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Open-source constraint solver.
/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2022, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.solver.trace;
import gnu.trove.stack.TIntStack;
import gnu.trove.stack.array.TIntArrayStack;
import org.chocosolver.solver.Solver;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.search.loop.monitors.IMonitorContradiction;
import org.chocosolver.solver.search.loop.monitors.IMonitorDownBranch;
import org.chocosolver.solver.search.loop.monitors.IMonitorRestart;
import org.chocosolver.solver.search.loop.monitors.IMonitorSolution;
import org.chocosolver.solver.search.loop.monitors.IMonitorUpBranch;
import org.chocosolver.solver.search.strategy.decision.Decision;
import org.chocosolver.solver.search.strategy.decision.DecisionPath;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.Variable;
import org.chocosolver.util.iterators.DisposableRangeIterator;
import java.io.Closeable;
import java.io.IOException;
/**
* Created by cprudhom on 22/10/2015.
* Project: choco.
*
* @author Charles Prud'homme
* @since 3.3.2
*/
public abstract class SearchViz implements IMonitorDownBranch, IMonitorUpBranch,
IMonitorSolution, IMonitorContradiction, IMonitorRestart, Closeable {
/**
* Reference to the model
*/
protected Solver mSolver;
/**
* Stacks of 'Parent Id' used when backtrack
*/
private final TIntStack pid_stack = new TIntArrayStack();
/**
* Stacks of 'Alternative' used when backtrack
*/
private final TIntStack alt_stack = new TIntArrayStack();
/**
* Stacks of current node, to deal with jumps
*/
private final TIntStack last_stack = new TIntArrayStack();
/**
* Node count: different from measures.getNodeCount() as we count failure nodes as well
*/
private int nc = 0;
/**
* restart id
*/
private int rid;
/**
* last node index sent
*/
private int last;
/**
* Is connection alive
*/
protected boolean connected;
/**
* set to true to send domain into 'info' field
*/
private final boolean sendDomain;
/**
* Format for solution output
*/
private final IMessage solutionMessage = new IMessage() {
@Override
public String print() {
StringBuilder s = new StringBuilder(32);
for (Variable v : mSolver.getModel().getVars()) {
s.append(v).append(' ');
}
return s.toString();
}
};
/**
* Format for domain output
* "{ "domains": {"VarA": "1..10, 12, 14..19", "VarB": "4"} }"
*/
private final IMessage domainMessage = new IMessage() {
@Override
public String print() {
StringBuilder s = new StringBuilder(32);
s.append("{\"domains\":{");
for (Variable v : mSolver.getModel().getVars()) {
if ((v.getTypeAndKind() & Variable.INT) > 0) {
s.append("\"").append(v.getName()).append("\":\"");
IntVar iv = (IntVar) v;
DisposableRangeIterator rit = iv.getRangeIterator(true);
while (rit.hasNext()) {
int from = rit.min();
int to = rit.max();
s.append(from);
if(from < to){
s.append("..").append(to);
}
s.append(',');
rit.next();
}
rit.dispose();
}
s.setLength(s.length() - 1);
s.append("\",");
}
s.setLength(s.length() - 1);
s.append("}}");
return s.toString();
}
};
/**
* Active connection to cp-profiler.
* This requires cp-profiler to be installed and launched before.
*
* @param aSolver solver to observe resolution
* @param sendDomain set to true to send domain into 'info' field (beware, it can increase the memory consumption
* and slow down the overall execution), set to false otherwise.
*/
public SearchViz(Solver aSolver, boolean sendDomain) {
this.mSolver = aSolver;
this.sendDomain = sendDomain;
if(connected = connect(mSolver.getModel().getName())) {
mSolver.plugMonitor(this);
}
alt_stack.push(-1); // -1 is alt for the root node
pid_stack.push(-1); // -1 is pid for the root node
last_stack.push(-1);
}
protected abstract boolean connect(String label);
protected abstract void disconnect();
protected abstract void sendNode(int nc, int pid, int alt, int kid, int rid, String label, String info);
protected abstract void sendSolution(int nc, int pid, int alt, int kid, int rid, String label, String info);
protected abstract void sendFailure(int nc, int pid, int alt, int kid, int rid, String label, String info);
protected abstract void sendRestart(int rid);
/**
* Close connection to cp-profiler.
*/
@Override
public final void close() throws IOException {
disconnect();
mSolver.unplugMonitor(this);
connected = false;
}
@Override
public final void beforeDownBranch(boolean left) {
if (left) {
DecisionPath dp = mSolver.getDecisionPath();
int last = dp.size() - 1;
if (last > 0) {
String pdec;
pdec = pretty(dp.getDecision(last - 1));
Decision dec = dp.getLastDecision();
int ari = dec.getArity();
sendNode(nc, pid_stack.peek(), alt_stack.pop(), ari, rid, pdec,
sendDomain? domainMessage.print():"");
for (int i = 0; i < ari; i++) {
pid_stack.push(nc); // each child will have the same pid
}
nc++;
alt_stack.push(0);
last_stack.push(nc - 1);
}
} else {
nc++;
alt_stack.push(1);
last_stack.push(last);
}
}
@Override
public final void beforeUpBranch() {
last = last_stack.pop();
while (pid_stack.peek() != last) {
pid_stack.pop();
}
pid_stack.pop();
}
@Override
public final void onSolution() {
String dec = pretty(mSolver.getDecisionPath().getLastDecision());
sendSolution(nc, pid_stack.peek(), alt_stack.pop(), 0, rid, dec, solutionMessage.print());
}
@Override
public final void onContradiction(ContradictionException cex) {
String dec = pretty(mSolver.getDecisionPath().getLastDecision());
sendFailure(nc, pid_stack.peek(), alt_stack.pop(), 0, rid, dec, cex.toString());
}
@Override
public final void afterRestart() {
sendRestart(++rid);
pid_stack.clear();
alt_stack.clear();
alt_stack.push(-1); // -1 is alt for the root node
pid_stack.push(-1); // -1 is pid for the root node
last_stack.push(-1);
nc = 0;
}
private static String pretty(Decision dec) {
if (dec == null) {
return "ROOT";
} else {
// to print decision correctly (since the previous one is sent)
int a = dec.getArity();
int b = dec.triesLeft();
dec.rewind();
while (dec.triesLeft() > b + 1) {
a--;
dec.buildNext();
}
String pretty = dec.toString();
while (a > b) {
b++;
dec.buildNext();
}
return pretty;
}
}
}