Optimize the drop-duplicate functionality

python/cugraph/cugraph/structure/graph_implementation/simpleDistributedGraph.py

@@ -95,6 +95,7 @@ def _make_plc_graph(
         weight_type,
         edge_id_type,
         edge_type_id,
+        drop_multi_edges,
     ):
         weights = None
         edge_ids = None
@@ -149,6 +150,7 @@ def _make_plc_graph(
             num_arrays=num_arrays,
             store_transposed=store_transposed,
             do_expensive_check=False,
+            drop_multi_edges=drop_multi_edges,
         )
         del edata_x
         gc.collect()
@@ -267,7 +269,7 @@ def __from_edgelist(
                 input_ddf,
                 source,
                 destination,
-                multi=self.properties.multi_edge,
+                multi=True,  # Deprecated parameter
                 symmetrize=not self.properties.directed,
             )
             value_col = None
@@ -277,7 +279,7 @@ def __from_edgelist(
                 source,
                 destination,
                 value_col_names,
-                multi=self.properties.multi_edge,
+                multi=True,  # Deprecated parameter
                 symmetrize=not self.properties.directed,
             )
 
@@ -364,6 +366,7 @@ def __from_edgelist(
                 self.weight_type,
                 self.edge_id_type,
                 self.edge_type_id_type,
+                not self.properties.multi_edge,
             )
             for w, edata in persisted_keys_d.items()
         }

python/cugraph/cugraph/structure/graph_implementation/simpleGraph.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2021-2023, NVIDIA CORPORATION.
+# Copyright (c) 2021-2024, 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
@@ -264,7 +264,7 @@ def __from_edgelist(
                 source,
                 destination,
                 edge_attr,
-                multi=self.properties.multi_edge,
+                multi=True,  # Deprecated parameter
                 symmetrize=not self.properties.directed,
             )
 
@@ -279,7 +279,7 @@ def __from_edgelist(
                 elist,
                 source,
                 destination,
-                multi=self.properties.multi_edge,
+                multi=True,  # Deprecated parameter
                 symmetrize=not self.properties.directed,
             )
 
@@ -298,7 +298,10 @@ def __from_edgelist(
             self._replicate_edgelist()
 
         self._make_plc_graph(
-            value_col=value_col, store_transposed=store_transposed, renumber=renumber
+            value_col=value_col,
+            store_transposed=store_transposed,
+            renumber=renumber,
+            drop_multi_edges=not self.properties.multi_edge,
         )
 
     def to_pandas_edgelist(
@@ -477,13 +480,15 @@ def view_edge_list(self):
                     edgelist_df[simpleGraphImpl.srcCol]
                     <= edgelist_df[simpleGraphImpl.dstCol]
                 ]
+
         elif not use_initial_input_df and self.properties.renumbered:
             # Do not unrenumber the vertices if the initial input df was used
             if not self.properties.directed:
                 edgelist_df = edgelist_df[
                     edgelist_df[simpleGraphImpl.srcCol]
                     <= edgelist_df[simpleGraphImpl.dstCol]
                 ]
+
             edgelist_df = self.renumber_map.unrenumber(
                 edgelist_df, simpleGraphImpl.srcCol
             )
@@ -506,6 +511,18 @@ def view_edge_list(self):
                             simpleGraphImpl.dstCol: dstCol,
                         }
                     )
+        if not self.properties.multi_edge:
+            if type(srcCol) is list and type(dstCol) is list:
+                vertex_col_name = srcCol + dstCol
+
+            else:
+                vertex_col_name = [srcCol, dstCol]
+
+            # Drop parallel edges for non MultiGraph
+            # FIXME: Drop multi edges with the CAPI instead.
+            edgelist_df = edgelist_df.groupby(
+                by=[*vertex_col_name], as_index=False
+            ).min()
 
         # FIXME: When renumbered, the MG API uses renumbered col names which
         # is not consistant with the SG API.
@@ -827,6 +844,14 @@ def number_of_edges(self, directed_edges=False):
         """
         Get the number of edges in the graph.
         """
+        if not self.properties.multi_edge:
+            #
+            # Drop parallel edges for non MultiGraph
+            # FIXME: Drop multi edges with the CAPI instead.
+            if self.edgelist is not None:
+                self.edgelist.edgelist_df = self.edgelist.edgelist_df.groupby(
+                    by=[simpleGraphImpl.srcCol, simpleGraphImpl.dstCol], as_index=False
+                ).min()
         # TODO: Move to Outer graphs?
         if directed_edges and self.edgelist is not None:
             return len(self.edgelist.edgelist_df)
@@ -1084,6 +1109,7 @@ def _make_plc_graph(
         value_col: Dict[str, cudf.DataFrame] = None,
         store_transposed: bool = False,
         renumber: bool = True,
+        drop_multi_edges: bool = False,
     ):
         """
         Parameters
@@ -1100,6 +1126,8 @@ def _make_plc_graph(
             Whether to renumber the vertices of the graph.
             Required if inputted vertex ids are not of
             int32 or int64 type.
+        drop_multi_edges: bool (default=False)
+            Whether to drop multi edges
         """
 
