Struct Cache 

pub struct Cache<E: Storage + Metrics, V: CodecShared>(/* private fields */);

Implementation of Cache storage.

Mutating functions consume the cache and return it only on success: an error (or a dropped future) destroys the handle.

Implementations

impl<E: Storage + Metrics, V: CodecShared> Cache<E, V>

pub async fn init(context: E, cfg: Config<V::Cfg>) -> Result<Self, Error>

Initialize a new Cache instance.

The in-memory index for Cache is populated during this call by replaying the journal.

pub async fn get(&self, index: u64) -> Result<Option<V>, Error>

Retrieve an item from the Cache.

pub fn next_gap(&self, index: u64) -> (Option<u64>, Option<u64>)

Retrieve the next gap in the Cache.

pub fn first(&self) -> Option<u64>

Returns the first index in the Cache.

pub fn missing_items(&self, start: u64, max: usize) -> Vec<u64>

Returns up to max missing items starting from start.

This method iterates through gaps between existing ranges, collecting missing indices until either max items are found or there are no more gaps to fill.

pub fn has(&self, index: u64) -> bool

Check if an item exists in the Cache.

pub async fn prune(self, min: u64) -> Result<Self, Error>

Prune Cache to the provided min.

If this is called with a min lower than the last pruned, nothing will happen.

pub async fn put(self, index: u64, value: V) -> Result<Self, Error>

Store an item in the Cache.

If the index already exists, put does nothing and returns. A put below the prune floor is satisfied without storing: pruning declared that range obsolete, so nothing is mutated and nothing below the floor is ever readable.

pub async fn sync(self) -> Result<Self, Error>

Sync all pending writes.

pub async fn put_sync(self, index: u64, value: V) -> Result<Self, Error>

Stores an item in the Cache and syncs it, plus any other pending writes, to disk.

If the index already exists, the cache is just synced. A put satisfied below the prune floor stored nothing, so it skips the sync.

pub async fn destroy(self) -> Result<(), Error>

Remove all persistent data created by this Cache.

Trait Implementations

impl<E: Storage + Metrics, V: CodecShared> Debug for Cache<E, V>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.