add gurobi solver (untested so far)

jastadd-mquat-benchmark/src/main/java/de/tudresden/inf/st/mquat/benchmark/SolverFactory.java

@@ -2,6 +2,7 @@ package de.tudresden.inf.st.mquat.benchmark;
 
 import de.tudresden.inf.st.mquat.solving.BenchmarkableSolver;
 import de.tudresden.inf.st.mquat.solving.ilp.GLPKSolver;
+import de.tudresden.inf.st.mquat.solving.ilp.GurobiSolver;
 import de.tudresden.inf.st.mquat.solving.ilp.ILPDirectSolver;
 import de.tudresden.inf.st.mquat.solving.genetic.GeneticSolver;
 import de.tudresden.inf.st.mquat.solving.ilp.SCIPSolver;
@@ -31,6 +32,7 @@ public class SolverFactory {
           new EMFeRSolver(),
           new GLPKSolver(),
           new SCIPSolver(),
+          new GurobiSolver(),
           new ILPDirectSolver(),
           new SimpleSolver(),
           new RandomSolver(0, 0),

jastadd-mquat-solver-ilp/src/main/java/de/tudresden/inf/st/mquat/solving/ilp/GurobiSolver.java

+package de.tudresden.inf.st.mquat.solving.ilp;
+
+import de.tudresden.inf.st.mquat.jastadd.model.ILP;
+import de.tudresden.inf.st.mquat.jastadd.model.IlpVariable;
+import de.tudresden.inf.st.mquat.solving.SolvingException;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class GurobiSolver extends ILPExternalSolver {
+
+  /**
+   * Create a new GLPK solver with default settings.
+   * Default is:
+   * <ul>
+   *   <li>1 minute timeout</li>
+   *   <li>delete temporary files on exit.</li>
+   * </ul>
+   * @see GurobiSolver#setDeleteFilesOnExit(boolean)
+   */
+  public GurobiSolver() {
+  }
+
+
+  @Override
+  protected String[] getCommand(Path lp, Path solution, long remainingTimeForSolvingInMillis) {
+    String[] command = {"gurobi_cl", " ResultFile=" + solution.toAbsolutePath(), "TimeLimit=" + remainingTimeForSolvingInMillis/1000, String.valueOf(lp.toAbsolutePath())};
+    return command;
+  }
+
+  @Override
+  protected void readFromPlainTextSolution(ILP ilp, Path solution, ILPSolution result,
+                                                List<IlpVariable> variablesSetToOne) throws SolvingException {
+    try (Stream<String> lines = Files.lines(solution)) {
+      for (String line : lines.collect(Collectors.toList())) {
+        if (line.startsWith("#")) {
+          // comment line
+
+          if (line.startsWith("# Objective Value =")) {
+            result.setObjective(Double.valueOf(line.substring(20).trim()));
+            logger.debug("read objective {}", Double.valueOf(line.substring(20).trim()));
+          }
+        } else {
+          String[] tokens = line.split("\\s+");
+          if (tokens.length == 2) {
+            // tokens: name, value
+            if (Math.round(Double.parseDouble(tokens[1])*1000000000)==1000000000) {
+              logger.debug("found new variable {} with value {}", tokens[0], tokens[1]);
+              IlpVariable variable = ilp.resolve(tokens[0]);
+              if (variable == null) {
+                throw new SolvingException("Could not find variable with name " + tokens[0]);
+              }
+              variablesSetToOne.add(variable);
+            }
+          }
+        }
+      }
+    } catch (IOException e) {
+      throw new SolvingException("Could not open solution file", e);
+    } catch (NumberFormatException e) {
+      throw new SolvingException("Could not parse solution file", e);
+    }
+  }
+
+  @Override
+  public String getName() {
+    return "ilp-gurobi";
+  }
+
+}

jastadd-mquat-solver-ilp/src/main/java/de/tudresden/inf/st/mquat/solving/ilp/ILPExternalSolver.java

@@ -75,7 +75,7 @@ public abstract class ILPExternalSolver extends AbstractILPSolver {
     try {
       lp = Files.createTempFile("ilp", ".lp");
 //      solution = Files.createTempFile("solution", null);
-      solutionReadable = Files.createTempFile("sol-read", null);
+      solutionReadable = Files.createTempFile("sol-read", ".sol");
     } catch (IOException e) { throw new SolvingException("Can not create lp or solution file", e); }
     if (!deleteFilesOnExit) {
       logger.info("Writing ILP to {}, solving now", lp.toAbsolutePath());

jastadd-mquat-solver-ilp/src/test/java/de/tudresden/inf/st/mquat/solving/GurobiHandwrittenTest.java

+package de.tudresden.inf.st.mquat.solving;
+
+import de.tudresden.inf.st.mquat.solving.ilp.GurobiSolver;
+
+public class GurobiHandwrittenTest extends HandwrittenTestSuite {
+  @Override
+  protected Solver getSolver() {
+    // set to false for debugging
+    return new GurobiSolver().setDeleteFilesOnExit(false);
+  }
+}