"""CSC format sampling graph."""
import textwrap
# pylint: disable= invalid-name
from typing import Dict, Optional, Union
import torch
from dgl.utils import recursive_apply
from ...base import EID, ETYPE, NID, NTYPE
from ...convert import to_homogeneous
from ...heterograph import DGLGraph
from ..base import etype_str_to_tuple, etype_tuple_to_str, ORIGINAL_EDGE_ID
from ..sampling_graph import SamplingGraph
from .sampled_subgraph_impl import CSCFormatBase, SampledSubgraphImpl
__all__ = [
"FusedCSCSamplingGraph",
"fused_csc_sampling_graph",
"load_from_shared_memory",
"from_dglgraph",
]
[docs]class FusedCSCSamplingGraph(SamplingGraph):
r"""A sampling graph in CSC format."""
def __repr__(self):
final_str = (
"{classname}(csc_indptr={csc_indptr},\n"
"indices={indices},\n"
"{metadata})"
)
classname_str = self.__class__.__name__
csc_indptr_str = str(self.csc_indptr)
indices_str = str(self.indices)
meta_str = f"total_num_nodes={self.total_num_nodes}, num_edges={self.num_edges},"
if self.node_type_offset is not None:
meta_str += f"\nnode_type_offset={self.node_type_offset},"
if self.type_per_edge is not None:
meta_str += f"\ntype_per_edge={self.type_per_edge},"
if self.node_type_to_id is not None:
meta_str += f"\nnode_type_to_id={self.node_type_to_id},"
if self.edge_type_to_id is not None:
meta_str += f"\nedge_type_to_id={self.edge_type_to_id},"
if self.node_attributes is not None:
meta_str += f"\nnode_attributes={self.node_attributes},"
if self.edge_attributes is not None:
meta_str += f"\nedge_attributes={self.edge_attributes},"
final_str = final_str.format(
classname=classname_str,
csc_indptr=csc_indptr_str,
indices=indices_str,
metadata=meta_str,
)
return textwrap.indent(
final_str, " " * (len(classname_str) + 1)
).strip()
def __init__(
self,
c_csc_graph: torch.ScriptObject,
):
super().__init__()
self._c_csc_graph = c_csc_graph
def __del__(self):
# torch.Tensor.pin_memory() is not an inplace operation. To make it
# truly in-place, we need to use cudaHostRegister. Then, we need to use
# cudaHostUnregister to unpin the tensor in the destructor.
# https://github.com/pytorch/pytorch/issues/32167#issuecomment-753551842
if hasattr(self, "_is_inplace_pinned"):
for tensor in self._is_inplace_pinned:
assert self._inplace_unpinner(tensor.data_ptr()) == 0
@property
def total_num_nodes(self) -> int:
"""Returns the number of nodes in the graph.
Returns
-------
int
The number of rows in the dense format.
"""
return self._c_csc_graph.num_nodes()
@property
def total_num_edges(self) -> int:
"""Returns the number of edges in the graph.
Returns
-------
int
The number of edges in the graph.
"""
return self._c_csc_graph.num_edges()
@property
def num_nodes(self) -> Union[int, Dict[str, int]]:
"""The number of nodes in the graph.
- If the graph is homogenous, returns an integer.
- If the graph is heterogenous, returns a dictionary.
Returns
-------
Union[int, Dict[str, int]]
The number of nodes. Integer indicates the total nodes number of a
homogenous graph; dict indicates nodes number per node types of a
heterogenous graph.
Examples
--------
>>> import dgl.graphbolt as gb, torch
>>> 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])
>>> 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)
>>> print(graph.num_nodes)
{'N0': 2, 'N1': 3}
"""
offset = self._node_type_offset_list
# Homogenous.
if offset is None or self.node_type_to_id is None:
return self._c_csc_graph.num_nodes()
# Heterogenous
else:
num_nodes_per_type = {
_type: (offset[_idx + 1] - offset[_idx])
for _type, _idx in self.node_type_to_id.items()
}
return num_nodes_per_type
@property
def num_edges(self) -> Union[int, Dict[str, int]]:
"""The number of edges in the graph.
- If the graph is homogenous, returns an integer.
- If the graph is heterogenous, returns a dictionary.
Returns
-------
Union[int, Dict[str, int]]
The number of edges. Integer indicates the total edges number of a
homogenous graph; dict indicates edges number per edge types of a
heterogenous graph.
Examples
--------
>>> import dgl.graphbolt as gb, torch
>>> 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])
>>> metadata = gb.GraphMetadata(ntypes, etypes)
>>> graph = gb.fused_csc_sampling_graph(indptr, indices, node_type_offset,
... type_per_edge, None, metadata)
>>> print(graph.num_edges)
{'N0:R0:N0': 2, 'N0:R1:N1': 1, 'N1:R2:N0': 2, 'N1:R3:N1': 3}
"""
type_per_edge = self.type_per_edge
# Homogenous.
if type_per_edge is None or self.edge_type_to_id is None:
return self._c_csc_graph.num_edges()
# Heterogenous
bincount = torch.bincount(type_per_edge)
num_edges_per_type = {}
for etype, etype_id in self.edge_type_to_id.items():
if etype_id < len(bincount):
num_edges_per_type[etype] = bincount[etype_id].item()
else:
num_edges_per_type[etype] = 0
return num_edges_per_type
@property
def csc_indptr(self) -> torch.tensor:
"""Returns the indices pointer in the CSC graph.
