Struct RowCache 

pub struct RowCache { /* private fields */ }

Bounded LRU row cache: stores the last max materialized rows, keyed by row index, to avoid re-fetching identical rows from a RowSource.

The eviction policy is LRU-approximate: the oldest-inserted entry is evicted when the cache is full. Entries are also bumped to the back of the deque on re-insertion (cache-hit update).

Implementations

impl RowCache

pub fn new(max: usize) -> Self

Create a new cache that holds at most max rows.

Setting max to 0 effectively disables caching (every lookup misses).

pub fn get(&self, index: usize) -> Option<&Vec<Cell>>

Look up a row by index. Returns None on a cache miss.

pub fn insert(&mut self, index: usize, cells: Vec<Cell>)

Insert or update a row in the cache.

If an entry for index already exists it is removed first so the refreshed entry goes to the back (most-recently-used position). When the cache is at capacity the front (least-recently-used) entry is evicted before insertion.

pub fn invalidate(&mut self)

Invalidate the entire cache. Call when the underlying RowSource changes.

pub fn len(&self) -> usize

Number of currently cached rows.

pub fn is_empty(&self) -> bool

Returns true when the cache holds no rows.