fn build_halfjoin<G, Tr, CF>(
    updates: Collection<G, (Row, G::Timestamp)>,
    trace: Arranged<G, Tr>,
    prev_key: Vec<MirScalarExpr>,
    prev_thinning: Vec<usize>,
    permutation: Permutation,
    comparison: CF,
    mut closure: JoinClosure,
) -> (
    Collection<G, (Row, G::Timestamp)>,
    Collection<G, DataflowError>,
)
where
    G: Scope<Timestamp = repr::Timestamp>,
    Tr: TraceReader<Time = G::Timestamp, Key = Row, Val = Row, R = Diff> + Clone + 'static,
    Tr::Batch: BatchReader<Tr::Key, Tr::Val, Tr::Time, Tr::R>,
    Tr::Cursor: Cursor<Tr::Key, Tr::Val, Tr::Time, Tr::R>,
    CF: Fn(&G::Timestamp, &G::Timestamp) -> bool + 'static,
{
    closure.permute(&permutation);
    let (updates, errs) = updates.map_fallible("DeltaJoinKeyPreparation", {
        // Reuseable allocation for unpacking.
        let mut datums = DatumVec::new();
        let mut row_packer = Row::default();
        move |(row, time)| {
            let temp_storage = RowArena::new();
            let datums_local = datums.borrow_with(&row);
            row_packer.clear();
            row_packer.try_extend(
                prev_key
                    .iter()
                    .map(|e| e.eval(&datums_local, &temp_storage)),
            )?;
            let row_key = row_packer.finish_and_reuse();
            row_packer.extend(prev_thinning.iter().map(|e| datums_local[*e]));
            let row_value = row_packer.finish_and_reuse();
            // Explicit drop to release borrow on `row` so that it can be returned.
            drop(datums_local);
            Ok((row_key, row_value, time))
        }
    });

    use differential_dataflow::AsCollection;
    use timely::dataflow::operators::OkErr;

    let mut datums = DatumVec::new();
    let mut row_builder = Row::default();

    let (oks, errs2) = dogsdogsdogs::operators::half_join::half_join_internal_unsafe(
        &updates,
        trace,
        |time| time.saturating_sub(1),
        comparison,
        // TODO(mcsherry): investigate/establish trade-offs here; time based had problems,
        // in that we seem to yield too much and do too little work when we do.
        |_timer, count| count > 1_000_000,
        // TODO(mcsherry): consider `RefOrMut` in `half_join` interface to allow re-use.
        move |key, stream_row, lookup_row, initial, time, diff1, diff2| {
            let temp_storage = RowArena::new();
            let mut datums_local = datums.borrow_with_many(&[key, stream_row, lookup_row]);
            let row = closure.apply(&mut datums_local, &temp_storage, &mut row_builder);
            let diff = diff1.clone() * diff2.clone();
            let dout = (row, time.clone());
            Some((dout, initial.clone(), diff))
        },
    )
    .inner
    .ok_err(|(data_time, init_time, diff)| {
        // TODO(mcsherry): consider `ok_err()` for `Collection`.
        match data_time {
            (Ok(data), time) => Ok((data.map(|data| (data, time)), init_time, diff)),
            (Err(err), _time) => Err((DataflowError::from(err), init_time, diff)),
        }
    });

    (
        oks.as_collection().flat_map(|x| x),
        errs.concat(&errs2.as_collection()),
    )
}
/// Constructs a `half_join` from supplied arguments.
///
/// This method exists to factor common logic from four code paths that are generic over the type of trace.
/// The `comparison` function should either be `le` or `lt` depending on which relation comes first in the
/// total order on relations (in order to break ties consistently).
///
/// The input and output streams are of pairs `(data, time)` where the `time` component can be greater than
/// the time of the update. This operator may manipulate `time` as part of this pair, but will not manipulate
/// the time of the update. This is crucial for correctness, as the total order on times of updates is used
/// to ensure that any two updates are matched at most once.
Constructs a `half_join` from supplied arguments.
This method exists to factor common logic from four code paths that are generic over the type of trace.