Returns
-------
torch.tensor
The indices pointer in the CSC graph. An integer tensor with
shape `(total_num_nodes+1,)`.
"""
return self._c_csc_graph.csc_indptr()
@csc_indptr.setter
def csc_indptr(self, csc_indptr: torch.tensor) -> None:
"""Sets the indices pointer in the CSC graph."""
self._c_csc_graph.set_csc_indptr(csc_indptr)
@property
def indices(self) -> torch.tensor:
"""Returns the indices in the CSC graph.
Returns
-------
torch.tensor
The indices in the CSC graph. An integer tensor with shape
`(total_num_edges,)`.
Notes
-------
It is assumed that edges of each node are already sorted by edge type
ids.
"""
return self._c_csc_graph.indices()
@indices.setter
def indices(self, indices: torch.tensor) -> None:
"""Sets the indices in the CSC graph."""
self._c_csc_graph.set_indices(indices)
@property
def node_type_offset(self) -> Optional[torch.Tensor]:
"""Returns the node type offset tensor if present. Do not modify the
returned tensor in place.
Returns
-------
torch.Tensor or None
If present, returns a 1D integer tensor of shape
`(num_node_types + 1,)`. The tensor is in ascending order as nodes
of the same type have continuous IDs, and larger node IDs are
paired with larger node type IDs. The first value is 0 and last
value is the number of nodes. And nodes with IDs between
`node_type_offset_[i]~node_type_offset_[i+1]` are of type id 'i'.
"""
return self._c_csc_graph.node_type_offset()
@property
def _node_type_offset_list(self) -> Optional[list]:
"""Returns the node type offset list if present.
Returns
-------
list or None
If present, returns a 1D integer list of shape
`(num_node_types + 1,)`. The list is in ascending order as nodes
of the same type have continuous IDs, and larger node IDs are
paired with larger node type IDs. The first value is 0 and last
value is the number of nodes. And nodes with IDs between
`node_type_offset_[i]~node_type_offset_[i+1]` are of type id 'i'.
"""
if (
not hasattr(self, "_node_type_offset_cached_list")
or self._node_type_offset_cached_list is None
):
self._node_type_offset_cached_list = self.node_type_offset
if self._node_type_offset_cached_list is not None:
self._node_type_offset_cached_list = (
self._node_type_offset_cached_list.tolist()
)
return self._node_type_offset_cached_list
@node_type_offset.setter
def node_type_offset(
self, node_type_offset: Optional[torch.Tensor]
) -> None:
"""Sets the node type offset tensor if present."""
self._c_csc_graph.set_node_type_offset(node_type_offset)
self._node_type_offset_cached_list = None
@property
def type_per_edge(self) -> Optional[torch.Tensor]:
"""Returns the edge type tensor if present.
Returns
-------
torch.Tensor or None
If present, returns a 1D integer tensor of shape (total_num_edges,)
containing the type of each edge in the graph.
"""
return self._c_csc_graph.type_per_edge()
@type_per_edge.setter
def type_per_edge(self, type_per_edge: Optional[torch.Tensor]) -> None:
"""Sets the edge type tensor if present."""
self._c_csc_graph.set_type_per_edge(type_per_edge)
@property
def node_type_to_id(self) -> Optional[Dict[str, int]]:
"""Returns the node type to id dictionary if present.
Returns
-------
Dict[str, int] or None
If present, returns a dictionary mapping node type to node type
id.
"""
return self._c_csc_graph.node_type_to_id()
@node_type_to_id.setter
def node_type_to_id(
self, node_type_to_id: Optional[Dict[str, int]]
) -> None:
"""Sets the node type to id dictionary if present."""
self._c_csc_graph.set_node_type_to_id(node_type_to_id)
@property
def edge_type_to_id(self) -> Optional[Dict[str, int]]:
"""Returns the edge type to id dictionary if present.
Returns
-------
Dict[str, int] or None
If present, returns a dictionary mapping edge type to edge type
id.
"""
return self._c_csc_graph.edge_type_to_id()
@edge_type_to_id.setter
def edge_type_to_id(
self, edge_type_to_id: Optional[Dict[str, int]]
) -> None:
"""Sets the edge type to id dictionary if present."""
self._c_csc_graph.set_edge_type_to_id(edge_type_to_id)
@property
def node_attributes(self) -> Optional[Dict[str, torch.Tensor]]:
"""Returns the node attributes dictionary.
Returns
-------
Dict[str, torch.Tensor] or None
If present, returns a dictionary of node attributes. Each key
represents the attribute's name, while the corresponding value
holds the attribute's specific value. The length of each value
should match the total number of nodes."
