Struct PreparedDbQuery 

pub struct PreparedDbQuery<T, C = PostcardCodec>
where
    C: CacheCodec,
{ /* private fields */ }

A prepared database query descriptor.

PreparedDbQuery keeps adapter state and stable query-cache metadata close together. It can cheaply create ordinary DbQuery values for each call, or execute loaders directly through load_id/fetch_with_id.

Implementations

impl<T, C> PreparedDbQuery<T, C>

where C: CacheCodec,

pub fn namespace(&self) -> &str

Return the namespace used for physical cache keys.

pub fn cache(&self) -> &HydraCache<C>

Return the underlying local cache.

pub fn prepared_policy(&self) -> &PreparedQueryPolicy

Return the prepared policy backing this descriptor.

pub fn name(&self) -> Option<&str>

Return the optional diagnostic operation name.

pub fn requires_id(&self) -> bool

Return whether this descriptor needs an id binding before execution.

pub fn static_key_value(&self) -> Option<&str>

Return the static logical key, if this descriptor has one.

pub fn entity_key_prefix(&self) -> Option<&str>

Return the precomputed entity key prefix, if this is an entity policy.

pub fn tags_value(&self) -> &[String]

Return the precomputed tags.

pub fn ttl_value(&self) -> Option<Duration>

Return the configured per-entry TTL.

pub fn to_query(&self) -> DbQuery<T, C>

Create a runtime query from a static prepared policy.

Entity-id policies should usually use PreparedDbQuery::for_id so the dynamic id becomes part of the key and entity invalidation tag.

pub fn for_id(&self, id: impl ToString) -> DbQuery<T, C>

Bind an id and create a runtime query.

pub async fn load<E, F, Fut>(&self, loader: F) -> Result<T, DbCacheError>

where T: Serialize + DeserializeOwned + Send + 'static, E: Error + Send + Sync + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

Fetch a cached value from a static prepared policy or run the loader.

pub async fn load_id<E, F, Fut>( &self, id: impl ToString, loader: F, ) -> Result<T, DbCacheError>

where T: Serialize + DeserializeOwned + Send + 'static, E: Error + Send + Sync + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

Bind an id, fetch a cached value, or run the loader.

pub async fn fetch_value_with<U, E, F, Fut>( &self, loader: F, ) -> Result<U, DbCacheError>

where U: Serialize + DeserializeOwned + Send + 'static, E: Error + Send + Sync + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<U, E>> + Send + 'static,

Fetch a static prepared value with an output type chosen by an adapter.

pub async fn fetch_value_with_id<U, E, F, Fut>( &self, id: impl ToString, loader: F, ) -> Result<U, DbCacheError>

where U: Serialize + DeserializeOwned + Send + 'static, E: Error + Send + Sync + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<U, E>> + Send + 'static,

Bind an id and fetch a value with an output type chosen by an adapter.

Trait Implementations

impl<T, C> Clone for PreparedDbQuery<T, C>

where C: CacheCodec,

fn clone(&self) -> PreparedDbQuery<T, C>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, C> Debug for PreparedDbQuery<T, C>

where C: CacheCodec,

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

Formats the value using the given formatter.