Template Class Graph

• Defined in File graph.hpp

Derived Type

• public holoscan::FlowGraph< NodeT, EdgeDataElementT > (Template Class FlowGraph)

template<typename NodeT = OperatorNodeType, typename EdgeDataElementT = OperatorEdgeDataElementType>
class Graph

Abstract base class for all graphs.

Subclassed by holoscan::FlowGraph< NodeT, EdgeDataElementT >

Public Types

using NodeType = NodeT

using NodePredicate = std::function<bool(const NodeT&)>

using EdgeDataElementType = EdgeDataElementT

using EdgeDataType = std::shared_ptr<EdgeDataElementT>

Public Functions

Graph() = default

virtual ~Graph() = default

Graph(const Graph&) = delete

Graph &operator=(const Graph&) = delete

virtual void add_node(const NodeT &node) = 0

Add the node to the graph.

Parameters

node – The node to add.

virtual void add_flow(const NodeType &node_u, const NodeType &node_v, const EdgeDataType &port_map) = 0

Add an edge to the graph.

Parameters

• node_u – A source node.

• node_v – A destination node.

• port_map – A map from the source node’s port name to the destination node’s port name(s).

virtual std::optional<EdgeDataType> get_port_map(const NodeType &node_u, const NodeType &node_v) const = 0

Get a mapping from the source node’s port name to the destination node’s port name(s).

Parameters

• node_u – A source node.

• node_v – A destination node.

Returns

A map from the source node’s port name to the destination node’s port name(s).

inline virtual bool is_empty() const

Check if the graph is empty.

Returns

true if the graph is empty. Otherwise, false.

virtual bool is_root(const NodeType &node) const = 0

Check if the node is a root node.

Parameters

node – A node in the graph.

Returns

true if the node is a root node.

virtual bool is_user_defined_root(const NodeType &node) const = 0

Check if the node is a user-defined root node. A user-defined root is the first node that is added to the graph.

Parameters

node – A node in the graph.

Returns

true if the node is a user-defined root node.

virtual bool is_leaf(const NodeType &node) const = 0

Check if the node is a leaf node.

Parameters

node – A node in the graph.

Returns

true if the node is a leaf node.

virtual std::vector<NodeType> has_cycle() const = 0

Returns a vector of root nodes of the cycles if the graph has cycle(s). Otherwise, an empty vector is returned.

Returns

Returns a vector of root nodes of cycles.

virtual std::vector<NodeType> get_root_nodes() const = 0

Get all root nodes.

Returns

A vector of root nodes.

virtual std::vector<NodeType> get_nodes() const = 0

Get all nodes.

The order of the nodes is not guaranteed.

Returns

A vector of all nodes.

virtual std::vector<NodeType> get_next_nodes(const NodeType &node) const = 0

Get the next nodes of the given node.

Parameters

node – A node in the graph.

Returns

A vector of next nodes.

virtual size_t get_outdegree(const NodeType &node, const std::string &port_name) const = 0

Get the outdegree of a given node of a given port.

Parameters

• node – A node in the graph.

• port_name – The name of the port in the given node.

Returns

The outdegree of the given node of the given port.

virtual NodeType find_node(const NodePredicate &pred) const = 0

Find a node in the graph that satisfies the given predicate.

Parameters

pred – A predicate.

Returns

The node if found, otherwise nullptr.

virtual NodeType find_node(const NodeType &node) const = 0

Find a node in the graph that is equal to the given node.

Parameters

node – The node to find.

Returns

The node in the graph if found, otherwise nullptr.

virtual NodeType find_node(const std::string &name) const = 0

Find a node in the graph whose name is equal to the given name.

Parameters

name – The name to find.

Returns

The node in the graph if found, otherwise nullptr.

virtual std::vector<NodeType> get_previous_nodes(const NodeType &node) const = 0

Get the previous nodes of the given node.

Parameters

node – A node in the graph.

Returns

A vector of previous nodes.

inline virtual void context(void *context)

Set the context.

Parameters

context – The context.

inline virtual void *context() const

Get the context.

Returns

The context.

virtual void remove_node(const NodeType &node) = 0

Remove a node (and all its edges) from the graph.

Parameters

node – The node to remove.

virtual std::pair<std::map<std::string, std::vector<std::string>>, std::map<std::string, std::vector<std::string>>> get_port_connectivity_maps() const = 0

Get port connectivity maps for the graph.

Returns a pair of two maps:

1. Input ports to connected output ports mapping

2. Output ports to connected input ports mapping

Each port is identified by a unique string.

Returns

A pair containing (input_to_output_map, output_to_input_map) where:

• input_to_output_map: Maps input port IDs to lists of connected output port IDs

• output_to_input_map: Maps output port IDs to lists of connected input port IDs

virtual std::string port_map_description() const = 0

Get a YAML-formatted description of the port connectivity maps.

Returns a human-readable YAML string that describes the port connectivity of the graph.

Returns

A YAML-formatted string describing the port connectivity maps

Protected Attributes

void *context_ = nullptr

The context.