"""
return self._c_csc_graph.node_attributes()
@node_attributes.setter
def node_attributes(
self, node_attributes: Optional[Dict[str, torch.Tensor]]
) -> None:
"""Sets the node attributes dictionary."""
self._c_csc_graph.set_node_attributes(node_attributes)
@property
def edge_attributes(self) -> Optional[Dict[str, torch.Tensor]]:
"""Returns the edge attributes dictionary.
Returns
-------
Dict[str, torch.Tensor] or None
If present, returns a dictionary of edge attributes. Each key
represents the attribute's name, while the corresponding value
holds the attribute's specific value. The length of each value
should match the total number of edges."
"""
return self._c_csc_graph.edge_attributes()
@edge_attributes.setter
def edge_attributes(
self, edge_attributes: Optional[Dict[str, torch.Tensor]]
) -> None:
"""Sets the edge attributes dictionary."""
self._c_csc_graph.set_edge_attributes(edge_attributes)
[docs] def in_subgraph(
self,
nodes: Union[torch.Tensor, Dict[str, torch.Tensor]],
) -> 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
edges of the given nodes. Subgraph is compacted according to the order
of passed-in `nodes`.
Parameters
----------
nodes: torch.Tensor or Dict[str, torch.Tensor]
IDs of the given seed nodes.
- If `nodes` is a tensor: It means the graph is homogeneous
graph, and ids inside are homogeneous ids.
- If `nodes` is a dictionary: The keys should be node type and
ids inside are heterogeneous ids.
Returns
-------
SampledSubgraphImpl
The in subgraph.
Examples
--------
>>> import dgl.graphbolt as gb
>>> import torch
>>> 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])
>>> 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)
>>> nodes = {"N0":torch.LongTensor([1]), "N1":torch.LongTensor([1, 2])}
>>> in_subgraph = graph.in_subgraph(nodes)
>>> print(in_subgraph.sampled_csc)
{'N0:R0:N0': CSCFormatBase(indptr=tensor([0, 0]),
indices=tensor([], dtype=torch.int64),
), 'N0:R1:N1': CSCFormatBase(indptr=tensor([0, 1, 2]),
indices=tensor([1, 0]),
), 'N1:R2:N0': CSCFormatBase(indptr=tensor([0, 2]),
indices=tensor([0, 1]),
), 'N1:R3:N1': CSCFormatBase(indptr=tensor([0, 1, 3]),
indices=tensor([0, 1, 2]),
)}
"""
if isinstance(nodes, dict):
nodes = self._convert_to_homogeneous_nodes(nodes)
# Ensure nodes is 1-D tensor.
assert nodes.dim() == 1, "Nodes should be 1-D tensor."
# Ensure that there are no duplicate nodes.
assert len(torch.unique(nodes)) == len(
nodes
), "Nodes cannot have duplicate values."
_in_subgraph = self._c_csc_graph.in_subgraph(nodes)
return self._convert_to_sampled_subgraph(_in_subgraph)
def _convert_to_homogeneous_nodes(self, nodes, timestamps=None):
homogeneous_nodes = []
homogeneous_timestamps = []
offset = self._node_type_offset_list
for ntype, ids in nodes.items():
ntype_id = self.node_type_to_id[ntype]
homogeneous_nodes.append(ids + offset[ntype_id])
if timestamps is not None:
homogeneous_timestamps.append(timestamps[ntype])
if timestamps is not None:
return torch.cat(homogeneous_nodes), torch.cat(
homogeneous_timestamps
)
return torch.cat(homogeneous_nodes)
def _convert_to_sampled_subgraph(
self,
C_sampled_subgraph: torch.ScriptObject,
) -> SampledSubgraphImpl:
"""An internal function used to convert a fused homogeneous sampled
subgraph to general struct 'SampledSubgraphImpl'."""
indptr = C_sampled_subgraph.indptr
indices = C_sampled_subgraph.indices
type_per_edge = C_sampled_subgraph.type_per_edge
column = C_sampled_subgraph.original_column_node_ids
original_edge_ids = C_sampled_subgraph.original_edge_ids
has_original_eids = (
self.edge_attributes is not None
and ORIGINAL_EDGE_ID in self.edge_attributes
)
if has_original_eids:
original_edge_ids = torch.ops.graphbolt.index_select(
self.edge_attributes[ORIGINAL_EDGE_ID], original_edge_ids
)
if type_per_edge is None:
# The sampled graph is already a homogeneous graph.
sampled_csc = CSCFormatBase(indptr=indptr, indices=indices)
else:
# UVA sampling requires us to move node_type_offset to GPU.
self.node_type_offset = self.node_type_offset.to(column.device)
# 1. Find node types for each nodes in column.
node_types = (
torch.searchsorted(self.node_type_offset, column, right=True)
- 1
)
