Added stop_search method - closes #46

Author: ankane

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.10.2 (unreleased)
+
+- Added `stop_search` method
+
 ## 0.10.1 (2023-03-20)
 
 - Added `domain` method to `SatIntVar`

ext/or-tools/constraint.cpp

@@ -1,9 +1,11 @@
 #include <google/protobuf/text_format.h>
 #include <ortools/sat/cp_model.h>
+#include <ortools/util/time_limit.h>
 
 #include "ext.h"
 
 using operations_research::Domain;
+using operations_research::TimeLimit;
 using operations_research::sat::BoolVar;
 using operations_research::sat::Constraint;
 using operations_research::sat::CpModelBuilder;
@@ -403,15 +405,19 @@ void init_constraint(Rice::Module& m) {
       [](Object self, CpModelBuilder& model, SatParameters& parameters, Object callback) {
         Model m;
 
+        std::atomic<bool> stopped(false);
+        m.GetOrCreate<TimeLimit>()->RegisterExternalBooleanAsLimit(&stopped);
+
         if (!callback.is_nil()) {
           // TODO figure out how to use callback with multiple cores
           parameters.set_num_search_workers(1);
 
           m.Add(NewFeasibleSolutionObserver(
-            [callback](const CpSolverResponse& r) {
+            [callback, &stopped](const CpSolverResponse& r) {
               // TODO find a better way to do this
               callback.call("response=", r);
               callback.call("on_solution_callback");
+              stopped = callback.attr_get("@stopped");
             })
           );
         }

lib/or_tools/cp_solver_solution_callback.rb

@@ -16,5 +16,9 @@ def value(expr)
     def objective_value
       @response.objective_value
     end
+
+    def stop_search
+      @stopped = true
+    end
   end
 end