ExpireJob job = new ExpireJob();
private boolean queryNode;
protected CompiledNetwork compiledNetwork;
/* always dirty after serialisation */
protected transient boolean dirty;
/* reset counter when dirty */
protected transient IdGenerator idGenerator;
public int getOtnIdCounter() {
return idGenerator.otnIdCounter;
}
public ObjectTypeNode() {
}
/**
* Construct given a semantic <code>ObjectType</code> and the provided
* unique id. All <code>ObjectTypdeNode</code> have node memory.
*
* @param id The unique id for the node.
* @param objectType The semantic object-type differentiator.
*/
public ObjectTypeNode(final int id,
final EntryPointNode source,
final ObjectType objectType,
final BuildContext context) {
super( id,
context.getPartitionId(),
context.getRuleBase().getConfiguration().isMultithreadEvaluation(),
source,
context.getRuleBase().getConfiguration().getAlphaNodeHashingThreshold() );
this.objectType = objectType;
idGenerator = new IdGenerator(id);
setObjectMemoryEnabled( context.isObjectTypeNodeMemoryEnabled() );
if ( ClassObjectType.DroolsQuery_ObjectType.isAssignableFrom( objectType ) ) {
queryNode = true;
}
this.dirty = true;
}
private static class IdGenerator {
private final int otnId;
private int otnIdCounter;
private IdGenerator(int otnId) {
this.otnId = otnId;
}
private Id nextId() {
return new Id(otnId, otnIdCounter++);
}
private void reset() {
otnIdCounter = 0;
}
}
public static Id DEFAULT_ID = new Id(-1, 0);
public static class Id {
private final int otnId;
private final int id;
public Id(int otnId, int id) {
this.otnId = otnId;
this.id = id;
}
@Override
public String toString() {
return "ObjectTypeNode.Id[" + otnId + "#" + id + "]";
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || !(o instanceof Id)) return false;
Id otherId = (Id) o;
return id == otherId.id && otnId == otherId.otnId;
}
@Override
public int hashCode() {
return 31 * otnId + 37 * id;
}
public boolean before(Id otherId) {
return otherId != null && ( otnId < otherId.otnId || ( otnId == otherId.otnId && id < otherId.id ) );
}
public int getId() {
return id;
}
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
super.readExternal( in );
objectType = (ObjectType) in.readObject();
// this is here as not all objectTypeNodes used ClassObjectTypes in packages (i.e. rules with those nodes did not exist yet)
// and thus have no wiring targets
if ( objectType instanceof ClassObjectType ) {
objectType = ((ReteooRuleBase) ((DroolsObjectInputStream) in).getRuleBase()).getClassFieldAccessorCache().getClassObjectType( (ClassObjectType) objectType );
}
objectMemoryEnabled = in.readBoolean();
expirationOffset = in.readLong();
queryNode = in.readBoolean();
dirty = true;
idGenerator = new IdGenerator(id);
}
public void writeExternal(ObjectOutput out) throws IOException {
super.writeExternal(out);
out.writeObject( objectType );
out.writeBoolean( objectMemoryEnabled );
out.writeLong( expirationOffset );
out.writeBoolean( queryNode );
}
public short getType() {
return NodeTypeEnums.ObjectTypeNode;
}
/**
* Retrieve the semantic <code>ObjectType</code> differentiator.
*
* @return The semantic <code>ObjectType</code> differentiator.
*/
public ObjectType getObjectType() {
return this.objectType;
}
@Override
public long calculateDeclaredMask(List<String> settableProperties) {
return 0;
}
public boolean isAssignableFrom(final ObjectType objectType) {
return this.objectType.isAssignableFrom( objectType );
}
public void setCompiledNetwork(CompiledNetwork compiledNetwork) {
this.compiledNetwork = compiledNetwork;
this.compiledNetwork.setObjectTypeNode( this );
}
/**
* Propagate the <code>FactHandleimpl</code> through the <code>Rete</code> network. All
* <code>FactHandleImpl</code> should be remembered in the node memory, so that later runtime rule attachmnents
* can have the matched facts propagated to them.
*
* @param factHandle The fact handle.
* @param context The propagation context.
* @param workingMemory The working memory session.