original_hetero_edge_ids = {}
sub_indices = {}
sub_indptr = {}
offset = self._node_type_offset_list
# 2. For loop each node type.
for ntype, ntype_id in self.node_type_to_id.items():
# Get all nodes of a specific node type in column.
nids = torch.nonzero(node_types == ntype_id).view(-1)
nids_original_indptr = indptr[nids + 1]
for etype, etype_id in self.edge_type_to_id.items():
src_ntype, _, dst_ntype = etype_str_to_tuple(etype)
if dst_ntype != ntype:
continue
# Get all edge ids of a specific edge type.
eids = torch.nonzero(type_per_edge == etype_id).view(-1)
src_ntype_id = self.node_type_to_id[src_ntype]
sub_indices[etype] = indices[eids] - offset[src_ntype_id]
cum_edges = torch.searchsorted(
eids, nids_original_indptr, right=False
)
sub_indptr[etype] = torch.cat(
(torch.tensor([0], device=indptr.device), cum_edges)
)
if has_original_eids:
original_hetero_edge_ids[etype] = original_edge_ids[
eids
]
if has_original_eids:
original_edge_ids = original_hetero_edge_ids
sampled_csc = {
etype: CSCFormatBase(
indptr=sub_indptr[etype],
indices=sub_indices[etype],
)
for etype in self.edge_type_to_id.keys()
}
return SampledSubgraphImpl(
sampled_csc=sampled_csc,
original_edge_ids=original_edge_ids,
)
[docs] def sample_neighbors(
self,
nodes: Union[torch.Tensor, Dict[str, torch.Tensor]],
fanouts: torch.Tensor,
replace: bool = False,
probs_name: Optional[str] = None,
) -> SampledSubgraphImpl:
"""Sample neighboring edges of the given nodes and return the induced
subgraph.
Parameters
----------
nodes: torch.Tensor or Dict[str, torch.Tensor]
IDs of the given seed nodes.
- If `nodes` is a tensor: It means the graph is homogeneous
graph, and ids inside are homogeneous ids.
- If `nodes` is a dictionary: The keys should be node type and
ids inside are heterogeneous ids.
fanouts: torch.Tensor
The number of edges to be sampled for each node with or without
considering edge types.
- When the length is 1, it indicates that the fanout applies to
all neighbors of the node as a collective, regardless of the
edge type.
- Otherwise, the length should equal to the number of edge
types, and each fanout value corresponds to a specific edge
type of the nodes.
The value of each fanout should be >= 0 or = -1.
- When the value is -1, all neighbors (with non-zero probability,
if weighted) will be sampled once regardless of replacement. It
is equivalent to selecting all neighbors with non-zero
probability when the fanout is >= the number of neighbors (and
replace is set to false).
- When the value is a non-negative integer, it serves as a
minimum threshold for selecting neighbors.
replace: bool
Boolean indicating whether the sample is preformed with or
without replacement. If True, a value can be selected multiple
times. Otherwise, each value can be selected only once.
probs_name: str, optional
An optional string specifying the name of an edge attribute used.
This attribute tensor should contain (unnormalized) probabilities
corresponding to each neighboring edge of a node. It must be a 1D
floating-point or boolean tensor, with the number of elements
equalling the total number of edges.
Returns
-------
SampledSubgraphImpl
The sampled subgraph.
Examples
--------
>>> import dgl.graphbolt as gb
>>> import torch
>>> ntypes = {"n1": 0, "n2": 1}
>>> etypes = {"n1:e1:n2": 0, "n2:e2:n1": 1}
>>> indptr = torch.LongTensor([0, 2, 4, 6, 7, 9])
>>> indices = torch.LongTensor([2, 4, 2, 3, 0, 1, 1, 0, 1])
>>> node_type_offset = torch.LongTensor([0, 2, 5])
>>> type_per_edge = torch.LongTensor([1, 1, 1, 1, 0, 0, 0, 0, 0])
>>> 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)
>>> nodes = {'n1': torch.LongTensor([0]), 'n2': torch.LongTensor([0])}
>>> fanouts = torch.tensor([1, 1])
>>> subgraph = graph.sample_neighbors(nodes, fanouts)
>>> print(subgraph.sampled_csc)
{'n1:e1:n2': CSCFormatBase(indptr=tensor([0, 1]),
indices=tensor([0]),
), 'n2:e2:n1': CSCFormatBase(indptr=tensor([0, 1]),
indices=tensor([2]),
)}
"""
if isinstance(nodes, dict):
nodes = self._convert_to_homogeneous_nodes(nodes)
return_eids = (
self.edge_attributes is not None
and ORIGINAL_EDGE_ID in self.edge_attributes
)
C_sampled_subgraph = self._sample_neighbors(
nodes,
fanouts,
replace=replace,
probs_name=probs_name,
return_eids=return_eids,
)
return self._convert_to_sampled_subgraph(C_sampled_subgraph)
def _check_sampler_arguments(self, nodes, fanouts, probs_name):
if nodes is not None:
assert nodes.dim() == 1, "Nodes should be 1-D tensor."
assert nodes.dtype == self.indices.dtype, (
f"Data type of nodes must be consistent with "
f"indices.dtype({self.indices.dtype}), but got {nodes.dtype}."
