Struct kdevice::cache::CacheEntry

pub struct CacheEntry<'a, T: Cache> { /* fields omitted */ }

Representing a client of a cache entry.

There may be several CacheEntry that refer to the same cache entry (i.e. same key) at a time. Therefore, Cache maintains reference counter for each in-memory cache entry. If the reference couter is not zero, it cannot be replace by another cache entyr. Once the the counter decreases to zero, it will be moved to the back of LRU and can be flushed to disk when replaced by another cache entry.

Implementations

impl<'a, T: Cache> CacheEntry<'a, T>

pub async fn lock(&'a self) -> Result<CacheGuard<'a, T>>

Lock and read the cache entry.

pub fn leak(self) -> CacheNodePtr<T::Key, T::Value>

Get pointer to this cache entry.

pub fn key(&self) -> T::Key

Get the key of this cache entry.

Safe since the key is immutable since referenced.

pub fn nref(&self) -> usize

Get the reference count of this cache entry.

Note that the count may changes after this function returns. You may need to lock the whole cache to make sure it is the latest ref count.

pub unsafe fn from_ptr(
    cache: &'a T,
    ptr: CacheNodePtr<T::Key, T::Value>
) -> Self

Restore the cache entry from a node pointer. Useful for non-RAII operations.

Trait Implementations

impl<'a, T: Cache> Drop for CacheEntry<'a, T>

fn drop(&mut self)

Executes the destructor for this type.