Struct DependencyGraph 

pub struct DependencyGraph { /* private fields */ }

Dependency graph for node relationships

Maintains a directed graph of node dependencies where an edge from A to B means “A depends on B” (B must start before A).

Implementations

impl DependencyGraph

pub fn new() -> Self

Create a new empty dependency graph

pub fn from_configs(configs: &[NodeConfig]) -> Result<Self>

Build dependency graph from node configurations

Arguments

• configs - Slice of node configurations

Returns

Dependency graph or error if dependencies are invalid

Errors

• Circular dependencies detected
• Undefined dependency references

pub fn add_node(&mut self, node_id: &str)

Add a node to the graph

pub fn add_dependency(&mut self, node_id: &str, dependency: &str) -> Result<()>

Add a dependency relationship

Arguments

• node_id - The dependent node
• dependency - The node that node_id depends on

Errors

Returns error if dependency node doesn’t exist

pub fn validate(&self) -> Result<()>

Validate the dependency graph

Checks for:

• Circular dependencies
• Undefined dependency references

pub fn topological_sort(&self) -> Result<Vec<String>>

Perform topological sort using Kahn’s algorithm

Returns nodes in dependency order (dependencies before dependents). This is the order for starting nodes.

Returns

Vector of node IDs in topological order

Errors

Returns error if graph has cycles

pub fn reverse_topological_sort(&self) -> Result<Vec<String>>

Get reverse topological sort (for shutdown order)

Returns nodes in reverse dependency order (dependents before dependencies). This is the order for stopping nodes.

pub fn startup_plan(&self) -> Result<StartupPlan>

Get startup plan with nodes grouped by dependency level

Nodes at the same level have no dependencies on each other and can be started in parallel.

Returns

StartupPlan with nodes grouped by level

pub fn shutdown_plan(&self) -> Result<ShutdownPlan>

Get shutdown plan (reverse of startup plan)

pub fn get_all_dependencies(&self, node_id: &str) -> HashSet<String>

Get all dependencies of a node (transitive closure)

Returns all nodes that must be started before this node.

pub fn get_all_dependents(&self, node_id: &str) -> HashSet<String>

Get all dependents of a node (transitive closure)

Returns all nodes that must be stopped before this node can be stopped.

pub fn can_start(&self, node_id: &str, running: &HashSet<String>) -> bool

Check if a node can be started

Returns true if all dependencies are in the provided running set.

pub fn can_stop(&self, node_id: &str, running: &HashSet<String>) -> bool

Check if a node can be stopped

Returns true if no dependents are in the provided running set.

pub fn get_direct_dependents(&self, node_id: &str) -> Vec<String>

Get nodes that depend on this node

pub fn get_direct_dependencies(&self, node_id: &str) -> Vec<String>

Get nodes this node depends on

pub fn node_count(&self) -> usize

Get the number of nodes in the graph

pub fn all_nodes(&self) -> Vec<String>

Get all node IDs

Trait Implementations

impl Clone for DependencyGraph

fn clone(&self) -> DependencyGraph

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DependencyGraph

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DependencyGraph

fn default() -> Self

Returns the “default value” for a type.