Trait CacheBackend

pub trait CacheBackend:
    Debug
    + Send
    + Sync {
    // Required methods
    fn backend_type(&self) -> &'static str;
    fn new() -> Self
       where Self: Sized;
    fn get(&self, key: CacheKey) -> Option<CacheValue>;
    fn get_random(&self) -> Option<CacheValue>;
    fn set(&mut self, key: CacheKey, image: CacheValue) -> Result<(), String>;
    fn remove(&mut self, key: &CacheKey) -> Option<CacheValue>;
    fn size(&self) -> usize;
    fn keys(&self) -> &[CacheKey];
    fn clear(&mut self) -> Result<(), String>;

    // Provided method
    fn is_empty(&self) -> bool { ... }
}

Required Methods

fn backend_type(&self) -> &'static str

report the type of the cache backend

fn new() -> Self

where Self: Sized,

Create a new cache backend

fn get(&self, key: CacheKey) -> Option<CacheValue>

Get an image from the cache by its key

fn get_random(&self) -> Option<CacheValue>

Get a random image from the cache

fn set(&mut self, key: CacheKey, image: CacheValue) -> Result<(), String>

Store an image in the cache with its key

Errors

Returns an error if the image cannot be stored (e.g. due to size limits), or if the image is invalid

fn remove(&mut self, key: &CacheKey) -> Option<CacheValue>

Remove an image from the cache by its key

fn size(&self) -> usize

Get the size of the cache

fn keys(&self) -> &[CacheKey]

Retrieve the keys in the cache

fn clear(&mut self) -> Result<(), String>

Clear the cache

Errors

Returns an error if the cache cannot be cleared.

Provided Methods

fn is_empty(&self) -> bool

Check if the cache is empty

Implementors

impl CacheBackend for FileSystemCache

impl CacheBackend for InMemoryCache