*/
public void assertObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
if ( dirty ) {
resetIdGenerator();
updateTupleSinkId( this, this );
dirty = false;
}
if ( objectMemoryEnabled && !(queryNode && !((DroolsQuery) factHandle.getObject()).isOpen()) ) {
final ObjectTypeNodeMemory memory = (ObjectTypeNodeMemory) workingMemory.getNodeMemory( this );
memory.memory.add( factHandle,
false );
}
if ( compiledNetwork != null ) {
compiledNetwork.assertObject( factHandle,
context,
workingMemory );
} else {
this.sink.propagateAssertObject( factHandle,
context,
workingMemory );
}
if ( context.getReaderContext() == null && this.objectType.isEvent() && this.expirationOffset >= 0 && this.expirationOffset != Long.MAX_VALUE ) {
// schedule expiration
WorkingMemoryReteExpireAction expire = new WorkingMemoryReteExpireAction( factHandle,
this );
TimerService clock = workingMemory.getTimerService();
long nextTimestamp = Math.max( clock.getCurrentTime(),
((EventFactHandle) factHandle).getEndTimestamp() + this.expirationOffset );
JobContext jobctx = new ExpireJobContext( expire,
workingMemory );
JobHandle handle = clock.scheduleJob( job,
jobctx,
new PointInTimeTrigger( nextTimestamp,
null,
null ) );
jobctx.setJobHandle( handle );
}
}
/**
* Retract the <code>FactHandleimpl</code> from the <code>Rete</code> network. Also remove the
* <code>FactHandleImpl</code> from the node memory.
*
* @param factHandle The fact handle.
* @param context The propagation context.
* @param workingMemory The working memory session.
*/
public void retractObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
if ( dirty ) {
resetIdGenerator();
updateTupleSinkId( this, this );
dirty = false;
}
if ( objectMemoryEnabled && !(queryNode && !((DroolsQuery) factHandle.getObject()).isOpen()) ) {
final ObjectTypeNodeMemory memory = (ObjectTypeNodeMemory) workingMemory.getNodeMemory( this );
memory.memory.remove(factHandle);
}
doRetractObject(factHandle, context, workingMemory);
}
public static void doRetractObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory ) {
for ( RightTuple rightTuple = factHandle.getFirstRightTuple(); rightTuple != null; ) {
RightTuple nextRightTuple = rightTuple.getHandleNext();
rightTuple.getRightTupleSink().retractRightTuple( rightTuple,
context,
workingMemory );
rightTuple = nextRightTuple;
}
factHandle.clearRightTuples();
for ( LeftTuple leftTuple = factHandle.getFirstLeftTuple(); leftTuple != null; leftTuple = leftTuple.getLeftParentNext() ) {
// must go via the LiaNode, so that the fact counter is updated, for linking
((LeftInputAdapterNode) leftTuple.getLeftTupleSink().getLeftTupleSource()).retractLeftTuple( leftTuple,
context,
workingMemory );
}
factHandle.clearLeftTuples();
}
protected void resetIdGenerator() {
idGenerator.reset();
}
public void modifyObject(InternalFactHandle factHandle,
ModifyPreviousTuples modifyPreviousTuples,
PropagationContext context,
InternalWorkingMemory workingMemory) {
if ( dirty ) {
resetIdGenerator();
updateTupleSinkId( this, this );
dirty = false;
}
context.setObjectType( objectType );
if ( compiledNetwork != null ) {
compiledNetwork.modifyObject( factHandle,
modifyPreviousTuples,
context.adaptModificationMaskForObjectType(objectType, workingMemory),
workingMemory );
} else {
this.sink.propagateModifyObject( factHandle,
modifyPreviousTuples,
context.adaptModificationMaskForObjectType(objectType, workingMemory),
workingMemory );
}
}
public void updateSink(final ObjectSink sink,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
if ( dirty ) {
resetIdGenerator();