The input and output streams are of pairs `(data, time)` where the `time` component can be greater than
the time of the update. This operator may manipulate `time` as part of this pair, but will not manipulate
the time of the update. This is crucial for correctness, as the total order on times of updates is used
to ensure that any two updates are matched at most once.
Constructs a ` half_join ` from supplied arguments . This method exists to factor common logic from four code paths that are generic over the type of trace . The input and output streams are of pairs ` ( data time ) ` where the ` time ` component can be greater than the time of the update . This operator may manipulate ` time ` as part of this pair but will not manipulate the time of the update . This is crucial for correctness as the total order on times of updates is used to ensure that any two updates are matched at most once .
fn build_halfjoin<G, Tr, CF>(
    updates: Collection<G, (Row, G::Timestamp)>,
    trace: Arranged<G, Tr>,
    prev_key: Vec<MirScalarExpr>,
    prev_thinning: Vec<usize>,
    permutation: Permutation,
    comparison: CF,
    mut closure: JoinClosure,
) -> (
    Collection<G, (Row, G::Timestamp)>,
    Collection<G, DataflowError>,
)
where
    G: Scope<Timestamp = repr::Timestamp>,
    Tr: TraceReader<Time = G::Timestamp, Key = Row, Val = Row, R = Diff> + Clone + 'static,
    Tr::Batch: BatchReader<Tr::Key, Tr::Val, Tr::Time, Tr::R>,
    Tr::Cursor: Cursor<Tr::Key, Tr::Val, Tr::Time, Tr::R>,
    CF: Fn(&G::Timestamp, &G::Timestamp) -> bool + 'static,
{
    closure.permute(&permutation);
    let (updates, errs) = updates.map_fallible("DeltaJoinKeyPreparation", {
        // Reuseable allocation for unpacking.
        let mut datums = DatumVec::new();
        let mut row_packer = Row::default();
        move |(row, time)| {
            let temp_storage = RowArena::new();
            let datums_local = datums.borrow_with(&row);
            row_packer.clear();
            row_packer.try_extend(
                prev_key
                    .iter()
                    .map(|e| e.eval(&datums_local, &temp_storage)),
            )?;
            let row_key = row_packer.finish_and_reuse();
            row_packer.extend(prev_thinning.iter().map(|e| datums_local[*e]));
            let row_value = row_packer.finish_and_reuse();
            // Explicit drop to release borrow on `row` so that it can be returned.
            drop(datums_local);
            Ok((row_key, row_value, time))
        }
    });
    use differential_dataflow::AsCollection;
    use timely::dataflow::operators::OkErr;
    let mut datums = DatumVec::new();
    let mut row_builder = Row::default();
    let (oks, errs2) = dogsdogsdogs::operators::half_join::half_join_internal_unsafe(
        &updates,
        trace,
        |time| time.saturating_sub(1),
        comparison,
        // TODO(mcsherry): investigate/establish trade-offs here; time based had problems,
        // in that we seem to yield too much and do too little work when we do.
        |_timer, count| count > 1_000_000,
        // TODO(mcsherry): consider `RefOrMut` in `half_join` interface to allow re-use.
        move |key, stream_row, lookup_row, initial, time, diff1, diff2| {
            let temp_storage = RowArena::new();
            let mut datums_local = datums.borrow_with_many(&[key, stream_row, lookup_row]);
            let row = closure.apply(&mut datums_local, &temp_storage, &mut row_builder);
            let diff = diff1.clone() * diff2.clone();
            let dout = (row, time.clone());
            Some((dout, initial.clone(), diff))
        },
    )
    .inner
    .ok_err(|(data_time, init_time, diff)| {
        // TODO(mcsherry): consider `ok_err()` for `Collection`.
