fn optimize_dataflow_filters(dataflow: &mut DataflowDesc) -> Result<(), TransformError> {
    // Contains id -> predicates map, describing those predicates that
    // can (but need not) be applied to the collection named by `id`.
    let mut predicates = HashMap::<Id, HashSet<expr::MirScalarExpr>>::new();

    // Propagate predicate information from outputs to inputs.
    optimize_dataflow_filters_inner(
        dataflow
            .objects_to_build
            .iter_mut()
            .rev()
            .map(|build_desc| (Id::Global(build_desc.id), build_desc.view.as_inner_mut())),
        &mut predicates,
    )?;

    // Push predicate information into the SourceDesc.
    for (source_id, (source_desc, _)) in dataflow.source_imports.iter_mut() {
        if let Some(list) = predicates.get(&Id::Global(*source_id)).clone() {
            // Install no-op predicate information if none exists.
            if source_desc.operators.is_none() {
                source_desc.operators = Some(LinearOperator {
                    predicates: Vec::new(),
                    projection: (0..source_desc.bare_desc.arity()).collect(),
                })
            }
            // Add any predicates that can be pushed to the source.
            if let Some(operator) = &mut source_desc.operators {
                operator.predicates.extend(list.iter().cloned());
                operator.predicates.sort();
            }
        }
    }

    Ok(())
}
/// Pushes predicate to dataflow inputs.
Pushes predicate to dataflow inputs.
Pushes predicate to dataflow inputs .
fn optimize_dataflow_filters(dataflow: &mut DataflowDesc) -> Result<(), TransformError> {
    // Contains id -> predicates map, describing those predicates that
    // can (but need not) be applied to the collection named by `id`.
    let mut predicates = HashMap::<Id, HashSet<expr::MirScalarExpr>>::new();
    // Propagate predicate information from outputs to inputs.
    optimize_dataflow_filters_inner(
        dataflow
            .objects_to_build
            .iter_mut()
            .rev()
            .map(|build_desc| (Id::Global(build_desc.id), build_desc.view.as_inner_mut())),
        &mut predicates,
    )?;
    // Push predicate information into the SourceDesc.
    for (source_id, (source_desc, _)) in dataflow.source_imports.iter_mut() {
        if let Some(list) = predicates.get(&Id::Global(*source_id)).clone() {
            // Install no-op predicate information if none exists.
            if source_desc.operators.is_none() {
                source_desc.operators = Some(LinearOperator {
                    predicates: Vec::new(),
                    projection: (0..source_desc.bare_desc.arity()).collect(),
                })
            }
            // Add any predicates that can be pushed to the source.
            if let Some(operator) = &mut source_desc.operators {
                operator.predicates.extend(list.iter().cloned());
                operator.predicates.sort();
            }
        }
    }
    Ok(())
}
fn optimize_dataflow_filters ( dataflow : & mut DataflowDesc ) -> Result < ( ) , TransformError > { // Contains id -> predicates map, describing those predicates that // can (but need not) be applied to the collection named by `id`. let mut predicates = HashMap :: < Id , HashSet < expr :: MirScalarExpr > > :: new ( ) ; // Propagate predicate information from outputs to inputs. optimize_dataflow_filters_inner ( dataflow . objects_to_build . iter_mut ( ) . rev ( ) . map ( | build_desc | ( Id :: Global ( build_desc . id ) , build_desc . view . as_inner_mut ( ) ) ) , & mut predicates , ) ? ; // Push predicate information into the SourceDesc. for ( source_id , ( source_desc , _ ) ) in dataflow . source_imports . iter_mut ( ) { if let Some ( list ) = predicates . get ( & Id :: Global ( * source_id ) ) . clone ( ) { // Install no-op predicate information if none exists. if source_desc . operators . is_none ( ) { source_desc . operators = Some ( LinearOperator { predicates : Vec :: new ( ) , projection : ( 0 .. source_desc . bare_desc . arity ( ) ) . collect ( ) , } ) } // Add any predicates that can be pushed to the source. if let Some ( operator ) = & mut source_desc . operators { operator . predicates . extend ( list . iter ( ) . cloned ( ) ) ; operator . predicates . sort ( ) ; } } } Ok ( ( ) ) }
Pushes predicate to dataflow inputs.
Pushes predicate to dataflow inputs .
dataflow
&mut DataflowDesc
dataflow
&mut DataflowDesc