/* Copyright 2008, 2009, 2010 by the Oxford University Computing Laboratory
This file is part of HermiT.
HermiT is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
HermiT 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with HermiT. If not, see <http://www.gnu.org/licenses/>.
*/
package org.semanticweb.HermiT.tableau;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.semanticweb.HermiT.existentials.ExistentialExpansionStrategy;
import org.semanticweb.HermiT.model.Atom;
import org.semanticweb.HermiT.model.DLClause;
import org.semanticweb.HermiT.model.DLPredicate;
import org.semanticweb.HermiT.model.NodeIDLessEqualThan;
import org.semanticweb.HermiT.model.NodeIDsAscendingOrEqual;
import org.semanticweb.HermiT.model.Variable;
import org.semanticweb.HermiT.monitor.TableauMonitor;
public class DLClauseEvaluator implements Serializable {
private static final long serialVersionUID=4639844159658590456L;
protected static final String CRLF=System.getProperty("line.separator");
protected final InterruptFlag m_interruptFlag;
protected final ExtensionManager m_extensionManager;
protected final ExtensionTable.Retrieval[] m_retrievals;
protected final Worker[] m_workers;
protected final DLClause m_bodyDLClause;
protected final List<DLClause> m_headDLClauses;
public DLClauseEvaluator(Tableau tableau,DLClause bodyDLClause,List<DLClause> headDLClauses,ExtensionTable.Retrieval firstAtomRetrieval,BufferSupply bufferSupply,ValuesBufferManager valuesBufferManager,GroundDisjunctionHeaderManager groundDisjunctionHeaderManager,Map<Integer,UnionDependencySet> unionDependencySetsBySize) {
m_interruptFlag=tableau.m_interruptFlag;
m_extensionManager=tableau.m_extensionManager;
DLClauseCompiler compiler=new DLClauseCompiler(bufferSupply,valuesBufferManager,groundDisjunctionHeaderManager,unionDependencySetsBySize,this,m_extensionManager,tableau.getExistentialsExpansionStrategy(),bodyDLClause,headDLClauses,firstAtomRetrieval);
m_retrievals=new ExtensionTable.Retrieval[compiler.m_retrievals.size()];
compiler.m_retrievals.toArray(m_retrievals);
m_workers=new Worker[compiler.m_workers.size()];
compiler.m_workers.toArray(m_workers);
m_bodyDLClause=bodyDLClause;
m_headDLClauses=headDLClauses;
}
public int getBodyLength() {
return m_bodyDLClause.getBodyLength();
}
public Atom getBodyAtom(int atomIndex) {
return m_bodyDLClause.getBodyAtom(atomIndex);
}
public int getNumberOfDLClauses() {
return m_headDLClauses.size();
}
public DLClause getDLClause(int dlClauseIndex) {
return m_headDLClauses.get(dlClauseIndex);
}
public int getHeadLength(int dlClauseIndex) {
return m_headDLClauses.get(dlClauseIndex).getHeadLength();
}
public Atom getHeadAtom(int dlClauseIndex,int atomIndex) {
return m_headDLClauses.get(dlClauseIndex).getHeadAtom(atomIndex);
}
public Object[] getTupleMatchedToBody(int atomIndex) {
return m_retrievals[atomIndex].getTupleBuffer();
}
public void evaluate() {
int programCounter=0;
while (programCounter<m_workers.length && !m_extensionManager.containsClash()) {
m_interruptFlag.checkInterrupt();
programCounter=m_workers[programCounter].execute(programCounter);
}
}
public String toString() {
StringBuffer buffer=new StringBuffer();
int maximalPCLength=String.valueOf(m_workers.length-1).length();
for (int programCounter=0;programCounter<m_workers.length;programCounter++) {
String programCounterString=String.valueOf(programCounter);
for (int count=maximalPCLength-programCounterString.length();count>0;--count)
buffer.append(' ');
buffer.append(programCounterString);
buffer.append(": ");
buffer.append(m_workers[programCounter].toString());
buffer.append(CRLF);
}
return buffer.toString();
}
public static class BufferSupply {
protected final List<Object[]> m_allBuffers;
protected final Map<Integer,List<Object[]>> m_availableBuffersByArity;
public BufferSupply() {
m_allBuffers=new ArrayList<Object[]>();
m_availableBuffersByArity=new HashMap<Integer,List<Object[]>>();
}
public void reuseBuffers() {
m_availableBuffersByArity.clear();
for (Object[] buffer : m_allBuffers) {
Integer arityInteger=Integer.valueOf(buffer.length);
List<Object[]> buffers=m_availableBuffersByArity.get(arityInteger);
if (buffers==null) {
buffers=new ArrayList<Object[]>();
m_availableBuffersByArity.put(arityInteger,buffers);
}
buffers.add(buffer);
