Parallelizing centrality algorithms

CMakeLists.txt

@@ -2,22 +2,18 @@ cmake_minimum_required(VERSION 3.23)
 
 project(easygraph)
 
+option(EASYGRAPH_ENABLE_OPENMP "Enable OpenMP acceleration (auto-detect)" ON)
+
 option(EASYGRAPH_ENABLE_GPU "EASYGRAPH_ENABLE_GPU" OFF)
 
 add_subdirectory(cpp_easygraph)
 
 if (EASYGRAPH_ENABLE_GPU)
-
     message("easygraph gpu module is enabled")
-
     add_subdirectory(gpu_easygraph)
-
     target_include_directories(cpp_easygraph
         PRIVATE gpu_easygraph
     )
-
 else()
-
     message("easygraph gpu module is disabled")
-
-endif()
+endif()

cpp_easygraph/CMakeLists.txt

@@ -1,6 +1,12 @@
 cmake_minimum_required(VERSION 3.23)
+
 project(cpp_easygraph)
+
 set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+option(EASYGRAPH_ENABLE_OPENMP "Enable OpenMP acceleration (auto-detect)" ON)
+option(EASYGRAPH_ENABLE_GPU "EASYGRAPH_ENABLE_GPU" OFF)
 
 file(GLOB SOURCES
     classes/*.cpp
@@ -11,8 +17,6 @@ file(GLOB SOURCES
 
 add_subdirectory(pybind11)
 
-option(EASYGRAPH_ENABLE_GPU "EASYGRAPH_ENABLE_GPU" OFF)
-
 if (EASYGRAPH_ENABLE_GPU)
 
     pybind11_add_module(cpp_easygraph
@@ -22,7 +26,7 @@ if (EASYGRAPH_ENABLE_GPU)
 
     set_property(TARGET cpp_easygraph PROPERTY CUDA_ARCHITECTURES all)
 
-    target_compile_definitions(cpp_easygraph 
+    target_compile_definitions(cpp_easygraph
         PRIVATE EASYGRAPH_ENABLE_GPU
     )
 
@@ -31,14 +35,52 @@ if (EASYGRAPH_ENABLE_GPU)
     )
 
 else()
-
     pybind11_add_module(cpp_easygraph
         ${SOURCES}
     )
 
 endif()
 
-set_target_properties(cpp_easygraph  PROPERTIES
-    LINK_SEARCH_START_STATIC ON
-    LINK_SEARCH_END_STATIC ON
-)
+if (EASYGRAPH_ENABLE_OPENMP)
+    if (APPLE AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+        find_path(EG_LIBOMP_INCLUDE_DIR
+            NAMES omp.h
+            PATHS
+                /opt/homebrew/opt/libomp/include
+                /usr/local/opt/libomp/include
+        )
+
+        find_library(EG_LIBOMP_LIBRARY
+            NAMES omp libomp
+            PATHS
+                /opt/homebrew/opt/libomp/lib
+                /usr/local/opt/libomp/lib
+        )
+
+        if (EG_LIBOMP_INCLUDE_DIR AND EG_LIBOMP_LIBRARY)
+            message(STATUS "libomp found: ${EG_LIBOMP_LIBRARY}")
+
+            set(OpenMP_C_FLAGS   "-Xpreprocessor -fopenmp" CACHE STRING "" FORCE)
+            set(OpenMP_CXX_FLAGS "-Xpreprocessor -fopenmp" CACHE STRING "" FORCE)
+
+            set(OpenMP_CXX_INCLUDE_DIR "${EG_LIBOMP_INCLUDE_DIR}" CACHE PATH "" FORCE)
+            set(OpenMP_omp_LIBRARY     "${EG_LIBOMP_LIBRARY}"     CACHE FILEPATH "" FORCE)
+        else()
+            message(STATUS
+                "libomp not found on macOS. OpenMP will be disabled.\n"
+                "To enable OpenMP, run: brew install libomp"
+            )
+        endif()
+    endif()
+
+    find_package(OpenMP QUIET)
+endif()
+
+if (OpenMP_CXX_FOUND)
+    message(STATUS "OpenMP found, enabling parallel acceleration.")
+    target_link_libraries(cpp_easygraph PRIVATE OpenMP::OpenMP_CXX)
+    target_compile_definitions(cpp_easygraph PRIVATE EASYGRAPH_USE_OPENMP=1)
+else()
+    message(STATUS "OpenMP not found, building in single-thread mode.")
+    target_compile_definitions(cpp_easygraph PRIVATE EASYGRAPH_USE_OPENMP=0)
+endif()

