Trait differential_dataflow::collection::trace::Trace [−] [src]

pub trait Trace where &'a Self: TraceRef<'a, Self::Key, Self::Index, Self::Value> {
    type Key: Data;
    type Index: LeastUpperBound;
    type Value: Data;
    fn set_difference(&mut self, time: Self::Index, accumulation: Compact<Self::Key, Self::Value>);

    fn trace<'a>(&'a self, key: &Self::Key) -> &'a Self::TIterator { ... }
    fn get_difference<'a>(&'a self, key: &Self::Key, time: &Self::Index) -> Option<&'a Self::VIterator> { ... }
    fn get_collection<'a>(&'a mut self, key: &Self::Key, time: &Self::Index) -> CollectionIterator<&'a Self::VIterator> { ... }
    fn interesting_times<'a>(&'a self, key: &Self::Key, time: &Self::Index, stash: &mut Vec<Self::Index>) { ... }
}

A collection trace, corresponding to quadruples (Key, Index, Value, Delta).

Associated Types

type Key: Data

The data-parallel key.

type Index: LeastUpperBound

Timestamp for changes to the collection.

type Value: Data

Values associated with each key.

Required Methods

fn set_difference(&mut self, time: Self::Index, accumulation: Compact<Self::Key, Self::Value>)

Introduces differences in accumulation at time.

Provided Methods

fn trace<'a>(&'a self, key: &Self::Key) -> &'a Self::TIterator

Iterates over times and differences for a specified key.

fn get_difference<'a>(&'a self, key: &Self::Key, time: &Self::Index) -> Option<&'a Self::VIterator>

Iterates over differences for a specified key and time.

fn get_collection<'a>(&'a mut self, key: &Self::Key, time: &Self::Index) -> CollectionIterator<&'a Self::VIterator>

Accumulates differences for key at times less than or equal to time.

The &mut self argument allows the trace to use stashed storage for a merge. This is currently not done, because it appears to require unsafe (the storage type involves a &'a, which cannot outlive this method).

fn interesting_times<'a>(&'a self, key: &Self::Key, time: &Self::Index, stash: &mut Vec<Self::Index>)

Populates stash with times for key, closes under least upper bound.

Implementors