Struct PlanContext 

pub struct PlanContext<T> {
    pub plan: Arc<dyn ExecutionPlan>,
    pub data: T,
    pub children: Vec<PlanContext<T>>,
}

A node context object beneficial for writing optimizer rules. This context encapsulating an ExecutionPlan node with a payload.

Since each wrapped node has it’s children within both the PlanContext.plan.children(), as well as separately within the PlanContext.children (which are child nodes wrapped in the context), it’s important to keep these child plans in sync when performing mutations.

Since there are two ways to access child plans directly -— it’s recommended to perform mutable operations via Self::update_plan_from_children. After mutating the PlanContext.children, or after creating the PlanContext, call update_plan_from_children to sync.

Fields

plan: Arc<dyn ExecutionPlan>

The execution plan associated with this context.

data: T

Custom data payload of the node.

children: Vec<PlanContext<T>>

Child contexts of this node.

Implementations

impl<T> PlanContext<T>

pub fn new( plan: Arc<dyn ExecutionPlan>, data: T, children: Vec<PlanContext<T>>, ) -> PlanContext<T>

pub fn update_plan_from_children( self, ) -> Result<PlanContext<T>, DataFusionError>

Update the PlanContext.plan.children() from the PlanContext.children, if the PlanContext.children have been changed.

impl<T> PlanContext<T>

where T: Default,

pub fn new_default(plan: Arc<dyn ExecutionPlan>) -> PlanContext<T>

Trait Implementations

impl<T> ConcreteTreeNode for PlanContext<T>

fn children(&self) -> &[PlanContext<T>]

Provides read-only access to child nodes.

fn take_children(self) -> (PlanContext<T>, Vec<PlanContext<T>>)

Detaches the node from its children, returning the node itself and its detached children.

fn with_new_children( self, children: Vec<PlanContext<T>>, ) -> Result<PlanContext<T>, DataFusionError>

Reattaches updated child nodes to the node, returning the updated node.

impl<T> Debug for PlanContext<T>

where T: Debug,

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

Formats the value using the given formatter.

impl<T> Display for PlanContext<T>

where T: Display,

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

Formats the value using the given formatter.