Expose graph_view method to count multi edges through C API and PLC (r…

…apidsai#4426) Python property graph class does some expensive dask calls to determine if a graph is a multi-graph. This PR exposes to the C API and the PLC layer the graph_view method that counts the number of multi-edges in the graph. Specifically, the function returns the number of extra edges exist. So if the edge `(u,v)` exists `k` times, that edge contributes `k-1` to the return value. If the return value of this function is greater than 0 then the graph is a multi-graph. If the return value is 0 then while the graph might be labeled a multi-graph, there are no multi-edges so it could be treated as a graph. Closes rapidsai#2417 Note that the property graph python code would still need to be modified to use this function. Authors: - Chuck Hastings (https://github.com/ChuckHastings) Approvers: - Seunghwa Kang (https://github.com/seunghwak) - Joseph Nke (https://github.com/jnke2016) - Alex Barghi (https://github.com/alexbarghi-nv) URL: rapidsai#4426
acostadon · May 17, 2024 · 78b380e · 78b380e
1 parent 64d5477
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diff --git a/cpp/include/cugraph_c/graph_functions.h b/cpp/include/cugraph_c/graph_functions.h
@@ -229,6 +229,26 @@ cugraph_error_code_t cugraph_allgather(const cugraph_resource_handle_t* handle,
  cugraph_induced_subgraph_result_t** result,
  cugraph_error_t** error);
 
+/**
+ * @brief Count multi_edges
+ *
+ * Count the number of multi-edges in the graph
+ *
+ * @param [in] handle Handle for accessing resources.
+ * @param [in] graph Pointer to graph
+ * @param [in] do_expensive_check A flag to run expensive checks for input arguments (if set to
+ * true)
+ * @param [out] result Where to store the count of multi-edges
+ * @param [out] error Pointer to an error object storing details of any error. Will
+ * be populated if error code is not CUGRAPH_SUCCESS
+ * @return error code
+ */
+cugraph_error_code_t cugraph_count_multi_edges(const cugraph_resource_handle_t* handle,
+ cugraph_graph_t* graph,
+ bool_t do_expensive_check,
+ size_t* result,
+ cugraph_error_t** error);
+
 /**
  * @brief Opaque degree result type
  */

diff --git a/cpp/src/c_api/graph_functions.cpp b/cpp/src/c_api/graph_functions.cpp
@@ -214,6 +214,44 @@ struct two_hop_neighbors_functor : public cugraph::c_api::abstract_functor {
  }
 };
 
+struct count_multi_edges_functor : public cugraph::c_api::abstract_functor {
+ raft::handle_t const& handle_{};
+ cugraph::c_api::cugraph_graph_t* graph_{nullptr};
+ size_t result_{};
+ bool do_expensive_check_{false};
+
+ count_multi_edges_functor(::cugraph_resource_handle_t const* handle,
+ ::cugraph_graph_t* graph,
+ bool do_expensive_check)
+ : abstract_functor(),
+ handle_(*reinterpret_cast<cugraph::c_api::cugraph_resource_handle_t const*>(handle)->handle_),
+ graph_(reinterpret_cast<cugraph::c_api::cugraph_graph_t*>(graph)),
+ do_expensive_check_(do_expensive_check)
+ {
+ }
+
+ template <typename vertex_t,
+ typename edge_t,
+ typename weight_t,
+ typename edge_type_type_t,
+ bool store_transposed,
+ bool multi_gpu>
+ void operator()()
+ {
+ if constexpr (!cugraph::is_candidate<vertex_t, edge_t, weight_t>::value) {
+ unsupported();
+ } else {
+ auto graph =
+ reinterpret_cast<cugraph::graph_t<vertex_t, edge_t, store_transposed, multi_gpu>*>(
+ graph_->graph_);
+
+ auto graph_view = graph->view();
+
+ result_ = static_cast<size_t>(graph_view.count_multi_edges(handle_));
+ }
+ }
+};
+
 } // namespace
 
 extern "C" cugraph_error_code_t cugraph_create_vertex_pairs(
@@ -281,3 +319,14 @@ extern "C" cugraph_error_code_t cugraph_two_hop_neighbors(
 
  return cugraph::c_api::run_algorithm(graph, functor, result, error);
 }
+
+extern "C" cugraph_error_code_t cugraph_count_multi_edges(const cugraph_resource_handle_t* handle,
+ cugraph_graph_t* graph,
+ bool_t do_expensive_check,
+ size_t* result,
+ cugraph_error_t** error)
+{
+ count_multi_edges_functor functor(handle, graph, do_expensive_check);
+
+ return cugraph::c_api::run_algorithm(graph, functor, result, error);
+}
diff --git a/cpp/tests/CMakeLists.txt b/cpp/tests/CMakeLists.txt
@@ -733,6 +733,7 @@ if(BUILD_CUGRAPH_MG_TESTS)
  ConfigureCTestMG(MG_CAPI_K_CORE_TEST c_api/mg_k_core_test.c)
  ConfigureCTestMG(MG_CAPI_INDUCED_SUBGRAPH_TEST c_api/mg_induced_subgraph_test.c)
  ConfigureCTestMG(MG_CAPI_DEGREES c_api/mg_degrees_test.c)
+ ConfigureCTestMG(MG_CAPI_COUNT_MULTI_EDGES c_api/mg_count_multi_edges_test.c)
  ConfigureCTestMG(MG_CAPI_EGONET_TEST c_api/mg_egonet_test.c)
  ConfigureCTestMG(MG_CAPI_TWO_HOP_NEIGHBORS_TEST c_api/mg_two_hop_neighbors_test.c)
 