)
assert fanouts.dim() == 1, "Fanouts should be 1-D tensor."
expected_fanout_len = 1
if self.edge_type_to_id:
expected_fanout_len = len(self.edge_type_to_id)
assert len(fanouts) in [
expected_fanout_len,
1,
], "Fanouts should have the same number of elements as etypes or \
should have a length of 1."
if fanouts.size(0) > 1:
assert (
self.type_per_edge is not None
), "To perform sampling for each edge type (when the length of \
`fanouts` > 1), the graph must include edge type information."
assert torch.all(
(fanouts >= 0) | (fanouts == -1)
), "Fanouts should consist of values that are either -1 or \
greater than or equal to 0."
if probs_name:
assert (
probs_name in self.edge_attributes
), f"Unknown edge attribute '{probs_name}'."
probs_or_mask = self.edge_attributes[probs_name]
assert probs_or_mask.dim() == 1, "Probs should be 1-D tensor."
assert (
probs_or_mask.size(0) == self.total_num_edges
), "Probs should have the same number of elements as the number \
of edges."
assert probs_or_mask.dtype in [
torch.bool,
torch.float16,
torch.bfloat16,
torch.float32,
torch.float64,
], "Probs should have a floating-point or boolean data type."
def _sample_neighbors(
self,
nodes: torch.Tensor,
fanouts: torch.Tensor,
replace: bool = False,
probs_name: Optional[str] = None,
return_eids: bool = False,
) -> torch.ScriptObject:
"""Sample neighboring edges of the given nodes and return the induced
subgraph.
Parameters
----------
nodes: torch.Tensor
IDs of the given seed nodes.
fanouts: torch.Tensor
The number of edges to be sampled for each node with or without
considering edge types.
- When the length is 1, it indicates that the fanout applies to
all neighbors of the node as a collective, regardless of the
edge type.
- Otherwise, the length should equal to the number of edge
types, and each fanout value corresponds to a specific edge
type of the nodes.
The value of each fanout should be >= 0 or = -1.
- When the value is -1, all neighbors (with non-zero probability,
if weighted) will be sampled once regardless of replacement. It
is equivalent to selecting all neighbors with non-zero
probability when the fanout is >= the number of neighbors (and
replace is set to false).
- When the value is a non-negative integer, it serves as a
minimum threshold for selecting neighbors.
replace: bool
Boolean indicating whether the sample is preformed with or
without replacement. If True, a value can be selected multiple
times. Otherwise, each value can be selected only once.
probs_name: str, optional
An optional string specifying the name of an edge attribute. This
attribute tensor should contain (unnormalized) probabilities
corresponding to each neighboring edge of a node. It must be a 1D
floating-point or boolean tensor, with the number of elements
equalling the total number of edges.
return_eids: bool, optional
Boolean indicating whether to return the original edge IDs of the
sampled edges.
Returns
-------
torch.classes.graphbolt.SampledSubgraph
The sampled C subgraph.
"""
# Ensure nodes is 1-D tensor.
self._check_sampler_arguments(nodes, fanouts, probs_name)
return self._c_csc_graph.sample_neighbors(
nodes,
fanouts.tolist(),
replace,
False,
return_eids,
probs_name,
)
[docs] def sample_layer_neighbors(
self,
nodes: Union[torch.Tensor, Dict[str, torch.Tensor]],
fanouts: torch.Tensor,
replace: bool = False,
probs_name: Optional[str] = None,
) -> SampledSubgraphImpl:
"""Sample neighboring edges of the given nodes and return the induced
subgraph via layer-neighbor sampling from the NeurIPS 2023 paper
`Layer-Neighbor Sampling -- Defusing Neighborhood Explosion in GNNs
<https://arxiv.org/abs/2210.13339>`__
Parameters
----------
nodes: torch.Tensor or Dict[str, torch.Tensor]
IDs of the given seed nodes.
- If `nodes` is a tensor: It means the graph is homogeneous
graph, and ids inside are homogeneous ids.
- If `nodes` is a dictionary: The keys should be node type and
ids inside are heterogeneous ids.
fanouts: torch.Tensor
The number of edges to be sampled for each node with or without
considering edge types.
- When the length is 1, it indicates that the fanout applies to
all neighbors of the node as a collective, regardless of the
edge type.
- Otherwise, the length should equal to the number of edge
types, and each fanout value corresponds to a specific edge
type of the nodes.
The value of each fanout should be >= 0 or = -1.
- When the value is -1, all neighbors (with non-zero probability,
if weighted) will be sampled once regardless of replacement. It
is equivalent to selecting all neighbors with non-zero
probability when the fanout is >= the number of neighbors (and
replace is set to false).
