reduce mutability where possible -> fixed!

kahypar · Oct 10, 2024 · 1d7973e · 1d7973e
1 parent b5082e0
commit 1d7973e
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Showing 4 changed files with 25 additions and 22 deletions.
diff --git a/mt-kahypar/partition/evo_partitioner.cpp b/mt-kahypar/partition/evo_partitioner.cpp
@@ -7,7 +7,7 @@ namespace mt_kahypar {
 
     template<typename TypeTraits>
     typename EvoPartitioner<TypeTraits>::PartitionedHypergraph EvoPartitioner<TypeTraits>::partition(
-        Hypergraph& hypergraph, Context& context, TargetGraph* target_graph) {
+        const Hypergraph& hypergraph, Context& context, TargetGraph* target_graph) {
         configurePreprocessing(hypergraph, context);
         setupContext(hypergraph, context, target_graph);
 
@@ -80,7 +80,7 @@ namespace mt_kahypar {
             out_stream.close();
         }
 
-        PartitionedHypergraph partitioned_hypergraph(context.partition.k, hypergraph);
+        PartitionedHypergraph partitioned_hypergraph(context.partition.k, const_cast<Hypergraph&>(hypergraph));
 
         std::vector<PartitionID> best = best_population.individualAt(best_population.best()).partition();
         partitioned_hypergraph.doParallelForAllNodes([&](const HypernodeID& hn) {
@@ -132,7 +132,7 @@ namespace mt_kahypar {
 
 
     template<typename TypeTraits>
-    std::string EvoPartitioner<TypeTraits>::generateInitialPopulation(EvoPartitioner<TypeTraits>::Hypergraph& hg, Context& context, TargetGraph* target_graph, Population& population) { 
+    std::string EvoPartitioner<TypeTraits>::generateInitialPopulation(const Hypergraph& hg, Context& context, TargetGraph* target_graph, Population& population) {
         context.partition.verbose_output = false;
         int timelimit = context.partition.time_limit;
         utils::Timer& timer = utils::Utilities::instance().getTimer(context.utility_id);
@@ -181,7 +181,8 @@ namespace mt_kahypar {
     }
 
     template<typename TypeTraits>
-    const Individual & EvoPartitioner<TypeTraits>::generateIndividual(EvoPartitioner<TypeTraits>::Hypergraph& hypergraph, Context& context, TargetGraph* target_graph, Population& population) { 
+    const Individual & EvoPartitioner<TypeTraits>::generateIndividual(const Hypergraph& input_hg, Context& context, TargetGraph* target_graph, Population& population) {
+        Hypergraph hypergraph = input_hg.copy(parallel_tag_t{});
         DegreeZeroHypernodeRemover<TypeTraits> degree_zero_hn_remover(context);
         LargeHyperedgeRemover<TypeTraits> large_he_remover(context);
         preprocess(hypergraph, context, target_graph);
@@ -225,7 +226,7 @@ namespace mt_kahypar {
 
 
     template<typename TypeTraits>
-    vec<PartitionID> EvoPartitioner<TypeTraits>::combinePartitions(const Context& context, Population& population, std::vector<size_t> ids) {
+    vec<PartitionID> EvoPartitioner<TypeTraits>::combinePartitions(const Context& context, Population& population, const std::vector<size_t>& ids) {
         vec<PartitionID> combined(population.individualAt(0).partition().size());
 
         std::unordered_map<std::string, int> tuple_to_block;
@@ -248,7 +249,7 @@ namespace mt_kahypar {
     }
 
     template<typename TypeTraits>
-    std::string EvoPartitioner<TypeTraits>::performCombine(EvoPartitioner<TypeTraits>::Hypergraph& hypergraph, const Context& context, TargetGraph* target_graph, Population& population) {
+    std::string EvoPartitioner<TypeTraits>::performCombine(const Hypergraph& input_hg, const Context& context, TargetGraph* target_graph, Population& population) {
         std::vector<size_t> parents;
         size_t best = population.randomIndividual();
         parents.push_back(best);
@@ -261,8 +262,9 @@ namespace mt_kahypar {
         }
         std::unordered_map<PartitionID, int> comm_to_block;
         vec<PartitionID> comms = combinePartitions(context, population, parents);
-        vec<PartitionID> part(hypergraph.initialNumNodes());
-
+        vec<PartitionID> part(input_hg.initialNumNodes());
+
+        Hypergraph hypergraph = input_hg.copy(parallel_tag_t{});
         PartitionedHypergraph partitioned_hypergraph(context.partition.k, hypergraph);
         for ( const HypernodeID& hn : hypergraph.nodes() ) { 
             partitioned_hypergraph.setOnlyNodePart(hn, population.individualAt(best).partition()[hn]);
@@ -291,7 +293,8 @@ namespace mt_kahypar {
     }
 
     template<typename TypeTraits>
-    std::string EvoPartitioner<TypeTraits>::performMutation(EvoPartitioner<TypeTraits>::Hypergraph& hypergraph, const Context& context, TargetGraph* target_graph, Population& population) {
+    std::string EvoPartitioner<TypeTraits>::performMutation(const Hypergraph& input_hg, const Context& context, TargetGraph* target_graph, Population& population) {
+        Hypergraph hypergraph = input_hg.copy(parallel_tag_t{});
         const size_t mutation_position = population.randomIndividual();
         std::vector<PartitionID> cur = population.individualAt(mutation_position).partition();
         PartitionedHypergraph partitioned_hypergraph(context.partition.k, hypergraph);
@@ -362,7 +365,7 @@ namespace mt_kahypar {
     }
 