}
}
public Object[] getBuffer(int arity) {
Object[] buffer;
Integer arityInteger=Integer.valueOf(arity);
List<Object[]> buffers=m_availableBuffersByArity.get(arityInteger);
if (buffers==null || buffers.isEmpty()) {
buffer=new Object[arity];
m_allBuffers.add(buffer);
}
else
buffer=buffers.remove(buffers.size()-1);
return buffer;
}
public Object[][] getAllBuffers() {
Object[][] result=new Object[m_allBuffers.size()][];
m_allBuffers.toArray(result);
return result;
}
}
public static class ValuesBufferManager {
public final Object[] m_valuesBuffer;
public final Map<DLPredicate,Integer> m_bodyDLPredicatesToIndexes;
public final int m_maxNumberOfVariables;
public ValuesBufferManager(Set<DLClause> dlClauses) {
Set<DLPredicate> bodyDLPredicates=new HashSet<DLPredicate>();
Set<Variable> variables=new HashSet<Variable>();
int maxNumberOfVariables=0;
for (DLClause dlClause : dlClauses) {
variables.clear();
for (int bodyIndex=dlClause.getBodyLength()-1;bodyIndex>=0;--bodyIndex) {
Atom atom=dlClause.getBodyAtom(bodyIndex);
bodyDLPredicates.add(atom.getDLPredicate());
for (int argumentIndex=0;argumentIndex<atom.getArity();argumentIndex++) {
Variable variable=atom.getArgumentVariable(argumentIndex);
if (variable!=null)
variables.add(variable);
}
}
if (variables.size()>maxNumberOfVariables)
maxNumberOfVariables=variables.size();
}
m_valuesBuffer=new Object[maxNumberOfVariables+bodyDLPredicates.size()];
m_bodyDLPredicatesToIndexes=new HashMap<DLPredicate,Integer>();
int predicateIndex=maxNumberOfVariables;
for (DLPredicate bodyDLPredicate : bodyDLPredicates) {
m_bodyDLPredicatesToIndexes.put(bodyDLPredicate,Integer.valueOf(predicateIndex));
m_valuesBuffer[predicateIndex]=bodyDLPredicate;
predicateIndex++;
}
m_maxNumberOfVariables=maxNumberOfVariables;
}
}
public static class GroundDisjunctionHeaderManager {
protected GroundDisjunctionHeader[] m_buckets;
protected int m_numberOfElements;
protected int m_threshold;
public GroundDisjunctionHeaderManager() {
m_buckets=new GroundDisjunctionHeader[1024];
m_threshold=(int)(m_buckets.length*0.75);
m_numberOfElements=0;
}
public GroundDisjunctionHeader get(DLPredicate[] dlPredicates) {
int hashCode=0;
for (int disjunctIndex=0;disjunctIndex<dlPredicates.length;disjunctIndex++)
hashCode=hashCode*7+dlPredicates[disjunctIndex].hashCode();
int bucketIndex=getIndexFor(hashCode,m_buckets.length);
GroundDisjunctionHeader entry=m_buckets[bucketIndex];
while (entry!=null) {
if (hashCode==entry.m_hashCode && entry.isEqual(dlPredicates))
return entry;
entry=entry.m_nextEntry;
}
entry=new GroundDisjunctionHeader(dlPredicates,hashCode,entry);
m_buckets[bucketIndex]=entry;
m_numberOfElements++;
if (m_numberOfElements>=m_threshold)
resize(m_buckets.length*2);
return entry;
}
protected void resize(int newCapacity) {
GroundDisjunctionHeader[] newBuckets=new GroundDisjunctionHeader[newCapacity];
for (int i=0;i<m_buckets.length;i++) {
GroundDisjunctionHeader entry=m_buckets[i];
while (entry!=null) {
GroundDisjunctionHeader nextEntry=entry.m_nextEntry;
int newIndex=getIndexFor(entry.hashCode(),newCapacity);
entry.m_nextEntry=newBuckets[newIndex];
newBuckets[newIndex]=entry;
entry=nextEntry;
}
}
m_buckets=newBuckets;
m_threshold=(int)(newCapacity*0.75);
}
protected static int getIndexFor(int hashCode,int tableLength) {
hashCode+=~(hashCode << 9);
hashCode^=(hashCode >>> 14);
hashCode+=(hashCode << 4);
hashCode^=(hashCode >>> 10);
return hashCode & (tableLength-1);
}
}
public static interface Worker {
int execute(int programCounter);
}
protected static interface BranchingWorker extends Worker {
int getBranchingAddress();
void setBranchingAddress(int branchingAddress);
}
protected static final class CopyValues implements Worker,Serializable {
private static final long serialVersionUID=-4323769483485648756L;
protected final Object[] m_fromBuffer;
protected final int m_fromIndex;
protected final Object[] m_toBuffer;
protected final int m_toIndex;
public CopyValues(Object[] fromBuffer,int fromIndex,Object[] toBuffer,int toIndex) {
m_fromBuffer=fromBuffer;
m_fromIndex=fromIndex;
m_toBuffer=toBuffer;
m_toIndex=toIndex;
}
public int execute(int programCounter) {
m_toBuffer[m_toIndex]=m_fromBuffer[m_fromIndex];
return programCounter+1;
}
public String toString() {