- When the value is a non-negative integer, it serves as a
minimum threshold for selecting neighbors.
replace: bool
Boolean indicating whether the sample is preformed with or
without replacement. If True, a value can be selected multiple
times. Otherwise, each value can be selected only once.
probs_name: str, optional
An optional string specifying the name of an edge attribute. This
attribute tensor should contain (unnormalized) probabilities
corresponding to each neighboring edge of a node. It must be a 1D
floating-point or boolean tensor, with the number of elements
equalling the total number of edges.
Returns
-------
SampledSubgraphImpl
The sampled subgraph.
Examples
--------
>>> import dgl.graphbolt as gb
>>> import torch
>>> ntypes = {"n1": 0, "n2": 1}
>>> etypes = {"n1:e1:n2": 0, "n2:e2:n1": 1}
>>> indptr = torch.LongTensor([0, 2, 4, 6, 7, 9])
>>> indices = torch.LongTensor([2, 4, 2, 3, 0, 1, 1, 0, 1])
>>> node_type_offset = torch.LongTensor([0, 2, 5])
>>> type_per_edge = torch.LongTensor([1, 1, 1, 1, 0, 0, 0, 0, 0])
>>> 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)
>>> nodes = {'n1': torch.LongTensor([0]), 'n2': torch.LongTensor([0])}
>>> fanouts = torch.tensor([1, 1])
>>> subgraph = graph.sample_layer_neighbors(nodes, fanouts)
>>> print(subgraph.sampled_csc)
{'n1:e1:n2': CSCFormatBase(indptr=tensor([0, 1]),
indices=tensor([0]),
), 'n2:e2:n1': CSCFormatBase(indptr=tensor([0, 1]),
indices=tensor([2]),
)}
"""
if isinstance(nodes, dict):
nodes = self._convert_to_homogeneous_nodes(nodes)
self._check_sampler_arguments(nodes, fanouts, probs_name)
has_original_eids = (
self.edge_attributes is not None
and ORIGINAL_EDGE_ID in self.edge_attributes
)
C_sampled_subgraph = self._c_csc_graph.sample_neighbors(
nodes,
fanouts.tolist(),
replace,
True,
has_original_eids,
probs_name,
)
return self._convert_to_sampled_subgraph(C_sampled_subgraph)
[docs] def temporal_sample_neighbors(
self,
nodes: Union[torch.Tensor, Dict[str, torch.Tensor]],
input_nodes_timestamp: Union[torch.Tensor, Dict[str, torch.Tensor]],
fanouts: torch.Tensor,
replace: bool = False,
probs_name: Optional[str] = None,
node_timestamp_attr_name: Optional[str] = None,
edge_timestamp_attr_name: Optional[str] = None,
) -> torch.ScriptObject:
"""Temporally Sample neighboring edges of the given nodes and return the induced
subgraph.
If `node_timestamp_attr_name` or `edge_timestamp_attr_name` is given,
the sampled neighbor or edge of an input node must have a timestamp
that is smaller than that of the input node.
Parameters
----------
nodes: torch.Tensor
IDs of the given seed nodes.
input_nodes_timestamp: torch.Tensor
Timestamps of the given seed nodes.
fanouts: torch.Tensor
The number of edges to be sampled for each node with or without
considering edge types.
- When the length is 1, it indicates that the fanout applies to
all neighbors of the node as a collective, regardless of the
edge type.
- Otherwise, the length should equal to the number of edge
types, and each fanout value corresponds to a specific edge
type of the nodes.
The value of each fanout should be >= 0 or = -1.
- When the value is -1, all neighbors (with non-zero probability,
if weighted) will be sampled once regardless of replacement. It
is equivalent to selecting all neighbors with non-zero
probability when the fanout is >= the number of neighbors (and
replace is set to false).
- When the value is a non-negative integer, it serves as a
minimum threshold for selecting neighbors.
replace: bool
Boolean indicating whether the sample is preformed with or
without replacement. If True, a value can be selected multiple
times. Otherwise, each value can be selected only once.
probs_name: str, optional
An optional string specifying the name of an edge attribute. This
attribute tensor should contain (unnormalized) probabilities
corresponding to each neighboring edge of a node. It must be a 1D
floating-point or boolean tensor, with the number of elements
equalling the total number of edges.
node_timestamp_attr_name: str, optional
An optional string specifying the name of an node attribute.
edge_timestamp_attr_name: str, optional
An optional string specifying the name of an edge attribute.
Returns
-------
SampledSubgraphImpl
The sampled subgraph.
"""
if isinstance(nodes, dict):
nodes, input_nodes_timestamp = self._convert_to_homogeneous_nodes(
nodes, input_nodes_timestamp
)
# Ensure nodes is 1-D tensor.
self._check_sampler_arguments(nodes, fanouts, probs_name)
has_original_eids = (
self.edge_attributes is not None
and ORIGINAL_EDGE_ID in self.edge_attributes
)
C_sampled_subgraph = self._c_csc_graph.temporal_sample_neighbors(
nodes,
input_nodes_timestamp,
fanouts.tolist(),
replace,
False,
has_original_eids,
probs_name,
node_timestamp_attr_name,
edge_timestamp_attr_name,
)
return self._convert_to_sampled_subgraph(C_sampled_subgraph)
[docs] def copy_to_shared_memory(self, shared_memory_name: str):
"""Copy the graph to shared memory.
