[DistGB] add verify logic for GraphBolt partitions (#7031)

python/dgl/distributed/partition.py

@@ -12,7 +12,7 @@
 
 from .. import backend as F, graphbolt as gb
 from ..base import dgl_warning, DGLError, EID, ETYPE, NID, NTYPE
-from ..convert import to_homogeneous
+from ..convert import heterograph, to_homogeneous
 from ..data.utils import load_graphs, load_tensors, save_graphs, save_tensors
 from ..partition import (
     get_peak_mem,
@@ -190,8 +190,71 @@ def _verify_dgl_partition(graph, part_id, gpb, ntypes, etypes):
 
 def _verify_graphbolt_partition(graph, part_id, gpb, ntypes, etypes):
     """Verify the partition of a GraphBolt graph."""
-    # [Rui][TODO]
-    _, _, _, _, _ = graph, part_id, gpb, ntypes, etypes
+    required_ndata_fields = [NID]
+    required_edata_fields = [EID]
+    assert all(
+        field in graph.node_attributes for field in required_ndata_fields
+    ), "the partition graph should contain node mapping to global node ID."
+    assert all(
+        field in graph.edge_attributes for field in required_edata_fields
+    ), "the partition graph should contain edge mapping to global edge ID."
+
+    num_nodes = graph.total_num_nodes
+    num_edges = graph.total_num_edges
+    local_src_ids = graph.indices
+    local_dst_ids = torch.repeat_interleave(
+        torch.arange(num_nodes), torch.diff(graph.csc_indptr)
+    )
+    global_src_ids = graph.node_attributes[NID][local_src_ids]
+    global_dst_ids = graph.node_attributes[NID][local_dst_ids]
+
+    etype_ids, type_wise_eids = gpb.map_to_per_etype(graph.edge_attributes[EID])
+    if graph.type_per_edge is not None:
+        assert torch.equal(etype_ids, graph.type_per_edge)
+    etype_ids, etype_ids_indices = torch.sort(etype_ids)
+    global_src_ids = global_src_ids[etype_ids_indices]
+    global_dst_ids = global_dst_ids[etype_ids_indices]
+    type_wise_eids = type_wise_eids[etype_ids_indices]
+
+    src_ntype_ids, src_type_wise_nids = gpb.map_to_per_ntype(global_src_ids)
+    dst_ntype_ids, dst_type_wise_nids = gpb.map_to_per_ntype(global_dst_ids)
+
+    data_dict = dict()
+    edge_ids = dict()
+    for c_etype, etype_id in etypes.items():
+        idx = etype_ids == etype_id
+        src_ntype, etype, dst_ntype = c_etype
+        if idx.sum() == 0:
+            continue
+        actual_src_ntype_ids = src_ntype_ids[idx]
+        actual_dst_ntype_ids = dst_ntype_ids[idx]
+        expected_src_ntype_ids = ntypes[src_ntype]
+        expected_dst_ntype_ids = ntypes[dst_ntype]
+        assert all(actual_src_ntype_ids == expected_src_ntype_ids), (
+            f"Unexpected types of source nodes for {c_etype}. Expected: "
+            f"{expected_src_ntype_ids}, but got: {actual_src_ntype_ids}."
+        )
+        assert all(actual_dst_ntype_ids == expected_dst_ntype_ids), (
+            f"Unexpected types of destination nodes for {c_etype}. Expected: "
+            f"{expected_dst_ntype_ids}, but got: {actual_dst_ntype_ids}."
+        )
+        data_dict[c_etype] = (src_type_wise_nids[idx], dst_type_wise_nids[idx])
+        edge_ids[c_etype] = type_wise_eids[idx]
+
+    # Make sure node/edge IDs are not out of range.
+    hg = heterograph(
+        data_dict, {ntype: gpb._num_nodes(ntype) for ntype in ntypes}
+    )
+    for etype in edge_ids:
+        hg.edges[etype].data[EID] = edge_ids[etype]
+    assert all(
+        hg.num_edges(etype) == len(eids) for etype, eids in edge_ids.items()
+    ), "The number of edges per etype in the partition graph is not correct."
+    assert num_edges == hg.num_edges(), (
+        f"The total number of edges in the partition graph is not correct. "
+        f"Expected: {num_edges}, but got: {hg.num_edges()}."
+    )
+    print(f"Partition {part_id} looks good!")
 
 
 def load_partition(part_config, part_id, load_feats=True, use_graphbolt=False):