Struct TopNStateCache

pub struct TopNStateCache<K: Ord + EstimateSize, V: EstimateSize> {
    table_row_count: Option<usize>,
    cache: EstimatedBTreeMap<K, V>,
    capacity: usize,
    synced: bool,
}

An implementation of StateCache that keeps a limited number of entries in an ordered in-memory map.

Fields

table_row_count: Option<usize>

cache: EstimatedBTreeMap<K, V>

capacity: usize

synced: bool

Implementations

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

pub fn new(capacity: usize) -> Self

pub fn with_table_row_count(capacity: usize, table_row_count: usize) -> Self

pub fn set_table_row_count(&mut self, table_row_count: usize)

fn row_count_matched(&self) -> bool

fn insert_synced(&mut self, key: K, value: V) -> Option<V>

Insert an entry with the assumption that the cache is SYNCED.

fn delete_synced(&mut self, key: &K) -> Option<V>

Delete an entry with the assumption that the cache is SYNCED.

pub fn capacity(&self) -> usize

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

Trait Implementations

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

fn clone(&self) -> TopNStateCache<K, V>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

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

fn estimated_heap_size(&self) -> usize

The estimated heap size of the current struct in bytes.

fn estimated_size(&self) -> usize

where Self: Sized,

The estimated total size of the current struct in bytes, including the estimated_heap_size and the size of Self.

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

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

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

type Key = K

type Value = V

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.

impl<K: Ord + EstimateSize, V: EstimateSize> StateCacheFiller for &mut TopNStateCache<K, V>

type Key = K

type Value = V

fn capacity(&self) -> Option<usize>

Get the capacity of the cache.

fn insert_unchecked(&mut self, key: Self::Key, value: Self::Value)

Insert an entry into the cache without cache validity check.

fn finish(self)

Finish syncing the cache with the state table. This should mark the cache as synced.