        match data_time {
            (Ok(data), time) => Ok((data.map(|data| (data, time)), init_time, diff)),
            (Err(err), _time) => Err((DataflowError::from(err), init_time, diff)),
        }
    });
    (
        oks.as_collection().flat_map(|x| x),
        errs.concat(&errs2.as_collection()),
    )
}
fn build_halfjoin < G , Tr , CF > ( updates : Collection < G , ( Row , G :: Timestamp ) > , trace : Arranged < G , Tr > , prev_key : Vec < MirScalarExpr > , prev_thinning : Vec < usize > , permutation : Permutation , comparison : CF , mut closure : JoinClosure , ) -> ( Collection < G , ( Row , G :: Timestamp ) > , Collection < G , DataflowError > , ) where G : Scope < Timestamp = repr :: Timestamp > , Tr : TraceReader < Time = G :: Timestamp , Key = Row , Val = Row , R = Diff > + Clone + ' static , Tr :: Batch : BatchReader < Tr :: Key , Tr :: Val , Tr :: Time , Tr :: R > , Tr :: Cursor : Cursor < Tr :: Key , Tr :: Val , Tr :: Time , Tr :: R > , CF : Fn ( & G :: Timestamp , & G :: Timestamp ) -> bool + ' static , { closure . permute ( & permutation ) ; let ( updates , errs ) = updates . map_fallible ( " " , { // Reuseable allocation for unpacking. let mut datums = DatumVec :: new ( ) ; let mut row_packer = Row :: default ( ) ; move | ( row , time ) | { let temp_storage = RowArena :: new ( ) ; let datums_local = datums . borrow_with ( & row ) ; row_packer . clear ( ) ; row_packer . try_extend ( prev_key . iter ( ) . map ( | e | e . eval ( & datums_local , & temp_storage ) ) , ) ? ; let row_key = row_packer . finish_and_reuse ( ) ; row_packer . extend ( prev_thinning . iter ( ) . map ( | e | datums_local [ * e ] ) ) ; let row_value = row_packer . finish_and_reuse ( ) ; // Explicit drop to release borrow on `row` so that it can be returned. drop ( datums_local ) ; Ok ( ( row_key , row_value , time ) ) } } ) ; use differential_dataflow :: AsCollection ; use timely :: dataflow :: operators :: OkErr ; let mut datums = DatumVec :: new ( ) ; let mut row_builder = Row :: default ( ) ; let ( oks , errs2 ) = dogsdogsdogs :: operators :: half_join :: half_join_internal_unsafe ( & updates , trace , | time | time . saturating_sub ( 1 ) , comparison , // TODO(mcsherry): investigate/establish trade-offs here; time based had problems, // in that we seem to yield too much and do too little work when we do. | _timer , count | count > 1_000_000 , // TODO(mcsherry): consider `RefOrMut` in `half_join` interface to allow re-use. move | key , stream_row , lookup_row , initial , time , diff1 , diff2 | { let temp_storage = RowArena :: new ( ) ; let mut datums_local = datums . borrow_with_many ( & [ key , stream_row , lookup_row ] ) ; let row = closure . apply ( & mut datums_local , & temp_storage , & mut row_builder ) ; let diff = diff1 . clone ( ) * diff2 . clone ( ) ; let dout = ( row , time . clone ( ) ) ; Some ( ( dout , initial . clone ( ) , diff ) ) } , ) . inner . ok_err ( | ( data_time , init_time , diff ) | { // TODO(mcsherry): consider `ok_err()` for `Collection`. match data_time { ( Ok ( data ) , time ) => Ok ( ( data . map ( | data | ( data , time ) ) , init_time , diff ) ) , ( Err ( err ) , _time ) => Err ( ( DataflowError :: from ( err ) , init_time , diff ) ) , } } ) ; ( oks . as_collection ( ) . flat_map ( | x | x ) , errs . concat ( & errs2 . as_collection ( ) ) , ) }
Constructs a `half_join` from supplied arguments.
Constructs a ` half_join ` from supplied arguments .
updates
Collection<G, (Row, G::Timestamp)>
trace
Arranged<G, Tr>
prev_key
Vec<MirScalarExpr>
prev_thinning
Vec<usize>
permutation
Permutation
comparison
CF
closure
JoinClosure
updates
Collection<G, (Row, G::Timestamp)>
trace
Arranged<G, Tr>
prev_key
Vec<MirScalarExpr>
prev_thinning
Vec<usize>
permutation
Permutation
comparison
CF
closure
JoinClosure