@@ -777,6 +778,7 @@ ConfigureCTest(CAPI_SIMILARITY_TEST c_api/similarity_test.c)
 ConfigureCTest(CAPI_K_CORE_TEST c_api/k_core_test.c)
 ConfigureCTest(CAPI_INDUCED_SUBGRAPH_TEST c_api/induced_subgraph_test.c)
 ConfigureCTest(CAPI_DEGREES c_api/degrees_test.c)
+ConfigureCTest(CAPI_COUNT_MULTI_EDGES c_api/count_multi_edges_test.c)
 ConfigureCTest(CAPI_EGONET_TEST c_api/egonet_test.c)
 ConfigureCTest(CAPI_TWO_HOP_NEIGHBORS_TEST c_api/two_hop_neighbors_test.c)
 ConfigureCTest(CAPI_K_TRUSS_TEST c_api/k_truss_test.c)

diff --git a/cpp/tests/c_api/count_multi_edges_test.c b/cpp/tests/c_api/count_multi_edges_test.c
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2024, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "c_test_utils.h" /* RUN_TEST */
+
+#include <cugraph_c/graph.h>
+#include <cugraph_c/graph_functions.h>
+
+#include <stdio.h>
+
+typedef int32_t vertex_t;
+typedef int32_t edge_t;
+typedef float weight_t;
+
+data_type_id_t vertex_tid = INT32;
+data_type_id_t edge_tid = INT32;
+data_type_id_t weight_tid = FLOAT32;
+data_type_id_t edge_id_tid = INT32;
+data_type_id_t edge_type_tid = INT32;
+
+/*
+ * Create graph and count multi-edges
+ */
+int generic_count_multi_edges_test(vertex_t* h_src,
+ vertex_t* h_dst,
+ weight_t* h_wgt,
+ size_t num_vertices,
+ size_t num_edges,
+ bool_t store_transposed,
+ bool_t is_symmetric,
+ bool_t is_multigraph,
+ size_t multi_edges_count)
+{
+ int test_ret_value = 0;
+
+ cugraph_error_code_t ret_code = CUGRAPH_SUCCESS;
+ cugraph_error_t* ret_error;
+
+ cugraph_resource_handle_t* handle = NULL;
+ cugraph_graph_t* graph = NULL;
+ size_t result = 0;
+
+ handle = cugraph_create_resource_handle(NULL);
+ TEST_ASSERT(test_ret_value, handle != NULL, "resource handle creation failed.");
+
+ ret_code = create_sg_test_graph(handle,
+ vertex_tid,
+ edge_tid,
+ h_src,
+ h_dst,
+ weight_tid,
+ h_wgt,
+ edge_type_tid,
+ NULL,
+ edge_id_tid,
+ NULL,
+ num_edges,
+ store_transposed,
+ FALSE,
+ is_symmetric,
+ is_multigraph,
+ &graph,
+ &ret_error);
+
+ TEST_ASSERT(test_ret_value, ret_code == CUGRAPH_SUCCESS, "create_test_graph failed.");
+ TEST_ALWAYS_ASSERT(ret_code == CUGRAPH_SUCCESS, cugraph_error_message(ret_error));
+
+ ret_code = cugraph_count_multi_edges(handle, graph, FALSE, &result, &ret_error);
+
+ TEST_ASSERT(test_ret_value, ret_code == CUGRAPH_SUCCESS, "cugraph_count_multi_edges failed.");
+
+ TEST_ASSERT(test_ret_value, result == multi_edges_count, "multi-edge count did not match");
+
+ cugraph_graph_free(graph);
+ cugraph_error_free(ret_error);
+
+ return test_ret_value;
+}
+
+int test_multi_edges_count()
+{
+ size_t num_edges = 14;
+ size_t num_vertices = 6;
+
+ vertex_t h_src[] = {0, 1, 1, 2, 2, 2, 3, 4, 0, 1, 1, 3, 0, 1};
+ vertex_t h_dst[] = {1, 3, 4, 0, 1, 3, 5, 5, 1, 3, 0, 1, 1, 0};
+ weight_t h_wgt[] = {1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0};
+ size_t multi_edge_count = 4;
+
+ return generic_count_multi_edges_test(
+ h_src, h_dst, h_wgt, num_vertices, num_edges, TRUE, TRUE, TRUE, multi_edge_count);
+}
+
+/******************************************************************************/
+
+int main(int argc, char** argv)
+{
+ int result = 0;
+ result |= RUN_TEST(test_multi_edges_count);
+ return result;
+}
diff --git a/cpp/tests/c_api/mg_count_multi_edges_test.c b/cpp/tests/c_api/mg_count_multi_edges_test.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2024, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mg_test_utils.h" /* RUN_TEST */