cpp_easygraph/cpp_easygraph.cpp

@@ -75,16 +75,20 @@ PYBIND11_MODULE(cpp_easygraph, m) {
         .def_property("pred", &DiGraph::get_pred,nullptr)
         .def("generate_linkgraph", &DiGraph_generate_linkgraph,py::arg("weight") = "weight");
 
+    m.def("cpp_degree_centrality", &degree_centrality, py::arg("G"));
+    m.def("cpp_in_degree_centrality", &in_degree_centrality, py::arg("G"));
+    m.def("cpp_out_degree_centrality", &out_degree_centrality, py::arg("G"));
     m.def("cpp_closeness_centrality", &closeness_centrality, py::arg("G"), py::arg("weight") = "weight", py::arg("cutoff") = py::none(), py::arg("sources") = py::none());
     m.def("cpp_betweenness_centrality", &betweenness_centrality, py::arg("G"), py::arg("weight") = "weight", py::arg("cutoff") = py::none(),py::arg("sources") = py::none(), py::arg("normalized") = py::bool_(true), py::arg("endpoints") = py::bool_(false));
     m.def("cpp_katz_centrality", &cpp_katz_centrality, py::arg("G"), py::arg("alpha") = 0.1, py::arg("beta") = 1.0, py::arg("max_iter") = 1000, py::arg("tol") = 1e-6, py::arg("normalized") = true);
+    m.def("cpp_eigenvector_centrality", &cpp_eigenvector_centrality, py::arg("G"), py::arg("max_iter") = 100, py::arg("tol") = 1.0e-6, py::arg("nstart") = py::none(), py::arg("weight") = py::none());
     m.def("cpp_k_core", &core_decomposition, py::arg("G"));
     m.def("cpp_density", &density, py::arg("G"));
     m.def("cpp_constraint", &constraint, py::arg("G"), py::arg("nodes") = py::none(), py::arg("weight") = py::none(), py::arg("n_workers") = py::none());
     m.def("cpp_effective_size", &effective_size, py::arg("G"), py::arg("nodes") = py::none(), py::arg("weight") = py::none(), py::arg("n_workers") = py::none());
     m.def("cpp_efficiency", &efficiency, py::arg("G"), py::arg("nodes") = py::none(), py::arg("weight") = py::none(), py::arg("n_workers") = py::none());
     m.def("cpp_hierarchy", &hierarchy, py::arg("G"), py::arg("nodes") = py::none(), py::arg("weight") = py::none(), py::arg("n_workers") = py::none());
-    m.def("cpp_pagerank", &_pagerank, py::arg("G"), py::arg("alpha") = 0.85, py::arg("max_iterator") = 500, py::arg("threshold") = 1e-6);
+    m.def("cpp_pagerank", &_pagerank, py::arg("G"), py::arg("alpha") = 0.85, py::arg("max_iterator") = 500, py::arg("threshold") = 1e-6, py::arg("weight") = py::none());
     m.def("cpp_dijkstra_multisource", &_dijkstra_multisource, py::arg("G"), py::arg("sources"), py::arg("weight") = "weight", py::arg("target") = py::none());    
     m.def("cpp_spfa", &_spfa, py::arg("G"), py::arg("source"), py::arg("weight") = "weight");
     m.def("cpp_clustering", &clustering, py::arg("G"), py::arg("nodes") = py::none(), py::arg("weight") = py::none());