[GraphBolt] Modify `InSubgraphSampler` to support csc format. (#6724)

Co-authored-by: Ubuntu <ubuntu@ip-172-31-0-133.us-west-2.compute.internal>

python/dgl/graphbolt/impl/fused_csc_sampling_graph.py

@@ -301,8 +301,11 @@ class FusedCSCSamplingGraph(SamplingGraph):
         self._c_csc_graph.set_edge_attributes(edge_attributes)
 
     def in_subgraph(
-        self, nodes: Union[torch.Tensor, Dict[str, torch.Tensor]]
-    ) -> FusedSampledSubgraphImpl:
+        self,
+        nodes: Union[torch.Tensor, Dict[str, torch.Tensor]],
+        # TODO: clean up once the migration is done.
+        output_cscformat=False,
+    ) -> Union[FusedSampledSubgraphImpl, SampledSubgraphImpl]:
         """Return the subgraph induced on the inbound edges of the given nodes.
 
         An in subgraph is equivalent to creating a new graph using the incoming
@@ -361,7 +364,10 @@ class FusedCSCSamplingGraph(SamplingGraph):
         ), "Nodes cannot have duplicate values."
 
         _in_subgraph = self._c_csc_graph.in_subgraph(nodes)
+        if not output_cscformat:
             return self._convert_to_fused_sampled_subgraph(_in_subgraph)
+        else:
+            return self._convert_to_sampled_subgraph(_in_subgraph)
 
     def _convert_to_fused_sampled_subgraph(
         self,

python/dgl/graphbolt/impl/in_subgraph_sampler.py

@@ -2,10 +2,13 @@
 
 from torch.utils.data import functional_datapipe
 
-from ..internal import unique_and_compact_node_pairs
+from ..internal import (
+    unique_and_compact_csc_formats,
+    unique_and_compact_node_pairs,
+)
 
 from ..subgraph_sampler import SubgraphSampler
-from .sampled_subgraph_impl import FusedSampledSubgraphImpl
+from .sampled_subgraph_impl import FusedSampledSubgraphImpl, SampledSubgraphImpl
 
 
 __all__ = ["InSubgraphSampler"]
@@ -56,13 +59,17 @@ class InSubgraphSampler(SubgraphSampler):
         self,
         datapipe,
         graph,
+        # TODO: clean up once the migration is done.
+        output_cscformat=False,
     ):
         super().__init__(datapipe)
         self.graph = graph
+        self.output_cscformat = output_cscformat
         self.sampler = graph.in_subgraph
 
     def _sample_subgraphs(self, seeds):
-        subgraph = self.sampler(seeds)
+        subgraph = self.sampler(seeds, self.output_cscformat)
+        if not self.output_cscformat:
             (
                 original_row_node_ids,
                 compacted_node_pairs,
@@ -73,5 +80,16 @@ class InSubgraphSampler(SubgraphSampler):
                 original_row_node_ids=original_row_node_ids,
                 original_edge_ids=subgraph.original_edge_ids,
             )
+        else:
+            (
+                original_row_node_ids,
+                compacted_csc_formats,
+            ) = unique_and_compact_csc_formats(subgraph.node_pairs, seeds)
+            subgraph = SampledSubgraphImpl(
+                node_pairs=compacted_csc_formats,
+                original_column_node_ids=seeds,
+                original_row_node_ids=original_row_node_ids,
+                original_edge_ids=subgraph.original_edge_ids,
+            )
         seeds = original_row_node_ids
         return (seeds, [subgraph])

tests/python/pytorch/graphbolt/impl/test_fused_csc_sampling_graph.py

@@ -532,7 +532,7 @@ def test_multiprocessing():
     F._default_context_str == "gpu",
     reason="Graph is CPU only at present.",
 )
-def test_in_subgraph_homogeneous():
+def test_in_subgraph_node_pairs_homogeneous():
     """Original graph in COO:
     1   0   1   0   1
     1   0   1   1   0
@@ -573,7 +573,7 @@ def test_in_subgraph_homogeneous():
     F._default_context_str == "gpu",
     reason="Graph is CPU only at present.",
 )
-def test_in_subgraph_heterogeneous():
+def test_in_subgraph_node_pairs_heterogeneous():
     """Original graph in COO:
     1   0   1   0   1
     1   0   1   1   0
@@ -659,6 +659,137 @@ def test_in_subgraph_heterogeneous():
     )
 
