Is this page helpful?

transform_reduce_v_frontier_outgoing_e_by_dst.cuh#

namespace cugraph

Functions

template<typename GraphViewType, typename KeyBucketType, typename EdgeSrcValueInputWrapper, typename EdgeDstValueInputWrapper, typename EdgeValueInputWrapper, typename EdgeOp, typename ReduceOp>
std::conditional_t<!std::is_same_v<typename ReduceOp::value_type, void>, std::tuple<dataframe_buffer_type_t<typename KeyBucketType::key_type>, detail::optional_dataframe_buffer_type_t<typename ReduceOp::value_type>>, dataframe_buffer_type_t<typename KeyBucketType::key_type>> transform_reduce_v_frontier_outgoing_e_by_dst(
raft::handle_t const &handle,
GraphViewType const &graph_view,
KeyBucketType const &frontier,
EdgeSrcValueInputWrapper edge_src_value_input,
EdgeDstValueInputWrapper edge_dst_value_input,
EdgeValueInputWrapper edge_value_input,
EdgeOp e_op,
ReduceOp reduce_op,
bool do_expensive_check = false
)

Iterate over outgoing edges from the current vertex frontier and reduce all edge functor outputs by (tagged-)destination ID.

Vertices are assumed to be tagged if KeyBucketType::key_type is a tuple of a vertex type and a tag type (KeyBucketType::key_type is identical to a vertex type otherwise).

Template Parameters:

  • GraphViewType – Type of the passed non-owning graph object.

  • KeyBucketType – Type of the vertex frontier bucket class which abstracts the current (tagged-)vertex frontier.

  • EdgeSrcValueInputWrapper – Type of the wrapper for edge source property values.

  • EdgeDstValueInputWrapper – Type of the wrapper for edge destination property values.

  • EdgeValueInputWrapper – Type of the wrapper for edge property values.

  • EdgeOp – Type of the quinary edge operator.

  • ReduceOp – Type of the binary reduction operator.

Parameters:

  • handle – RAFT handle object to encapsulate resources (e.g. CUDA stream, communicator, and handles to various CUDA libraries) to run graph algorithms.

  • graph_view – Non-owning graph object.

  • frontier – KeyBucketType class object for the current vertex frontier.

  • edge_src_value_input – Wrapper used to access source input property values (for the edge sources assigned to this process in multi-GPU). Use either cugraph::edge_src_property_t::view() (if e_op needs to access source property values) or cugraph::edge_src_dummy_property_t::view() (if e_op does not access source property values). Use update_edge_src_property to fill the wrapper.

  • edge_dst_value_input – Wrapper used to access destination input property values (for the edge destinations assigned to this process in multi-GPU). Use either cugraph::edge_dst_property_t::view() (if e_op needs to access destination property values) or cugraph::edge_dst_dummy_property_t::view() (if e_op does not access destination property values). Use update_edge_dst_property to fill the wrapper.

  • edge_value_input – Wrapper used to access edge input property values (for the edges assigned to this process in multi-GPU). Use either cugraph::edge_property_t::view() (if e_op needs to access edge property values) or cugraph::edge_dummy_property_t::view() (if e_op does not access edge property values).

  • e_op – Quinary operator takes edge (tagged-)source, edge destination, property values for the source, destination, and edge and 1) just returns (return value = void, if vertices are not tagged and ReduceOp::value_type is void, in this case, e_op is dummy and won’t be called); 2) returns a value to be reduced (if vertices are not tagged and ReduceOp::value_type is not void); 3) returns a tag (if vertices are tagged and ReduceOp::value_type is void); or 4) returns a tuple of a tag and a value to be reduced (if vertices are tagged and ReduceOp::value_type is not void).

  • reduce_op – Binary operator that takes two input arguments and reduce the two values to one. There are pre-defined reduction operators in prims/reduce_op.cuh. It is recommended to use the pre-defined reduction operators whenever possible as the current (and future) implementations of graph primitives may check whether ReduceOp is a known type (or has known member variables) to take a more optimized code path. See the documentation in the reduce_op.cuh file for instructions on writing custom reduction operators.

Returns:

Tuple of key values and payload values (if ReduceOp::value_type is not void) or just key values (if ReduceOp::value_type is void). Keys in the return values are sorted in ascending order using a vertex ID as the primary key and a tag (if relevant) as the secondary key.