Trait StateCache

pub trait StateCache: EstimateSize {
    type Key: Ord + EstimateSize;
    type Value: EstimateSize;
    type Filler<'a>: StateCacheFiller<Key = Self::Key, Value = Self::Value> + 'a
       where Self: 'a;

    // Required methods
    fn is_synced(&self) -> bool;
    fn begin_syncing(&mut self) -> Self::Filler<'_>;
    fn insert(
        &mut self,
        key: Self::Key,
        value: Self::Value,
    ) -> Option<Self::Value>;
    fn delete(&mut self, key: &Self::Key) -> Option<Self::Value>;
    fn apply_batch(
        &mut self,
        batch: impl IntoIterator<Item = (Op, Self::Key, Self::Value)>,
    );
    fn clear(&mut self);
    fn values(&self) -> impl Iterator<Item = &Self::Value>;
    fn first_key_value(&self) -> Option<(&Self::Key, &Self::Value)>;
}

A common interface for state table cache.

Required Associated Types

type Key: Ord + EstimateSize

type Value: EstimateSize

type Filler<'a>: StateCacheFiller<Key = Self::Key, Value = Self::Value> + 'a where Self: 'a

Type of state cache filler, for syncing the cache with the state table.

Required Methods

fn is_synced(&self) -> bool

Check if the cache is synced with the state table.

fn begin_syncing(&mut self) -> Self::Filler<'_>

Begin syncing the cache with the state table.

fn insert(&mut self, key: Self::Key, value: Self::Value) -> Option<Self::Value>

Insert an entry into the cache. Should not break cache validity.

fn delete(&mut self, key: &Self::Key) -> Option<Self::Value>

Delete an entry from the cache. Should not break cache validity.

fn apply_batch( &mut self, batch: impl IntoIterator<Item = (Op, Self::Key, Self::Value)>, )

Apply a batch of operations to the cache. Should not break cache validity.

fn clear(&mut self)

Clear the cache.

fn values(&self) -> impl Iterator<Item = &Self::Value>

Iterate over the values in the cache.

fn first_key_value(&self) -> Option<(&Self::Key, &Self::Value)>

Get the reference of first key-value pair in the cache.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl StateCache for StateTableWatermarkCache

type Filler<'a> = &'a mut TopNStateCache<DefaultOrdered<OwnedRow>, ()>

type Key = DefaultOrdered<OwnedRow>

type Value = ()

impl<K: Ord + EstimateSize, V: EstimateSize> StateCache for OrderedStateCache<K, V>

type Filler<'a> = &'a mut OrderedStateCache<K, V> where Self: 'a

type Key = K

type Value = V

impl<K: Ord + EstimateSize, V: EstimateSize> StateCache for TopNStateCache<K, V>

type Filler<'a> = &'a mut TopNStateCache<K, V> where Self: 'a

type Key = K

type Value = V