Source code for dgl.graphbolt.impl.fused_csc_sampling_graph

"""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 _indptr_node_type_offset_list(self) -> Optional[list]: """Returns the indptr node type offset list which presents the column id space when it does not match the global id space. It is useful when we slice a subgraph from another FusedCSCSamplingGraph. 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'. """ return ( self._indptr_node_type_offset_list_ if hasattr(self, "_indptr_node_type_offset_list_") else None ) @_indptr_node_type_offset_list.setter def _indptr_node_type_offset_list( self, indptr_node_type_offset_list: Optional[torch.Tensor] ): """Sets the indptr node type offset list if present.""" self._indptr_node_type_offset_list_ = indptr_node_type_offset_list @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." _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_node_offsets = [0] homogeneous_timestamps = [] offset = self._node_type_offset_list for ntype, ntype_id in self.node_type_to_id.items(): ids = nodes.get(ntype, []) if len(ids) > 0: homogeneous_nodes.append(ids + offset[ntype_id]) if timestamps is not None: homogeneous_timestamps.append(timestamps[ntype]) homogeneous_node_offsets.append( homogeneous_node_offsets[-1] + len(ids) ) if timestamps is not None: return torch.cat(homogeneous_nodes), torch.cat( homogeneous_timestamps ) return torch.cat(homogeneous_nodes), homogeneous_node_offsets def _convert_to_sampled_subgraph( self, C_sampled_subgraph: torch.ScriptObject, seed_offsets: Optional[list] = None, ) -> 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 etype_offsets = C_sampled_subgraph.etype_offsets if etype_offsets is not None: etype_offsets = etype_offsets.tolist() 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 and etype_offsets is None: # The sampled graph is already a homogeneous graph. sampled_csc = CSCFormatBase(indptr=indptr, indices=indices) else: offset = self._node_type_offset_list original_hetero_edge_ids = {} sub_indices = {} sub_indptr = {} if etype_offsets is None: # 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 ) 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 ] else: edge_offsets = [0] for etype, etype_id in self.edge_type_to_id.items(): src_ntype, _, dst_ntype = etype_str_to_tuple(etype) ntype_id = self.node_type_to_id[dst_ntype] edge_offsets.append( edge_offsets[-1] + seed_offsets[ntype_id + 1] - seed_offsets[ntype_id] + 1 ) for etype, etype_id in self.edge_type_to_id.items(): src_ntype, _, dst_ntype = etype_str_to_tuple(etype) ntype_id = self.node_type_to_id[dst_ntype] sub_indptr[etype] = indptr[ edge_offsets[etype_id] : edge_offsets[etype_id + 1] ] sub_indices[etype] = indices[ etype_offsets[etype_id] : etype_offsets[etype_id + 1] ] if has_original_eids: original_hetero_edge_ids[etype] = original_edge_ids[ etype_offsets[etype_id] : etype_offsets[ etype_id + 1 ] ] 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, seeds: 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 ---------- seeds: 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]), )} """ return_eids = ( self.edge_attributes is not None and ORIGINAL_EDGE_ID in self.edge_attributes ) seed_offsets = None if isinstance(seeds, dict): seeds, seed_offsets = self._convert_to_homogeneous_nodes(seeds) elif seeds is None: seed_offsets = self._indptr_node_type_offset_list C_sampled_subgraph = self._sample_neighbors( seeds, seed_offsets, fanouts, replace=replace, probs_name=probs_name, return_eids=return_eids, ) return self._convert_to_sampled_subgraph( C_sampled_subgraph, seed_offsets )
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, seeds: torch.Tensor, seed_offsets: Optional[list], 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 ---------- seeds: torch.Tensor IDs of the given seed nodes. seeds_offsets: list, optional The offsets of the given seeds, seeds[seed_offsets[i]: seed_offsets[i + 1]] has node type i. 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(seeds, fanouts, probs_name) return self._c_csc_graph.sample_neighbors( seeds, seed_offsets, fanouts.tolist(), replace, False, # is_labor return_eids, probs_name, None, # random_seed, labor parameter 0, # seed2_contribution, labor_parameter )
