Struct LiquidCache 

pub struct LiquidCache { /* private fields */ }

Cache storage for liquid cache.

Example (async read):

use liquid_cache::cache::{LiquidCacheBuilder, EntryID};
use arrow::array::UInt64Array;
use std::sync::Arc;

tokio_test::block_on(async {
let storage = LiquidCacheBuilder::new().build();

let entry_id = EntryID::from(0);
let arrow_array = Arc::new(UInt64Array::from_iter_values(0..32));
storage.insert(entry_id, arrow_array.clone()).await;

// Get the arrow array back asynchronously
let retrieved = storage.get(&entry_id).await.unwrap();
assert_eq!(retrieved.as_ref(), arrow_array.as_ref());
});

Implementations

impl LiquidCache

Builder returned by LiquidCache::insert for configuring cache writes.

pub fn stats(&self) -> CacheStats

Return current cache statistics: counts and resource usage.

pub fn insert<'a>( self: &'a Arc<Self>, entry_id: EntryID, batch_to_cache: ArrayRef, ) -> Insert<'a>

Insert a batch into the cache.

pub fn get<'a>(&'a self, entry_id: &'a EntryID) -> Get<'a>

Create a Get builder for the provided entry.

pub fn eval_predicate<'a>( &'a self, entry_id: &'a EntryID, predicate: &'a Arc<dyn PhysicalExpr>, ) -> EvaluatePredicate<'a>

Create an EvaluatePredicate builder for evaluating predicates on cached data.

pub async fn try_read_liquid( &self, entry_id: &EntryID, ) -> Option<LiquidArrayRef>

Try to read a liquid array from the cache. Returns None if the cached data is not in liquid format.

pub fn for_each_entry(&self, f: impl FnMut(&EntryID, &CacheEntry))

Iterate over all entries in the cache. No guarantees are made about the order of the entries. Isolation level: read-committed

pub fn reset(&self)

Reset the cache.

pub fn is_cached(&self, entry_id: &EntryID) -> bool

Check if a batch is cached.

pub fn config(&self) -> &CacheConfig

Get the config of the cache.

pub fn budget(&self) -> &BudgetAccounting

Get the budget of the cache.

pub fn tracer(&self) -> &CacheTracer

Get the tracer of the cache.

pub fn observer(&self) -> &Observer

Access the cache observer (runtime stats, debug event trace, and optional cache tracing).

pub fn compressor_states( &self, entry_id: &EntryID, ) -> Arc<LiquidCompressorStates>

Get the compressor states of the cache.

pub fn add_squeeze_hint( &self, entry_id: &EntryID, expression: Arc<CacheExpression>, )

Add a squeeze hint for an entry.

pub async fn flush_all_to_disk(&self)

Flush all entries to disk.

impl LiquidCache

pub fn consume_event_trace(&self) -> EventTrace

Consume the trace of the cache, for testing only.

Trait Implementations

impl Debug for LiquidCache

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

Formats the value using the given formatter.