         if value_col is None:
@@ -1163,6 +1191,7 @@ def _make_plc_graph(
             renumber=renumber,
             do_expensive_check=True,
             input_array_format=input_array_format,
+            drop_multi_edges=drop_multi_edges,
         )
 
     def to_directed(self, DiG, store_transposed=False):
@@ -1306,6 +1335,14 @@ def neighbors(self, n):
             n = node[0]
 
         df = self.edgelist.edgelist_df
+
+        vertex_col_name = [simpleGraphImpl.srcCol, simpleGraphImpl.dstCol]
+
+        if not self.properties.multi_edge:
+            # Drop parallel edges for non MultiGraph
+            # FIXME: Drop multi edges with the CAPI instead.
+            df = df.groupby(by=[*vertex_col_name], as_index=False).min()
+
         neighbors = df[df[simpleGraphImpl.srcCol] == n][
             simpleGraphImpl.dstCol
         ].reset_index(drop=True)

python/cugraph/cugraph/structure/symmetrize.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2019-2023, NVIDIA CORPORATION.
+# Copyright (c) 2019-2024, 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
@@ -15,6 +15,7 @@
 import cudf
 import dask_cudf
 from dask.distributed import default_client
+import warnings
 
 
 def symmetrize_df(
@@ -54,6 +55,11 @@ def symmetrize_df(
         Name of the column in the data frame containing the weight ids
 
     multi : bool, optional (default=False)
+        [Deprecated,  Multi will be removed in future version,  and the removal
+        of multi edges will no longer be supported from 'symmetrize'.
+        Multi edges will be removed upon  creation of graph instance directly
+        based on if the graph is `curgaph.MultiGraph` or `cugraph.Graph`.]
+
         Set to True if graph is a Multi(Di)Graph. This allows multiple
         edges instead of dropping them.
 
@@ -84,6 +90,12 @@ def symmetrize_df(
     if multi:
         return result
     else:
+        warnings.warn(
+            "Multi is deprecated and the removal of multi edges will no longer be "
+            "supported from 'symmetrize'. Multi edges will be removed upon creation "
+            "of graph instance.",
+            FutureWarning,
+        )
         vertex_col_name = src_name + dst_name
         result = result.groupby(by=[*vertex_col_name], as_index=False).min()
         return result
@@ -128,6 +140,11 @@ def symmetrize_ddf(
         Name of the column in the data frame containing the weight ids
 
     multi : bool, optional (default=False)
+        [Deprecated,  Multi will be removed in future version,  and the removal
+        of multi edges will no longer be supported from 'symmetrize'.
+        Multi edges will be removed upon  creation of graph instance directly
+        based on if the graph is `curgaph.MultiGraph` or `cugraph.Graph`.]
+
         Set to True if graph is a Multi(Di)Graph. This allows multiple
         edges instead of dropping them.
 
@@ -167,6 +184,12 @@ def symmetrize_ddf(
     if multi:
         return result
     else:
+        warnings.warn(
+            "Multi is deprecated and the removal of multi edges will no longer be "
+            "supported from 'symmetrize'. Multi edges will be removed upon creation "
+            "of graph instance.",
+            FutureWarning,
+        )
         vertex_col_name = src_name + dst_name
         result = _memory_efficient_drop_duplicates(
             result, vertex_col_name, len(workers)
@@ -181,6 +204,7 @@ def symmetrize(
     value_col_name=None,
     multi=False,
     symmetrize=True,
+    do_expensive_check=False,
 ):
     """
     Take a dataframe of source destination pairs along with associated
@@ -208,6 +232,11 @@ def symmetrize(
         weights column name.
 
     multi : bool, optional (default=False)
+        [Deprecated,  Multi will be removed in future version,  and the removal
+        of multi edges will no longer be supported from 'symmetrize'.
+        Multi edges will be removed upon  creation of graph instance directly
+        based on if the graph is `curgaph.MultiGraph` or `cugraph.Graph`.]
+
         Set to True if graph is a Multi(Di)Graph. This allows multiple
         edges instead of dropping them.
 
