Trait timely::dataflow::scopes::Scope[−][src]

pub trait Scope: ScopeParent {
    fn name(&self) -> String;

    fn addr(&self) -> Vec<usize>;

    fn add_edge(&self, source: Source, target: Target);

    fn allocate_operator_index(&mut self) -> usize;

    fn add_operator_with_indices(
        &mut self, 
        operator: Box<Operate<Self::Timestamp>>, 
        local: usize, 
        global: usize
    );

    fn scoped<T: Timestamp, R, F: FnOnce(&mut Child<Self, T>) -> R>(
        &mut self, 
        func: F
    ) -> R;

    fn add_operator(&mut self, operator: Box<Operate<Self::Timestamp>>) -> usize { ... }

    fn add_operator_with_index(
        &mut self, 
        operator: Box<Operate<Self::Timestamp>>, 
        index: usize
    ) { ... }
}

The fundamental operations required to add and connect operators in a timely dataflow graph.

Importantly, this is often a shared object, backed by a Rc<RefCell<>> wrapper. Each method takes a shared reference, but can be thought of as first calling .clone() and then calling the method. Each method does not hold the RefCell's borrow, and should prevent accidental panics.

Required Methods

A useful name describing the scope.

ⓘImportant traits for Vec<u8>

A sequence of scope identifiers describing the path from the Root to this scope.

Connects a source of data with a target of the data. This only links the two for the purposes of tracking progress, rather than effect any data movement itself.

Allocates a new scope-local operator index.

This method is meant for use with add_operator_with_index, which accepts a scope-local operator index allocated with this method. This method does cause the scope to expect that an operator will be added, and it is an error not to eventually add such an operator.

Adds a child Operate to the builder's scope using supplied indices.

The two indices are the scope-local operator index, and a worker-unique index used for e.g. logging.

Creates a Subgraph from a closure acting on a Child scope, and returning whatever the closure returns.

Commonly used to create new timely dataflow subgraphs, either creating new input streams and the input handle, or ingressing data streams and returning the egresses stream.

Examples

use timely::dataflow::Scope;
use timely::dataflow::operators::{Input, Enter, Leave};

timely::execute_from_args(std::env::args(), |worker| {
    // must specify types as nothing else drives inference.
    let input = worker.dataflow::<u64,_,_>(|child1| {
        let (input, stream) = child1.new_input::<String>();
        let output = child1.scoped::<u32,_,_>(|child2| {
            stream.enter(child2).leave()
        });
        input
    });
});

Provided Methods

Adds a child Operate to the builder's scope. Returns the new child's index.

Adds a child Operate to the builder's scope using a supplied index.

This is used internally when there is a gap between allocate a child identifier and adding the child, as happens in subgraph creation.

Implementors