updateTupleSinkId( this, this );
dirty = false;
}
// Regular updateSink
final ObjectTypeNodeMemory memory = (ObjectTypeNodeMemory) workingMemory.getNodeMemory( this );
Iterator it = memory.memory.iterator();
for ( ObjectEntry entry = (ObjectEntry) it.next(); entry != null; entry = (ObjectEntry) it.next() ) {
sink.assertObject( (InternalFactHandle) entry.getValue(),
context,
workingMemory );
}
}
/**
* Rete needs to know that this ObjectTypeNode has been added
*/
public void attach( BuildContext context ) {
this.source.addObjectSink( this );
}
public void networkUpdated(UpdateContext updateContext) {
this.dirty = true;
}
protected static void updateTupleSinkId( ObjectTypeNode otn,
ObjectSource source ) {
for ( ObjectSink sink : source.sink.getSinks() ) {
if ( sink instanceof BetaNode ) {
((BetaNode) sink).setRightInputOtnId( otn.nextOtnId() );
} else if ( sink instanceof LeftInputAdapterNode ) {
for ( LeftTupleSink liaChildSink : ((LeftInputAdapterNode) sink).getSinkPropagator().getSinks() ) {
liaChildSink.setLeftInputOtnId( otn.nextOtnId() );
}
} else if ( sink instanceof WindowNode ) {
((WindowNode) sink).setRightInputOtnId( otn.nextOtnId() );
updateTupleSinkId( otn, (WindowNode) sink );
} else if ( sink instanceof AlphaNode ) {
updateTupleSinkId( otn, (AlphaNode) sink );
}
}
}
public Id nextOtnId() {
return idGenerator.nextId();
}
/**
* OTN needs to override remove to avoid releasing the node ID, since OTN are
* never removed from the rulebase in the current implementation
*
*/
public void remove(RuleRemovalContext context,
ReteooBuilder builder,
InternalWorkingMemory[] workingMemories) {
doRemove( context,
builder,
workingMemories );
}
/**
* OTN needs to override remove to avoid releasing the node ID, since OTN are
* never removed from the rulebase in the current implementation
*/
protected void doRemove(final RuleRemovalContext context,
final ReteooBuilder builder,
final InternalWorkingMemory[] workingMemories) {
if ( !context.getRuleBase().getConfiguration().isPhreakEnabled() && context.getCleanupAdapter() != null ) {
for ( InternalWorkingMemory workingMemory : workingMemories ) {
CleanupAdapter adapter = context.getCleanupAdapter();
final ObjectTypeNodeMemory memory = (ObjectTypeNodeMemory) workingMemory.getNodeMemory( this );
Iterator it = memory.memory.iterator();
for ( ObjectEntry entry = (ObjectEntry) it.next(); entry != null; entry = (ObjectEntry) it.next() ) {
InternalFactHandle handle = (InternalFactHandle) entry.getValue();
for ( LeftTuple leftTuple = handle.getFirstLeftTuple(); leftTuple != null; leftTuple = leftTuple.getLeftParentNext() ) {
adapter.cleanUp( leftTuple,
workingMemory );
}
}
}
context.setCleanupAdapter( null );
}
}
/**
* Creates memory for the node using PrimitiveLongMap as its optimised for storage and reteivals of Longs.
* However PrimitiveLongMap is not ideal for spase data. So it should be monitored incase its more optimal
* to switch back to a standard HashMap.
*/
public Memory createMemory(final RuleBaseConfiguration config, InternalWorkingMemory wm) {
return new ObjectTypeNodeMemory(this);
}
public boolean isObjectMemoryEnabled() {
return this.objectMemoryEnabled;
}
public void setObjectMemoryEnabled(boolean objectMemoryEnabled) {
this.objectMemoryEnabled = objectMemoryEnabled;
}
public String toString() {
return "[ObjectTypeNode(" + this.id + ")::" + ((EntryPointNode) this.source).getEntryPoint() + " objectType=" + this.objectType + " expiration=" + this.expirationOffset + "ms ]";
}
/**
* Uses he hashCode() of the underlying ObjectType implementation.