@@ -234,8 +263,9 @@ def symmetrize(
     if "edge_id" in input_df.columns and symmetrize:
         raise ValueError("Edge IDs are not supported on undirected graphs")
 
-    csg.null_check(input_df[source_col_name])
-    csg.null_check(input_df[dest_col_name])
+    if do_expensive_check:  # FIXME: Optimize this check as it is currently expensive
+        csg.null_check(input_df[source_col_name])
+        csg.null_check(input_df[dest_col_name])
 
     if isinstance(input_df, dask_cudf.DataFrame):
         output_df = symmetrize_ddf(

python/cugraph/cugraph/tests/data_store/test_property_graph.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2021-2023, NVIDIA CORPORATION.
+# Copyright (c) 2021-2024, 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
@@ -1176,10 +1176,12 @@ def test_extract_subgraph_vertex_prop_condition_only(
         )
     # Should result in two edges, one a "relationship", the other a "referral"
     expected_edgelist = cudf.DataFrame(
-        {"src": [89216, 78634], "dst": [78634, 89216], "weights": [99, 8]}
+        {"src": [78634, 89216], "dst": [89216, 78634], "weights": [8, 99]}
     )
 
     if G.renumbered:
+        # FIXME: Can only use the attribute 'edgelist.edgelist_df' for directed
+        # graphs
         actual_edgelist = G.unrenumber(
             G.edgelist.edgelist_df, "src", preserve_order=True
         )
@@ -1472,7 +1474,7 @@ def test_extract_subgraph_no_query(dataset1_PropertyGraph, as_pg_first):
     # referrals has 3 edges with the same src/dst, so subtract 2 from
     # the total count since this is not creating a multigraph..
     num_edges -= 2
-    assert len(G.edgelist.edgelist_df) == num_edges
+    assert len(G.view_edge_list()) == num_edges
 
 
 @pytest.mark.sg

python/cugraph/cugraph/tests/sampling/test_uniform_neighbor_sample.py

@@ -146,7 +146,10 @@ def test_uniform_neighbor_sample_simple(input_combo):
     # Retrieve the input dataframe.
     # FIXME: in simpleGraph and simpleDistributedGraph, G.edgelist.edgelist_df
     # should be 'None' if the datasets was never renumbered
+    # FIXME: Drop multi edges with the CAPI instead.
+    vertex_col_name = ["src", "dst"]
     input_df = G.edgelist.edgelist_df
+    input_df = input_df.groupby(by=[*vertex_col_name], as_index=False).min()
 
     result_nbr = uniform_neighbor_sample(
         G,

python/cugraph/cugraph/tests/structure/test_graph.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2019-2023, NVIDIA CORPORATION.
+# Copyright (c) 2019-2024, 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
@@ -197,6 +197,7 @@ def test_add_adj_list_to_edge_list(graph_file):
     G.from_cudf_adjlist(offsets, indices, None)
 
     edgelist = G.view_edge_list()
+    edgelist = edgelist.sort_values(["src", "dst"]).reset_index(drop=True)
     sources_cu = edgelist["src"]
     destinations_cu = edgelist["dst"]
     compare_series(sources_cu, sources_exp)
@@ -215,7 +216,7 @@ def test_view_edge_list_from_adj_list(graph_file):
     indices = cudf.Series(Mcsr.indices)
     G = cugraph.Graph(directed=True)
     G.from_cudf_adjlist(offsets, indices, None)
-    edgelist_df = G.view_edge_list()
+    edgelist_df = G.view_edge_list().sort_values(["src", "dst"]).reset_index(drop=True)
     Mcoo = Mcsr.tocoo()
     src1 = Mcoo.row
     dst1 = Mcoo.col
@@ -672,6 +673,7 @@ def test_neighbors(graph_file):
         nx_neighbors = [i for i in Gnx.neighbors(n)]
         cu_neighbors.sort()
         nx_neighbors.sort()
+
         assert cu_neighbors == nx_neighbors
 
 

python/pylibcugraph/pylibcugraph/graphs.pyx

@@ -463,9 +463,9 @@ cdef class MGGraph(_GPUGraph):
             edge_type_view_ptr_ptr,
             store_transposed,
             num_arrays,
-            do_expensive_check,
             drop_self_loops,
             drop_multi_edges,
+            do_expensive_check,
             &(self.c_graph_ptr),
             &error_ptr)