+
+#include <cugraph_c/graph.h>
+#include <cugraph_c/graph_functions.h>
+
+#include <stdio.h>
+
+typedef int32_t vertex_t;
+typedef int32_t edge_t;
+typedef float weight_t;
+
+data_type_id_t vertex_tid = INT32;
+data_type_id_t edge_tid = INT32;
+data_type_id_t weight_tid = FLOAT32;
+data_type_id_t edge_id_tid = INT32;
+data_type_id_t edge_type_tid = INT32;
+
+/*
+ * Create graph and count multi-edges
+ */
+int generic_count_multi_edges_test(const cugraph_resource_handle_t* handle,
+ vertex_t* h_src,
+ vertex_t* h_dst,
+ weight_t* h_wgt,
+ size_t num_vertices,
+ size_t num_edges,
+ bool_t store_transposed,
+ bool_t is_symmetric,
+ bool_t is_multigraph,
+ size_t multi_edges_count)
+{
+ int test_ret_value = 0;
+
+ cugraph_error_code_t ret_code = CUGRAPH_SUCCESS;
+ cugraph_error_t* ret_error;
+
+ cugraph_graph_t* graph = NULL;
+ size_t result = 0;
+
+ ret_code = create_mg_test_graph_new(handle,
+ vertex_tid,
+ edge_tid,
+ h_src,
+ h_dst,
+ weight_tid,
+ h_wgt,
+ edge_type_tid,
+ NULL,
+ edge_id_tid,
+ NULL,
+ num_edges,
+ store_transposed,
+ FALSE,
+ is_symmetric,
+ is_multigraph,
+ &graph,
+ &ret_error);
+
+ TEST_ASSERT(test_ret_value, ret_code == CUGRAPH_SUCCESS, "create_test_graph failed.");
+ TEST_ALWAYS_ASSERT(ret_code == CUGRAPH_SUCCESS, cugraph_error_message(ret_error));
+
+ ret_code = cugraph_count_multi_edges(handle, graph, FALSE, &result, &ret_error);
+
+ TEST_ASSERT(test_ret_value, ret_code == CUGRAPH_SUCCESS, "cugraph_count_multi_edges failed.");
+
+ TEST_ASSERT(test_ret_value, result == multi_edges_count, "multi-edge count did not match");
+
+ cugraph_graph_free(graph);
+ cugraph_error_free(ret_error);
+
+ return test_ret_value;
+}
+
+int test_multi_edges_count(const cugraph_resource_handle_t* handle)
+{
+ size_t num_edges = 14;
+ size_t num_vertices = 6;
+
+ vertex_t h_src[] = {0, 1, 1, 2, 2, 2, 3, 4, 0, 1, 1, 3, 0, 1};
+ vertex_t h_dst[] = {1, 3, 4, 0, 1, 3, 5, 5, 1, 3, 0, 1, 1, 0};
+ weight_t h_wgt[] = {1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0};
+ size_t multi_edge_count = 4;
+
+ return generic_count_multi_edges_test(
+ handle, h_src, h_dst, h_wgt, num_vertices, num_edges, TRUE, TRUE, TRUE, multi_edge_count);
+}
+
+/******************************************************************************/
+
+int main(int argc, char** argv)
+{
+ void* raft_handle = create_mg_raft_handle(argc, argv);
+ cugraph_resource_handle_t* handle = cugraph_create_resource_handle(raft_handle);
+
+ int result = 0;
+ result |= RUN_MG_TEST(test_multi_edges_count, handle);
+
+ cugraph_free_resource_handle(handle);
+ free_mg_raft_handle(raft_handle);
+
+ return result;
+}
diff --git a/python/pylibcugraph/pylibcugraph/_cugraph_c/graph_functions.pxd b/python/pylibcugraph/pylibcugraph/_cugraph_c/graph_functions.pxd
@@ -183,6 +183,17 @@ cdef extern from "cugraph_c/graph_functions.h":
  cugraph_error_t** error
  )
 
+ ###########################################################################
+ # count multi-edges
+ cdef cugraph_error_code_t \
+ cugraph_count_multi_edges(
+ const cugraph_resource_handle_t *handle,
+ cugraph_graph_t* graph,
+ bool_t do_expenive_check,
+ size_t *result,
+ cugraph_error_t** error
+ )
+
  ###########################################################################
  # degrees
  ctypedef struct cugraph_degrees_result_t: