fn build_update_stream<G, Tr>(
    trace: Arranged<G, Tr>,
    as_of: Antichain<G::Timestamp>,
    source_relation: usize,
    mut initial_closure: JoinClosure,
    permutation: Permutation,
) -> (Collection<G, Row>, 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>,
{
    use crate::operator::StreamExt;
    use differential_dataflow::AsCollection;
    use timely::dataflow::channels::pact::Pipeline;

    let mut row_builder = Row::default();
    initial_closure.permute(&permutation);
    let (ok_stream, err_stream) =
        trace
            .stream
            .unary_fallible(Pipeline, "UpdateStream", move |_, _| {
                let mut datums = DatumVec::new();
                Box::new(move |input, ok_output, err_output| {
                    input.for_each(|time, data| {
                        let mut ok_session = ok_output.session(&time);
                        let mut err_session = err_output.session(&time);
                        for wrapper in data.iter() {
                            let batch = &wrapper;
                            let mut cursor = batch.cursor();
                            while let Some(key) = cursor.get_key(batch) {
                                while let Some(val) = cursor.get_val(batch) {
                                    cursor.map_times(batch, |time, diff| {
                                        // note: only the delta path for the first relation will see
                                        // updates at start-up time
                                        if source_relation == 0 || !as_of.elements().contains(&time)
                                        {
                                            let temp_storage = RowArena::new();
                                            let mut datums_local =
                                                datums.borrow_with_many(&[key, val]);
                                            if !initial_closure.is_identity() {
                                                match initial_closure
                                                    .apply(
                                                        &mut datums_local,
                                                        &temp_storage,
                                                        &mut row_builder,
                                                    )
                                                    .transpose()
                                                {
                                                    Some(Ok(row)) => ok_session.give((
                                                        row,
                                                        time.clone(),
                                                        diff.clone(),
                                                    )),
                                                    Some(Err(err)) => err_session.give((
                                                        err,
                                                        time.clone(),
                                                        diff.clone(),
                                                    )),
                                                    None => {}
                                                }
                                            } else {
                                                let row = {
                                                    row_builder.clear();
                                                    row_builder.extend(&*datums_local);
                                                    row_builder.finish_and_reuse()
                                                };
                                                ok_session.give((row, time.clone(), diff.clone()));
                                            }
                                        }
                                    });
                                    cursor.step_val(batch);
                                }
                                cursor.step_key(batch);
                            }
                        }
                    });
                })
            });

    (
        ok_stream.as_collection(),
        err_stream.as_collection().map(DataflowError::from),
    )
}
/// Builds the beginning of the update stream of a delta path.
///
/// At start-up time only the delta path for the first relation sees updates, since any updates fed to the
/// other delta paths would be discarded anyway due to the tie-breaking logic that avoids double-counting
/// updates happening at the same time on different relations.
Builds the beginning of the update stream of a delta path.
At start-up time only the delta path for the first relation sees updates, since any updates fed to the
other delta paths would be discarded anyway due to the tie-breaking logic that avoids double-counting
updates happening at the same time on different relations.
Builds the beginning of the update stream of a delta path . At start - up time only the delta path for the first relation sees updates since any updates fed to the other delta paths would be discarded anyway due to the tie - breaking logic that avoids double - counting updates happening at the same time on different relations .