return "Copy "+m_fromIndex+" --> "+m_toIndex;
}
}
protected static final class CopyDependencySet implements Worker,Serializable {
private static final long serialVersionUID=705172386083123813L;
protected final ExtensionTable.Retrieval m_retrieval;
protected final DependencySet[] m_targetDependencySets;
protected final int m_targetIndex;
public CopyDependencySet(ExtensionTable.Retrieval retrieval,DependencySet[] targetDependencySets,int targetIndex) {
m_retrieval=retrieval;
m_targetDependencySets=targetDependencySets;
m_targetIndex=targetIndex;
}
public int execute(int programCounter) {
m_targetDependencySets[m_targetIndex]=m_retrieval.getDependencySet();
return programCounter+1;
}
public String toString() {
return "Copy dependency set to "+m_targetIndex;
}
}
protected static final class BranchIfNotEqual implements BranchingWorker,Serializable {
private static final long serialVersionUID=-1880147431680856293L;
protected int m_notEqualProgramCounter;
protected final Object[] m_buffer;
protected final int m_index1;
protected final int m_index2;
public BranchIfNotEqual(int notEqualProgramCounter,Object[] buffer,int index1,int index2) {
m_notEqualProgramCounter=notEqualProgramCounter;
m_buffer=buffer;
m_index1=index1;
m_index2=index2;
}
public int execute(int programCounter) {
if (m_buffer[m_index1].equals(m_buffer[m_index2]))
return programCounter+1;
else
return m_notEqualProgramCounter;
}
public int getBranchingAddress() {
return m_notEqualProgramCounter;
}
public void setBranchingAddress(int branchingAddress) {
m_notEqualProgramCounter=branchingAddress;
}
public String toString() {
return "Branch to "+m_notEqualProgramCounter+" if "+m_index1+" != "+m_index2;
}
}
protected static final class BranchIfNotNodeIDLessEqualThan implements BranchingWorker,Serializable {
private static final long serialVersionUID=2484359261424674914L;
protected int m_notLessProgramCounter;
protected final Object[] m_buffer;
protected final int m_index1;
protected final int m_index2;
public BranchIfNotNodeIDLessEqualThan(int notLessProgramCounter,Object[] buffer,int index1,int index2) {
m_notLessProgramCounter=notLessProgramCounter;
m_buffer=buffer;
m_index1=index1;
m_index2=index2;
}
public int execute(int programCounter) {
if (((Node)m_buffer[m_index1]).getNodeID()<=((Node)m_buffer[m_index2]).getNodeID())
return programCounter+1;
else
return m_notLessProgramCounter;
}
public int getBranchingAddress() {
return m_notLessProgramCounter;
}
public void setBranchingAddress(int branchingAddress) {
m_notLessProgramCounter=branchingAddress;
}
public String toString() {
return "Branch to "+m_notLessProgramCounter+" if "+m_index1+".ID > "+m_index2+".ID";
}
}
protected static final class BranchIfNotNodeIDsAscendingOrEqual implements BranchingWorker,Serializable {
private static final long serialVersionUID=8053779312249250349L;
protected int m_branchProgramCounter;
protected final Object[] m_buffer;
protected final int[] m_nodeIndexes;
public BranchIfNotNodeIDsAscendingOrEqual(int branchProgramCounter,Object[] buffer,int[] nodeIndexes) {
m_branchProgramCounter=branchProgramCounter;
m_buffer=buffer;
m_nodeIndexes=nodeIndexes;
}
public int execute(int programCounter) {
boolean strictlyAscending=true;
boolean allEqual=true;
int lastNodeID=((Node)m_buffer[m_nodeIndexes[0]]).getNodeID();
for (int index=1;index<m_nodeIndexes.length;index++) {
int nodeID=((Node)m_buffer[m_nodeIndexes[index]]).getNodeID();
if (lastNodeID>=nodeID)
strictlyAscending=false;
if (nodeID!=lastNodeID)
allEqual=false;
lastNodeID=nodeID;
}
if ((!strictlyAscending && allEqual) || (strictlyAscending && !allEqual))
return programCounter+1;
else
return m_branchProgramCounter;
}
public int getBranchingAddress() {
return m_branchProgramCounter;
}
public void setBranchingAddress(int branchingAddress) {
m_branchProgramCounter=branchingAddress;
}
public String toString() {
return "Branch to "+m_branchProgramCounter+" if node IDs are not ascending or equal";
}
}
protected static final class OpenRetrieval implements Worker,Serializable {
private static final long serialVersionUID=8246610603084803950L;
protected final ExtensionTable.Retrieval m_retrieval;
public OpenRetrieval(ExtensionTable.Retrieval retrieval) {
m_retrieval=retrieval;
}
public int execute(int programCounter) {
