Trait Readable

pub trait Readable {
    // Required methods
    fn read<T, R>(&self, col: u32, key: &dyn Key<T, Target = R>) -> Option<T>
       where T: Decodable,
             R: Deref<Target = [u8]>;
    fn exists<T, R>(&self, col: u32, key: &dyn Key<T, Target = R>) -> bool
       where R: Deref<Target = [u8]>;

    // Provided methods
    fn read_with_cache<K, T, C>(
        &self,
        col: u32,
        cache: &RwLock<C>,
        key: &K,
    ) -> Option<T>
       where K: Key<T> + Eq + Hash + Clone,
             T: Clone + Decodable,
             C: Cache<K, T> { ... }
    fn exists_with_cache<K, T, R, C>(
        &self,
        col: u32,
        cache: &RwLock<C>,
        key: &K,
    ) -> bool
       where K: Eq + Hash + Key<T, Target = R>,
             R: Deref<Target = [u8]>,
             C: Cache<K, T> { ... }
}

Should be used to read values from database.

Required Methods

fn read<T, R>(&self, col: u32, key: &dyn Key<T, Target = R>) -> Option<T>

where T: Decodable, R: Deref<Target = [u8]>,

Returns value for given key.

fn exists<T, R>(&self, col: u32, key: &dyn Key<T, Target = R>) -> bool

where R: Deref<Target = [u8]>,

Returns true if given value exists.

Provided Methods

fn read_with_cache<K, T, C>( &self, col: u32, cache: &RwLock<C>, key: &K, ) -> Option<T>

where K: Key<T> + Eq + Hash + Clone, T: Clone + Decodable, C: Cache<K, T>,

Returns value for given key either in cache or in database.

fn exists_with_cache<K, T, R, C>( &self, col: u32, cache: &RwLock<C>, key: &K, ) -> bool

where K: Eq + Hash + Key<T, Target = R>, R: Deref<Target = [u8]>, C: Cache<K, T>,

Returns true if given value exists either in cache or in database.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<KVDB: KeyValueDB + ?Sized> Readable for KVDB