 
+@unittest.skipIf(
+    F._default_context_str == "gpu",
+    reason="Graph is CPU only at present.",
+)
+def test_in_subgraph_homo():
+    """Original graph in COO:
+    1   0   1   0   1
+    1   0   1   1   0
+    0   1   0   1   0
+    0   1   0   0   1
+    1   0   0   0   1
+    """
+    # Initialize data.
+    total_num_nodes = 5
+    total_num_edges = 12
+    indptr = torch.LongTensor([0, 3, 5, 7, 9, 12])
+    indices = torch.LongTensor([0, 1, 4, 2, 3, 0, 1, 1, 2, 0, 3, 4])
+    assert indptr[-1] == total_num_edges
+    assert indptr[-1] == len(indices)
+
+    # Construct FusedCSCSamplingGraph.
+    graph = gb.fused_csc_sampling_graph(indptr, indices)
+
+    # Extract in subgraph.
+    nodes = torch.LongTensor([4, 1, 3])
+    in_subgraph = graph.in_subgraph(nodes, output_cscformat=True)
+
+    # Verify in subgraph.
+    assert torch.equal(
+        in_subgraph.node_pairs.indices, torch.LongTensor([0, 3, 4, 2, 3, 1, 2])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs.indptr, torch.LongTensor([0, 3, 5, 7])
+    )
+    assert in_subgraph.original_column_node_ids is None
+    assert in_subgraph.original_row_node_ids is None
+    assert torch.equal(
+        in_subgraph.original_edge_ids, torch.LongTensor([9, 10, 11, 3, 4, 7, 8])
+    )
+
+
+@unittest.skipIf(
+    F._default_context_str == "gpu",
+    reason="Graph is CPU only at present.",
+)
+def test_in_subgraph_hetero():
+    """Original graph in COO:
+    1   0   1   0   1
+    1   0   1   1   0
+    0   1   0   1   0
+    0   1   0   0   1
+    1   0   0   0   1
+
+    node_type_0: [0, 1]
+    node_type_1: [2, 3, 4]
+    edge_type_0: node_type_0 -> node_type_0
+    edge_type_1: node_type_0 -> node_type_1
+    edge_type_2: node_type_1 -> node_type_0
+    edge_type_3: node_type_1 -> node_type_1
+    """
+    # Initialize data.
+    total_num_nodes = 5
+    total_num_edges = 12
+    ntypes = {
+        "N0": 0,
+        "N1": 1,
+    }
+    etypes = {
+        "N0:R0:N0": 0,
+        "N0:R1:N1": 1,
+        "N1:R2:N0": 2,
+        "N1:R3:N1": 3,
+    }
+    indptr = torch.LongTensor([0, 3, 5, 7, 9, 12])
+    indices = torch.LongTensor([0, 1, 4, 2, 3, 0, 1, 1, 2, 0, 3, 4])
+    node_type_offset = torch.LongTensor([0, 2, 5])
+    type_per_edge = torch.LongTensor([0, 0, 2, 2, 2, 1, 1, 1, 3, 1, 3, 3])
+    assert indptr[-1] == total_num_edges
+    assert indptr[-1] == len(indices)
+    assert node_type_offset[-1] == total_num_nodes
+    assert all(type_per_edge < len(etypes))
+
+    # Construct FusedCSCSamplingGraph.
+    graph = gb.fused_csc_sampling_graph(
+        indptr,
+        indices,
+        node_type_offset=node_type_offset,
+        type_per_edge=type_per_edge,
+        node_type_to_id=ntypes,
+        edge_type_to_id=etypes,
+    )
+
+    # Extract in subgraph.
+    nodes = {
+        "N0": torch.LongTensor([1]),
+        "N1": torch.LongTensor([2, 1]),
+    }
+    in_subgraph = graph.in_subgraph(nodes, output_cscformat=True)
+
+    # Verify in subgraph.
+    assert torch.equal(
+        in_subgraph.node_pairs["N0:R0:N0"].indices, torch.LongTensor([])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N0:R0:N0"].indptr, torch.LongTensor([0, 0])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N0:R1:N1"].indices, torch.LongTensor([0, 1])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N0:R1:N1"].indptr, torch.LongTensor([0, 1, 2])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N1:R2:N0"].indices, torch.LongTensor([0, 1])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N1:R2:N0"].indptr, torch.LongTensor([0, 2])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N1:R3:N1"].indices, torch.LongTensor([1, 2, 0])
+    )
+    assert torch.equal(
+        in_subgraph.node_pairs["N1:R3:N1"].indptr, torch.LongTensor([0, 2, 3])
+    )
+    assert in_subgraph.original_column_node_ids is None
+    assert in_subgraph.original_row_node_ids is None
+    assert torch.equal(
+        in_subgraph.original_edge_ids, torch.LongTensor([3, 4, 9, 10, 11, 7, 8])
+    )
+
+
 @unittest.skipIf(
     F._default_context_str == "gpu",
     reason="Graph is CPU only at present.",