m_retrieval.open();
return programCounter+1;
}
public String toString() {
return "Open "+m_retrieval.getBindingsBuffer()[m_retrieval.getBindingPositions()[0]];
}
}
protected static final class NextRetrieval implements Worker,Serializable {
private static final long serialVersionUID=-2787897558147109082L;
protected final ExtensionTable.Retrieval m_retrieval;
public NextRetrieval(ExtensionTable.Retrieval retrieval) {
m_retrieval=retrieval;
}
public int execute(int programCounter) {
m_retrieval.next();
return programCounter+1;
}
public String toString() {
return "Next "+m_retrieval.getBindingsBuffer()[m_retrieval.getBindingPositions()[0]];
}
}
protected static final class HasMoreRetrieval implements BranchingWorker,Serializable {
private static final long serialVersionUID=-2415094151423166585L;
protected int m_eofProgramCounter;
protected final ExtensionTable.Retrieval m_retrieval;
public HasMoreRetrieval(int eofProgramCounter,ExtensionTable.Retrieval retrieval) {
m_eofProgramCounter=eofProgramCounter;
m_retrieval=retrieval;
}
public int execute(int programCounter) {
if (m_retrieval.afterLast())
return m_eofProgramCounter;
else
return programCounter+1;
}
public int getBranchingAddress() {
return m_eofProgramCounter;
}
public void setBranchingAddress(int branchingAddress) {
m_eofProgramCounter=branchingAddress;
}
public String toString() {
return "Branch to "+m_eofProgramCounter+" if "+m_retrieval.getBindingsBuffer()[m_retrieval.getBindingPositions()[0]]+" is empty";
}
}
protected static final class JumpTo implements BranchingWorker,Serializable {
private static final long serialVersionUID=-6957866973028474739L;
protected int m_jumpTo;
public JumpTo(int jumpTo) {
m_jumpTo=jumpTo;
}
public int execute(int programCounter) {
return m_jumpTo;
}
public int getBranchingAddress() {
return m_jumpTo;
}
public void setBranchingAddress(int branchingAddress) {
m_jumpTo=branchingAddress;
}
public String toString() {
return "Jump to "+m_jumpTo;
}
}
protected static final class CallMatchStartedOnMonitor implements Worker,Serializable {
private static final long serialVersionUID=8736659573939242252L;
protected final TableauMonitor m_tableauMonitor;
protected final DLClauseEvaluator m_dlClauseEvaluator;
protected final int m_dlClauseIndex;
public CallMatchStartedOnMonitor(TableauMonitor tableauMonitor,DLClauseEvaluator dlClauseEvaluator,int dlClauseIndex) {
m_tableauMonitor=tableauMonitor;
m_dlClauseEvaluator=dlClauseEvaluator;
m_dlClauseIndex=dlClauseIndex;
}
public int execute(int programCounter) {
m_tableauMonitor.dlClauseMatchedStarted(m_dlClauseEvaluator,m_dlClauseIndex);
return programCounter+1;
}
public String toString() {
return "Monitor -> Match started";
}
}
protected static final class CallMatchFinishedOnMonitor implements Worker,Serializable {
private static final long serialVersionUID=1046400921858176361L;
protected final TableauMonitor m_tableauMonitor;
protected final DLClauseEvaluator m_dlClauseEvaluator;
protected final int m_dlClauseIndex;
public CallMatchFinishedOnMonitor(TableauMonitor tableauMonitor,DLClauseEvaluator dlClauseEvaluator,int dlClauseIndex) {
m_tableauMonitor=tableauMonitor;
m_dlClauseEvaluator=dlClauseEvaluator;
m_dlClauseIndex=dlClauseIndex;
}
public int execute(int programCounter) {
m_tableauMonitor.dlClauseMatchedFinished(m_dlClauseEvaluator,m_dlClauseIndex);
return programCounter+1;
}
public String toString() {
return "Monitor -> Match finished";
}
}
protected static final class SetClash implements Worker,Serializable {
private static final long serialVersionUID=-4981087765064918953L;
protected final ExtensionManager m_extensionManager;
protected final DependencySet m_dependencySet;
public SetClash(ExtensionManager extensionManager,DependencySet dependencySet) {
m_extensionManager=extensionManager;
m_dependencySet=dependencySet;
}
public int execute(int programCounter) {
m_extensionManager.setClash(m_dependencySet);
return programCounter+1;
}
public String toString() {
return "Set clash";
}
}
protected static final class DeriveUnaryFact implements Worker,Serializable {
private static final long serialVersionUID=7883620022252842010L;
protected final ExtensionManager m_extensionManager;
protected final Object[] m_valuesBuffer;
protected final boolean[] m_coreVariables;
