Trait PerBufferCacheExt 

pub trait PerBufferCacheExt<T> {
    // Required methods
    fn get_for(&self, id: BufferId) -> Option<Arc<T>>;
    fn insert_for(&self, id: BufferId, value: T);
    fn remove_for(&self, id: BufferId);
    fn retain<F: FnMut(BufferId, &T) -> bool>(&self, predicate: F);
    fn is_empty_snapshot(&self) -> bool;
}

Convenience trait carrying the standard read / insert / remove operations for a PerBufferCache.

All operations are non-blocking. Writes use a copy-on-write pattern: load the current Arc<HashMap>, clone the inner HashMap, mutate, store. Concurrent writers may race; the last-writer-wins outcome is acceptable for LSP feature caches (each buffer’s writer is itself single-flight via cancellation tokens; cross-buffer races are independent).

Required Methods

fn get_for(&self, id: BufferId) -> Option<Arc<T>>

Wait-free read: returns a detached Arc<T> snapshot of the cache entry for id, or None if no entry exists. The returned Arc is independent of any subsequent store; the renderer can hold it across the frame.

fn insert_for(&self, id: BufferId, value: T)

Store (or replace) the cache entry for id. Copy-on- write: clones the current HashMap, inserts, stores.

fn remove_for(&self, id: BufferId)

Remove the cache entry for id if present. No-op when the entry doesn’t exist. Copy-on-write semantics.

fn retain<F: FnMut(BufferId, &T) -> bool>(&self, predicate: F)

Retain only entries matching the predicate. Mirrors HashMap::retain’s semantics: the predicate sees each (BufferId, &T); entries returning false are dropped.

Copy-on-write: if no entries need to be dropped, the underlying Arc is unchanged. Used by LSP */refresh drains to evict per-server caches when a server’s invalidation notification arrives.

fn is_empty_snapshot(&self) -> bool

Returns true when no entries exist. Wait-free.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<T> PerBufferCacheExt<T> for PerBufferCache<T>