tests/python/pytorch/graphbolt/impl/test_in_subgraph_sampler.py

@@ -62,7 +62,7 @@ def test_index_select_csc(indptr_dtype, indices_dtype, idtype, is_pinned):
     assert torch.equal(cpu_indices, gpu_indices.cpu())
 
 
-def test_InSubgraphSampler_homo():
+def test_InSubgraphSampler_node_pairs_homo():
     """Original graph in COO:
     1   0   1   0   1   0
     1   0   0   1   0   1
@@ -109,7 +109,7 @@ def test_InSubgraphSampler_homo():
     assert original_node_pairs(mn) == ([1, 2], [3, 3])
 
 
-def test_InSubgraphSampler_hetero():
+def test_InSubgraphSampler_node_pairs_hetero():
     """Original graph in COO:
     1   0   1   0   1   0
     1   0   0   1   0   1
@@ -198,3 +198,175 @@ def test_InSubgraphSampler_hetero():
     for etype, pairs in mn.sampled_subgraphs[0].node_pairs.items():
         assert torch.equal(pairs[0], expected_node_pairs[etype][0])
         assert torch.equal(pairs[1], expected_node_pairs[etype][1])
+
+
+def test_InSubgraphSampler_homo():
+    """Original graph in COO:
+    1   0   1   0   1   0
+    1   0   0   1   0   1
+    0   1   0   1   0   0
+    0   1   0   0   1   0
+    1   0   0   0   0   1
+    0   0   1   0   1   0
+    """
+    indptr = torch.LongTensor([0, 3, 5, 7, 9, 12, 14])
+    indices = torch.LongTensor([0, 1, 4, 2, 3, 0, 5, 1, 2, 0, 3, 5, 1, 4])
+    graph = gb.fused_csc_sampling_graph(indptr, indices)
+
+    seed_nodes = torch.LongTensor([0, 5, 3])
+    item_set = gb.ItemSet(seed_nodes, names="seed_nodes")
+    batch_size = 1
+    item_sampler = gb.ItemSampler(item_set, batch_size=batch_size)
+
+    in_subgraph_sampler = gb.InSubgraphSampler(
+        item_sampler, graph, output_cscformat=True
+    )
+
+    it = iter(in_subgraph_sampler)
+
+    def original_indices(minibatch):
+        sampled_subgraph = minibatch.sampled_subgraphs[0]
+        _indices = sampled_subgraph.original_row_node_ids[
+            sampled_subgraph.node_pairs.indices
+        ]
+        return _indices
+
+    mn = next(it)
+    assert torch.equal(mn.seed_nodes, torch.LongTensor([0]))
+    assert torch.equal(
+        mn.sampled_subgraphs[0].node_pairs.indptr, torch.tensor([0, 3])
+    )
+    assert torch.equal(original_indices(mn), torch.tensor([0, 1, 4]))
+
+    mn = next(it)
+    assert torch.equal(mn.seed_nodes, torch.LongTensor([5]))
+    assert torch.equal(
+        mn.sampled_subgraphs[0].node_pairs.indptr, torch.tensor([0, 2])
+    )
+    assert torch.equal(original_indices(mn), torch.tensor([1, 4]))
+
+    mn = next(it)
+    assert torch.equal(mn.seed_nodes, torch.LongTensor([3]))
+    assert torch.equal(
+        mn.sampled_subgraphs[0].node_pairs.indptr, torch.tensor([0, 2])
+    )
+    assert torch.equal(original_indices(mn), torch.tensor([1, 2]))
+
+
+def test_InSubgraphSampler_hetero():
+    """Original graph in COO:
+    1   0   1   0   1   0
+    1   0   0   1   0   1
+    0   1   0   1   0   0
+    0   1   0   0   1   0
+    1   0   0   0   0   1
+    0   0   1   0   1   0
+    node_type_0: [0, 1, 2]
+    node_type_1: [3, 4, 5]
+    edge_type_0: node_type_0 -> node_type_0
+    edge_type_1: node_type_0 -> node_type_1
+    edge_type_2: node_type_1 -> node_type_0
+    edge_type_3: node_type_1 -> node_type_1
+    """
+    ntypes = {
+        "N0": 0,
+        "N1": 1,
+    }
+    etypes = {
+        "N0:R0:N0": 0,
+        "N0:R1:N1": 1,
+        "N1:R2:N0": 2,
+        "N1:R3:N1": 3,
+    }
+    indptr = torch.LongTensor([0, 3, 5, 7, 9, 12, 14])
+    indices = torch.LongTensor([0, 1, 4, 2, 3, 0, 5, 1, 2, 0, 3, 5, 1, 4])