protected final DependencySet m_dependencySet;
protected final DLPredicate m_dlPredicate;
protected final int m_argumentIndex;
public DeriveUnaryFact(ExtensionManager extensionManager,Object[] valuesBuffer,boolean[] coreVariables,DependencySet dependencySet,DLPredicate dlPredicate,int argumentIndex) {
m_extensionManager=extensionManager;
m_valuesBuffer=valuesBuffer;
m_coreVariables=coreVariables;
m_dependencySet=dependencySet;
m_argumentIndex=argumentIndex;
m_dlPredicate=dlPredicate;
}
public int execute(int programCounter) {
Node argument=(Node)m_valuesBuffer[m_argumentIndex];
boolean isCore=m_coreVariables[m_argumentIndex];
m_extensionManager.addAssertion(m_dlPredicate,argument,m_dependencySet,isCore);
return programCounter+1;
}
public String toString() {
return "Derive unary fact";
}
}
protected static final class DeriveBinaryFact implements Worker,Serializable {
private static final long serialVersionUID=1823363493615682288L;
protected final ExtensionManager m_extensionManager;
protected final Object[] m_valuesBuffer;
protected final DependencySet m_dependencySet;
protected final DLPredicate m_dlPredicate;
protected final int m_argumentIndex1;
protected final int m_argumentIndex2;
public DeriveBinaryFact(ExtensionManager extensionManager,Object[] valuesBuffer,DependencySet dependencySet,DLPredicate dlPredicate,int argumentIndex1,int argumentIndex2) {
m_extensionManager=extensionManager;
m_valuesBuffer=valuesBuffer;
m_dependencySet=dependencySet;
m_dlPredicate=dlPredicate;
m_argumentIndex1=argumentIndex1;
m_argumentIndex2=argumentIndex2;
}
public int execute(int programCounter) {
Node argument1=(Node)m_valuesBuffer[m_argumentIndex1];
Node argument2=(Node)m_valuesBuffer[m_argumentIndex2];
m_extensionManager.addAssertion(m_dlPredicate,argument1,argument2,m_dependencySet,true);
return programCounter+1;
}
public String toString() {
return "Derive binary fact";
}
}
protected static final class DeriveTernaryFact implements Worker,Serializable {
private static final long serialVersionUID=1823363493615682288L;
protected final ExtensionManager m_extensionManager;
protected final Object[] m_valuesBuffer;
protected final DependencySet m_dependencySet;
protected final DLPredicate m_dlPredicate;
protected final int m_argumentIndex1;
protected final int m_argumentIndex2;
protected final int m_argumentIndex3;
public DeriveTernaryFact(ExtensionManager extensionManager,Object[] valuesBuffer,DependencySet dependencySet,DLPredicate dlPredicate,int argumentIndex1,int argumentIndex2,int argumentIndex3) {
m_extensionManager=extensionManager;
m_valuesBuffer=valuesBuffer;
m_dependencySet=dependencySet;
m_dlPredicate=dlPredicate;
m_argumentIndex1=argumentIndex1;
m_argumentIndex2=argumentIndex2;
m_argumentIndex3=argumentIndex3;
}
public int execute(int programCounter) {
Node argument1=(Node)m_valuesBuffer[m_argumentIndex1];
Node argument2=(Node)m_valuesBuffer[m_argumentIndex2];
Node argument3=(Node)m_valuesBuffer[m_argumentIndex3];
m_extensionManager.addAssertion(m_dlPredicate,argument1,argument2,argument3,m_dependencySet,true);
return programCounter+1;
}
public String toString() {
return "Derive ternary fact";
}
}
protected static final class DeriveDisjunction implements Worker,Serializable {
private static final long serialVersionUID=-3546622575743138887L;
protected final Tableau m_tableau;
protected final Object[] m_valuesBuffer;
protected final boolean[] m_coreVariables;
protected final DependencySet m_dependencySet;
protected final GroundDisjunctionHeader m_groundDisjunctionHeader;
protected final int[] m_copyIsCore;
protected final int[] m_copyValuesToArguments;
public DeriveDisjunction(Object[] valuesBuffer,boolean[] coreVariables,DependencySet dependencySet,Tableau tableau,GroundDisjunctionHeader groundDisjunctionHeader,int[] copyIsCore,int[] copyValuesToArguments) {
m_valuesBuffer=valuesBuffer;
m_coreVariables=coreVariables;
m_dependencySet=dependencySet;
m_tableau=tableau;
m_groundDisjunctionHeader=groundDisjunctionHeader;
m_copyIsCore=copyIsCore;
m_copyValuesToArguments=copyValuesToArguments;
}
public void clear() {
}
public int execute(int programCounter) {
Node[] arguments=new Node[m_copyValuesToArguments.length];
for (int argumentIndex=m_copyValuesToArguments.length-1;argumentIndex>=0;--argumentIndex)
