Struct CacheHandle 

pub struct CacheHandle { /* private fields */ }

A Cache backend plus the active CacheMode and TTLs. Cheap to clone (clones share the backend); clone it out of the Context to call get_or_fetch with a closure that borrows the context.

Implementations

impl CacheHandle

pub fn new( backend: Arc<dyn Cache>, config: CacheConfig, mode: CacheMode, ) -> Self

config.enabled == false forces CacheMode::Off.

pub fn with_mode(&self, mode: CacheMode) -> Self

The same backend with another mode; still off if disabled in config.

pub fn mode(&self) -> CacheMode

pub fn config(&self) -> &CacheConfig

pub fn ttl(&self, kind: CacheKind) -> u64

pub fn backend(&self) -> &Arc<dyn Cache>

The backend, for housekeeping outside the mode rules.

pub async fn get<T: DeserializeOwned>(&self, key: &CacheKey) -> Option<T>

A fresh cached value, if reads are enabled and one exists. Any problem reading or decoding the entry is a miss.

pub async fn lookup<T: DeserializeOwned>( &self, key: &CacheKey, ) -> Option<Fetched<T>>

Like get, with the time the entry was fetched.

pub async fn lookup_stale<T: DeserializeOwned>( &self, key: &CacheKey, ) -> Option<Fetched<T>>

The stored value for key even if it has expired (but not yet been pruned), for falling back when the live call fails. None when the mode is off.

pub async fn put<T: Serialize>(&self, key: &CacheKey, value: &T) -> Result<()>

Store a value (no-op when writes are off or the kind’s TTL is 0).

pub async fn get_or_fetch<T, F, Fut>( &self, key: &CacheKey, fetch: F, ) -> Result<T>

where T: Serialize + DeserializeOwned, F: FnOnce() -> Fut, Fut: Future<Output = Result<T>>,

Return the cached value for key, or run fetch, store its result (best-effort) and return it. Errors from fetch are returned and never cached. Prefer T = serde_json::Value holding the raw upstream response.

pub async fn get_or_fetch_meta<T, F, Fut>( &self, key: &CacheKey, fetch: F, ) -> Result<Fetched<T>>

where T: Serialize + DeserializeOwned, F: FnOnce() -> Fut, Fut: Future<Output = Result<T>>,

get_or_fetch that also says whether the value came from the cache and how old it is.

pub async fn index_restaurants( &self, rows: &[RestaurantRow], seen_from: Option<(f64, f64)>, ) -> Result<()>

Upsert restaurants seen in a list response (no-op when writes are off).

pub async fn index_items(&self, items: &[ItemRow]) -> Result<()>

Upsert individual items (no-op when writes are off).

pub async fn index_menu( &self, restaurant: &RestaurantRow, categories: &[CategoryRow], items: &[ItemRow], seen_from: Option<(f64, f64)>, ) -> Result<()>

Store a full menu (no-op when writes are off).

pub async fn search_restaurants( &self, q: &RestaurantQuery, ) -> Result<Vec<RestaurantHit>>

Query restaurants in the catalog (works in every mode: it only reads what earlier fetches stored).

pub async fn search_items(&self, q: &ItemQuery) -> Result<Vec<ItemHit>>

Query menu items in the catalog.

pub async fn restaurant(&self, id: &str) -> Result<Option<RestaurantHit>>

One restaurant by id.

pub async fn cached_image(&self, url: &str) -> Option<CachedImage>

The cached image for url, if present. None when the mode is off.

pub async fn store_image( &self, url: &str, bytes: &[u8], content_type: &str, ) -> Result<CachedImage>

Store downloaded image bytes (refused when writes are off).

pub async fn fetch_image(&self, url: &str) -> Result<CachedImage>

The cached image for url, downloading it first if needed. Only Grab CDN URLs are fetched (image_url_allowed); no cookies are sent.

Trait Implementations

impl Clone for CacheHandle

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CacheHandle

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

Formats the value using the given formatter.