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write_diffs

differential_dataflow::columnar::arrangement::trie_merger

Function write_diffs 

Source 
pub fn write_diffs<U: ColumnarUpdate>(
    diffs0: <Lists<ContainerOf<U::Diff>> as Borrow>::Borrowed<'_>,
    diffs1: <Lists<ContainerOf<U::Diff>> as Borrow>::Borrowed<'_>,
    time_survey: &[Report],
    output: &mut Lists<ContainerOf<U::Diff>>,
)
Expand description

Write the diff layer from a time survey and two diff inputs.

The time survey is the item-level survey for the time layer, which doubles as the list survey for diffs (one diff list per time entry).

  • This(lo, hi): bulk-copy diff lists from input 0.
  • That(lo, hi): bulk-copy diff lists from input 1.
  • Both(t0, t1): consolidate the two singleton diffs. Push [sum] if non-zero, or an empty list [] if they cancel.