arguments[argumentIndex]=(Node)m_valuesBuffer[m_copyValuesToArguments[argumentIndex]];
boolean[] isCore=new boolean[m_copyIsCore.length];
for (int copyIndex=m_copyIsCore.length-1;copyIndex>=0;--copyIndex) {
int copyFrom=m_copyIsCore[copyIndex];
if (copyFrom==-1)
isCore[copyIndex]=true;
else
isCore[copyIndex]=m_coreVariables[copyFrom];
}
GroundDisjunction groundDisjunction=new GroundDisjunction(m_tableau,m_groundDisjunctionHeader,arguments,isCore,m_tableau.m_dependencySetFactory.getPermanent(m_dependencySet));
if (!groundDisjunction.isSatisfied(m_tableau))
m_tableau.addGroundDisjunction(groundDisjunction);
return programCounter+1;
}
public String toString() {
return "Derive disjunction";
}
}
protected static final class DLClauseCompiler {
protected final DLClauseEvaluator m_dlClauseEvalautor;
protected final BufferSupply m_bufferSupply;
protected final ValuesBufferManager m_valuesBufferManager;
protected final GroundDisjunctionHeaderManager m_groundDisjunctionHeaderManager;
protected final ExtensionManager m_extensionManager;
protected final ExistentialExpansionStrategy m_existentialExpansionStrategy;
protected final DLClause m_bodyDLClause;
protected final List<DLClause> m_headDLClauses;
protected final List<Variable> m_variables;
protected final Set<Variable> m_boundSoFar;
protected final boolean[] m_coreVariables;
protected final UnionDependencySet m_unionDependencySet;
protected final List<ExtensionTable.Retrieval> m_retrievals;
protected final List<Worker> m_workers;
protected final List<Integer> m_labels;
public DLClauseCompiler(BufferSupply bufferSupply,ValuesBufferManager valuesBufferManager,GroundDisjunctionHeaderManager groundDisjunctionHeaderManager,Map<Integer,UnionDependencySet> unionDependencySetsBySize,DLClauseEvaluator dlClauseEvalautor,ExtensionManager extensionManager,ExistentialExpansionStrategy existentialExpansionStrategy,DLClause bodyDLClause,List<DLClause> headDLClauses,ExtensionTable.Retrieval firstAtomRetrieval) {
m_bufferSupply=bufferSupply;
m_valuesBufferManager=valuesBufferManager;
m_groundDisjunctionHeaderManager=groundDisjunctionHeaderManager;
m_dlClauseEvalautor=dlClauseEvalautor;
m_extensionManager=extensionManager;
m_existentialExpansionStrategy=existentialExpansionStrategy;
m_bodyDLClause=bodyDLClause;
m_headDLClauses=headDLClauses;
m_variables=new ArrayList<Variable>();
int numberOfRealAtoms=0;
for (int bodyIndex=0;bodyIndex<getBodyLength();bodyIndex++) {
Atom atom=getBodyAtom(bodyIndex);
for (int argumentIndex=0;argumentIndex<atom.getArity();argumentIndex++) {
Variable variable=atom.getArgumentVariable(argumentIndex);
if (variable!=null && !m_variables.contains(variable) && occursInBodyAtomsAfter(variable,bodyIndex+1))
m_variables.add(variable);
}
if (!atom.getDLPredicate().equals(NodeIDLessEqualThan.INSTANCE) && !(atom.getDLPredicate() instanceof NodeIDsAscendingOrEqual))
numberOfRealAtoms++;
}
for (int dlClauseIndex=0;dlClauseIndex<getNumberOfHeads();dlClauseIndex++) {
for (int headIndex=0;headIndex<getHeadLength(dlClauseIndex);headIndex++) {
Atom atom=getHeadAtom(dlClauseIndex,headIndex);
for (int argumentIndex=0;argumentIndex<atom.getArity();argumentIndex++) {
Variable variable=atom.getArgumentVariable(argumentIndex);
if (variable!=null && !m_variables.contains(variable))
m_variables.add(variable);
}
}
}
m_boundSoFar=new HashSet<Variable>();
m_coreVariables=new boolean[m_variables.size()];
Integer numberOfRealAtomsInteger=Integer.valueOf(numberOfRealAtoms);
UnionDependencySet unionDependencySet=unionDependencySetsBySize.get(numberOfRealAtomsInteger);
if (unionDependencySet==null) {
unionDependencySet=new UnionDependencySet(numberOfRealAtoms);
unionDependencySetsBySize.put(numberOfRealAtomsInteger,unionDependencySet);
}
m_unionDependencySet=unionDependencySet;
m_retrievals=new ArrayList<ExtensionTable.Retrieval>();
m_workers=new ArrayList<Worker>();
m_labels=new ArrayList<Integer>();
m_labels.add(null);
m_retrievals.add(firstAtomRetrieval);
int afterRule=addLabel();
compileCheckUnboundVariableMatches(getBodyAtom(0),firstAtomRetrieval,afterRule);
compileGenerateBindings(firstAtomRetrieval,getBodyAtom(0));
m_workers.add(new CopyDependencySet(firstAtomRetrieval,m_unionDependencySet.m_dependencySets,0));
compileBodyAtom(1,afterRule);
