timely/dataflow/operators/
partition.rs

1//! Partition a stream of records into multiple streams.
2
3use crate::container::CapacityContainerBuilder;
4use crate::dataflow::operators::core::Partition as PartitionCore;
5use crate::dataflow::{Scope, Stream};
6use crate::Data;
7
8/// Partition a stream of records into multiple streams.
9pub trait Partition<G: Scope, D: Data, D2: Data, F: Fn(D) -> (u64, D2)> {
10    /// Produces `parts` output streams, containing records produced and assigned by `route`.
11    ///
12    /// # Examples
13    /// ```
14    /// use timely::dataflow::operators::{ToStream, Partition, Inspect};
15    ///
16    /// timely::example(|scope| {
17    ///     let streams = (0..10).to_stream(scope)
18    ///                          .partition(3, |x| (x % 3, x));
19    ///
20    ///     streams[0].inspect(|x| println!("seen 0: {:?}", x));
21    ///     streams[1].inspect(|x| println!("seen 1: {:?}", x));
22    ///     streams[2].inspect(|x| println!("seen 2: {:?}", x));
23    /// });
24    /// ```
25    fn partition(&self, parts: u64, route: F) -> Vec<Stream<G, D2>>;
26}
27
28impl<G: Scope, D: Data, D2: Data, F: Fn(D)->(u64, D2)+'static> Partition<G, D, D2, F> for Stream<G, D> {
29    fn partition(&self, parts: u64, route: F) -> Vec<Stream<G, D2>> {
30        PartitionCore::partition::<CapacityContainerBuilder<_>, _, _>(self, parts, route)
31    }
32}