+    node_type_offset = torch.LongTensor([0, 3, 6])
+    type_per_edge = torch.LongTensor([0, 0, 2, 0, 2, 0, 2, 1, 1, 1, 3, 3, 1, 3])
+    graph = gb.fused_csc_sampling_graph(
+        csc_indptr=indptr,
+        indices=indices,
+        node_type_offset=node_type_offset,
+        type_per_edge=type_per_edge,
+        node_type_to_id=ntypes,
+        edge_type_to_id=etypes,
+    )
+
+    item_set = gb.ItemSetDict(
+        {
+            "N0": gb.ItemSet(torch.LongTensor([1, 0, 2]), names="seed_nodes"),
+            "N1": gb.ItemSet(torch.LongTensor([0, 2, 1]), names="seed_nodes"),
+        }
+    )
+    batch_size = 2
+    item_sampler = gb.ItemSampler(item_set, batch_size=batch_size)
+
+    in_subgraph_sampler = gb.InSubgraphSampler(
+        item_sampler, graph, output_cscformat=True
+    )
+
+    it = iter(in_subgraph_sampler)
+
+    mn = next(it)
+    assert torch.equal(mn.seed_nodes["N0"], torch.LongTensor([1, 0]))
+    expected_node_pairs = {
+        "N0:R0:N0": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 1, 3]),
+            indices=torch.LongTensor([2, 1, 0]),
+        ),
+        "N0:R1:N1": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0]), indices=torch.LongTensor([])
+        ),
+        "N1:R2:N0": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 1, 2]), indices=torch.LongTensor([0, 1])
+        ),
+        "N1:R3:N1": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0]), indices=torch.LongTensor([])
+        ),
+    }
+    for etype, pairs in mn.sampled_subgraphs[0].node_pairs.items():
+        assert torch.equal(pairs.indices, expected_node_pairs[etype].indices)
+        assert torch.equal(pairs.indptr, expected_node_pairs[etype].indptr)
+
+    mn = next(it)
+    assert mn.seed_nodes == {
+        "N0": torch.LongTensor([2]),
+        "N1": torch.LongTensor([0]),
+    }
+    expected_node_pairs = {
+        "N0:R0:N0": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 1]), indices=torch.LongTensor([1])
+        ),
+        "N0:R1:N1": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 2]), indices=torch.LongTensor([2, 0])
+        ),
+        "N1:R2:N0": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 1]), indices=torch.LongTensor([1])
+        ),
+        "N1:R3:N1": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 0]), indices=torch.LongTensor([])
+        ),
+    }
+    for etype, pairs in mn.sampled_subgraphs[0].node_pairs.items():
+        assert torch.equal(pairs.indices, expected_node_pairs[etype].indices)
+        assert torch.equal(pairs.indptr, expected_node_pairs[etype].indptr)
+
+    mn = next(it)
+    assert torch.equal(mn.seed_nodes["N1"], torch.LongTensor([2, 1]))
+    expected_node_pairs = {
+        "N0:R0:N0": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0]), indices=torch.LongTensor([])
+        ),
+        "N0:R1:N1": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 1, 2]), indices=torch.LongTensor([0, 1])
+        ),
+        "N1:R2:N0": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0]), indices=torch.LongTensor([])
+        ),
+        "N1:R3:N1": gb.CSCFormatBase(
+            indptr=torch.LongTensor([0, 1, 3]),
+            indices=torch.LongTensor([1, 2, 0]),
+        ),
+    }
+    for etype, pairs in mn.sampled_subgraphs[0].node_pairs.items():
+        assert torch.equal(pairs.indices, expected_node_pairs[etype].indices)
+        assert torch.equal(pairs.indptr, expected_node_pairs[etype].indptr)