87 lines
2.7 KiB
Python
87 lines
2.7 KiB
Python
"""In-subgraph sampler for GraphBolt."""
|
|
|
|
from torch.utils.data import functional_datapipe
|
|
|
|
from ..internal import unique_and_compact_csc_formats
|
|
|
|
from ..subgraph_sampler import SubgraphSampler
|
|
from .sampled_subgraph_impl import SampledSubgraphImpl
|
|
|
|
|
|
__all__ = ["InSubgraphSampler"]
|
|
|
|
|
|
@functional_datapipe("sample_in_subgraph")
|
|
class InSubgraphSampler(SubgraphSampler):
|
|
"""Sample the subgraph induced on the inbound edges of the given nodes.
|
|
|
|
Functional name: :obj:`sample_in_subgraph`.
|
|
|
|
In-subgraph sampler is responsible for sampling a subgraph from given data,
|
|
returning an induced subgraph along with compacted information.
|
|
|
|
Parameters
|
|
----------
|
|
datapipe : DataPipe
|
|
The datapipe.
|
|
graph : FusedCSCSamplingGraph
|
|
The graph on which to perform in_subgraph sampling.
|
|
|
|
Examples
|
|
-------
|
|
>>> import dgl.graphbolt as gb
|
|
>>> import torch
|
|
>>> 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)
|
|
>>> item_set = gb.ItemSet(len(indptr) - 1, names="seeds")
|
|
>>> item_sampler = gb.ItemSampler(item_set, batch_size=2)
|
|
>>> insubgraph_sampler = gb.InSubgraphSampler(item_sampler, graph)
|
|
>>> for _, data in enumerate(insubgraph_sampler):
|
|
... print(data.sampled_subgraphs[0].sampled_csc)
|
|
... print(data.sampled_subgraphs[0].original_row_node_ids)
|
|
... print(data.sampled_subgraphs[0].original_column_node_ids)
|
|
CSCFormatBase(indptr=tensor([0, 3, 5]),
|
|
indices=tensor([0, 1, 2, 3, 4]),
|
|
)
|
|
tensor([0, 1, 4, 2, 3])
|
|
tensor([0, 1])
|
|
CSCFormatBase(indptr=tensor([0, 2, 4]),
|
|
indices=tensor([2, 3, 4, 0]),
|
|
)
|
|
tensor([2, 3, 0, 5, 1])
|
|
tensor([2, 3])
|
|
CSCFormatBase(indptr=tensor([0, 3, 5]),
|
|
indices=tensor([2, 3, 1, 4, 0]),
|
|
)
|
|
tensor([4, 5, 0, 3, 1])
|
|
tensor([4, 5])
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
datapipe,
|
|
graph,
|
|
):
|
|
super().__init__(datapipe)
|
|
self.graph = graph
|
|
self.sampler = graph.in_subgraph
|
|
|
|
def sample_subgraphs(
|
|
self, seeds, seeds_timestamp, seeds_pre_time_window=None
|
|
):
|
|
subgraph = self.sampler(seeds)
|
|
(
|
|
original_row_node_ids,
|
|
compacted_csc_formats,
|
|
_,
|
|
) = unique_and_compact_csc_formats(subgraph.sampled_csc, seeds)
|
|
subgraph = SampledSubgraphImpl(
|
|
sampled_csc=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])
|