Struct Cache 

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

An in-memory key-value cache that is automatically synced to disk.

The goal is simplicity, ease of use, and ease of distribution. All data is stored in a single file, which is automatically loaded into memory when using the cache.

Warning

No Edits

The biggest constraint for the cache is that values should never change for a given key. There is no update possible; if a value is reinserted a second time with a different value but the same key, an error will arise.

This is important to keep the file format simple: there is no metadata, no headers, just a plain separator between each cache entry. Therefore, it isn’t possible to edit previously saved content.

No Big Files

The cache isn’t optimized for space; use it for small caches.

Implementations

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

where K: CacheKey, V: CacheValue,

pub fn new<P>(path: P, option: CacheOption) -> Cache<K, V>

where P: AsRef<Path>,

Create a new cache and load the data from the provided path if it exists.

pub fn for_each<F>(&mut self, func: F)

where F: FnMut(&K, &V),

Iterate over all values of the cache.

pub fn get(&self, key: &K) -> Option<&V>

Fetch an item from the cache.

pub fn values(&self) -> impl Iterator<Item = &V>

Return all values in the cache.

pub fn len(&self) -> usize

The size of the cache.

pub fn is_empty(&self) -> bool

If the cache is empty.

pub fn insert(&mut self, key: K, value: V) -> Result<(), CacheError<K, V>>

Insert a new item to the cache.

Panic if an item with a different value exists in the cache.

Trait Implementations

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

where K: Debug, V: Debug,

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

Formats the value using the given formatter.

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

where K: CacheKey, V: CacheValue,

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

Formats the value using the given formatter.