Parameters
----------
shared_memory_name : str
Name of the shared memory.
Returns
-------
FusedCSCSamplingGraph
The copied FusedCSCSamplingGraph object on shared memory.
"""
return FusedCSCSamplingGraph(
self._c_csc_graph.copy_to_shared_memory(shared_memory_name),
)
def _apply_to_members(self, fn):
"""Apply passed fn to all members of `FusedCSCSamplingGraph`."""
self.csc_indptr = recursive_apply(self.csc_indptr, fn)
self.indices = recursive_apply(self.indices, fn)
self.node_type_offset = recursive_apply(self.node_type_offset, fn)
self.type_per_edge = recursive_apply(self.type_per_edge, fn)
self.node_attributes = recursive_apply(self.node_attributes, fn)
self.edge_attributes = recursive_apply(self.edge_attributes, fn)
return self
[docs] def to(self, device: torch.device) -> None: # pylint: disable=invalid-name
"""Copy `FusedCSCSamplingGraph` to the specified device."""
def _to(x):
return x.to(device) if hasattr(x, "to") else x
def _pin(x):
return x.pin_memory() if hasattr(x, "pin_memory") else x
# Create a copy of self.
self2 = fused_csc_sampling_graph(
self.csc_indptr,
self.indices,
self.node_type_offset,
self.type_per_edge,
self.node_type_to_id,
self.edge_type_to_id,
self.node_attributes,
self.edge_attributes,
)
return self2._apply_to_members(_pin if device == "pinned" else _to)
[docs] def pin_memory_(self):
"""Copy `FusedCSCSamplingGraph` to the pinned memory in-place. Returns
the same object modified in-place."""
# torch.Tensor.pin_memory() is not an inplace operation. To make it
# truly in-place, we need to use cudaHostRegister. Then, we need to use
# cudaHostUnregister to unpin the tensor in the destructor.
# https://github.com/pytorch/pytorch/issues/32167#issuecomment-753551842
cudart = torch.cuda.cudart()
if not hasattr(self, "_is_inplace_pinned"):
self._is_inplace_pinned = set()
def _pin(x):
if hasattr(x, "pin_memory_"):
x.pin_memory_()
elif (
isinstance(x, torch.Tensor)
and not x.is_pinned()
and x.device.type == "cpu"
):
assert (
x.is_contiguous()
), "Tensor pinning is only supported for contiguous tensors."
assert (
cudart.cudaHostRegister(
x.data_ptr(), x.numel() * x.element_size(), 0
)
== 0
)
self._is_inplace_pinned.add(x)
self._inplace_unpinner = cudart.cudaHostUnregister
return x
return self._apply_to_members(_pin)
[docs]def fused_csc_sampling_graph(
csc_indptr: torch.Tensor,
indices: torch.Tensor,
node_type_offset: Optional[torch.tensor] = None,
type_per_edge: Optional[torch.tensor] = None,
node_type_to_id: Optional[Dict[str, int]] = None,
edge_type_to_id: Optional[Dict[str, int]] = None,
node_attributes: Optional[Dict[str, torch.tensor]] = None,
edge_attributes: Optional[Dict[str, torch.tensor]] = None,
) -> FusedCSCSamplingGraph:
"""Create a FusedCSCSamplingGraph object from a CSC representation.
Parameters
----------
csc_indptr : torch.Tensor
Pointer to the start of each row in the `indices`. An integer tensor
with shape `(total_num_nodes+1,)`.
indices : torch.Tensor
Column indices of the non-zero elements in the CSC graph. An integer
tensor with shape `(total_num_edges,)`.
node_type_offset : Optional[torch.tensor], optional
Offset of node types in the graph, by default None.
type_per_edge : Optional[torch.tensor], optional
Type ids of each edge in the graph, by default None.
node_type_to_id : Optional[Dict[str, int]], optional
Map node types to ids, by default None.
edge_type_to_id : Optional[Dict[str, int]], optional
Map edge types to ids, by default None.
node_attributes: Optional[Dict[str, torch.tensor]], optional
Node attributes of the graph, by default None.
edge_attributes: Optional[Dict[str, torch.tensor]], optional
Edge attributes of the graph, by default None.
Returns
-------
FusedCSCSamplingGraph
The created FusedCSCSamplingGraph object.
