Released under the GNU Lesser General Public License version 3.

diff -Nur bliss-0.73/graph.cc bliss-0.73p/graph.cc
--- bliss-0.73/graph.cc	2015-09-01 10:23:10.000000000 +0200
+++ bliss-0.73p/graph.cc	2017-12-21 14:36:32.068702372 +0100
@@ -67,6 +67,9 @@
 
   report_hook = 0;
   report_user_param = 0;
+  
+  limit_search_nodes = 0;
+  limit_generators = 0;
 }
 
 
@@ -609,13 +612,7 @@
 
 
 
-
-typedef struct {
-  unsigned int splitting_element;
-  unsigned int certificate_index;
-  unsigned int subcertificate_length;
-  UintSeqHash eqref_hash;
-} PathInfo;
+// struct PathInfo moved to graph.hh by Thomas Rehn, 2011-07-12
 
 
 void
@@ -745,7 +742,7 @@
   initialize_certificate();
 
   std::vector<TreeNode> search_stack;
-  std::vector<PathInfo> first_path_info;
+  // first_path_info moved to graph.hh by Thomas Rehn, 2011-07-12
   std::vector<PathInfo> best_path_info;
 
   search_stack.clear();
@@ -1054,6 +1051,8 @@
       const unsigned int child_level = current_level+1;
       /* Update some statistics */
       stats.nof_nodes++;
+      if (limit_search_nodes && stats.nof_nodes >= limit_search_nodes)
+         break;
       if(search_stack.size() > stats.max_level)
 	stats.max_level = search_stack.size();
 
@@ -1642,6 +1641,8 @@
 			     best_path_automorphism);
 	    /* Update statistics */
 	    stats.nof_generators++;
+       if (limit_generators && stats.nof_generators >= limit_generators)
+          break;
 	  }
 	  
 	/*
@@ -1733,6 +1734,8 @@
 
       /* Update statistics */
       stats.nof_generators++;
+      if (limit_generators && stats.nof_generators >= limit_generators)
+          break;
       continue;
 
     } /* while(!search_stack.empty()) */
@@ -5452,7 +5455,7 @@
   component.clear();
   component_elements = 0;
   sh_return = 0;
-  unsigned int sh_first  = 0;
+  unsigned int sh_first  = 1 << 31;
   unsigned int sh_size   = 0;
   unsigned int sh_nuconn = 0;
 
diff -Nur bliss-0.73/graph.hh bliss-0.73p/graph.hh
--- bliss-0.73/graph.hh	2015-09-01 10:23:10.000000000 +0200
+++ bliss-0.73p/graph.hh	2017-12-21 14:36:35.388797479 +0100
@@ -20,6 +20,9 @@
   along with bliss.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+/** This is a patched version of bliss by Thomas Rehn extended by method AbstractGraph::set_search_limits() */
+#define BLISS_PATCH_PRESENT
+
 /**
  * \namespace bliss
  * The namespace bliss contains all the classes and functions of the bliss
@@ -111,6 +114,14 @@
 
 
 
+/** moved here from graph.cc by Thomas Rehn, 2011-07-12 */
+typedef struct {
+  unsigned int splitting_element;
+  unsigned int certificate_index;
+  unsigned int subcertificate_length;
+  UintSeqHash eqref_hash;
+} PathInfo;
+
 
 
 
@@ -284,7 +295,20 @@
     opt_use_long_prune = active;
   }
 
-
+  /// information vector about first path
+  /** added by Thomas Rehn, 2011-07-12 */
+  std::vector<PathInfo> get_first_path_info() { return first_path_info; }
+  
+  /// limits number of search nodes and generators during the backtrack search
+  /** added by Thomas Rehn, 2012-01-12
+   *
+   * \param searchNodeLimit if non-zero, limits the number of search nodes in search tree
+   * \param generatorLimit  if non-zero, limits the maximal number of automorphism group generators to be found
+   */
+  void set_search_limits(const unsigned int searchNodeLimit, const unsigned int generatorLimit) {
+     limit_search_nodes = searchNodeLimit;
+     limit_generators = generatorLimit;
+  }
 
 protected:
   /** \internal
@@ -519,6 +543,11 @@
 
 
 
+  /** added by Thomas Rehn, 2011-07-12 */
+  std::vector<PathInfo> first_path_info;
+  
+  unsigned int limit_search_nodes;
+  unsigned int limit_generators;
 };
 
 
@@ -747,7 +776,6 @@
    */
   void set_splitting_heuristic(const SplittingHeuristic shs) {sh = shs; }
   
-
 };