Trait LookupTable

Source

pub trait LookupTable: Send + Sync {
    // Required methods
    fn get_cached(&self, key: &[u8]) -> LookupResult;
    fn get(&self, key: &[u8]) -> LookupResult;
    fn insert(&self, key: &[u8], value: RecordBatch);
    fn invalidate(&self, key: &[u8]);
    fn len(&self) -> usize;

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

Expand description

Synchronous lookup table interface for Ring 0 operators.

Implementations must be Send + Sync to allow sharing across threads in the thread-per-core runtime. The hot-path method is get_cached which should be < 500ns.

Writes (insert/invalidate) come from the Ring 1 CDC adapter or bulk-load path, not from the hot path.

Required Methods§

Source

fn get_cached(&self, key: &[u8]) -> LookupResult

Look up a key in the in-memory cache only (Ring 0).

This is the fast path — must not block or perform I/O. Returns LookupResult::NotFound on cache miss; callers should then try get for a deeper lookup.

§Performance

Target: < 500ns

Source

fn get(&self, key: &[u8]) -> LookupResult

Look up a key, potentially checking slower storage tiers.

May check a disk cache, remote cache, or trigger an async source query. Returns LookupResult::Pending if the lookup requires an async fetch that hasn’t completed yet.

Source