*/
public int hashCode() {
return this.objectType.hashCode() ^ this.source.hashCode();
}
public boolean equals(final Object object) {
if ( this == object ) {
return true;
}
if ( object == null || !(object instanceof ObjectTypeNode) ) {
return false;
}
final ObjectTypeNode other = (ObjectTypeNode) object;
return this.objectType.equals(other.objectType) && this.source.equals(other.source);
}
private boolean usesDeclaration(final Constraint[] constraints) {
boolean usesDecl = false;
for ( int i = 0; !usesDecl && i < constraints.length; i++ ) {
usesDecl = this.usesDeclaration( constraints[i] );
}
return usesDecl;
}
private boolean usesDeclaration(final Constraint constraint) {
boolean usesDecl = false;
final Declaration[] declarations = constraint.getRequiredDeclarations();
for ( int j = 0; !usesDecl && j < declarations.length; j++ ) {
usesDecl = (declarations[j].getPattern().getObjectType() == this.objectType);
}
return usesDecl;
}
private boolean usesDeclaration(final EvalCondition condition) {
boolean usesDecl = false;
final Declaration[] declarations = condition.getRequiredDeclarations();
for ( int j = 0; !usesDecl && j < declarations.length; j++ ) {
usesDecl = (declarations[j].getPattern().getObjectType() == this.objectType);
}
return usesDecl;
}
/**
* @return the entryPoint
*/
public EntryPointId getEntryPoint() {
return ((EntryPointNode) this.source).getEntryPoint();
}
public long getExpirationOffset() {
return expirationOffset;
}
public void setExpirationOffset(long expirationOffset) {
this.expirationOffset = expirationOffset;
if ( !this.objectType.getValueType().equals( ValueType.QUERY_TYPE ) ) {
if ( this.expirationOffset > 0 ) {
// override memory enabled settings
this.setObjectMemoryEnabled( true );
} else if ( this.expirationOffset == 0 ) {
// disable memory
this.setObjectMemoryEnabled( false );
}
}
}
public static class ExpireJob
implements
Job {
public void execute(JobContext ctx) {
ExpireJobContext context = (ExpireJobContext) ctx;
context.workingMemory.queueWorkingMemoryAction( context.expireAction );
}
}
public static class ExpireJobContext
implements
JobContext,
Externalizable {
public WorkingMemoryReteExpireAction expireAction;
public InternalWorkingMemory workingMemory;
public JobHandle handle;
public ExpireJobContext(WorkingMemoryReteExpireAction expireAction,
InternalWorkingMemory workingMemory) {
super();
this.expireAction = expireAction;
this.workingMemory = workingMemory;
}
public JobHandle getJobHandle() {
return this.handle;
}
public void setJobHandle(JobHandle jobHandle) {
this.handle = jobHandle;
}
public WorkingMemoryReteExpireAction getExpireAction() {
return expireAction;
}
public void setExpireAction(WorkingMemoryReteExpireAction expireAction) {
this.expireAction = expireAction;
}
public InternalWorkingMemory getWorkingMemory() {
return workingMemory;
}
public void setWorkingMemory(InternalWorkingMemory workingMemory) {
this.workingMemory = workingMemory;
}
public JobHandle getHandle() {
return handle;
}
public void setHandle(JobHandle handle) {
this.handle = handle;
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
//this.behavior = (O)
}
public void writeExternal(ObjectOutput out) throws IOException {
// TODO Auto-generated method stub
}
}
public static class ExpireJobContextTimerOutputMarshaller
implements
TimersOutputMarshaller {
public void write(JobContext jobCtx,
MarshallerWriteContext outputCtx) throws IOException {
outputCtx.writeShort( PersisterEnums.EXPIRE_TIMER );
// ExpireJob, no state
ExpireJobContext ejobCtx = (ExpireJobContext) jobCtx;
WorkingMemoryReteExpireAction expireAction = ejobCtx.getExpireAction();
outputCtx.writeInt( expireAction.getFactHandle().getId() );
outputCtx.writeUTF( expireAction.getNode().getEntryPoint().getEntryPointId() );
outputCtx.writeUTF( ((ClassObjectType) expireAction.getNode().getObjectType()).getClassType().getName() );
DefaultJobHandle jobHandle = (DefaultJobHandle) ejobCtx.getJobHandle();
PointInTimeTrigger trigger = (PointInTimeTrigger) jobHandle.getTimerJobInstance().getTrigger();