fn build_update_stream<G, Tr>(
    trace: Arranged<G, Tr>,
    as_of: Antichain<G::Timestamp>,
    source_relation: usize,
    mut initial_closure: JoinClosure,
    permutation: Permutation,
) -> (Collection<G, Row>, 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>,
{
    use crate::operator::StreamExt;
    use differential_dataflow::AsCollection;
    use timely::dataflow::channels::pact::Pipeline;
    let mut row_builder = Row::default();
    initial_closure.permute(&permutation);
    let (ok_stream, err_stream) =
        trace
            .stream
            .unary_fallible(Pipeline, "UpdateStream", move |_, _| {
                let mut datums = DatumVec::new();
                Box::new(move |input, ok_output, err_output| {
                    input.for_each(|time, data| {
                        let mut ok_session = ok_output.session(&time);
                        let mut err_session = err_output.session(&time);
                        for wrapper in data.iter() {
                            let batch = &wrapper;
                            let mut cursor = batch.cursor();
                            while let Some(key) = cursor.get_key(batch) {
                                while let Some(val) = cursor.get_val(batch) {
                                    cursor.map_times(batch, |time, diff| {
                                        // note: only the delta path for the first relation will see
                                        // updates at start-up time
                                        if source_relation == 0 || !as_of.elements().contains(&time)
                                        {
                                            let temp_storage = RowArena::new();
                                            let mut datums_local =
                                                datums.borrow_with_many(&[key, val]);
                                            if !initial_closure.is_identity() {
                                                match initial_closure
                                                    .apply(
                                                        &mut datums_local,
                                                        &temp_storage,
                                                        &mut row_builder,
                                                    )
                                                    .transpose()
                                                {
                                                    Some(Ok(row)) => ok_session.give((
                                                        row,
                                                        time.clone(),
                                                        diff.clone(),
                                                    )),
                                                    Some(Err(err)) => err_session.give((
                                                        err,
                                                        time.clone(),
                                                        diff.clone(),
                                                    )),
                                                    None => {}
                                                }
                                            } else {
                                                let row = {
                                                    row_builder.clear();
                                                    row_builder.extend(&*datums_local);
                                                    row_builder.finish_and_reuse()
                                                };
                                                ok_session.give((row, time.clone(), diff.clone()));
                                            }
                                        }
                                    });
                                    cursor.step_val(batch);
                                }
                                cursor.step_key(batch);
                            }
                        }
                    });
                })
            });
    (
        ok_stream.as_collection(),
        err_stream.as_collection().map(DataflowError::from),
    )
}
fn build_update_stream < G , Tr > ( trace : Arranged < G , Tr > , as_of : Antichain < G :: Timestamp > , source_relation : usize , mut initial_closure : JoinClosure , permutation : Permutation , ) -> ( Collection < G , Row > , 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 > , { use crate :: operator :: StreamExt ; use differential_dataflow :: AsCollection ; use timely :: dataflow :: channels :: pact :: Pipeline ; let mut row_builder = Row :: default ( ) ; initial_closure . permute ( & permutation ) ; let ( ok_stream , err_stream ) = trace . stream . unary_fallible ( Pipeline , " " , move | _ , _ | { let mut datums = DatumVec :: new ( ) ; Box :: new ( move | input , ok_output , err_output | { input . for_each ( | time , data | { let mut ok_session = ok_output . session ( & time ) ; let mut err_session = err_output . session ( & time ) ; for wrapper in data . iter ( ) { let batch = & wrapper ; let mut cursor = batch . cursor ( ) ; while let Some ( key ) = cursor . get_key ( batch ) { while let Some ( val ) = cursor . get_val ( batch ) { cursor . map_times ( batch , | time , diff | { // note: only the delta path for the first relation will see // updates at start-up time if source_relation == 0 || ! as_of . elements ( ) . contains ( & time ) { let temp_storage = RowArena :: new ( ) ; let mut datums_local = datums . borrow_with_many ( & [ key , val ] ) ; if ! initial_closure . is_identity ( ) { match initial_closure . apply ( & mut datums_local , & temp_storage , & mut row_builder , ) . transpose ( ) { Some ( Ok ( row ) ) => ok_session . give ( ( row , time . clone ( ) , diff . clone ( ) , ) ) , Some ( Err ( err ) ) => err_session . give ( ( err , time . clone ( ) , diff . clone ( ) , ) ) , None => { } } } else { let row = { row_builder . clear ( ) ; row_builder . extend ( & * datums_local ) ; row_builder . finish_and_reuse ( ) } ; ok_session . give ( ( row , time . clone ( ) , diff . clone ( ) ) ) ; } } } ) ; cursor . step_val ( batch ) ; } cursor . step_key ( batch ) ; } } } ) ; } ) } ) ; ( ok_stream . as_collection ( ) , err_stream . as_collection ( ) . map ( DataflowError :: from ) , ) }
Builds the beginning of the update stream of a delta path.
Builds the beginning of the update stream of a delta path .
trace
Arranged<G, Tr>
as_of
Antichain<G::Timestamp>
source_relation
usize
initial_closure
JoinClosure
permutation
Permutation
trace
Arranged<G, Tr>
as_of
Antichain<G::Timestamp>
source_relation
usize
initial_closure
JoinClosure
permutation
Permutation