     template<typename TypeTraits>
-    std::string EvoPartitioner<TypeTraits>::performEvolution(EvoPartitioner<TypeTraits>::Hypergraph& hg, Context& context, TargetGraph* target_graph, Population& population) { 
+    std::string EvoPartitioner<TypeTraits>::performEvolution(const Hypergraph& hg, Context& context, TargetGraph* target_graph, Population& population) {
         context.partition.verbose_output = false;
         int timelimit = context.partition.time_limit;
         utils::Timer& timer = utils::Utilities::instance().getTimer(context.utility_id);
@@ -397,9 +400,9 @@ namespace mt_kahypar {
                     }
                 case EvoDecision::combine: 
                     {
-                        std::lock_guard<std::mutex> lock(_history_mutex);
                         std::string h = performCombine(hg_copy, evo_context, target_graph, population);
                         combinations++;
+                        std::lock_guard<std::mutex> lock(_history_mutex);
                         history += h;
                         ++context.evolutionary.iteration;
                         break;

diff --git a/mt-kahypar/partition/evo_partitioner.h b/mt-kahypar/partition/evo_partitioner.h
@@ -15,28 +15,28 @@ class EvoPartitioner {
     using PartitionedHypergraph = typename TypeTraits::PartitionedHypergraph;
 
     public:
-    static PartitionedHypergraph partition(Hypergraph& hypergraph,
+    static PartitionedHypergraph partition(const Hypergraph& hypergraph,
                                            Context& context,
                                            TargetGraph* target_graph = nullptr);
-    static std::string generateInitialPopulation(EvoPartitioner<TypeTraits>::Hypergraph& hg,
+    static std::string generateInitialPopulation(const Hypergraph& hg,
                                     Context& context,
                                     TargetGraph* target_graph,
                                     Population& population);
-    static const Individual & generateIndividual(EvoPartitioner<TypeTraits>::Hypergraph& hg,
+    static const Individual & generateIndividual(const Hypergraph& hg,
                                             Context& context,
                                             TargetGraph* target_graph,
                                             Population& population);
-    static std::string performEvolution(EvoPartitioner<TypeTraits>::Hypergraph& hg,
+    static std::string performEvolution(const Hypergraph& hg,
                                     Context& context,
                                     TargetGraph* target_graph,
                                     Population& population);
 
     private:
     static EvoDecision decideNextMove(const Context& context);
     static EvoMutateStrategy decideNextMutation(const Context& context);
-    static vec<PartitionID> combinePartitions(const Context& context, Population& population, std::vector<size_t> ids);
-    static std::string performCombine(EvoPartitioner<TypeTraits>::Hypergraph& hg, const Context& context, TargetGraph* target_graph, Population& population);
-    static std::string performMutation(EvoPartitioner<TypeTraits>::Hypergraph& hg, const Context& context, TargetGraph* target_graph, Population& population);
+    static vec<PartitionID> combinePartitions(const Context& context, Population& population, const std::vector<size_t>& ids);
+    static std::string performCombine(const Hypergraph& hg, const Context& context, TargetGraph* target_graph, Population& population);
+    static std::string performMutation(const Hypergraph& hg, const Context& context, TargetGraph* target_graph, Population& population);
 };
 
 }  // namespace mt_kahypar
diff --git a/mt-kahypar/partition/multilevel.cpp b/mt-kahypar/partition/multilevel.cpp
@@ -210,7 +210,7 @@ namespace {
     const Context& context,
     const TargetGraph* target_graph,
     const bool is_vcycle,
-    std::unordered_map<PartitionID, int> comm_to_block) {
+    const std::unordered_map<PartitionID, int>& comm_to_block) {
     //disableTimerAndStats(context);
     using Hypergraph = typename TypeTraits::Hypergraph;
     using PartitionedHypergraph = typename TypeTraits::PartitionedHypergraph;
@@ -246,7 +246,7 @@ namespace {
       // of the input hypergraph as community IDs
       const Hypergraph& hypergraph = phg.hypergraph();
       phg.doParallelForAllNodes([&](const HypernodeID hn) {
-        const PartitionID part_id = comm_to_block[hypergraph.communityID(hn)];
+        const PartitionID part_id = comm_to_block.at(hypergraph.communityID(hn));
         ASSERT(part_id != kInvalidPartition && part_id < context.partition.k);
         ASSERT(phg.partID(hn) == kInvalidPartition);
         phg.setOnlyNodePart(hn, part_id);
@@ -371,7 +371,7 @@ template<typename TypeTraits>
 void Multilevel<TypeTraits>::evolutionPartitionVCycle(Hypergraph& hypergraph,
                                              PartitionedHypergraph& partitioned_hg,
                                              const Context& context,
-                                             std::unordered_map<PartitionID, int> comm_to_block,
+                                             const std::unordered_map<PartitionID, int>& comm_to_block,
                                              const TargetGraph* target_graph) {
 
   //disableTimerAndStats(context);

diff --git a/mt-kahypar/partition/multilevel.h b/mt-kahypar/partition/multilevel.h
@@ -60,7 +60,7 @@ class Multilevel {
   static void evolutionPartitionVCycle(Hypergraph& hypergraph,
                               PartitionedHypergraph& partitioned_hg,
                               const Context& context,
-                              std::unordered_map<PartitionID, int> comm_to_block,
+                              const std::unordered_map<PartitionID, int>& comm_to_block,
                               const TargetGraph* target_graph = nullptr);
 };