Struct VarTypedMapShard 

pub struct VarTypedMapShard<'tree, K: Key + Send + Sync + Hash + Eq, T: Send + Sync, C: Codec<T> + Clone, H: TypedWriteHook<K, T>> { /* private fields */ }

Handle for atomic multi-key operations on a single shard of a VarTypedMap. Obtained via VarTypedMap::atomic. The shard + index locks are held for the lifetime of this struct — keep the closure short.

Implementations

impl<K: Key + Send + Sync + Hash + Eq, T: Send + Sync, C: Codec<T> + Clone, H: TypedWriteHook<K, T>> VarTypedMapShard<'_, K, T, C, H>

pub fn put(&mut self, key: &K, value: &T) -> DbResult<bool>

Insert or overwrite key. Returns true if the key already existed (overwrite), false for a fresh insert.

pub fn insert(&mut self, key: &K, value: &T) -> DbResult<()>

pub fn delete(&mut self, key: &K) -> DbResult<bool>

pub fn try_get(&self, key: &K) -> DbResult<Option<T>>

pub fn get_or_err(&self, key: &K) -> DbResult<T>

pub fn try_contains(&self, key: &K) -> DbResult<bool>

pub fn update( &mut self, key: &K, f: impl FnOnce(&T) -> T, ) -> DbResult<Option<T>>

Atomically read-modify-write within the shard. Returns Some(new_value) if the key existed, None if absent.

pub fn fetch_update( &mut self, key: &K, f: impl FnOnce(&T) -> T, ) -> DbResult<Option<T>>

Like update, but returns Some(old_value) instead of the new one.

pub fn upsert<U: IntoUpsert<T>>( &mut self, key: &K, f: impl FnOnce(Option<&T>) -> U, ) -> DbResult<U::Out>

Decide-and-write within the shard. The closure must be short — shard lock is held.

Trait Implementations

impl<K: Key + Send + Sync + Hash + Eq, T: Send + Sync, C: Codec<T> + Clone, H: TypedWriteHook<K, T>> Send for VarTypedMapShard<'_, K, T, C, H>