outputCtx.writeLong( trigger.hasNextFireTime().getTime() );
}
public ProtobufMessages.Timers.Timer serialize(JobContext jobCtx,
MarshallerWriteContext outputCtx) {
// ExpireJob, no state
ExpireJobContext ejobCtx = ( ExpireJobContext ) jobCtx;
WorkingMemoryReteExpireAction expireAction = ejobCtx.getExpireAction();
DefaultJobHandle jobHandle = ( DefaultJobHandle ) ejobCtx.getJobHandle();
PointInTimeTrigger trigger = ( PointInTimeTrigger ) jobHandle.getTimerJobInstance().getTrigger();
return ProtobufMessages.Timers.Timer.newBuilder()
.setType( ProtobufMessages.Timers.TimerType.EXPIRE )
.setExpire( ProtobufMessages.Timers.ExpireTimer.newBuilder()
.setHandleId( expireAction.getFactHandle().getId() )
.setEntryPointId( expireAction.getNode().getEntryPoint().getEntryPointId() )
.setClassName( ((ClassObjectType)expireAction.getNode().getObjectType()).getClassType().getName() )
.setNextFireTimestamp( trigger.hasNextFireTime().getTime() )
.build() )
.build();
}
}
public static class ExpireJobContextTimerInputMarshaller
implements
TimersInputMarshaller {
public void read(MarshallerReaderContext inCtx) throws IOException,
ClassNotFoundException {
InternalFactHandle factHandle = inCtx.handles.get( inCtx.readInt() );
String entryPointId = inCtx.readUTF();
EntryPointNode epn = ((ReteooRuleBase) inCtx.wm.getRuleBase()).getRete().getEntryPointNode( new EntryPointId( entryPointId ) );
String className = inCtx.readUTF();
Class< ? > cls = ((ReteooRuleBase) inCtx.wm.getRuleBase()).getRootClassLoader().loadClass( className );
ObjectTypeNode otn = epn.getObjectTypeNodes().get( new ClassObjectType( cls ) );
long nextTimeStamp = inCtx.readLong();
TimerService clock = inCtx.wm.getTimerService();
JobContext jobctx = new ExpireJobContext( new WorkingMemoryReteExpireAction( factHandle, otn ),
inCtx.wm );
JobHandle handle = clock.scheduleJob( job,
jobctx,
new PointInTimeTrigger( nextTimeStamp,
null,
null ) );
jobctx.setJobHandle( handle );
}
public void deserialize(MarshallerReaderContext inCtx,
Timer _timer) throws ClassNotFoundException {
ExpireTimer _expire = _timer.getExpire();
InternalFactHandle factHandle = inCtx.handles.get( _expire.getHandleId() );
EntryPointNode epn = ((ReteooRuleBase)inCtx.wm.getRuleBase()).getRete().getEntryPointNode( new EntryPointId( _expire.getEntryPointId() ) );
Class<?> cls = ((ReteooRuleBase)inCtx.wm.getRuleBase()).getRootClassLoader().loadClass( _expire.getClassName() );
ObjectTypeNode otn = epn.getObjectTypeNodes().get( new ClassObjectType( cls ) );
TimerService clock = inCtx.wm.getTimerService();
JobContext jobctx = new ExpireJobContext( new WorkingMemoryReteExpireAction(factHandle, otn),
inCtx.wm );
JobHandle handle = clock.scheduleJob( job,
jobctx,
new PointInTimeTrigger( _expire.getNextFireTimestamp(),
null,
null ) );
jobctx.setJobHandle( handle );
}
}
public void byPassModifyToBetaNode(InternalFactHandle factHandle,
ModifyPreviousTuples modifyPreviousTuples,
PropagationContext context,
InternalWorkingMemory workingMemory) {
throw new UnsupportedOperationException( "This should never get called, as the PropertyReactive first happens at the AlphaNode" );
}
public static class ObjectTypeNodeMemory implements Memory {
public ObjectHashSet memory = new ObjectHashSet();
private ObjectTypeNode otn;
ObjectTypeNodeMemory(ObjectTypeNode otn) {
this.otn = otn;
}
public short getNodeType() {
return NodeTypeEnums.ObjectTypeNode;
}
public ObjectHashSet getObjectHashSet() {
return memory;
}
public SegmentMemory getSegmentMemory() {
throw new UnsupportedOperationException();
}
public void setSegmentMemory(SegmentMemory segmentMemory) {
throw new UnsupportedOperationException();
}
public Memory getPrevious() {
throw new UnsupportedOperationException();
}
public void setPrevious(Memory previous) {
throw new UnsupportedOperationException();
}
public void nullPrevNext() {
throw new UnsupportedOperationException();
}
public void setNext(Memory next) {
throw new UnsupportedOperationException();
}
public Memory getNext() {
throw new UnsupportedOperationException();
}
public String toString() {
return "ObjectTypeMemory " + otn;
}
}
}