Examples
--------
>>> ntypes = {'n1': 0, 'n2': 1, 'n3': 2}
>>> etypes = {'n1:e1:n2': 0, 'n1:e2:n3': 1}
>>> csc_indptr = torch.tensor([0, 2, 5, 7, 8])
>>> indices = torch.tensor([1, 3, 0, 1, 2, 0, 3, 2])
>>> node_type_offset = torch.tensor([0, 1, 2, 4])
>>> type_per_edge = torch.tensor([0, 1, 0, 1, 1, 0, 0, 0])
>>> graph = graphbolt.fused_csc_sampling_graph(csc_indptr, indices,
... node_type_offset=node_type_offset,
... type_per_edge=type_per_edge,
... node_type_to_id=ntypes, edge_type_to_id=etypes,
... node_attributes=None, edge_attributes=None,)
>>> print(graph)
FusedCSCSamplingGraph(csc_indptr=tensor([0, 2, 5, 7, 8]),
indices=tensor([1, 3, 0, 1, 2, 0, 3, 2]),
total_num_nodes=4, num_edges={'n1:e1:n2': 5, 'n1:e2:n3': 3},
node_type_offset=tensor([0, 1, 2, 4]),
type_per_edge=tensor([0, 1, 0, 1, 1, 0, 0, 0]),
node_type_to_id={'n1': 0, 'n2': 1, 'n3': 2},
edge_type_to_id={'n1:e1:n2': 0, 'n1:e2:n3': 1},)
"""
if node_type_to_id is not None and edge_type_to_id is not None:
node_types = list(node_type_to_id.keys())
edge_types = list(edge_type_to_id.keys())
node_type_ids = list(node_type_to_id.values())
edge_type_ids = list(edge_type_to_id.values())
# Validate node_type_to_id.
assert all(
isinstance(x, str) for x in node_types
), "Node type name should be string."
assert all(
isinstance(x, int) for x in node_type_ids
), "Node type id should be int."
assert len(node_type_ids) == len(
set(node_type_ids)
), "Multiple node types shoud not be mapped to a same id."
# Validate edge_type_to_id.
for edge_type in edge_types:
src, edge, dst = etype_str_to_tuple(edge_type)
assert isinstance(edge, str), "Edge type name should be string."
assert (
src in node_types
), f"Unrecognized node type {src} in edge type {edge_type}"
assert (
dst in node_types
), f"Unrecognized node type {dst} in edge type {edge_type}"
assert all(
isinstance(x, int) for x in edge_type_ids
), "Edge type id should be int."
assert len(edge_type_ids) == len(
set(edge_type_ids)
), "Multiple edge types shoud not be mapped to a same id."
if node_type_offset is not None:
assert len(node_type_to_id) + 1 == node_type_offset.size(
0
), "node_type_offset length should be |ntypes| + 1."
return FusedCSCSamplingGraph(
torch.ops.graphbolt.fused_csc_sampling_graph(
csc_indptr,
indices,
node_type_offset,
type_per_edge,
node_type_to_id,
edge_type_to_id,
node_attributes,
edge_attributes,
),
)
[docs]def load_from_shared_memory(
shared_memory_name: str,
) -> FusedCSCSamplingGraph:
"""Load a FusedCSCSamplingGraph object from shared memory.
Parameters
----------
shared_memory_name : str
Name of the shared memory.
Returns
-------
FusedCSCSamplingGraph
The loaded FusedCSCSamplingGraph object on shared memory.
"""
return FusedCSCSamplingGraph(
torch.ops.graphbolt.load_from_shared_memory(shared_memory_name),
)
[docs]def from_dglgraph(
g: DGLGraph,
is_homogeneous: bool = False,
include_original_edge_id: bool = False,
) -> FusedCSCSamplingGraph:
"""Convert a DGLGraph to FusedCSCSamplingGraph."""
homo_g, ntype_count, _ = to_homogeneous(
g, ndata=g.ndata, edata=g.edata, return_count=True
)
if is_homogeneous:
node_type_to_id = None
edge_type_to_id = None
else:
# Initialize metadata.
node_type_to_id = {ntype: g.get_ntype_id(ntype) for ntype in g.ntypes}
edge_type_to_id = {
etype_tuple_to_str(etype): g.get_etype_id(etype)
for etype in g.canonical_etypes
}
# Obtain CSC matrix.
indptr, indices, edge_ids = homo_g.adj_tensors("csc")
ntype_count.insert(0, 0)
node_type_offset = (
None
if is_homogeneous
else torch.cumsum(torch.LongTensor(ntype_count), 0)
)
# Assign edge type according to the order of CSC matrix.
type_per_edge = (
None
if is_homogeneous
else torch.index_select(homo_g.edata[ETYPE], dim=0, index=edge_ids)
)
node_attributes = {}
edge_attributes = {}
for feat_name, feat_data in homo_g.ndata.items():
if feat_name not in (NID, NTYPE):
node_attributes[feat_name] = feat_data
for feat_name, feat_data in homo_g.edata.items():
if feat_name not in (EID, ETYPE):
edge_attributes[feat_name] = feat_data
if include_original_edge_id:
# Assign edge attributes according to the original eids mapping.
edge_attributes[ORIGINAL_EDGE_ID] = torch.index_select(
homo_g.edata[EID], dim=0, index=edge_ids
)
return FusedCSCSamplingGraph(
torch.ops.graphbolt.fused_csc_sampling_graph(
indptr,
indices,
node_type_offset,
type_per_edge,
node_type_to_id,
edge_type_to_id,
node_attributes,
edge_attributes,
),
)