Struct kvarn::comprash::Cache

pub struct Cache<K, V, H = DefaultHasher> { /* private fields */ }

A general cache with size and item count limits.

When size limit is reached, a pseudo-random element is removed and the new one inserted. See Cache::discard_one.

The insert method, Cache::cache, has type-specific implementations. This enables clever inserting of data, independently from this struct. Therefore, the Cache::insert function should only be used in those implementations of this struct.

Implementations

impl<K, V> Cache<K, V, DefaultHasher>

pub fn new(max_items: usize, size_limit: usize) -> Self

Creates a new Cache. See Cache and CacheOut for more info about what the parameters do.

pub fn with_size_limit(size_limit: usize) -> Self

Creates a new Cache with size_limit and default max_items.

pub fn clear(&mut self)

Clears the cache.

impl<K: Eq + Hash, V, H> Cache<K, V, H>

pub fn get<Q: ?Sized + Hash + Eq>(&self, key: &Q) -> CacheOut<&V>where
    K: Borrow<Q>,

Get value at key from the cache.

See HashMap::get for more info.

pub fn get_with_lifetime<Q: ?Sized + Hash + Eq>(
    &self,
    key: &Q
) -> CacheOut<&CacheItem<V>>where
    K: Borrow<Q>,

Gets the CacheItem at key from the cache. Consider using Self::get for most operations.

This includes all lifetime information about the item in the cache. See CacheItem for more info about this.

pub fn get_mut<Q: ?Sized + Hash + Eq>(&mut self, key: &Q) -> CacheOut<&V>where
    K: Borrow<Q>,

Get a mutable reference to the value at key from the cache.

See HashMap::get for more info.

pub fn get_mut_with_lifetime<Q: ?Sized + Hash + Eq>(
    &mut self,
    key: &Q
) -> CacheOut<&mut CacheItem<V>>where
    K: Borrow<Q>,

Gets a mutable reference to the CacheItem at key from the cache. Consider using Self::get for most operations.

This includes all lifetime information about the item in the cache. See CacheItem for more info about this.

pub fn contains<Q: ?Sized + Hash + Eq>(&self, key: &Q) -> boolwhere
    K: Borrow<Q>,

Returns true if the cache contains key.

See HashMap::contains_key for more info.

pub fn remove<Q: ?Sized + Hash + Eq>(&mut self, key: &Q) -> CacheOut<V>where
    K: Borrow<Q>,

Removes a key-value pair from the cache, returning the value, if present.

See HashMap::remove and CacheOut::Present.

pub fn insert(
    &mut self,
    value_length: usize,
    key: K,
    value: V,
    lifetime: Option<Duration>
) -> CacheOut<V>where
    H: Hasher,

Inserts a value at key into this cache. value_length should be the size, in bytes, of value.

See bottom of Cache for more info about when to use this.

impl<K, V, H: Hasher> Cache<K, V, H>

pub fn feed_hasher(&mut self, data: &[u8])

Writes to the internal hasher to increase quality of output.

Should be used by implementors of the cache method to add to the internal hasher with their data.

The hasher is used when selecting a item to remove from the cache.

impl<K: Eq + Hash, V, H: Hasher> Cache<K, V, H>

pub fn discard_one(&mut self)

Discards one key-value pair pseudo-randomly.

impl<K: Eq + Hash, H: Hasher> Cache<K, VariedResponse, H>

pub fn cache(
    &mut self,
    key: K,
    response: VariedResponse
) -> CacheOut<VariedResponse>

Caches a CompressedResponse and returns the previous response, if any.

impl<K: Eq + Hash> Cache<K, Bytes>

pub fn cache(&mut self, key: K, contents: Bytes) -> CacheOut<Bytes>

Caches a Bytes and returns the previous bytes, if any.

Trait Implementations

impl<K: Debug, V: Debug, H: Debug> Debug for Cache<K, V, H>

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

Formats the value using the given formatter.

impl<K, V> Default for Cache<K, V>

fn default() -> Self

Returns the “default value” for a type.