[docs] def sample_layer_neighbors( self, seeds: Union[torch.Tensor, Dict[str, torch.Tensor]], fanouts: torch.Tensor, replace: bool = False, probs_name: Optional[str] = None, random_seed: torch.Tensor = None, seed2_contribution: float = 0.0, ) -> 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://proceedings.neurips.cc/paper_files/paper/2023/file/51f9036d5e7ae822da8f6d4adda1fb39-Paper-Conference.pdf>`__ Parameters ---------- seeds: 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. random_seed: torch.Tensor, optional An int64 tensor with one or two elements. The passed random_seed makes it so that for any seed node ``s`` and its neighbor ``t``, the rolled random variate ``r_t`` is the same for any call to this function with the same random seed. When sampling as part of the same batch, one would want identical seeds so that LABOR can globally sample. One example is that for heterogenous graphs, there is a single random seed passed for each edge type. This will sample much fewer nodes compared to having unique random seeds for each edge type. If one called this function individually for each edge type for a heterogenous graph with different random seeds, then it would run LABOR locally for each edge type, resulting into a larger number of nodes being sampled. If this function is called without a ``random_seed``, we get the random seed by getting a random number from GraphBolt. Use this argument with identical random_seed if multiple calls to this function are used to sample as part of a single batch. If given two numbers, then the ``seed2_contribution`` argument determines the interpolation between the two random seeds. seed2_contribution: float, optional A float value between [0, 1) that determines the contribution of the second random seed, ``random_seed[-1]``, to generate the random variates. 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 random_seed is not None: assert ( 1 <= len(random_seed) <= 2 ), "There should be a 1 or 2 random seeds." if len(random_seed) == 2: assert ( 0 <= seed2_contribution <= 1 ), "seed2_contribution should be in [0, 1]." has_original_eids = ( self.edge_attributes is not None and ORIGINAL_EDGE_ID in self.edge_attributes ) seed_offsets = None if isinstance(seeds, dict): seeds, seed_offsets = self._convert_to_homogeneous_nodes(seeds) elif seeds is None: seed_offsets = self._indptr_node_type_offset_list self._check_sampler_arguments(seeds, fanouts, probs_name) C_sampled_subgraph = self._c_csc_graph.sample_neighbors( seeds, seed_offsets, fanouts.tolist(), replace, True, has_original_eids, probs_name, random_seed, seed2_contribution, ) return self._convert_to_sampled_subgraph( C_sampled_subgraph, seed_offsets )
[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 sample_negative_edges_uniform( self, edge_type, node_pairs, negative_ratio ): """ Sample negative edges by randomly choosing negative source-destination edges according to a uniform distribution. For each edge ``(u, v)``, it is supposed to generate `negative_ratio` pairs of negative edges ``(u, v')``, where ``v'`` is chosen uniformly from all the nodes in the graph. ``u`` is exactly same as the corresponding positive edges. It returns positive edges concatenated with negative edges. In negative edges, negative sources are constructed from the corresponding positive edges. Parameters ---------- edge_type: str The type of edges in the provided node_pairs. Any negative edges sampled will also have the same type. If set to None, it will be considered as a homogeneous graph. node_pairs : torch.Tensor A 2D tensors that represent the N pairs of positive edges in source-destination format, with 'positive' indicating that these edges are present in the graph. It's important to note that within the context of a heterogeneous graph, the ids in these tensors signify heterogeneous ids. negative_ratio: int The ratio of the number of negative samples to positive samples. Returns ------- torch.Tensor A 2D tensors represents the N pairs of positive and negative source-destination node pairs. In the context of a heterogeneous graph, both the input nodes and the selected nodes are represented by heterogeneous IDs, and the formed edges are of the input type `edge_type`. Note that negative refers to false negatives, which means the edge could be present or not present in the graph. """ if edge_type: _, _, dst_ntype = etype_str_to_tuple(edge_type) max_node_id = self.num_nodes[dst_ntype] else: max_node_id = self.total_num_nodes pos_src = node_pairs[:, 0] num_negative = node_pairs.shape[0] * negative_ratio negative_seeds = ( torch.cat( ( pos_src.repeat_interleave(negative_ratio), torch.randint( 0, max_node_id, (num_negative,), dtype=node_pairs.dtype, device=node_pairs.device, ), ), ) .view(2, num_negative) .T ) seeds = torch.cat((node_pairs, negative_seeds)) return seeds
[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, ), )