setLabelProgramCounter(afterRule);
for (Worker worker : m_workers)
if (worker instanceof BranchingWorker) {
BranchingWorker branchingWorker=(BranchingWorker)worker;
int branchingAddress=branchingWorker.getBranchingAddress();
if (branchingAddress<0) {
int resolvedAddress=m_labels.get(-branchingAddress);
branchingWorker.setBranchingAddress(resolvedAddress);
}
}
}
protected int getNumberOfHeads() {
return m_headDLClauses.size();
}
protected int getBodyLength() {
return m_bodyDLClause.getBodyLength();
}
protected Atom getBodyAtom(int atomIndex) {
return m_bodyDLClause.getBodyAtom(atomIndex);
}
protected int getHeadLength(int dlClauseIndex) {
return m_headDLClauses.get(dlClauseIndex).getHeadLength();
}
protected Atom getHeadAtom(int dlClauseIndex,int atomIndex) {
return m_headDLClauses.get(dlClauseIndex).getHeadAtom(atomIndex);
}
protected boolean occursInBodyAtomsAfter(Variable variable,int startIndex) {
for (int argumentIndex=startIndex;argumentIndex<getBodyLength();argumentIndex++)
if (getBodyAtom(argumentIndex).containsVariable(variable))
return true;
return false;
}
protected void compileBodyAtom(int bodyAtomIndex,int lastAtomNextElement) {
if (bodyAtomIndex==getBodyLength()) {
m_existentialExpansionStrategy.dlClauseBodyCompiled(m_workers,m_bodyDLClause,m_variables,m_valuesBufferManager.m_valuesBuffer,m_coreVariables);
compileHeads();
}
else if (getBodyAtom(bodyAtomIndex).getDLPredicate().equals(NodeIDLessEqualThan.INSTANCE)) {
Atom atom=getBodyAtom(bodyAtomIndex);
int variable1Index=m_variables.indexOf(atom.getArgumentVariable(0));
int variable2Index=m_variables.indexOf(atom.getArgumentVariable(1));
assert variable1Index!=-1;
assert variable2Index!=-1;
m_workers.add(new BranchIfNotNodeIDLessEqualThan(lastAtomNextElement,m_valuesBufferManager.m_valuesBuffer,variable1Index,variable2Index));
compileBodyAtom(bodyAtomIndex+1,lastAtomNextElement);
}
else if (getBodyAtom(bodyAtomIndex).getDLPredicate() instanceof NodeIDsAscendingOrEqual) {
Atom atom=getBodyAtom(bodyAtomIndex);
int[] nodeIndexes=new int[atom.getArity()];
for (int index=0;index<atom.getArity();index++) {
nodeIndexes[index]=m_variables.indexOf(atom.getArgumentVariable(index));
assert nodeIndexes[index]!=-1;
}
m_workers.add(new BranchIfNotNodeIDsAscendingOrEqual(lastAtomNextElement,m_valuesBufferManager.m_valuesBuffer,nodeIndexes));
compileBodyAtom(bodyAtomIndex+1,lastAtomNextElement);
}
else {
// Each atom is compiled into the following structure:
//
// retrieval.open()
// loopStart: if (!retrieval.hasMore) goto afterLoop
// if (!retrieval.unboundVariableMatches) goto nextElement
// generate bindings - copy bindings from the retrieval to the values buffer
// copy the dependency set from the retrieval into the union dependency set
// < the code for the next atom >
// nextElement: retrieval.next
// goto loopStart
// afterLoop:
//
// NodeIDLessEqualThan and NodeIDsAscendingOrEqual atoms are compiled such that they
// immediately jump to the next element of the previous regular atom.
int afterLoop=addLabel();
int nextElement=addLabel();
Atom atom=getBodyAtom(bodyAtomIndex);
int[] bindingPositions=new int[atom.getArity()+1];
bindingPositions[0]=m_valuesBufferManager.m_bodyDLPredicatesToIndexes.get(atom.getDLPredicate()).intValue();
for (int argumentIndex=0;argumentIndex<atom.getArity();argumentIndex++) {
Variable variable=atom.getArgumentVariable(argumentIndex);
if (variable!=null && m_boundSoFar.contains(variable))
bindingPositions[argumentIndex+1]=m_variables.indexOf(variable);
else
bindingPositions[argumentIndex+1]=-1;
}
ExtensionTable.Retrieval retrieval=m_extensionManager.getExtensionTable(atom.getArity()+1).createRetrieval(bindingPositions,m_valuesBufferManager.m_valuesBuffer,m_bufferSupply.getBuffer(atom.getArity()+1),false,ExtensionTable.View.EXTENSION_THIS);
m_retrievals.add(retrieval);
m_workers.add(new OpenRetrieval(retrieval));
int loopStart=m_workers.size();
m_workers.add(new HasMoreRetrieval(afterLoop,retrieval));
compileCheckUnboundVariableMatches(atom,retrieval,nextElement);
compileGenerateBindings(retrieval,atom);
m_workers.add(new CopyDependencySet(retrieval,m_unionDependencySet.m_dependencySets,m_retrievals.size()-1));
compileBodyAtom(bodyAtomIndex+1,nextElement);
setLabelProgramCounter(nextElement);
