Struct merino_cache::redis::Suggester

pub struct Suggester {
    inner: Box<dyn SuggestionProvider>,
    redis_connection: ConnectionManager,
    metrics_client: StatsdClient,
    default_ttl: Duration,
    default_lock_timeout: Duration,
}

A suggester that uses Redis to cache previous results.

Fields

inner: Box<dyn SuggestionProvider>

The suggester to query on cache-miss.

redis_connection: ConnectionManager

Connection to Redis.

metrics_client: StatsdClient

The Statsd client used to record statistics.

default_ttl: Duration

The default amount of time a cache entry is valid, unless overridden by inner.

default_lock_timeout: Duration

Default lock timeout

Implementations

impl Suggester

pub fn new_boxed<'__async_fut>(
    settings: Settings,
    config: RedisCacheConfig,
    metrics_client: StatsdClient,
    provider: Box<dyn SuggestionProvider + 'static>
) -> impl '__async_fut + Future<Output = Result<Box<Self>, SetupError>> where
    Settings: '__async_fut,
    RedisCacheConfig: '__async_fut,
    StatsdClient: '__async_fut,
    Box<dyn SuggestionProvider + 'static>: '__async_fut, 

Create a Redis suggestion provider from settings that wraps provider. Opens a connection to Redis.

Errors

Fails if it cannot connect to Redis.

async fn get_key(&self, key: &str) -> Result<CacheCheckResult, SuggestError>

Retrieve an item from the cache

If the item retrieved cannot be deserialized, it will be deleted. If there is no TTL for the retrieved item, one will be added to it.

fn queue_store_key(
    &self,
    key: &str,
    suggestions: Vec<Suggestion>,
    lock: String
) -> Result<(), SuggestError>

Queue a command to store an entry in the cache.

This runs as a separate task, and this function returns before the operation is complete.

Errors

Returns an error if the command cannot be queued. Does not error if the command fails to run to completion.

fn queue_delete_key(&self, key: &str) -> Result<(), SuggestError>

Queue a command to delete a key from the cache.

This runs as a separate task, and this function returns before the deletion is complete.

Errors

Returns an error if the command cannot be queued. Does not error if the command fails to run to completion.

fn queue_set_key_ttl(
    &self,
    key: &str,
    ttl: Duration
) -> Result<(), SuggestError>

Queue a command to set the TTL of a key in the cache.

This runs as a separate task, and this function returns before the operation is complete.

Errors

Returns an error if the command cannot be queued. Does not error if the command fails to run to completion.

Trait Implementations

impl SuggestionProvider for Suggester

fn reconfigure<'life0, 'life1, 'async_trait>(
    &'life0 mut self,
    new_config: Value,
    make_fresh: &'life1 MakeFreshType
) -> Pin<Box<dyn Future<Output = Result<(), SetupError>> + Send + 'async_trait>> where
    'life0: 'async_trait,
    'life1: 'async_trait,
    Self: 'async_trait, 

Reconfigure the Redis provider.

Note that the reconfiguration will not wipe out the Redis cache. It only reconfigures the inner provider and other cache settings such as default_ttl for the subsequent cache operations.

fn name(&self) -> String

An operator-visible name for this suggestion provider.

fn cache_inputs(
    &self,
    req: &SuggestionRequest,
    cache_inputs: &mut dyn CacheInputs
)

Generate a set of cache inputs for a given query specific to this provider. Any property of the query that affects how suggestions are generated should be included.

fn suggest<'life0, 'async_trait>(
    &'life0 self,
    request: SuggestionRequest
) -> Pin<Box<dyn Future<Output = Result<SuggestionResponse, SuggestError>> + Send + 'async_trait>> where
    'life0: 'async_trait,
    Self: 'async_trait, 

Provide suggested results for query.

fn is_null(&self) -> bool

Return if this provider is null and can be ignored. Providers that set this to true should be ignored in any place where suggestions are needed. Providers with this set to true likely only serve as a blank space where we may need a provider but can’t otherwise supply one.

fn cache_key(&self, req: &SuggestionRequest) -> String

Use Self::cache_inputs to generate a single cache key. This function should not normally be overridden by provider implementations.