Trait nebari::tree::Reducer

pub trait Reducer<Index, ReducedIndex = Index>: Debug + Clone + Send + Sync {
    fn reduce<'a, Indexes, IndexesIter>(&self, indexes: Indexes) -> ReducedIndex
    where
        Index: 'a,
        Indexes: IntoIterator<Item = &'a Index, IntoIter = IndexesIter> + ExactSizeIterator,
        IndexesIter: Iterator<Item = &'a Index> + ExactSizeIterator + Clone;
    fn rereduce<'a, ReducedIndexes, ReducedIndexesIter>(
        &self, 
        values: ReducedIndexes
    ) -> ReducedIndex
    where
        Self: 'a,
        ReducedIndex: 'a,
        ReducedIndexes: IntoIterator<Item = &'a ReducedIndex, IntoIter = ReducedIndexesIter> + ExactSizeIterator,
        ReducedIndexesIter: Iterator<Item = &'a ReducedIndex> + ExactSizeIterator + Clone;
}

Reduces one or more Indexes or instances of Self into a single Self value.

This trait is used to collect statistics within the B-Tree. The Index value is stored at the KeyEntry level, and each Interior entry contains Self, which is calculated by calling Reducer::reduce() on all stored Indexes.

When an Interior node points to other interior nodes, it calculates the stored value by calling Reducer::rereduce() with all the stored Self values.

Required methods

fn reduce<'a, Indexes, IndexesIter>(&self, indexes: Indexes) -> ReducedIndex where
    Index: 'a,
    Indexes: IntoIterator<Item = &'a Index, IntoIter = IndexesIter> + ExactSizeIterator,
    IndexesIter: Iterator<Item = &'a Index> + ExactSizeIterator + Clone, 

Reduces one or more indexes into a single reduced index.

fn rereduce<'a, ReducedIndexes, ReducedIndexesIter>(
    &self,
    values: ReducedIndexes
) -> ReducedIndex where
    Self: 'a,
    ReducedIndex: 'a,
    ReducedIndexes: IntoIterator<Item = &'a ReducedIndex, IntoIter = ReducedIndexesIter> + ExactSizeIterator,
    ReducedIndexesIter: Iterator<Item = &'a ReducedIndex> + ExactSizeIterator + Clone, 

Reduces one or more previously-reduced indexes into a single reduced index.

Implementations on Foreign Types

impl<Index> Reducer<Index, ()> for ()

fn reduce<'a, Indexes, IndexesIter>(&self, _indexes: Indexes) -> Self where
    Index: 'a,
    Indexes: IntoIterator<Item = &'a Index, IntoIter = IndexesIter> + ExactSizeIterator,
    IndexesIter: Iterator<Item = &'a Index> + ExactSizeIterator + Clone, 

fn rereduce<'a, ReducedIndexes, ReducedIndexesIter>(
    &self,
    _values: ReducedIndexes
) -> Self where
    Self: 'a,
    ReducedIndexes: IntoIterator<Item = &'a (), IntoIter = ReducedIndexesIter> + ExactSizeIterator,
    ReducedIndexesIter: Iterator<Item = &'a ()> + ExactSizeIterator + Clone, 

Implementors

impl<EmbeddedIndexer, EmbeddedIndex, EmbeddedStats> Reducer<UnversionedByIdIndex<EmbeddedIndex>, ByIdStats<EmbeddedStats>> for ByIdIndexer<EmbeddedIndexer> where
    EmbeddedIndexer: Reducer<EmbeddedIndex, EmbeddedStats>,
    EmbeddedIndex: EmbeddedIndex<Indexer = EmbeddedIndexer, Reduced = EmbeddedStats>, 

impl<EmbeddedIndexer, EmbeddedIndex, EmbeddedStats> Reducer<VersionedByIdIndex<EmbeddedIndex>, ByIdStats<EmbeddedStats>> for ByIdIndexer<EmbeddedIndexer> where
    EmbeddedIndexer: Reducer<EmbeddedIndex, EmbeddedStats>,
    EmbeddedIndex: EmbeddedIndex<Indexer = EmbeddedIndexer, Reduced = EmbeddedStats>,