m_workers.add(new NextRetrieval(retrieval));
m_workers.add(new JumpTo(loopStart));
setLabelProgramCounter(afterLoop);
}
}
protected void compileHeads() {
for (int dlClauseIndex=0;dlClauseIndex<getNumberOfHeads();dlClauseIndex++) {
if (m_extensionManager.m_tableauMonitor!=null)
m_workers.add(new CallMatchStartedOnMonitor(m_extensionManager.m_tableauMonitor,m_dlClauseEvalautor,dlClauseIndex));
if (getHeadLength(dlClauseIndex)==0)
m_workers.add(new SetClash(m_extensionManager,m_unionDependencySet));
else if (getHeadLength(dlClauseIndex)==1) {
Atom atom=getHeadAtom(dlClauseIndex,0);
switch (atom.getArity()) {
case 1:
m_workers.add(new DeriveUnaryFact(m_extensionManager,m_valuesBufferManager.m_valuesBuffer,m_coreVariables,m_unionDependencySet,atom.getDLPredicate(),m_variables.indexOf(atom.getArgumentVariable(0))));
break;
case 2:
m_workers.add(new DeriveBinaryFact(m_extensionManager,m_valuesBufferManager.m_valuesBuffer,m_unionDependencySet,atom.getDLPredicate(),m_variables.indexOf(atom.getArgumentVariable(0)),m_variables.indexOf(atom.getArgumentVariable(1))));
break;
case 3:
m_workers.add(new DeriveTernaryFact(m_extensionManager,m_valuesBufferManager.m_valuesBuffer,m_unionDependencySet,atom.getDLPredicate(),m_variables.indexOf(atom.getArgumentVariable(0)),m_variables.indexOf(atom.getArgumentVariable(1)),m_variables.indexOf(atom.getArgumentVariable(2))));
break;
default:
throw new IllegalArgumentException("Unsupported atom arity.");
}
}
else {
int totalNumberOfArguments=0;
for (int headIndex=0;headIndex<getHeadLength(dlClauseIndex);headIndex++)
totalNumberOfArguments+=getHeadAtom(dlClauseIndex,headIndex).getArity();
DLPredicate[] headDLPredicates=new DLPredicate[getHeadLength(dlClauseIndex)];
int[] copyIsCore=new int[getHeadLength(dlClauseIndex)];
int[] copyValuesToArguments=new int[totalNumberOfArguments];
int index=0;
for (int headIndex=0;headIndex<getHeadLength(dlClauseIndex);headIndex++) {
Atom atom=getHeadAtom(dlClauseIndex,headIndex);
headDLPredicates[headIndex]=atom.getDLPredicate();
for (int argumentIndex=0;argumentIndex<atom.getArity();argumentIndex++) {
Variable variable=atom.getArgumentVariable(argumentIndex);
int variableIndex=m_variables.indexOf(variable);
assert variableIndex!=-1;
copyValuesToArguments[index++]=variableIndex;
}
if (headDLPredicates[headIndex].getArity()==1) {
Variable variable=atom.getArgumentVariable(0);
copyIsCore[headIndex]=m_variables.indexOf(variable);
}
else
copyIsCore[headIndex]=-1;
}
GroundDisjunctionHeader groundDisjunctionHeader=m_groundDisjunctionHeaderManager.get(headDLPredicates);
m_workers.add(new DeriveDisjunction(m_valuesBufferManager.m_valuesBuffer,m_coreVariables,m_unionDependencySet,m_extensionManager.m_tableau,groundDisjunctionHeader,copyIsCore,copyValuesToArguments));
}
if (m_extensionManager.m_tableauMonitor!=null)
m_workers.add(new CallMatchFinishedOnMonitor(m_extensionManager.m_tableauMonitor,m_dlClauseEvalautor,dlClauseIndex));
}
}
protected void compileCheckUnboundVariableMatches(Atom atom,ExtensionTable.Retrieval retrieval,int jumpIndex) {
for (int outerArgumentIndex=0;outerArgumentIndex<atom.getArity();outerArgumentIndex++) {
Variable variable=atom.getArgumentVariable(outerArgumentIndex);
if (variable!=null && !m_boundSoFar.contains(variable)) {
for (int innerArgumentIndex=outerArgumentIndex+1;innerArgumentIndex<atom.getArity();innerArgumentIndex++) {
if (variable.equals(atom.getArgument(innerArgumentIndex)))
m_workers.add(new BranchIfNotEqual(jumpIndex,retrieval.getTupleBuffer(),outerArgumentIndex+1,innerArgumentIndex+1));
}
}
}
}
protected void compileGenerateBindings(ExtensionTable.Retrieval retrieval,Atom atom) {
for (int argumentIndex=0;argumentIndex<atom.getArity();argumentIndex++) {
Variable variable=atom.getArgumentVariable(argumentIndex);
if (variable!=null && !m_boundSoFar.contains(variable)) {
int variableIndex=m_variables.indexOf(variable);
if (variableIndex!=-1) {
m_workers.add(new CopyValues(retrieval.getTupleBuffer(),argumentIndex+1,m_valuesBufferManager.m_valuesBuffer,variableIndex));
m_boundSoFar.add(variable);
}
}
}
}
protected int addLabel() {
int labelIndex=m_labels.size();
m_labels.add(null);
return -labelIndex;
}
protected void setLabelProgramCounter(int labelID) {
m_labels.set(-labelID,Integer.valueOf(m_workers.size()));
}
}
}